Comparing DNA Results – Different Tests at the Same Testing Company

Posted on May 18, 2023 by Roberta Estes

Several people have asked about different tests at the same DNA testing company. They wondered if matching is affected, meaning whether your matches are different if you have two different tests at the same company. Specifically, they asked if you are better off purchasing a test AT a DNA testing vendor that allows uploads, rather than uploading a test from a different vendor. Does it make a difference to the tester or their matches? Do they have the same matches?

These are great questions, and the answer isn’t conclusive. It varies based on several factors.

Having multiple tests at the same DNA testing company can occur in three ways:

The same person tests twice at the same DNA testing company.
The same person tests once at the DNA testing company and uploads a test from a different testing company. Only two of the primary four DNA testing companies accept uploads from other vendors – FamilyTreeDNA and MyHeritage.
The same person uploads two different files from other DNA testing companies to the DNA testing company in question. For example, the DNA company could be FamilyTreeDNA and the two uploaded DNA files could be from either MyHeritage, 23andMe or Ancestry.

All DNA testing companies allow users to download their raw DNA data files. This enables the tester to upload their DNA file to the vendors who accept uploaded files. Both FamilyTreeDNA and MyHeritage provide matching for free, but advanced tools require a small unlock fee of $19 and $29, respectively.

Testing Company	Accepts Uploads from Other Companies	Download Upload Instructions
23andMe	No	Instructions here
Ancestry	No	Instructions here
FamilyTreeDNA	Yes, some	Instructions here
MyHeritage	Yes, some	Instructions here

I wrote about developing a DNA testing and transfer/upload strategy, here, and about which companies accept which tests, here.

Not all DNA files are created equal. Therefore, not all files from vendors are compatible with other vendors for various reasons.

Multiple Tests at the Same DNA Testing Company

I have at least two tests at each of the four major vendors. I did this for research purposes, meaning to write articles to share with you.

If you actually test twice at a vendor, meaning purchase two separate tests and take them yourself, you will have two test results at that testing company. At some companies, specifically 23andMe, if you purchase a new test through their “upgrade” procedure, you won’t have two tests, just the newer one.

However, if you’re testing at the DNA testing company, and also uploading, I generally don’t recommend more than one test at each vendor. All it really does is clog up people’s match lists with no or little additional benefit. At 23andMe, with their restrictions on the size of your match list, if everyone had two tests, the effective match limit would be half of their stated limit of about 1500 matches for earlier testers and about 5000 for current testers with subscriptions.

So, in essence, I’m telling you to “do as I say, not as I do.” We all have better things to do with our money rather pay for the same test twice. If you haven’t tested your Y-DNA or mitochondrial DNA, that’s much more beneficial than two autosomal tests at one vendor.

Chips and Chip Evolution

Before we begin the side-by-side comparison, let’s briefly discuss DNA testing chips and how they work.

Each DNA testing company purchases DNA processing equipment. Illumina is the big dog in this arena. Illumina defines the capacity and structure of each chip. In part, how the testing companies use that capacity, or space on each chip, is up to each company. This means that the different testing companies test many of the same autosomal DNA SNP locations, but not all of the same locations.

Furthermore, the individual testing companies can specify a number of “other” locations to be included on their chip, up to the chip maximum size limit. The testing companies who offer Y-DNA or mitochondrial DNA haplogroups from autosomal tests use part of their chip array space for selected known haplogroup-defining SNP locations. This does NOT mean that Y-DNA or mitochondrial DNA is autosomal, just that the testing company used part of their chip array space to target these SNPs in your genome. Of course, for your most refined haplogroup and Y-DNA or mitochondrial DNA matching, you have to take those specific tests at FamilyTreeDNA .

This means that each testing company includes and reports many of the same, but also some different SNP locations when they scan your DNA.

In the lab, after your DNA is extracted from either your saliva or the cheek swab, it’s placed on this array chip which is then placed in the processing equipment.

There are several steps in processing your DNA. Each DNA location specified on the chip is scanned and read multiple times, and the results are recorded. The final output is the raw DNA results file that you see if/when you download your raw DNA file.

Here’s an example from my file. The RSID is the reference SNP cluster ID which is the naming convention used for specific SNPs. It’s not relevant to you, but it is to the lab, along with the chromosome number and position, which is in essence the address on the chromosome.

In the Result column, your file reports one nucleotide (T, A, C or G) that you inherited from each parent at each tested position. They are not listed in “parent order” because your DNA is not organized in that fashion. There’s no way for the lab to know which nucleotide came from which parent, unless they are the same, of course. You can read about nucleotides, here.

When you upload your raw DNA file to a different DNA testing company (vendor), they have to work with a file that isn’t entirely compatible with the files they generate, or the other files uploaded from other DNA testing companies.

In addition to dealing with different file formats and contents from multiple DNA vendors, companies change their own chips and file structure from time to time. In some cases, it’s a forced change by the chip manufacturer. Other times, the vendors want to include different locations or make improvements. For example, with 23andMe’s focus on health, they probably add new medically related SNP locations regularly. Regardless of why, some DNA files include locations not included in other files and are not 100% compatible.

Looking at the first few entries in my example file above, let’s say that the testing vendor included the first ten positions, but an uploaded file from another company did not. Or perhaps the chip changed, and a different version of the company’s own file contains different positions.

DNA testing companies have to “fill in the blanks” for compatibility, and they do this using a technique called imputation. Illumina forced their customers to adopt imputation in 2017 when they dropped the capacity of their chip. I was initially quite skeptical, but imputation has worked surprisingly well. Some of the matching differences you will see when comparing the results of two different DNA files is a result of imputation.

I wrote about imputation in an early article here. Please note the companies have fixed many issues with imputation and improved matching greatly, but the concepts and imputation processes still apply. The downloaded raw data files are your results BEFORE imputation, meaning that it’s up to any company where you upload to process your raw file in the same way they would process a file that they generated. A lot goes on behind the scenes when you upload a file to a DNA testing company.

At both 23andMe and Ancestry, you know that all of your matches tested there, meaning they did not upload a file from another testing company. You don’t know and can’t tell what chip was utilized when your matches tested. The only way to determine a chip testing version, aside from knowing the date or remembering the chip version from when you tested, is to look at the beginning of the raw data download file, although not all files contain that information.

Ok, now that you understand the landscape, let’s look at my results at each company.

23andMe

I tested twice at 23andMe on two different chip versions, V3 and V4, which tested some different locations of my DNA. Neither of these chips is the current version. I originally tested twice to evaluate the differences between the two test versions which you can read about, here.

23andMe named their ethnicity results Ancestry Composition.

They last updated my V3 test’s Ancestry Composition results on July 28, 2021.

The percentages are shown at left, and the country locations are highlighted at right for my 23andMe V3 test.

Click to enlarge any graphic

The 23andMe V4 test was also updated for the last time on July 28, 2021.

The ethnicity results differ substantially between the two chip versions, even though they were both updated on the same date.

In October of 2020, in an effort to “encourage” their customers to pay for a new test on their V5 chip, 23andMe announced that there would be no ethnicity updates on older tests. So, I really don’t know for sure when my tests were actually updated. Just note how different the results are. It’s also worth mentioning that 23andMe does not show trace amounts on their map, so even though my Indigenous American results were found, they aren’t displayed on the map.

Indigenous is, however, shown in yellow on their DNA Chromosome Painting.

No other testing company restricts updates, penalizing their customers who purchased earlier versions of tests.

Matches at 23andMe

23andMe limits your matches to about 1500 unless you have purchased the current test, including health AND pay for an annual $69 subscription which buys you about 5000 matches. I have not purchased this test.

Your number of actual matches displayed/retained is also affected by how many people you have communicated with, or at least initiated communications with. 23andMe does not roll those people off of your match list.

I have 1803 matches on both of my tests, meaning I’ve reached out to about 300 people who would have otherwise been removed from my match list. 23andMe retains your highest matches, deleting lower matches after you reach the maximum match threshold.

I’ve randomly evaluated several of the same matches at each vendor, at least five maternal and five paternal, separated by a blank row. I wanted to determine whether they match me on the same number of centimorgans, meaning the same amount of DNA, on both tests, and the same number of segments.

Match	23and Me V3	23and Me V4
Patricia	292 cM – 12 segments	Same as V3
Joe	148 cM, 8 segments	Same
Emily	73 cM, 4 segs	72 cM, 4 seg
Roland	27 cM, 1 seg	Same
Ian	62 cM, 4 seg	Same

Stacy	469 cM, 16 segments	482 cM, 16 segments
Harold	134 cM, 6 segments	Same
Dean	69 cM, 3 seg	Same
Carl	95 cM, 4 seg	Same
Debbie	83 cM, 4 seg	84 cM, 4 seg

As you can see, the matches are either exact or xclose.

Please note that bolded matches are also found at another company. I will include a summary table at the end comparing the same match across multiple vendors.

23and Me Summary

The 23andMe V3 and V4 match results are very close. Since the match limit is the same, and the results are so close between tests, they are essentially identical in terms of matching.

The ethnicity results are similar, but the V4 test reflects a broader region. Italian baffles me in both versions.

Ethnicity should never be taken at face value at any DNA testing company, especially with smaller percentages which could be noise or a combination of other regions which just happens to resemble Italy, in my case.

I don’t know what type of comparison the current chip would yield since I suspect it has more medical and less genealogical SNPs on board.

Reprocessing Tests

This is probably a good place to note that it’s very expensive for any company to update their customer’s ethnicity results because every single customer’s DNA results file must be completely rerun. Note that this does not mean their DNA itself is retested. The output raw data file is reprocessed using a new algorithm.

Rerunning means reprocessing that specific portion of every test, meaning the vendors must rent “time in the cloud.” We are talking millions of dollars for each run. I don’t know how much it costs per test, but think about the expense if it takes $1 to rerun each test in the vendor’s database. Ancestry has more than 20 million tests.

While we, as consumers, are always chomping at the bit for new and better ethnicity results – the testing companies need to be sure it really is “better,” not just different before they invest the money to reprocess and update results.

This is probably why 23andMe decided to cease updating older kits. The newer tests require a subscription which is recurring revenue.

The same is true when DNA testing companies need to rematch their entire user base. This happens when the criteria for matching changes. For example, Ancestry purged a large number of matches for all of their customers back in 2020. While match algorithm changes necessitate rematching, with associated costs, this change also provided Ancestry with the huge benefit of eliminating approximately half of their customer’s matches. This freed up storage space, either physically in their data center or space rented in the cloud, representing substantial cost-savings.

How long can a DNA testing company reasonably be expected to continue investing in a product which never generates additional revenue but for which the maintenance and reinvestment costs never end?

Ancestry and MyHeritage both hope to offset the expenses of maintaining their customer’s DNA tests and providing free updates by selling subscriptions to their record services. 23andMe wants you to purchase a new test and a yearly subscription. FamilyTreeDNA wants you to purchase a Big Y-DNA and mitochondrial DNA test.

OK, now let’s look at my matches at Ancestry.

Ancestry

I’ve taken two Ancestry tests, V1 and V2. There were some differences, which I wrote about here and here. V2 is no longer the current chip.

Except for 23andMe who wants their customers to purchase their most current test, the other companies no longer routinely announce new chip versions. They just go about their business. The only way you know that a vendor actually changed something is when the other companies who accept uploads suddenly encounter an issue with file formats. It always takes a few weeks to sort that out.

My Ancestry V1 test’s ethnicity results don’t show my Native American ethnicity.

Ancestry results were updated in June 2022

However, my V2 results do include Native American ethnicity.

Matches at Ancestry

I have many more matches on my V1 test at Ancestry because I took steps to preserve my smaller matches when Ancestry initiated its massive purge in 2020. I wrote about that here and here.

Ancestry’s SideView breaks matches down into maternal, paternal, and unassigned based on your side selection. You tell Ancestry which side is which. You may be able to determine which “side” is maternal or paternal either by your ethnicity or shared matches. While SideView is not always accurate, it’s a good place to begin.

Match Category	Ancestry V1 Test	Ancestry V2 Test
Maternal	15,587	15,116
Paternal	42,247	41,870
Both	2	2
Unassigned	48,999	4,127
Total	106,835	61,115

Ancestry either displays all your matches or your matches by side, which I used to compile the table above. I suspect that Ancestry is not assigning any of the smaller preserved matches to “sides” based on the numbers above.

Ancestry implemented a process called Timber that removes DNA that they feel is “too matchy,” meaning you match enough people in this region that they think it’s a pileup region for you personally, and therefore not useful. In some cases, enough DNA is removed causing that person to no longer be considered a match because they fall beneath the match threshold. I am not a fan of Timber.

Your match amount shown is AFTER Timber has removed those segments. Unweighted shared DNA is your pre-Timber match amount.

You can view the Unweighted shared DNA by clicking on the amount of shared DNA on your match list.

You can read Ancestry’s Matching White Paper, here.

Let’s take a look at my matches. I’ve listed both weighted and unweighted where they are different.

Match	Ancestry V1	Ancestry V2
Michael	755 cM, 35 seg	737 cM, 33 seg
Edward	66 cM, 4 seg (unweighted 86 cM)	65 cM, 4 seg (unweighted 86 cM)
Tom	59 cM, 3 seg (unweighted 63)	Same
Jonathon	43 cM, 4 seg, (unweighted 52 cM)	Same
Matthew	20 cM, 2 seg (unweighted 35 cM)	Same

Harold	132 cM, 7 seg	135 cM, 6 seg
Dean	67 cM, 4 seg (unweighted 78 cM)	66 cM, 4 seg (unweighted 78 cM)
Debbie	93 cM, 5 seg	Same
Valli	142 cM, 3 seg	Same
Jared	20 cM, 1 seg (unweighted 22 cM)	Same

Timber only removes DNA when the match is under 90 cM. Almost every match under 90 cM has some DNA removed.

Ancestry Summary

The results of the two Ancestry tests are very close.

In some circumstances, no DNA is removed by Timber, so the unweighted is the same as the weighted. However, in other cases, a significant amount is removed. 15 cM of Matthew’s 35 cM was removed by Timber, reducing his total to 20 cM.

Remember that Ancestry does not show shared matches unless they are greater than 20 cM, which is different than any other DNA testing company.

At one point, Ancestry was selling a health test that was also a genealogy test. That test utilized a different chip that is not accepted for uploads by other vendors. The results of that test might well be different that the “normal” Ancestry tests focused on genealogy. The Ancestry health test is no longer offered.

Companies that Accept Uploads

DNA testing companies that accept uploaded DNA files from other DNA testing companies need to process the uploaded file, just like a file that is generated in their own lab. Of course, they must deal with the differences between uploaded files and their own file format. The processing includes imputation and formulates the uploaded file so that it works with the tools that they provide for their customers, including ethnicity (by whatever name they use) matching, family matching (bucketing), advanced matching, the match matrix, triangulation, AutoClusters, Theories of Family Relativity, and other advanced tools.

Of course, the testing company accepting uploads can only work with the DNA locations provided by the original DNA testing company in the uploaded file.

Matching and some additional tools are free to uploaders, but advanced tools require an inexpensive unlock.

FamilyTreeDNA

I took a test at FamilyTreeDNA, plus uploaded a copy of both of my Ancestry DNA files.

FamilyTreeDNA named their population (ethnicity) test myOrigins and the current version is V3. I wrote about the rollout and comparison in September of 2020, here.

My DNA test taken at FamilyTreeDNA, above, reveals Native American segments that match reference populations found both in North and South America and the Caribbean Islands.

At FamilyTreeDNA, my Ancestry V1 uploaded file results show Native American population matches only in North America.

Interestingly, my Ancestry V1 file processed AT Ancestry did not reveal Native American ancestry, but the same file uploaded to and processed at FamilyTreeDNA did show Native American results, reflecting the difference between the vendors’ internal algorithms and reference populations utilized.

My myOrigins results from my Ancestry V2 uploaded file at FamilyTreeDNA also include my North American Native American segments. The V2 test also showed Native American ethnicity at Ancestry, so clearly something changed in Ancestry’s algorithm, locations tested, and/or reference populations between V1 and V2.

Fortunately, FamilyTreeDNA provides both chromosome painting and a population download file so I can match those Native segments with my autosomal matches to identify which of my ancestors contributed those specific segments.

One of my Native segments is shown in pink on Chromosome1. My mother has a Native segment in exactly the same location, so I know that this segment originated with my mother’s ancestors.

I downloaded the myOrigins population segment file and painted my results at DNAPainter, along with the matches where I can identify our common ancestor. This allowed me to pinpoint the ancestral line that contributed this Native segment in my maternal line. You can read about using DNAPainter, here.

FamilyTreeDNA Matches

I have significantly more matches at FamilyTreeDNA on their test than on either of my Ancestry tests that I uploaded. However, nearly the same number are maternally or paternally assigned through Family Matching, with the remainder unassigned. You can read about Family Matching here.

Match Category	FamilyTreeDNA Test	Ancestry V1 at FamilyTreeDNA	Ancestry V2 at FamilyTreeDNA
Paternal	3,479	3,572	3,422
Maternal	1,549	1,536	1,477
Both	3	3	3
All	8,154	6,397	6,579

Family matching, aka bucketing, automatically assigns my matches as maternal and paternal by linking known relatives to their place in my tree.

I completed the following match chart using my original test taken at FamilyTreeDNA, plus the same match at FamilyTreeDNA for both of my Ancestry tests.

In other words, Cheryl matched me at 467 cM on 21 segments on the original test taken at FamilyTreeDNA. She matched me on 473 cM and 21 segments on my Ancestry V1 test uploaded to FamilyTreeDNA and on 483 cM and 22 segments on the Ancestry V2 test uploaded to FamilyTreeDNA.

Match	FamilyTreeDNA	Ancestry V1 at FTDNA	Ancestry V2 at FTDNA
Cheryl	467 cM, 21 seg	473 cM, 21 seg	483 cM, 22 seg
Patricia	195 cM, 11 seg	189 cM, 11 seg	188 cM, 11 seg
Tom	77 cM, 4 seg	71 cM, 4 seg	76 cM, 4 seg
Thomas	72 cM, 3 seg	71 cM, 3 seg	74 cM, 3 seg
Roland	29 cM, 1 seg	35 cM, 2 seg	35 cM, 2 seg
Rex	62 cM, 4 seg	55 cM, 3 seg	57 cM, 3 seg
Don	395 cM, 18 seg	362 cM, 15 seg	398 cM, 18 seg
Ian	64 cM, 4 seg	56 cM, 4 seg	64 cM, 4 seg

Stacy	490 cM, 18 seg	494 cM, 15 seg	489 cM, 14 seg
Harold	127 cM, 5 cM	133 cM, 6 seg	143 cM, 6 seg
Dean	81 cM, 4 seg	75 cM, 3 seg	83 cM, 4 seg
Carl	103 cM, 4 seg	101 cM, 4 seg	102 cM, 4 seg
Debbie	99 cM, 5 seg	97 cM, 5 seg	99 cM, 5 seg
David	373 cM, 16 seg	435 cM, 19 seg	417 cM, 18 seg
Amos	176 cM, 7 seg	177 cM. 8 seg	177 cM, 7 seg
Buster	387 cM, 15 seg	396 cM, 16 seg	402 cM, 17 seg
Charlene	461 cM, 21 seg	450 cM, 21 seg	448 cM, 20 seg
Carol	65 cM, 6 seg	64 cM, 6 seg	65 cM, 6 seg

I have tested many of my cousins at FamilyTreeDNA and encouraged others to test or upload. I’ve attempted to include enough people so that I can have common matches at least at one other DNA testing company for comparison.

FamilyTreeDNA Summary

The matches are relatively close, with a few being exact.

Interestingly, some of the segment counts are different. In most cases, this results from one segment being broken into multiple segments by one or more of the tests, but not always. In the couple that I checked, the entire segment seems to descend from the same ancestral couple, so the break is likely a result of not all of the same DNA locations being tested, plus the limits of imputation.

MyHeritage

I have two tests at MyHeritage. One taken at MyHeritage, and an uploaded file from FamilyTreeDNA.

MyHeritage displays both ethnicity results and Genetic Groups which maps groups of people that you match. I left the Genetic Groups setting at the highest confidence level. Shifting it to lower displays additional Genetic Groups, some of which overlap with or are within ethnicity regions.

My test taken at MyHeritage, above, shows several ethnicities and Genetic Groups, but no Native American.

My FamilyTreeDNA kit processed at MyHeritage shows the same ethnicity regions, one additional Genetic Group, plus Native American heritage in the Amazon which is rather surprising given that I don’t show Native in North American regions where I’m positive my Native ancestors lived.

MyHeritage Matching

At MyHeritage, I compared the results of the test I took with MyHeritage, and a test I uploaded from FamilyTreeDNA. Fewer than half of my matches can be assigned to a parent via shared matching.

Matches	MyHeritage Test	FamilyTreeDNA at MyHeritage
Paternal	4,422	6,501
Maternal	2,660	3,655
Total	13,233	16,147

I have rounded my matches at MyHeritage to the closest cM.

Match	MyHeritage Test	FamilyTreeDNA at MyHeritage
Michael	801 cM, 32 seg	823 cM, 31 segments
Cheryl	467 cM, 23 seg	477 cM, 23 seg
Roland	No match	28 cM, 1 seg
Patty	156 cM, 9 seg	151 cM, 9 seg
Rex	43 cM, 4 seg	53 cM, 3 seg
Don	369 cM, 16 seg	382 cM, 17 seg

David	449 cM, 17 seg	460 cM, 17 seg
Charlene	454 cM, 23 seg	477 cM, 24 seg
Buster	408 cM, 15 seg	410 cM, 16 seg
Amos	183 cM, 8 seg	Same
Carol	78 cM, 6 seg	87 cM, 7 seg

MyHeritage Summary

I was surprised to discover that Roland had no match with the MyHeritage test, but did with the FamilyTreeDNA test. I wonder if this is a searching or matching glitch, especially since both companies use the same chip. 28 cM in one segment is a reasonably large match, and even if it was divided in two, it would still be over the matching threshold. I know this is a valid match because Roland triangulates with me and several cousins, I’m positive of our common ancestor, and he also matches me at both FamilyTreeDNA and 23andMe.

Other than that, the matches are reasonably close, with one being exact.

Your Matches Aren’t Everyplace

I unsuccessfully searched for someone who was a match to me in all four databases. Ancestry does not permit match downloads, so I had to search manually. People don’t always use the same names in different databases.

Surprisingly, I was unable to find one match who is in all of the databases. Many people only suggest testing at Ancestry because they have the largest database, but if you look at the following comparison chart that I’ve created, you’ll see that 16 of 26 people, or 62% were not at Ancestry. Conversely, many people were at Ancestry and not elsewhere. I could not find five maternal and five paternal matches at Ancestry that I could identify as matches in another database. 40% were not elsewhere.

If you think for one minute that it doesn’t matter for genealogy if you’re in all four major databases, please reconsider. It surely does matter.

Every single vendor has matches that the others don’t. Substantial, important matches. I have found first and second-cousin matches in every database that weren’t elsewhere.

Many of the original testers have passed away and can’t test again. My mother can never test at either 23andMe or Ancestry, but she is at both FamilyTreeDNA and MyHeritage because I could upgrade her kit at FamilyTreeDNA after she died. I uploaded her to MyHeritage. Of course, because she is a generation closer to our ancestors, she has many valuable matches that I don’t.

Each vendor provides either an email address or a messaging platform for you to contact your matches. Don’t be discouraged if they don’t answer. Just today, I received a reply that was years in the making.

Genealogists hope for immediate gratification, but we are actually in this for the long game. Play it with every tool at your disposal.

The Answer

Does it matter if you test at a DNA testing company, or upload a file?

I know this was a very long answer to what my readers hoped was a simple yes or no question.

There is no consistent answer at either FamilyTreeDNA or MyHeritage, the two DNA testing companies that accept uploads. Be sure you’re in both databases. My closest two matches that I did not test were found at MyHeritage. Here’s a direct link to upload at MyHeritage.

Of the vendors, those two should be the closest to each other because they are both processed in the GenebyGene lab, but again, the actual chip version, when the test was originally taken, and each vendor’s internal processing will result in differences. Neither the original test at the DNA testing company nor the uploaded files have consistently higher or lower matches. Neither type of test or upload appears to be universally more or less accurate. Differences in either direction seem to occur on a match-by-match basis. Many are so close as to be virtually equivalent, with a few seemingly random exceptions. Of course, we always have to consider Timber.

If you upload, unlock the advanced features at both FamilyTreeDNA and MyHeritage.

If you upload to a DNA testing company, you may discover in the future that some features and functions will only be available to original testers.

Personally, if I had the option, I would test at the company directly simply because it eliminates or at least reduces the possibility of future incompatibilities – with the exception of 23andMe which has chosen to not provide consistent updates to older tests. I’m incredibly grateful I didn’t test my mother or now deceased family members at 23andMe, and only there. I would be heartsick, heartbroken, and furious.

Our DNA is an extremely valuable resource for our genealogy. It’s the gift that truly keeps on giving, day after day, even when other records don’t exist. Be sure you and your family members are in each database one way or another, and test your Y-DNA (for males) and mitochondrial DNA (for everyone) to have a complete arsenal at your disposal.

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DNA Purchases and Free Uploads

FamilyTreeDNA – Y, mitochondrial and autosomal DNA testing
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Newspapers.com – Search newspapers for your ancestors
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DNA for Native American Genealogy – by Roberta Estes, for those ordering the e-book from anyplace, or paperback within the United States
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DNA: In Search Of…Your Grandparents

Posted on April 7, 2023 by Roberta Estes

Are you searching for an unknown relative or trying to unravel and understand unexpected results? Maybe you discovered that one or both of your parents is not your biological parent. Maybe one of your siblings might be a half-sibling instead. Or maybe you suddenly have an unexpected match that looks to be an unknown close relative, possibly a half-sibling. Perhaps there’s a close match you can’t place.

Or, are you searching for the identity of your grandparent or grandparents? If you’re searching for your parent or parents, often identifying your grandparents is a necessary step to narrow the parent-candidates.

I’ve written an entire series of “In Search of Unknown Family” articles, permanently listed together, here. They will step you through the search process and help you understand how to unravel your results. If you’re new, reading these, in order, before proceeding, would be a good idea.

Prior to beginning this series, I wrote the article, Identifying Unknown Parents and Individuals Using DNA Matching which explains the process in general. In other words, how searching for unknown people, specifically unknown parents, works. I recommend that you read this article as a primer, as it takes you step-by-step through the tools and processes, in general, building a foundational understanding for the following articles.
First Steps When Your DNA Results are Ready – Sticking Your Toe in the Genealogy Water is an excellent resource for people just beginning to work with DNA results.
I introduced the “In Search of” series in the article, DNA: In Search of…New Series Launches.
In the article, DNA: In Search of…What Do You Mean I’m Not Related to My Family? – and What Comes Next? we discussed the discovery that something was amiss when you don’t match a family member that you expect to match, then how to make sure a vial or upload mix-up didn’t happen. Next, I covered the basics of the four kinds of DNA tests you’ll be able to use to solve your mystery.
In the article, In Search of…Vendor Features, Strengths, and Testing Strategies, we discussed testing goals and strategies, including testing with and uploading to multiple autosomal DNA vendors, Y-DNA, and mitochondrial DNA testing. We reviewed the vendor’s strengths and the benefits of combining vendor information and resources.
In the article, DNA: In Search of…Signs of Endogamy, we discussed the signs of endogamy and various ways to determine if you or your recent ancestors descend from an endogamous population.
In the article, DNA: In Search of…Full and Half-Siblings we discussed how to determine if you have a sibling match, if they are a half or full sibling, and how to discern the difference.
In the article, Connect Your DNA test, and Others, to Your Tree, I explained how to optimize your DNA tests in order to take advantage of the features offered by each our primary DNA testing vendors.
In the article, How to Share DNA Results and Tree Access at Ancestry, I wrote step-by-step instructions for providing access to another person to allow them to view your DNA results, AND to share your tree – which are two different things. If you have a mystery match, and they are willing to allow you access, in essence “to drive,” you can just send them the link to this article that provides detailed instructions. Note that Ancestry has changed the user interface slightly with the rollout of their new “sides” matches.
In the article, How Am I Related to That Close Match?, we step through the process of narrowing down the possibilities of how an unexpectedly close match is related to you – and what to do next.
Not all of your ancestors contribute an X chromosome to you. In the article, X Chromosome Master Class, I’ve described how you can utilize the X chromosome when seeking to identify certain people in your tree. Conversely, an X chromosome match can effectively eliminate some relationships.

Identifying a Grandparent

I saved this “grandparents” article for later in the series because you will need the tools and techniques I’ve introduced in the earlier articles. Identifying grandparents is often the most challenging of any of the relationships we’ve covered so far. In part because each of those four individuals occupies a different place in your tree, meaning their X, Y-DNA and mitochondrial DNA is carried by different, and not all, descendants. This means we sometimes have to utilize different tools and techniques.

If you’re trying to identify any of your four grandparents, females are sometimes more challenging than males.

Why?

Women don’t have a Y chromosome to test. This can be a double handicap. Female testers can’t test a Y chromosome, and maternal ancestors don’t have a Y chromosome to match.

Of course, every circumstance differs. You may not have a male to test for paternal lines either.

The maternal grandfather can be uniquely challenging, because two types of DNA, Y-DNA and mitochondrial DNA matching are immediately eliminated for all testers.

While I’ve focused on the maternal grandfather in this example, these techniques can be utilized for all four grandparents as well as for parents. At the end, I’ll review other grandparent relationships and additional tools you might be able to utilize for each one.

In addition to autosomal DNA, we can also utilize mitochondrial DNA, Y-DNA and sometimes X DNA in certain situations.

Testing, Tests and Vendors

As you recall, only men have a Y chromosome (blue arrow), so only genetic males can take a Y-DNA test. Men pass their Y chromosome from father to son in each generation. Daughters don’t receive a Y chromosome.

Everyone has their mother’s mitochondrial DNA (pink arrow.) Women pass their mitochondrial DNA to both sexes of their children, but only females pass it on. In the current generation, represented by the son and daughter, above, the mother’s yellow heart-shaped mitochondrial DNA is inherited by both sexes of her children. In the current generation, males and females can both test for their mother’s mitochondrial DNA.

Of course, everyone has autosomal DNA, inherited from all of their ancestral lines through at least the 5^th or 6^th generation, and often further back in time. Autosomal DNA is divided in half in each generation, as children inherit half of each parents’ autosomal DNA (with the exception of the X chromosome, which males only inherit from their mother.)

The four major vendors, Ancestry, 23andMe, FamilyTreeDNA and MyHeritage sell autosomal DNA tests, but only FamilyTreeDNA sells Y-DNA and mitochondrial DNA tests.

Only 23andMe and FamilyTreeDNA report X matching.

All vendors except Ancestry provide segment location information along with a chromosome browser.

You can read about the vendor’s strengths and weaknesses in the third article, here.

Ordering Y and Mitochondrial DNA Tests

If you’re seeking the identities of grandparents, the children and parents, above, can test for the following types of DNA in addition to autosomal:

Person in Pedigree	Y-DNA	Mitochondrial
Son	His father’s blue star	His mother’s pink heart
Daughter	None	Her mother’s pink heart
Father	His father’s blue star	His mother’s gold heart
Mother	None	Her mother’s pink heart

Note that none of the people shown above in the direct pedigree line carry the Y-DNA of the green maternal grandfather. However, if the mother has a full sibling, the green “Male Child,” he will carry the Y-DNA of the maternal grandfather. Just be sure the mother and her brother are full siblings, because otherwise, the brother’s Y-DNA may not have been inherited from your mother’s father. I wrote about full vs half sibling determination, here.

Let’s view this from a slightly different perspective. For each grandparent in the tree, which of the two testers, son or daughter, if either, carry that ancestor’s DNA of the types listed in the columns.

Ancestor in Tree	Y-DNA	Mitochondrial DNA	Autosomal DNA	X DNA
Paternal Grandfather	Son	Neither	Son, daughter	Neither
Paternal Grandmother	Has no Y chromosome	None (father has it, doesn’t pass it on to son or daughter)	Son, daughter	Daughter (son does not receive father’s X chromosome)
Maternal Grandfather	Neither	Neither	Son, daughter	Son, daughter (potentially)
Maternal Grandmother	Has no Y chromosome	Son, daughter	Son, daughter	Son, daughter (potentially)

Obtaining the Y-DNA and mitochondrial DNA of those grandparents from their descendants will provide hints and may be instrumental in identifying the grandparent.

FamilyTreeDNA

You’ll need to order Y-DNA (males only) and mitochondrial DNA tests separately from autosomal DNA tests. They are three completely different tests.

At FamilyTreeDNA, the autosomal DNA test is called Family Finder to differentiate it from their Y-DNA and mitochondrial DNA tests.

Their autosomal test is called Family Finder whether you order a test from FamilyTreeDNA, or upload your results to their site from another vendor (instructions here.)

I recommend ordering the Big Y-700 Y-DNA test if possible, and if not, the highest resolution Y-DNA test you can afford. The Big Y-700 is the most refined Y-DNA test available, includes multiple tools and places Big Y-700 testers on the Time Tree through the Discover tool, providing relatively precise estimates of when those men shared a common ancestor. If you’ve already purchased a lower-precision Y-DNA test at FamilyTreeDNA, you can easily upgrade.

I wrote about using the Discover tool here. The recently added Group Time Tree draws a genetic Y-DNA tree of Big-Y testers in common projects, showing earliest known ancestors and the date of the most recent common ancestor.

You need to make sure your Family Finder, mitochondrial DNA and Y-DNA (if you’re a male) tests are ordered from the same account at FamilyTreeDNA.

You want all 3 of your tests on the same account (called a kit number) so that you can use the advanced search features that display people who match you on combinations of multiple kinds of tests. For example, if you’re a male, do your Y-DNA matches also match you on the autosomal Family Finder test, and if so, how closely? Advanced matching also provides X matching tools.

X DNA is included in autosomal tests. X DNA has a distinct matching pattern for males and females which makes it uniquely useful for genealogy. I wrote about X DNA matching here.

If you upload your autosomal results to FamilyTreeDNA from another company, you’re only uploading a raw DNA file, not the DNA itself, so FamilyTreeDNA will need to send you a swab kit to test your Y-DNA and mitochondrial DNA. If you upload your autosomal DNA, simply sign in to your kit, purchase the Y-DNA and/or mitochondrial DNA tests and they will send you a swab kit.

If you test directly at FamilyTreeDNA, you can add any test easily by simply signing in and placing an order. They will use your archived DNA from your swab sample, as long as there’s enough left and it’s of sufficient quality.

Fish In All Ponds

The first important thing to do in your grandparent search is to be sure you’re fishing in all ponds. In other words, be sure you’ve tested at all 4 vendors, or uploaded files to FamilyTreeDNA and MyHeritage.

When you upload files to those vendors, be sure to purchase the unlock for their advanced tools, because you’re going to utilize everything possible.

If you have relatively close matches at other vendors, ask if they will upload their files too. The upload is free. Not only will they receive additional matches, and another set of ethnicity results, their results will help you by associating your matches with specific sides of your family.

Why Order Multiple Tests Now Instead of Waiting?

I encourage testers to order their tests at the beginning of their journey, not one at a time. Each new test from a vendor takes about 6-8 weeks from the time you initially order – they send the test, you swab or spit, return it, and they process your DNA. Of course, uploading takes far less time.

If you’re adding elapsed time, two autosomal tests (Ancestry and 23andMe), two uploads (FamilyTreeDNA and MyHeritage,) a Y-DNA and a mitochondrial DNA test, if all purchased serially, one after the other, means you’ll be waiting about 6-8 months.

Do you want to wait 6-8 months? Can you afford to?

Part of that answer has to do with what, exactly, you’re seeking.

A Name or Information?

Are you seeking the name of a person, or are you seeking information about that person? With grandparents, you may be hoping to meet them, and time may be of the essence. Time delayed may not be able to be recovered or regained.

Most people don’t just want to put a name to the person they are seeking – they want to learn about them. You will have different matches at each company. Even after you identify the person you seek, the people you match at each company may have information about them, their photos, know about their life, family, and their ancestors. They may be able and willing to facilitate an introduction if that’s what you seek.

One cousin that I assisted discovered that his father had died just 6 weeks before he made the connection. He was heartsick.

Having data from all vendors simultaneously will allow you to compile that data and work with it together as well as separately. Using your “best” matches at each company, augmented by both Y-DNA and mitochondrial DNA can make MUCH shorter work of this search.

Your Y-DNA, if you’re a male will give you insights into your surname line, and the Big-Y test now comes with estimates of how far in the past you share a common ancestor with other men that have taken the Big-Y test. This can be a HUGE boon to a male trying to figure out his surname line.

Y-DNA and mitochondrial DNA, respectively, will eliminate many people from being your mother or father, or your direct paternal or direct maternal line ancestor. Both provide insights into which population and where that population originated as well. In other words, it provides you lineage-specific information not available elsewhere.

Your Y-DNA and mitochondrial DNA can also provide critically important information about whether that direct line ancestor belonged to an endogamous population, and where they came from.

Strategies

You may be tempted to think that you only need to test at one vendor, or at the vendor with the largest database, but that’s not necessarily true.

Here’s a table of my closest matches at the 4 vendors.

Vendor	Closest Maternal	Closest Paternal	Comments
Ancestry	1C, 1C1R	Half 1C, 2C	I recognized both of the maternal and neither of the paternal.
23andMe	2C, 2C	1C1R, half-gr-niece	Recognized both maternal, one paternal
MyHeritage	Mother uploaded, 1C	Half-niece, half 1C	Recognized both maternal, one paternal
FamilyTreeDNA	Mother tested, 1C1R	Parent/child, half-gr-niece	Recognized all 4

To be clear, I tested my mother at FamilyTreeDNA before she passed away, but if I was an adoptee searching for my mother, that’s the first database she would be in. As her family, we were able to order the Family Finder test from her archived DNA after she had passed away. I then uploaded her DNA file to MyHeritage, but she’ll never be at either 23andMe or Ancestry because they don’t accept uploads and she clearly can’t test.

Additionally, being able to identify maternal matches by viewing shared matches with my mother separates out close matches from my paternal side.

Let’s put this another way, I stand a MUCH BETTER chance of unraveling this mystery with the combined closest matches of all 4 databases instead of the top ones from just one database.

I’m providing analysis methodologies for working with results from all of the vendors together, in case your answer is not immediately obvious. Taking multiple tests facilitates using all of these tools immediately, not months later. Solving the puzzle sooner means you may not miss valuable connection opportunities.

You may also discover that the door slams shut with some people, but another match may be unbelievably helpful. Don’t unnecessarily limit your possibilities.

Here’s the testing and upload strategy I recommend.

What	When	Ancestry	23andMe	MyHeritage	FamilyTreeDNA	GEDmatch
Order autosomal test	Initially	Yes	Yes	Upload	Upload	Upload
Order Big-Y DNA test if male	Initially				Yes
Order mitochondrial DNA test	Initially				Yes
Upload free autosomal file	From Ancestry or 23andMe			Yes	Yes	Yes
Unlock Advanced Tools	When upload file			$29	$19	$9.95 month
Includes X Matching		No	Yes	No	Yes	Yes
Chromosome Browser, segment location information		No	Yes	Yes	Yes	Yes

When you upload a DNA file to a vendor site, only upload one file per site, per tester. Otherwise, multiple tests simply glom up everyone’s match list with multiple matches to the same person and can be very confusing.

One person took an autosomal test at a company that accepts uploads, forgot about it, uploaded a file from another vendor later, and immediately thought she had found her parent. She had not. She “found” herself.
Another person though she had found two sisters, but one person had uploaded their own file from two different vendors.

Multiple vendor sites reveal multiple close matches to different people which increase your opportunity to discover INFORMATION about your family, not just the identity of the person.

Match Ranges

Given that we are searching for an unknown maternal grandfather, your mother may not have had any (known) full siblings. The “best” match would be to a full or half siblings to your parents, or their descendants, depending on how old your grandparents would be.

Let’s take the “worst case” scenario, meaning there are no full siblings AND there are many possible generations between you and the people you may match.

Now, let’s look at DNAPainter’s Shared cM tool.

You’re going to be looking for someone who is either your mother’s half sibling on her father’s side, or who is a full sibling.

If your mother is adopted, it’s possible that she has or had full siblings. If your mother was born circa 1920, it’s likely that you will be matching the next generation, or two, or three.

However, if your mother was born later, you could be matching her siblings directly.

I’m going to assume half siblings for this example, because they are more difficult than full siblings.

Full sibling relationships for your mother’s siblings are listed at right. Your full aunt or uncle at top, then their descendant generations below.

At left, in red, are the half-sibling relationships and the matching amounts.

You can see that if you’re dealing with half 1C3R (half first cousin three times removed,) you may not match.

Therefore, in order to isolate matches, it’s imperative to test every relevant relative possible.

Who’s Relevant for DNA Testing?

Who is relevant to test If you’re attempting to identify your maternal grandfather?

The goal is to be able to assign matches to the most refined ancestor possible. In other words, if you can assign someone to either your grandmother’s line, or your grandfather’s line, that’s better than assigning the person to your grandparents jointly.

Always utilize the tests of the people furthest up the tree, meaning the oldest generations. Their DNA is less-diluted, meaning it has been divided fewer times. Think about who is living and might be willing to test.

You need to be able to divide your matches between your parents, and then between your grandparents on your mother’s side.

Test your parents, of course, and any of their known siblings, half or full.
If those siblings have passed away, test as many of their children as you can.
If any of your grandparents are living, test them
If BOTH of your grandparents on the same side aren’t available to test, test any, preferably all, living aunts or uncles.
If your maternal grandmother had siblings, test them or their descendants if they are deceased.
If your parents are deceased, test your aunts, uncles, full siblings and half-siblings on your mother’s side. (Personally, I’d test all half-siblings, not just maternal.)
Half-siblings are particularly valuable because there is no question which “side” your shared DNA came from. They will match people you don’t because they received part of your parent’s DNA that you did not.

Furthermore, shared matches to half-siblings unquestionably identify which parent those matches are through.

Essentially, you’re trying to account for all matches that can be assigned to your grandparents whose identities you know – leaving only people who descend from your unknown maternal grandfather.

Testing your own descendants will not aid your quest. There is no need to test them for this purpose, given that they received half of your DNA.

I wrote about why testing close relatives is important in the article Superpower: Your Aunts’ and Uncles’ DNA is Your DNA Too – Maximize Those Matches!

Create or Upload a Tree

Three of the four major vendors, plus GEDMatch, support and utilize family trees.

You’ll want to either upload or create a tree at each of the vendor sites.

You can either upload a GEDCOM file from your home computer genealogy software, or you can create a tree at one of the vendors, download it, and upload to the others. I described that process at Ancestry, here.

Goal

Your goal is to work with your highest matches first to determine how they are related to you, thereby eliminating matches to known lineages.

Assuming you’re only searching for the identity of one grandparent, it’s beneficial to have done enough of your genealogy on your three known grandparents to be able to assign matches from those lines to those sides.

Step 1 is to check each vendor for close matches that might fall into that category.

The Top 15 at Each Vendor

Your closest several autosomal matches are the most important and insightful. I begin with the top 15 autosomal results at each vendor, initially, which provides me with the best chance of meaningful close relationship discoveries.

Create a Spreadsheet or Chart

I hate to use that S word (spreadsheet), because I don’t want non-technical people to be discouraged. So, I’m going to show you how I set up a spreadsheet and you can simply create a chart or even draw this out on paper if you wish.

I’ve color-coded columns for each of my 4 grandparents. The green column is the target Maternal Grandfather whose identity I’m seeking.

I match our first example; Erik, at 417 cM. Based on various pieces of information, taken together, I’ve determined that I’m Erik’s half 1C1R. His 8 great-grandparent surnames, or the ones he has provided, indicate that I’m related to Eric on my paternal grandfather’s line.

You’ll want to record your closest matches in this fashion.

Let’s look at how to find this information and work with the tools at the individual vendors.

23andMe

Let’s start at 23andMe, because they create a potential genetic tree for you, which may or may not be accurate.

I have two separate tests at 23andMe. One is a V3 and one is a V4 test. I keep one in its pristine state, and I work with the second one. You’ll see two of “me” in the tree, and that’s why.

23andMe makes it easy to see estimated relationships, although they are not always correct. Generally, they are close, and they can be quite valuable.

Click on any image to enlarge

The maternal and paternal “sides” may not be positioned where genealogists are used to seeing them. Remember, 23andMe has no genealogy trees, so they are attempting to construct a genetic tree based on how people are related to you and to each other, with no prior knowledge. They do sometimes have issues with half-relationships, so I’d encourage you to use this tree to isolate people to the three grandparents you know.

In my case, I was able to determine the maternal and paternal sides easily based on known cousins. This is the perfect example of why it’s important to test known relatives from both sides of your family.

My paternal side, at right, in blue, was easy because I recognized my half-sister’s family, and because of known cousins who I recognized from having tested elsewhere. I’ve worked with them for years. The blue stars show people I could identify, mostly second cousins.

My maternal side is at left, in red. Normally, for genealogists, the maternal side is at right, and the paternal at left, so don’t make assumptions, and don’t let this positioning throw you.

I’m pretending I don’t know who my maternal grandfather is. I was able to identify my maternal grandmother’s side based on a known second cousin.

That leaves my target – my maternal grandfather’s line.

All of the matches to the left of the red circle would, by process of elimination, be on my maternal grandfather’s side.

The next step would be to figure out how the 5 people descending from my maternal grandfather’s line are related to each other – through which of their ancestors.

On the DNA Relatives match list, here’s what needs to be checked:

Do your matches share surnames with you or your ancestors?
Do they show surnames in common with each other?
Is there a common location?
Birth year which helps you understand their potential generation.
Did they list their grandparents’ birthplaces?
Did they provide a family tree link?
Do they also match each other using the Relatives in Common feature?
Do they triangulate, indicated by “DNA Overlap” in Relatives in Common?
Who else is on the Relatives in Common list, and what do they have in common with each other?
Looking at your Ancestry Composition compared with theirs, what are your shared populations, and are they relevant? If you are both 100% European, then shared populations aren’t useful, but if both people share the same minority ancestry, especially on the same segments, it may indeed be relevant – especially if it can’t be accounted for on the known sides of the family.

Reach out to these people and see what they know about their genealogy, if they have tested elsewhere, and if they have a genealogy tree someplace that you can view.

If they can tell you their grandparents’ names, birth and death dates and locations, you can check public sources like WikiTree, FamilySearch and Geni, or build trees for them. You can also use Newspaper resources, like Newspapers.com, NewspaperArchive and the newspapers at MyHeritage.

I added the top 15 23andMe matches into the spreadsheet I created.

You’ll notice that not many people at 23andMe enter surnames. However, if you can identify individuals from your 3 known lines, you can piggyback the rest by using Relatives in Common in conjunction with the genetic tree placement.

Be sure to check all the people that are connected to the target line in your genetic tree.

You’ll want to harvest your DNA segments to paint at DNAPainter if you don’t solve this mystery with initial reviews at each vendor.

I wrote about Triangulation in Action at 23andMe, here.
I wrote several articles about using DNAPainter, here.
Instructions to download your DNA matches and their segment data can be found here. 23andMe results cannot be sorted by X chromosome matches, but you can sort the downloaded spreadsheet by X matching.

Ancestry

Let’s move to Ancestry next.

At Ancestry, you’ll want to start with your closest matches on your match list.

Ancestry classifies “Close Matches” as anyone 200 cM or greater, which probably won’t reach as far down as the matches we’ll want to include.

Some of the categories in the Shared cM Chart from DNAPainter, above, don’t work based on ages, so I’ve eliminated those. I also know, for example, that someone who could fall in the grandparent/grandchild category (blue star,) in my case, does not, so must be a different relationship.

Second cousins, who share great-grandparents, can be expected to share about 229 cM of DNA on average, or between 41 and 592 cM. First cousins share 866 cM, and half first cousins share 449 cM on average.

I have 13 close matches (over 200 cM), but I’m including my top 15 at each vendor, so I added two more. You can always go back and add more matches if necessary. Just keep in mind that the smaller the match, the greater the probability that it came from increasingly distant generations before your grandparents. Your sweet spot to identify grandparents is between 1C and 2C.

I need to divide my close matches into 4 groups, each one equating to a grandparent. Record this on your spreadsheet.

You can group your matches at Ancestry using colored dots, which means you can sort by those groups.

You can also select a “side” for a match by clicking on “Yes” under the question, “Do you recognize them?”

Initially, you want to determine if this person is related to you on your mother’s or father side, and hopefully, through which grandparent.

Recently, Ancestry added a feature called SideView which allows testers to indicate, based on ethnicity, which side is “parent 1” and which side is “parent 2.” I wrote about that, here.

Make your selection, assuming you can tell which “side” of you descends from which parent based on ethnicity and/or shared matches. How you label “parent 1,” meaning either maternal or paternal, determines how Ancestry assigns your matches, when possible.

Using these tools, which may not be completely accurate, plus shared matches with people you can identify, divide your matches among your three known grandparents, meaning that the people you cannot assign will be placed in the fourth “unknown” column.

On my spreadsheet, I assign all of my closest matches to one of my grandparents. Michael is my first cousin (1C) and we share both maternal grandparents, so he’s not helpful in the division because he can’t be assigned to only one grandparent.

The green maternal grandfather is who I’m attempting to identify.

There are 4 people, highlighted in yellow, who don’t fall into the other three grandparent lines, so they get added to the green column and will be my focus.

I would be inclined to continue adding matches using a process known as the Leeds Method, until I had several people in each category. Looking back at the DNAPainter cM chart, at this point, we don’t have anyone below 200 cM and the matches we need might be below that threshold. The more matches you have to work with, the better.

At Ancestry, you cannot download your matches into a spreadsheet, nor can you work with other clustering tools such as Genetic Affairs, so you’ll have to build out your spreadsheet manually.

Check for the same types of information that I reviewed at 23andMe:

Review trees, if your matches have them, minimally recording the surnames of their 8 great-grandparents.
Review shared matches, looking for common names in the trees in recent generations.
View shared matches with people with whom you have a “Common Ancestor” indication, which means a ThruLine. You won’t have Thrulines with your target grandparent, of course, but Thrulines will allow you to place the match in one of the other columns. I wrote about ThruLines here, here and here.
ThruLines sometimes suggests ancestors based on other people’s trees, so be EXCEEDINGLY careful with potential ancestor suggestions. That’s not to say you should discount those suggestions. Just treat them as tree hints that may have been copy/pasted hundreds of times, because that’s what they are.

I make notes on each match so I can easily see the connection by scanning without opening the match.

Now, I have a total of 30 entries on my spreadsheet, 15 from 23and Me and 15 from Ancestry.

Why Not Use Autosclusters?

Even with vendors who allow or provide cluster tools, I don’t use an automated autocluster tool at this point. Autocluster tools often omit your closest matches because your closest matches would be in nearly half of all your clusters, which isn’t exactly informative. However, for this purpose, those are the very matches we need to evaluate.

After identifying groups of people that represent the missing grandparent, using our spreadsheet methodology, autoclusters could be useful to identify common surnames and even to compare the trees of our matches using AutoTree, AutoPedigree and AutoKinship. AutoClusters cannot be utilized at Ancestry, but is available through MyHeritage and at GEDmatch, or through Genetic Affairs for 23andMe and FamilyTreeDNA.

Next, let’s move to FamilyTreeDNA.

FamilyTreeDNA

FamilyTreeDNA is the only vendor that provides Family Matching, also known as “bucketing.” FamilyTreeDNA assigns your matches to either a paternal or maternal bucket, or both, based on triangulated matches with someone you’ve linked to a profile in your tree.

The key to Family Matching is to link known Family Finder matches to their profile cards in your tree.

Clicking on the Family Tree link at the top of your personal page allows you to link your matches to the profile cards of your matches.

FamilyTreeDNA utilizes these linked matches to assign those people, and matches who match you and those people, both, on at least one common segment, to the maternal or paternal tabs on your match list.

Always link as many known people as possible (red stars) which will result in more matches being bucketed and assigned to parents’ sides for you, even if neither parent is available to test.

I wrote about Triangulation in Action at FamilyTreeDNA, here.

You can see at the top of my match list that I have a total of 8000 matches of which 3422 are paternal, 1517 are maternal and 3 match on both sides. Full siblings, their (and my) children and their descendants will always match on both sides. People with endogamy across both parents may have several matches on both sides.

If your relevant parent has tested, always work from their test.

Because we are searching for the maternal grandfather, in this case, we can ignore all tests that are bucketed as paternal matches.

Given that we are searching for my maternal grandfather, I probably have not been able to link as many maternal matches, other than possibly ones from my maternal grandmother. This means that the maternal grandfather’s matches are not bucketed because there are no identified matches to link on that side of my tree.

If you sort by maternal and paternal tabs, you’ll miss people who aren’t bucketed, meaning they have no maternal or paternal icon, so I recommend simply scanning down the list and processing maternal matches and non-bucketed matches.

By being able to confidently ignore paternally bucketed matches and only processing maternal and non-assigned matches, this is equivalent to processing the first 48 total matches. If I were to only look at the first 15 matches, 12 were paternal and only 3 are maternal.

Using bucketing at FamilyTreeDNA is very efficient and saves a lot of work.

Omitting paternal matches also means we are including smaller matches which could potentially be from common ancestors further back in the tree. Or, they could be younger testers. Or simply smaller by the randomness of recombination.

FamilyTreeDNA is a goldmine, with 16 of 20 maternal matches being from the unknown maternal grandfather.

Next, let’s see what’s waiting at MyHeritage.

MyHeritage

MyHeritage is particularly useful if your lineage happens to be from Europe. Of course, if you’re searching for an unknown person, you probably have no idea where they or their ancestors are from. Two of my best matches first appeared at MyHeritage.

Of course, your matches with people who descend from your unknown maternal grandfather won’t have any Theories of Family Relativity, as that tool is based on BOTH a DNA match plus a tree or document match. However, Theories is wonderful to group your matches to your other three grandparents.

MyHeritage provides a great deal of information for each match, including common surnames with your tree. If you recognize the surnames (and shared matches) as paternal or maternal, then you can assign the match. However, the matches you’re most interested in are the highest matches without any surnames in common with you – which likely point to the missing maternal grandfather.

However, those people may, and probably do, have surnames in common with each other.

Of the matches who aren’t attributed to the other three grandparents, the name Ferverda arises again and again. So does Miller, which suggests the grandparent or great-grandparent couple may well be Ferverda/Miller.

Let’s continue working through the process with our spreadsheet and see what we can discover about those surnames.

Our 60 Results

Of the 60 total results, 15 from each vendor, a total of 24 cannot be assigned to other columns through bucketing or shared matches, so are associated with the maternal grandfather. Of course, Michael who descends from both of my maternal grandparents won’t be helpful initially.

Cheryl, Donald and Michael are duplicates at different vendors, but the rest are not.

Of the relevant matches, the majority, 12 are from FamilyTreeDNA, four each are from Ancestry and MyHeritage, and three are from 23andMe.

Of the names provided in the surname fields of matches, in matches’ trees in the first few generations, and the testers’ surnames, Ferverda is repeated 12 times, for 50% of the time. Miller is repeated 9 times, so it’s likely that either of those are the missing grandfather’s surname. Of course, if we had Y-DNA, we’d know the answer to that immediately.

Comparing trees of my matches, we find John Ferverda as the common ancestor between two different matches. John is the son of Hiram Ferverda and Eva Miller who are found in several trees.

That’s a great hint. But is this the breakthrough I need?

What’s Next?

The next step is to look for connections between the maternal grandmother, Edith Lore, who is known in our example, and a Ferverda male. He is probably one of the sons of Hiram Ferverda and Eva Miller. Do they lived in the same area? In close proximity? Do they attend the same church or school? Are they neighbors or live close to the family or some of their relatives? Does she have connections with Ferverda family members? We are narrowing in.

Some of Hiram and Eva’s sons might be able to be eliminated based on age or other factors, or at least be less likely candidates. Any of their children who had moved out of state when the child was conceived would be less likely candidates. Age would be a factor, as would opportunity.

Target testing of the Ferverda sons’ children, or the descendants of their children would (probably) be able to pinpoint which of their sons is more closely related to me (or my mother) than the rest.

In our case, indeed, John Ferverda is the son we are searching for and his descendant, Michael is the highest match on the list. Cheryl and Donald descend from John’s brother, which eliminates him as a candidate. Another tester descends from a third Ferverda son, which eliminates that son as well.

Michael, my actual first cousin with a 755 cM match at one vendor, and 822 cM at a second vendor, is shown by the MyHeritage cM Explainer with an 88% probability that he is my first cousin.

However, when I’m trying to identify the maternal grandfather, which is half of that couple, I need to focus one generation further back in time to eliminate other candidates.

The second and third closest matches are both Donald at 395 cM and Cheryl at 467 cM who also share the same Ferverda/Miller lineage and are the children of my maternal grandfather’s brother.

On the spreadsheet, I need to look at the trees of people who have both Ferverda and Miller, which brought me to both Cheryl and Donald, then Michael, which allowed me to identify John Ferverda, unquestionably, as my grandfather based on the cM match amounts.

Cheryl and Donald, who are confirmed full siblings, and my mother either have to be first cousins, or half siblings. Their match with mother is NOT in the half-sibling range for one sibling, and on the lower edge with the other. Mother also matches Michael as a nephew, not more distantly as she would if he were a first cousin once removed (1C1R) instead of a nephew.

Evaluating these matches combined confirms that my maternal grandfather is indeed John Ferverda.

What About X DNA?

The X chromosome has a unique inheritance path which is sometimes helpful in this circumstance, especially to males.

Women inherit an X chromosome from both parents, but males inherit an X chromosome from ONLY their mother. A male inherits a Y chromosome from his father which is what makes him male. Women inherit two X chromosomes, one from each parent, and no Y, which is what makes them female.

Therefore, if you are a male and are struggling with which side of your tree matches are associated with, the X chromosome may be of help.

Your mother passed her X chromosome to you, which could be:

Her entire maternal X, meaning your maternal grandmother’s X chromosome
Her entire paternal X, meaning your maternal grandfather’s X chromosome (which descends from his mother)
Some combination of your maternal grandmother and maternal grandfather’s chromosomes

One thing we know positively is that a male’s X matches are ALWAYS from their maternal side only, so that should help when dividing a male’s matches maternally or paternally. Note – be aware of potential pedigree collapse, endogamy and identical-by-chance matches if it looks like a male has a X match on his father’s side.

Unfortunately, the X chromosome cannot assist females in the same way, because females inherit an X from both parents. Therefore, they can match people in the same was as a male, but also in additional ways.

Females will match their paternal grandmother on her entire X chromosome, and will match one or both of their maternal grandparents on the X chromosome.
Females will NEVER match their paternal grandfather’s X chromosome because their father did not inherit an X chromosome from his father.
Males will match one or both of their maternal grandparents on their X chromosome.
Males will NEVER match their paternal grandparents, because males do not receive an X chromosome from their father.

The usefulness of X DNA matching depends on the inheritance path of both the tester AND their match.

When Can Y-DNA or Mitochondrial DNA Help with Grandparent Identification?

If you recall, I selected the maternal grandfather as the person to seek because no tester carries either the Y-DNA or mitochondrial DNA of their maternal grandfather. In other words, this was the most difficult identification, meaning that any of the other three grandparents would be, or at least could be, easier with the benefit of Y-DNA and/or mitochondrial DNA testing.

In addition to matching, both Y-DNA and mitochondrial DNA will provide testers with location origins, both continental and often much more specific locations based on where other testers and matches are from.

Y-DNA often provides a surname.

Let’s see how these tests, matches and results can assist us.

Paternal grandfather – If I was a male descended from John Ferverda paternally, I could have tested both my autosomal DNA PLUS my Y-DNA, which would have immediately revealed the Ferverda surname via Y-DNA. Two Ferverda men are shown in the Ferverda surname DNA project, above.

That revelation would have confirmed the Ferverda surname when combined with the high frequency of Ferverda found among autosomal matches on the spreadsheet.

Maternal grandmother – If we were searching for a maternal grandmother, both the male and female sibling testers (as shown in the pedigree chart) would have her mitochondrial DNA which could provide matches to relevant descendants. Mitochondrial DNA at both FamilyTreeDNA and 23andMe could also eliminate anyone who does not match on a common haplogroup, when comparing 23andMe results to 23andMe results, and FamilyTreeDNA to FamilyTreeDNA results at the same level.

At 23andMe, only base level haplogroups are provided, but they are enough to rule out a direct matrilineal line ancestor.

At FamilyTreeDNA, the earlier HVR1 and HVR2 tests provide base level haplogroups, while full sequence testing provides granular, specific haplogroups. Full sequence is the recommended testing level.

Paternal grandmother – If we were searching for a paternal grandmother, testers would, of course, need either their father to test his mitochondrial DNA, or for one of his siblings to test which could be used in the same way as described for maternal grandmother matching.

Summary

Successfully identifying a grandparent is dependent on many factors. Before you make that identification, it’s very difficult to know which are more or less important.

For example, if the grandparent is from a part of the world with few testers, you will have far fewer matches, potentially, than other lines from more highly tested regions. In my case, two of my four grandparents’ families, including Ferverda, immigrated in the 1850s, so they had fewer matches than families that have been producing large families in the US for generations.

Endogamy may be a factor.

Family size in past and current generations may be a factor.

Simple luck may be a factor.

Therefore, it’s always wise to test your DNA, and that of your parents and close relatives if possible, and upload to all of the autosomal databases. Then construct an analysis plan based on:

How you descend from the grandparent in question, meaning do you carry their X DNA, Y-DNA or mitochondrial DNA.
Who else is available to test their autosomal DNA to assist with shared matches and the process of elimination.
Who else is available to test for Y-DNA and/or mitochondrial DNA of the ancestor in question.

If you don’t find the answer initially, schedule a revisit of your matches periodically and update your spreadsheet. Sometimes DNA and genealogy is a waiting same.

Just remember, luck always favors the prepared!

Resources

You may find the following resource articles beneficial in addition to the links provided throughout this article.

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X Chromosome Master Class

Posted on March 28, 2023 by Roberta Estes

The X chromosome can be especially useful to genetic genealogists because it has a unique inheritance path. Thanks to that characteristic, some of the work of identifying your common ancestor is done just by simply HAVING an X match.

Unfortunately, X-DNA and X matching is both underutilized and somewhat misunderstood – in part because not all vendors utilize the X chromosome for matching.

The X chromosome has the capability of reaching further back in time and breaking down brick walls that might fall no other way.

Hopefully, you will read this article, follow along with your own DNA results and make important discoveries.

Let’s get started!

Who Uses the X Chromosome?

The X chromosome is autosomal in nature, meaning it recombines under some circumstances, but you only inherit your X chromosome from certain ancestors.

It’s important to understand why, and how to utilize the X chromosome for matching. In this article, I’ve presented this information in a variety of ways, including case studies, because people learn differently.

Of the four major testing vendors, only two provide X-DNA match results.

FamilyTreeDNA – provides X chromosome results and advanced matching capabilities including filtered X matching
23andMe – provides X chromosome results, but not filtered X matching without downloading your results in spreadsheet format
Ancestry and MyHeritage do not provide X-DNA results but do include the X in your raw DNA file so you can upload to vendors who do provide X matching
GEDmatch – not a DNA testing vendor but a third-party matching database that provides X matching in addition to other tools

It’s worth noting at this point that X-DNA and mitochondrial DNA is not the same thing. I wrote about that, here. The source of this confusion is that the X chromosome and mitochondrial DNA are both associated in some way with descent from females – but they are very different and so is their inheritance path.

So, what is X-DNA and how does it work?

What is X-DNA?

Everyone inherits two copies of each of chromosomes 1-22, one copy of each chromosome from each of your parents.

That’s why DNA matching works and each match can be identified as “maternal” or “paternal,” depending on how your match is related to you. Each valid match (excluding identical by chance matches) will be related either maternally, or paternally, or sometimes, both.

Your 23^rd chromosome is your sex determination chromosome and is inherited differently. Chromosome 23 is comprised of X and Y DNA.

Everyone inherits one copy of chromosome 23 from each parent.

Males inherit a Y chromosome from their father, which is what makes males male. They do not inherit an X chromosome from their father.
Males always inherit an X chromosome from their mother.
Females inherit an X chromosome from both parents, which is what makes them female. Females have two X chromosomes, and no Y chromosome.

Chromosome 23	Father Contributes	Mother Contributes
Male Child	Y chromosome	X chromosome
Female Child	X chromosome	X chromosome

X-DNA and mitochondrial DNA are often confused, but they are not the same thing. In fact, they are completely different.

Mitochondrial DNA, in BOTH males and females is always inherited from only the mother and only descends from the direct matrilineal line, so only the mother’s mother’s mother’s direct line. X DNA can be inherited from a number of ancestors based on a specific inheritance path.

Everyone has both X-DNA AND mitochondrial DNA.

Because males don’t inherit an X chromosome from their father, X chromosome matching has a unique and specific pattern of descent which allows testers who match to immediately eliminate some potential common ancestors.

Males only inherit an X chromosome from their mother, which means they can only have legitimate X matches on their mother’s side of their tree.
Females, on the other hand, inherit an X chromosome from both their mother and father. Their father only has one X chromosome to contribute, so his daughter receives her paternal grandmother’s X chromosome intact.
Both males and females inherit their mother’s X chromosome just like any of the other 22 autosomes. I wrote about chromosomes, here.

However, the unique X chromosome inheritance path provides us with a fourth very useful type of DNA for genealogy, in addition to Y-DNA, mitochondrial and autosomal DNA.

For the vendors who provide X-matching, it’s included with your autosomal test and does not need to be purchased separately.

The Unique X Chromosome

The X chromosome, even though it is autosomal in nature, meaning it does recombine and divide in certain circumstances, is really its own distinct tool that is not equivalent to autosomal matching in the way we’re accustomed. We just need to learn about the message it’s delivering and how to interpret X matches.

FamilyTreeDNA is one of two vendors who utilizes X chromosome matching, along with 23andMe, which is another good reason to encourage your matches at other vendors to upload their DNA file to FamilyTreeDNA for free matching.

The four major vendors do include X-DNA results in their raw DNA download file, even if they don’t provide X-matching themselves. This means you can upload the results to either FamilyTreeDNA or GEDmatch where you can obtain X matches. I provided step-by-step download/upload instructions for each vendor here.

Let’s look how X matching is both different, and beneficial.

My X Chromosome Family Tree

We are going to build a simple case study. A case study truly is worth 1000 descriptions.

This fan chart of my family tree colorizes the X chromosome inheritance path. In this chart, males are colored blue and females pink, but the salient point is that I can inherit some portion of (or all of) a copy of my X chromosome from the colorized ancestors, and only those ancestors.

Because males don’t inherit an X chromosome from their father, they CANNOT inherit any portion of an X chromosome from their father’s ancestors.

Looking at my father’s half of the chart, at left, you see that I inherited an X chromosome from both of my parents, but my father only inherited an X chromosome from his mother, Ollie Bolton. His father’s portion of the tree is uncolored, so no X chromosome could have descended from his paternal ancestors to him. Therefore he could not pass any X chromosome segments to me from his paternal side – because he doesn’t have X DNA from his father.

Hence, I didn’t inherit an X chromosome from any of the people whose positions in the chart are uncolored, meaning I can only inherit an X chromosome from the pink or blue people.

Essentially any generational male to male, meaning father/son relationship is an X-DNA blocker.

I know positively that I inherited my paternal grandmother, Ollie Bolton’s entire X chromosome, because hers is the only X chromosome my father, in the fan chart above, had to give me. His entire paternal side of the fan chart is uncolored.

Men only ever inherit their X chromosome from their mother. The only exception to this is if a male has the rare genetic condition of Klinefelter Syndrome, also known as XXY. If you are an adult male, it’s likely that you’ll already know if you have Klinefelters, so that’s probably the last possibility you should consider if you appear to have paternal X matches, not the first.

Sometimes, men appear to have X matches on their father’s side, but (barring Klinefelter’s) this is impossible. Those matches must either be identical by chance, or somehow related in an unknown way on their mother’s side.

Everyone inherits an X chromosome from their mother that is some combination of the X from her father and mother. It’s possible to inherit all of your maternal grandmother or maternal grandfather’s X chromosome, meaning they did not recombine during meiosis.

Using DNA Painter as an X Tool

I use DNAPainter to track my matches and correlate segments with ancestors.

I paint my DNA segments for all my chromosomes at DNAPainter which provides me with a central tracking mechanism that is visual in nature and allows me to combine matches from multiple vendors who provide segment information. I provide step-by-step instructions for using DNAPainter, here.

This is my maternal X chromosome with my matches painted. I’ve omitted my matches’ names for privacy.

On the left side of the shaded grey column, those matches are from my maternal grandmother’s ancestors. On the right side, those matches are from my maternal grandfather’s ancestors.

The person in the grey column descends from unknown ancestors. In other words, I can tell that they descend from my maternal line, but I can’t (yet) determine through which of my two maternal grandparents.

There’s also an area to the right of the grey column where there are no matches painted, so I don’t know yet whether I inherited this portion of my X chromosome from my maternal grandmother or maternal grandfather.

The small darker pink columnar band is simply marking the centromere of the chromosome and does not concern us for this discussion.

Click on any image to enlarge

In this summary view of my paternal X chromosome, above, it appears that I may well have inherited my entire X chromosome from my paternal great-grandmother. We know, based on our inheritance rules that I clearly received my paternal grandmother’s X chromosome, because that’s all my father had to give me.

However, by painting my matches based on their ancestors, and selecting the summary view, you can see that most of my paternal X chromosome can be accounted for, with the exception of rather small regions with the red arrows.

It’s not terribly unusual for either a male or female to inherit their entire maternal X chromosome from one grandparent, or in this case, great-grandparent.

Of course, a male doesn’t inherit an X chromosome from their father, but a female can inherit her paternal X chromosome from either or both paternal grandparents.

Does Size Matter?

Generally speaking, an X match needs to be larger than a match on the other chromosomes to be considered genealogically equivalent in the same timeframe as other autosomal matches. This is due to:

The unique inheritance pattern, meaning fewer recombination events occurred.
The fact that X-DNA is NOT inherited from several lines.
The X chromosome has lower SNP density, meaning it contains fewer SNPs, so there are fewer possible locations to match when compared to the other chromosomes.

I know this equivalency requirement sounds negative, but it’s actually not. It means 7 cM (centimorgans) of DNA on the X chromosome will reach back further in time, so you may carry the DNA of an ancestor on the X chromosome that you no longer carry on other chromosomes. It may also mean that older segments remain larger. It’s actually a golden opportunity.

It sounds much more positive to say that a 16 cM X match for a female, or a 13 cM X match for a male is about the same as a 7 cM match for any other autosomal match in the same generation.

Of course, if the 7 cM match gets divided in the following generation, it has slipped below the matching threshold. If a 16 or 13 cM X match gets divided, it’s still a match. Plus, in some generations, if passed from father to daughter, it’s not divided or recombined. So a 7 cM X match may well be descended from ancestors further back in time.

X Chromosome Differences are Important!

Working with our great-great grandparent’s generation, we have 16 direct ancestors as illustrated in the earlier fan chart.

Given that females inherit from 8 X-chromosome ancestors in total, they are going to inherit an average of 45.25 cM of X-DNA from each of those ancestors. Females have two X chromosomes for a total length of 362 cM of X-DNA from both parents.

A male only has one X chromosome, 181 cM in length, so he will receive an average of 36.2 cM from each of 5 ancestors, and it’s all from his mother’s side.

In this chart, I’ve shown the total number of cMs for all of the autosomes, meaning chromosomes 1-22 and, separately, the X for males and females.

The average total cM for chromosomes 1-22 individually is 304 cM. (Yes, each chromosome is a different length, but that doesn’t matter for averages.)
That 304 cM can be inherited from any of 16 ancestors (in your great-grandparent’s generation)
The total number of cM on the X chromosomes for both parents for females totals 362
The total cM of X-DNA for males is 181 cM
The calculated average cM inherited for the X chromosome in the same generation is significantly different, shown in the bottom row.

The actual average for males and females for any ancestor on any random non-X chromosome (in the gg-grandparent generation) is still 19 cM. Due to the inheritance pattern of the X chromosome, the female X-chromosome average inheritance is 45.25 cM and the male average is 36.2 cM, significantly higher than the average of 19 cM that genetic genealogists have come to expect at this relationship distance on the other chromosomes, combined.

How Do I Interpret an X Match?

It’s important to remember when looking at X matching that you’re only looking at the amount of DNA from one chromosome. When you’re looking at any other matching amount, you’re looking at a total match across all chromosomes, as reported by that vendor. Vendors report total matching DNA differently.

The total amount of matching autosomal DNA does not include the X chromosome cMs at FamilyTreeDNA. X-DNA matching cMs are reported separately.
The total amount of matching autosomal DNA does include the X chromosome cMs in the total cM match at 23andMe
X-DNA is not used for matching or included in the match amount at either MyHeritage or Ancestry, but is included in the raw DNA data download files for all four vendors.
The total match amount shows the total for 22 (or 23) chromosomes, NOT just the X chromosome(s). That’s not apples to apples.

Therefore, an X match of 45 cM for a female or 36 for a male is NOT (necessarily) equivalent to a 19 cM non-X match. That 19 cM is the total for 22 chromosomes, while the X match amount is just for one chromosome.

You might consider a 20 cM match on the regular autosomes significant, but a 20 cM X-only match *could* be only roughly equivalent to a 10ish cM match on chromosomes 1-22 in the same generation. That’s the dog-leg inheritance pattern at work.

This is why FamilyTreeDNA does not report an X-only match if there is no other autosomal match. A 19 cM X match is not equivalent to a 19cM match on chromosomes 1-22. Not to mention, calculating relationships based on cM ranges becomes more difficult when the X is included.

However, the flip side is that because of the inheritance pattern of the X chromosome, that 19 cM match, if valid and not IBC, may well reach significantly further back in time than a regular autosomal matches. This can be particularly important for people seeking either Native or enslaved African ancestors for whom traditional records are elusive if they exist at all.

Critical Take-Away Messages

Here are the critical take-away messages:

Because there are fewer ancestral lineages contributing to the tester’s X chromosome, the amount of X chromosomal DNA that a tester inherits from the ancestors who contribute to their X chromosome is increased substantially.
The DNA of the contributing ancestors is more likely to be inherited, because there are fewer other possible contributing ancestors, meaning fewer recombination events or DNA divisions/recombinations.
X-DNA is also more likely to be inherited because when passed from mother to son, it’s passed intact and not admixed with the DNA of the father.
X matches cannot be compared equally to either percentages or cM amounts on any of the other chromosomes, or autosomal DNA in total, because X matching only reports the amount on one single chromosome, while your total cM match amount reports the amount of DNA that matches from all chromosomes (which includes the X at 23andMe).
If you have X matches at 23andMe and/or FamilyTreeDNA, you can expect your total matching to be higher at 23andMe because they include the X matching cM in the total amount of shared DNA. FamilyTreeDNA provides the amount of X matching DNA separately, but not included in the total. MyHeritage and Ancestry do not include X matching DNA.

For clarity, at FamilyTreeDNA, you can see my shared DNA match with my mother. Of course, I match her on the total length of all my chromosomes, which is 3563 cM, the total Shared DNA for chromosomes 1-22. This includes all chromosomes except for the X chromosome which is reported separately at 181 cM. The longest contiguous block of shared DNA is 284 cM, the entire length of chromosome 1, the longest chromosome.

Because I’m a female, I match both parents on the full length of all 23 chromosomes, including 181 cM on both X chromosomes, respectively. Males will only match their mother on their X chromosome, meaning their total autosomal DNA match to their father, because the X is excluded, is 181 cM less than to their mother.

This difference in the amount of shared DNA with each parent, plus the differences in how DNA totals are reported by various vendors is also challenging for tools like DNAPainter’s Shared cM Tool which is based on the crowd sourced Shared cM Project that averages shared DNA numbers for known relationships at various vendors and translates those numbers into possible relationships for unknown matches.

Not all vendors report their total amount of shared DNA the same way. This is true for both X-DNA and half identical (HIR) versus fully identical (FIR) segments at 23andMe. This isn’t to say either approach is right or wrong, just to alert you to the differences.

Said Another Way

Let’s look at this another way.

If the average on any individual chromosome is 19 cMs for a relationship that’s 5 generations back in time. The average X-DNA for the same distance relationship is substantially more, which means that:

The X-DNA probably reaches further back in time than an equivalent relationship on any other autosome.
The X-DNA will have (probably) divided fewer times, and more DNA will descend from individual ancestors.
The inheritance path, meaning potential ancestors who contributed the X chromosomal DNA, is reduced significantly.

It’s challenging to draw equivalences when comparing X-DNA matching to the other chromosomes due to several variables that make interpretation difficult.

Based on the X-match size in comparison to the expected 19 cM single chromosome match at this genealogical distance, what is the comparable X-DNA segment size to the minimum 7 cM size generally accepted as valid on other chromosomes? What would be equal to a 7 cM segment on any other single random autosomal match, even though we know the inheritance probabilities are different and this isn’t apples to apples? Let’s pretend that it is.

This calculation presumes at the great-great-grandparent level that the 19 cM is in one single segment on a single chromosome. Now let’s divide 19 cM by 7 cM, which is 2.7, then divide the X amounts by the same number for the 7 cM equivalent of 16.75 cM for a female and 13.4 cM for a male.

When people say that you need a “larger X match to be equivalent to a regular autosomal match,” this is the phenomenon being referenced. Clearly a 7 cM X match is less relevant, meaning not equivalent, in the same generation as a 7 cM regular autosomal match.

Still, X matching compared to match amounts shown on the other chromosomes is never exact;u apples to apples because:

You’re comparing one X chromosome to the combined DNA amounts of many chromosomes.
The limited recombination path.
DNA from the other autosomes is less likely to be inherited from a specific ancestor.
The X chromosome has a lower SNP density than the other chromosomes, meaning fewer SNPs per cM.
The X-DNA may well reach further back in time because it has been divided less frequently.

Bottom Line

The X chromosome is different and holds clues that the other autosomes can’t provide.

Don’t dismiss X matches even if you can’t identify a common ancestor. Given the inheritance path, and the reduced number of divisions, your X-DNA may descend from an ancestor further back in time. I certainly would NOT dismiss X matches with smaller cMs than the 13 and 16 shown above, even though they are considered “equivalent” in the same generation.

X chromosome matching can’t really be equated to matching on the other chromosomes. They are two distinct tools, so they can’t be interpreted identically.

Different vendors treat the X chromosome differently, making comparison challenging.

23andMe includes not only the X chromosome in their cM total, but doubles the Fully Identical Regions (FIR) when people, such as full siblings, share the same DNA from both parents. I wrote about that here.
Ancestry does not include the X in their cM match calculations.
Neither does MyHeritage.
FamilyTreeDNA shows an X match only when it’s accompanied by a match on another chromosome.

The Shared cM Project provides an average of all of the data input by crowdsourcing from all vendors, by relationship, which means that the cM values for some relationships are elevated when compared to the same relationship or even same match were it to be reported from a different vendor.

The Best Part!

The X chromosome inheritance pattern means that you’re much more likely to carry some amount of a contributing ancestor’s X-DNA than on any other chromosome.

X-DNA may well be “older” because it’s not nearly as likely to be divided, given that there are fewer opportunities for recombination.
When you’re tracking your X-DNA back in your tree, whenever you hit a male, you get an automatic “bump” back a generation to his mother. It’s like the free bingo X-DNA square!
You can immediately eliminate many ancestors as your most recent common ancestor (MRCA) with an X-DNA match.
Because X-DNA reaches further back in time, sometimes you match people who descend from common ancestors further back in time as well.

If you match someone on multiple segments, if one of those matching segments is X-DNA, that segment is more likely to descend from a different ancestor than the segments on chromosomes 1-22. I’ve found many instances where an X match descends from a different ancestor than matching DNA segments on the autosomes. Always evaluate X matches carefully.

Sometimes X-DNA is exactly what you need to solve a mystery.

Ok, now let’s step through how to use X-DNA in a real-life example.

Using X DNA to Solve a Mystery

Let’s say that I have a 30 cM X match with a male.

I know immediately that our most recent common ancestor (MRCA) is on HIS mother’s side.
I know, based on my fan chart, which ancestral lines are eliminated in my tree. I’ve immediately narrowed the ancestors from 16 to 5 on his side and 16 to 8 on my side.
Two matching males is even easier, because you know immediately that the common ancestor must be on both of their mother’s sides, with only 5 candidate lines each at the great-great-grandparent generation.

Female to female matches are slightly more complex, but there are still several immediately eliminated lines each. That means you’ve already eliminated roughly half of the possible relationships by matching another female on their X chromosome.

In this match with a female second cousin, I was able to identify who she was via our common ancestor based on the X chromosome path. In this chart, I’m showing the relevant halves of her chart at left (paternal), and mine (maternal), side by side.

I added blockers on her chart and mine too.

As it turns out, we both inherited most of our X chromosome from our great-grandparents, marked above with the black stars.

Several lines are blocked, and my grandfather’s X chromosome is not a possibility because the common ancestor is my maternal grandmother’s parents. My grandfather is not one of her ancestors.

Having identified this match as my closest relative (other than my mother) to descend on my mother’s maternal side, I was able to map that portion of my X chromosome to my great-grandparents Nora Kirsch and Curtis Benjamin Lore.

My X Chromosome at DNA Painter

Here’s my maternal X chromosome at DNAPainter and how I utilized chromosome painting to push the identification of the ancestors whose X chromosome I inherited back an additional two generations.

Using that initial X chromosome match with my second cousin, shown by the arrow at bottom of the graphic, I mapped a large segment of my maternal X chromosome to my maternal great-grandparents.

By viewing the trees of subsequent X maternal matches, I was then able to push those common segments, shown painted directly above that match with the same color, back another two generations, to Joseph Hill, born in 1790, and Nabby Hall. I was able to do that based on the fact that other matches descend from Joseph and Nabby through different children, meaning we all triangulate on that common segment. I wrote about triangulation at DNAPainter, here.

I received no known X-DNA from my great-grandmother, Nora Kirsch, although a small portion of my X chromosome is still unassigned in yellow as “Uncertain.”

I received a small portion of my maternal X chromosome, in magenta, at left, from my maternal great-great-grandparents, John David Miller and Margaret Lentz.

The X chromosome is a powerful tool and can reach far back in time.

In some cases, the X, and other chromosomes can be inherited intact from one grandparent. I could have inherited my mother’s entire copy of her mother’s, or her father’s X chromosome based on random recombination, or not. As it turns out, I didn’t, and I know that because I’ve mapped my chromosomes to identify my ancestors based on common ancestors with my matches.

X-DNA Advanced Matches at FamilyTreeDNA

At FamilyTreeDNA, the Advanced Matches tab includes the ability to search for X matches, either within the entire database, or within specific projects. I find the project selection to be particularly useful.

For example, within the Claxton project, my father’s maternal grandmother’s line, I recognize my match, Joy, which provides me an important clue as to the possible common ancestor(s) of our shared segments.

Joy’s tree shows that her 4-times great-grandparents are my 3-times great-grandparents, meaning we are 4^th cousins once removed and share 17 cM of DNA on our X chromosome across two segments.

Don’t be deceived by the physical appearance of “size” on your chromosomes. The first segment that spans the centromere, or “waist” of the chromosome, above, is 10.29 cM, and the smaller segment at right is 7.02 cM. SNPs are not necessarily evenly distributed along chromosomes.

Remember, an X or other autosomal match doesn’t necessarily mean the entire match is contained in one segment so long as it’s large enough to be divided in two parts and survive the match threshold.

It’s worth noting that Joy and I actually share at least two different, unrelated ancestral lines, so I need to look at Joy’s blocked lines to see if one of those common ancestral lines is not a possibility for our X match. It’s important to evaluate all possible ancestors, plus the inheritance path to eliminate any lineage that involves a father to son inheritance on the X chromosome.

Last but not least, you may match on your X chromosome through a different ancestor than on other chromosomes. Every matching segment has its own individual history. It’s not safe to assume.

Now, take a look at your X chromosome matches at FamilyTreeDNA, 23andMe, and GedMatch. What will you discover?

_____________________________________________________________

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DNA Purchases and Free Uploads

FamilyTreeDNA – Y, mitochondrial and autosomal DNA testing
MyHeritage DNA – Autosomal DNA test
MyHeritage FREE DNA file upload – Upload your DNA file from other vendors free
AncestryDNA – Autosomal DNA test
23andMe Ancestry – Autosomal DNA only, no Health
23andMe Ancestry Plus Health

Genealogy Products and Services

MyHeritage FREE Tree Builder – Genealogy software for your computer
MyHeritage Subscription with Free Trial
Legacy Family Tree Webinars – Genealogy and DNA classes, subscription-based, some free
Legacy Family Tree Software – Genealogy software for your computer
Newspapers.com – Search newspapers for your ancestors
NewspaperArchive – Search different newspapers for your ancestors

My Book

DNA for Native American Genealogy – by Roberta Estes, for those ordering the e-book from anyplace, or paperback within the United States
DNA for Native American Genealogy – for those ordering the paperback outside the US

Genealogy Books

Genealogical.com – Lots of wonderful genealogy research books

Genealogy Research

Legacy Tree Genealogists – Professional genealogy research

The Best of 2022

Posted on January 6, 2023 by Roberta Estes

It’s that time of year where we look both backward and forward.

Thank you for your continued readership! Another year under our belts!

I always find it interesting to review the articles you found most interesting this past year.

In total, I published 97 articles in 2022, of which 56 were directly instructional about genetic genealogy. I say “directly instructional,” because, as you know, the 52 Ancestors series of articles are instructional too, but told through the lives of my ancestors. That leaves 41 articles that were either 52 Ancestors articles, or general in nature.

It has been quite a year.

2022 Highlights

In a way, writing these articles serves as a journal for the genetic genealogy community. I never realized that until I began scanning titles a year at a time.

Highlights of 2022 include:

Multiple ancient DNA burial sites with Y and mitochondrial DNA results
Being a guest on Shamele Jordon’s Genealogy Quick Start television program and the Research Like a Pro Podcast with Nicole Dyer and Diana Elder. I participated in several other special events with organizations in 2022 as well. (No wonder I’m tired.)
Several RootsTech articles – RootsTech offered so much in 2022 – and 2023 is going to be amazing too, both in person and virtually. You can still view the 2022 articles here.
Genetic Affairs released their amazing AutoKinship
The East Coast Genetic Genealogy Conference (ECGGC) launched for the first time in 2022 and will also be having a 2023 fall conference, October 6-8. Yes, I’m planning to present there too, hopefully in person.
The 1950 census release on April Fool’s Day – I still can’t find my mother.
The Million Mito team update and also the publication of the amazing haplogroup L7 discovery paper, plus an accompanying video. At year-end, the team was honored that our paper was included in the Nature’s Editor’s Choice Collection.
Mitochondrial DNA webinar at Legacy Family Tree Webinars. That’s still available along with hundreds of other titles, here.
Ancestry’s SideView and that Ancestry only shows shared matches of 20 cM and greater which is very confusing for genealogists. Also, how to share DNA results and tree access with others, which is crucial for research.
FamilyTreeDNA’s amazing DISCOVER Haplogroup Reports tool for Y-DNA launched. Not long after that, their Y-DNA tree passed 60,000 branches.
Tips and tricks for working with Theories of Family Relativity at MyHeritage. What a great tool!
I launched the new In Search Of series to celebrate the 10^th anniversary of this blog. I then created a resource page that includes all six of the In Search Of articles to date, and there will be more in 2023. 2022 topics include:
- Discovering that (ouch) you’re not genetically related to your family
- Endogamy
- Vendor comparisons and testing strategy
- How to tell the difference between full and half siblings
- Determining match relationships,
Downloading Match and Segment files at the various vendors
Endogamy – how to tell if you have it and what to do
Vendor Features, Strengths and Testing Strategies – these details change often
Why connecting your DNA test (correctly) is important at each vendor and how to do it
Tools to determine if your female ancestor was Native American, or not.
Full or half siblings and how to tell the difference
Big Y-DNA case study with a jaw-dropping outcome
MyHeritage’s new artificial intelligence (AI) time machine lets you see yourself and your ancestors in period and historical settings. I’m still super geeked by this and you’re likely to see more from me about this in 2023. This is just pure fun!!
Basic education critical for everyone about your chromosomes and genealogy. You can’t understand genetic genealogy without understanding this basic information, and why people who match you on the same segment may not match each other. Don’t be lulled into incorrect conclusions.

Which articles were your favorites that were published in 2022, and why?

Your Favorites

Often, the topics I select for articles are directly related to your comments, questions and suggestions, especially if I haven’t covered the topic previously, or it needs to be featured again. Things change in this industry, often. That’s a good thing!

However, some articles become forever favorites. Current articles don’t have enough time to amass the number of views accumulated over years for articles published earlier, so recently published articles are often NOT found in the all-time favorites list.

Based on views, what are my readers’ favorites and what do they find most useful?

In the chart below, the 2022 ranking is not just the ranking of articles published in 2022, but the ranking of all articles based on 2022 views alone. Not surprisingly, six of the 15 favorite 2022 articles were published in 2022.

The All-Time Ranking is the ranking for those 2022 favorites IF they fell within the top 15 in the forever ranking, over the entire decade+ that this blog has existed.

Drum roll please!!!

Article Title	Publication Date	2022 Ranking	All-Time Ranking
Concepts – Calculating Ethnicity Percentages	January 2017	1	2
Proving Native American Ancestry Using DNA	December 2012	2	1
Ancestral DNA Percentages – How Much of Them in in You?	June 2017	3	5
AutoKinship at GEDmatch by Genetic Affairs	February 2022	4
442 Ancient Viking Skeletons Hold DNA Surprises – Does Your Y or Mitochondrial DNA Match? Daily Updates Here	September 2020	5
The Origins of Zana of Abkhazia	July 2021	6
Full or Half Siblings	April 2019	7	15
Ancestry Rearranged the Furniture	January 2022	8
DNA from 459 Ancient British Isles Burials Reveals Relationships – Does Yours Match?	February 2022	9
DNA Inherited from Grandparents and Great-Grandparents	January 2020	10
Ancestry Only Shows Shared Matches of 20 cM and Greater – What That Means & Why It Matters	May 2022	11
How Much Indian Do I Have in Me???	June 2015	12	8
Top Ten RootsTech 2022 DNA Sessions + All DNA Session Links	March 2022	13
FamilyTreeDNA DISCOVER Launches – Including Y DNA Haplogroup Ages	June 2022	14
Ancient Ireland’s Y and Mitochondrial DNA – Do You Match???	November 2020	15

2023 Suggestions

I have a few articles already in the works for 2023, including some surprises. I’ll unveil one very soon.

We will be starting out with:

Information about RootsTech where I’ll be giving at least 7 presentations, in person, and probably doing a book signing too. Yes, I know, 7 sessions – what was I thinking? I’ve just missed everyone so very much.
An article about how accurately Ancestry’s ThruLines predicts Potential Ancestors and a few ways to prove, or disprove, accuracy.
The continuation of the “In Search Of” series.

As always, I’m open for 2023 suggestions.

In the comments, let me know what topics you’d like to see.

_____________________________________________________________

Follow DNAexplain on Facebook, here or follow me on Twitter, here.

Share the Love!

You’re always welcome to forward articles or links to friends and share on social media.

If you haven’t already subscribed (it’s free,) you can receive an email whenever I publish by clicking the “follow” button on the main blog page, here.

You Can Help Keep This Blog Free

Thank you so much.

DNA Purchases and Free Uploads

FamilyTreeDNA – Y, mitochondrial and autosomal DNA testing
MyHeritage DNA – Autosomal DNA test
MyHeritage FREE DNA file upload – Upload your DNA file from other vendors free
AncestryDNA – Autosomal DNA test
23andMe Ancestry – Autosomal DNA only, no Health
23andMe Ancestry Plus Health

Genealogy Products and Services

MyHeritage FREE Tree Builder – Genealogy software for your computer
MyHeritage Subscription with Free Trial
Legacy Family Tree Webinars – Genealogy and DNA classes, subscription-based, some free
Legacy Family Tree Software – Genealogy software for your computer
Newspapers.com – Search newspapers for your ancestors
NewspaperArchive – Search different newspapers for your ancestors

My Book

DNA for Native American Genealogy – by Roberta Estes, for those ordering the e-book from anyplace, or paperback within the United States
DNA for Native American Genealogy – for those ordering the paperback outside the US

Genealogy Books

Genealogical.com – Lots of wonderful genealogy research books

Genealogy Research

Legacy Tree Genealogists – Professional genealogy research

In Search of…How Am I Related to That Close Match?

Posted on October 18, 2022 by Roberta Estes

My friend recently reached out to me for some help with a close match at Ancestry. Which vendor doesn’t matter – the process for figuring out who my friend is related to her match would be essentially the same at any vendor.

My friend has no idea who the match is, nor how they are related. That match has not replied, nor is any of her information recognizable, such as an account name or photo. She has no tree, so there are literally no clues provided by the match.

We need to turn to science and old-fashioned sleuthing.

This eighth article in the “In Search of…” series steps you through the process I’m stepping my friend through.

This process isn’t difficult, per se, but there are several logical, sequential steps. I strongly recommend you read through this (at least) once, then come back and work through the process if you’re trying to solve a similar mystery.

The “In Search of…” Series

Please note that I’ve written an entire series of “In Search of…” articles that will step you through the search process and help you understand how to unravel your results. If you’re new, reading these, in order, before proceeding, would be a good idea.

I introduced the “In Search of” series in the article, DNA: In Search of…New Series Launches.
In the second article, DNA: In Search of…What Do You Mean I’m Not Related to My Family? – and What Comes Next? we discussed the discovery that something was amiss when you don’t match a family member that you expect to match, then how to make sure a vial or upload mix-up didn’t happen. Next, I covered the basics of the four kinds of DNA tests you’ll be able to use to solve your mystery.
In the third article, In Search of…Vendor Features, Strengths, and Testing Strategies, we discussed testing goals and strategies, including testing with and uploading to multiple autosomal DNA vendors, Y DNA, and mitochondrial DNA testing. We reviewed the vendor’s strengths and the benefits of combining vendor information and resources.
In the fourth article, DNA: In Search of…Signs of Endogamy, we discussed the signs of endogamy and various ways to determine if you or your recent ancestors descend from an endogamous population.
In the fifth article, DNA: In Search of…Full and Half-Siblings we discussed how to determine if you have a sibling match, if they are a half or full sibling, and how to discern the difference.
In the sixth article, Connect Your DNA test, and Others, to Your Tree, I explained how to optimize your DNA tests in order to take advantage of the features offered by each our primary DNA testing vendors.
In the seventh article, How to Share DNA Results and Tree Access at Ancestry, I wrote step-by-step instructions for providing access to another person to allow them to view your DNA results, AND to share your tree – which are two different things. If you have a mystery match, and they are willing to allow you access, in essence “to drive,” you can just send them the link to this article that provides detailed instructions. Note that Ancestry has changed the user interface slightly with the rollout of their new “sides” matches, but I can’t provide the new interface screenshots yet because my account has not been upgraded.

Sarah – The Mystery Match

My friend, who I’ll be calling the Tester, matches Sarah (not her name) at 554 cM. At that close level, you don’t have to worry about segments being removed by Timber at Ancestry, so that is an actual cM match level. Timber only removes segments when the match is under 90 cM. Other vendors don’t remove cMs at all.

Ancestry shows the possible relationships at that level as follows:

Some of these relationships can be immediately dismissed in this situation. For example, the Tester knows that Sarah is not her grandchild or great-grandchild.

Our tester does not have any full siblings, or any known half-siblings, but like many genealogists, she is always open-minded. Both of her parents are living, and her father has already tested. Sarah does not match her father. So, this match is on her mother’s side.

It’s obvious that Sarah is not a full sibling, nor is she a half-sibling, based on the cM values, but she might be a child, or grandchild of a maternal half-sibling.

Let’s begin with observations and questions that will help our Tester determine how she and Sarah are related.

It’s clear that IF this is a half-sibling descendant match, it’s on her mother’s side, because Sarah does not match our Tester’s father.
The tester’s mother has six siblings, none of whom have tested directly, but three of whom have children or grandchildren who have tested.
By viewing shared matches, Sarah matches known relatives of BOTH the maternal grandmother AND maternal grandfather of our tester, which means Sarah is NOT the product of an unknown half-sibling of her mother. Remember, Ancestry does not display shared matches of less than 20 cM. Other vendors do not restrict your shared matches.
Ancestry does not provide mitochondrial DNA information, so that cannot be utilized, but could be utilized if this match was at FamilyTreeDNA, and partially utilized in an exclusionary manner if the match was at 23andMe.

DNAPainter

DNAPainter’s Shared cM Tool provides a nice visual display of possible relationships, so I entered the matching cM amount

The returned relationships are similar to Ancestry’s possible relationships.

The grid display shows the possible relationships. Relationships that fall outside of this probability range are muted.

The color shading is by generation, meaning dark grey is through great-great-grandparents, apricot is through great-grandparents, green is through grandparents, grey is through one or both parents, and blue are your own descendants.

Based on known factors, I put a red X in the boxes that can’t apply to Sarah and our Tester after evaluating each relationship. I bracketed the statistically most likely relationships in red, although I must loudly say, “do not ignore those other possibilities.”

Let’s step through the logic which will be different for everyone’s own situation, of course.

Age alone eliminates the great and half-great grandparents, aunts, and uncles. They are all deceased and would be well over 100 years old if they were living.
The green half relationships are eliminated because we know via shared matches that Sarah matches BOTH of the Tester’s maternal grandparent’s sides.
We know that Sarah is not a second cousin because second cousins match only ONE maternal grandparent’s ancestor’s descendants, and Sarah matches both of the tester’s maternal grandparents through their descendants. In other words, Sarah and our Tester both match people who descend from both of the Tester’s maternal grandmother AND grandfather’s lines, which, unless they are related, means Sarah’s closest common ancestor (MCRA – most recent common ancestor) with our Tester are either her maternal grandparents, or her mother.
Therefore, we know that Sarah cannot be any of the apricot-colored relationships because she matches BOTH of our Tester’s maternal grandparents. She would only be related through one of the Tester’s maternal grandparents to be related on the apricot level.
Sarah cannot be a full great-niece or nephew, or great or great-great niece or nephew because the Tester has no full siblings, confirmed by the fact that Sarah does not match the Tester’s father.
We know that Sarah is not the great-grandchild of the Tester, in part due to age, but the definitive scientific ax to that possibility is that Sarah does not match our Tester’s father. (Yes, our Tester does match her father at the appropriate level.)

We know that Sarah is somehow a descendant of BOTH of Tester’s maternal grandparents, so must be in either the green band of relationships, the grey half-relationships, or the blue direct relationships. All of these relationships would be descended from the Tester’s maternal grandparents (plural.)

We’ve eliminated the blue direct relationship because Sarah does not match the Tester’s father. This removes the possibility that the Tester’s children have an unknown great-grandchild, although in this case, age removes that possibility anyway.

This process-of-elimination leaves as possible relationships:

Grey band half niece/nephew and half great-niece/nephew, meaning that the Tester has an unknown half-sibling on their mother’s side whose child or grandchild has tested.
Green band first cousin which means that the tester descends from one of the Tester’s maternal aunts or uncles. Given that Sarah is not a known child of any of the Tester’s six aunts and uncles, that opens the possibility that her mother’s sibling has a previously unknown child. Three of the Tester’s mother’s siblings are females, and three are males.
Green band first cousin once removed is one generation further down the tree, meaning a child of a first cousin.

Using facts we know, we’ve already restricted the possible relationships to four.

Hypothesis and Shared Matches

In situations like this, I use a spreadsheet, create hypothesis scenarios and look for eliminators.

I worked with the Tester to assemble an easy spreadsheet with each of her mother’s siblings in a column, along with their year of birth. All names have been changed.

The hypothesis we are working with is that the Tester’s mother has a previously unknown child and that Sarah is that person’s child or grandchild.

Across the top of our spreadsheet, which you could also simply create as a chart, I’ve written the names of the maternal grandparents.

The Tester’s mother, Susie, is shown in the boxes that are colored red, and her siblings are listed in their birth order. Siblings who have anyone in their line who has tested are shown by colored boxes.

The Tester is shown in red beneath her mother, Susie, and a potential mystery half-sibling is shown beneath Susie.

This is important – the relationships shown are FROM THE PERSPECTIVE OF THE TESTER.

This means, at far left, with the red arrow, these people at the top, meaning the mother’s siblings are the Tester’s aunts and uncles.

The next generation down are the Tester’s first cousins, followed by the next row, with 1C1R. The cell colors in that column correspond to the DNAPainter generation columns.

In the red “Mother” group, you’ll see that I’ve included that mystery half-sibling and beneath, the relationships that could exist at that same generation level. So, if the mystery half-sibling had a child, that person would be the half-niece/nephew of the Tester.

The cM value pointed to by the arrows, is the cM value at which the TESTER matches that person.

In this case, Ginger’s son, Jacob matches our Tester at 946 cM, which is exactly normal for a first cousin. Ginger’s son, Aaron, has not tested, but his daughter, Crystal, has and matches our Tester at 445 cM.

Three of the Tester’s aunts/uncles, John, Jim, and Elsie are not represented in this matrix, because no one from their line has yet tested. The Tester has contacted members of those families asking if they will accept a testing scholarship.

Analysis Grids

Some of the children of our Tester’s aunts/uncles have tested, and their matches to Sarah are shown in the bottom row in yellow, on the chart below.

Of course, obtaining Sarah’s matching cM information required the Tester to contact her aunts/uncles and cousins to ask them to look at their match to Sarah at Ancestry.

For each set of relationships with Sarah, I’ve prepared a mini-relationship grid below Sarah’s matches with one of the Tester’s aunts/uncles’ descendants.

If Sarah is related to the Tester through an unknown half-sibling, Sarah will match the tester more closely than she will match any of the children of the Tester’s aunts and uncles.
If Sarah descends through one of the Tester’s aunts’ or uncles’ lines, Sarah will match someone in those lines more closely than our Tester, but we may need to compensate for generations in our analysis.

I pasted the DNAPainter image in the spreadsheet in a convenient place to remind myself of which relationships are possible between our Tester and Sarah, then I created a small grid beneath the Tester’s match to Sarah, who is the yellow row.

Let me explain, beginning with our Tester’s match to Sarah.

Tester’s Match to Sarah

The Tester matches Sarah at 554 cM, which can potentially be a number of different relationships. I’ve listed the possible relationships with the most likely, at 87%, at the top. I have not listed any relationships we’ve positively eliminated, even though they would be scientifically possible.

I can’t do this for our Tester’s Uncle David, because the Tester has not yet heard back from David’s son, Gary, as to how many cMs he shares with Sarah.

Our tester’s aunts, Ginger and Barbara do have descendants who have tested, so let’s evaluate those relationships.

Ginger and Sarah

We know less about Ginger and Sarah than we do about our Tester and Sarah. However, many of the same relationship constraints remain constant.

For example, we know that Sarah matches both of Ginger’s grandparents, because Ginger is our tester’s aunt, Susie’s full sibling.
Our tester and all of the other family members who have tested match on both maternal grandparents’ sides.
Therefore, we also know that the 2C relationships won’t work either because Sarah matches both maternal grandparents.
Based on ages, it’s very unlikely that Sarah is a great-grandchild of Ginger’s children, in part, because I’m operating under the assumption that Sarah is old enough to purchase her own test, so not a child. Ancestry’s terms of service require testers to be 18 years of age to purchase or activate a DNA test. Also, Sarah’s test is not managed by someone else.
We don’t know about great-nieces and nephews though, because if one of Ginger’s sibling’s children had an unknown child, that person could be Sarah or Sarah’s parent.

Ginger’s son Jacob

Using the closest match in Ginger’s line, her son Jacob, we find the following possibilities using Jacob’s match to Sarah of 284cM.

The DNAPainter grid shows the more distant relationship clearly.

You can quickly determine that Sarah probably does not descend from Ginger’s line, but let’s add this to our spreadsheet for completeness.

You can see that the MOST likely relationship, of the possible relationships based on our known factors, is 1C2R, which is the least likely relationship between our Tester and Sarah. It’s important to note that our Tester and Jacob are in the same generation, so we don’t need to do any compensating for a generational difference.

Comparing those relationships, you can see that the least likely relationship between Sarah and Jacob is much more likely between Sarah and our Tester.

Therefore, we can rule out Ginger’s line as a candidate. Sarah is not a descendant of Ginger.

Let’s move on to Barbara’s line.

Barbara’s Daughter Cindy

This time, we’re going to do a bit of inferring because we do have a generational difference.

Barbara’s granddaughter, Mary, has tested and matches Sarah at 230 cM. While we know that Sarah probably wouldn’t match Mary’s mother, Cindy, at exactly double that, 460 cM, it would certainly be close.

So, for purposes of this comparison, I’m using 460 cM for Sarah to match Cindy.

That makes this comparison in the same generation as Ginger and our Tester to Sarah. We are comparing apples to apples and not apples to half an apple (an apple once removed, technically, but I digress.) 😊

You can see that this analysis is MUCH closer to the cM amounts and relationship possibilities of Sarah and our Tester.

Here are the possible relationships of Sarah and Cindy, with the most likely being boxed in red.

Where Are We?

Here is my completed spreadsheet, so far, less the two DNAPainter graphs for Ginger and Barbara’s lines.

To date, we’ve eliminated Ginger as Sarah’s ancestor.

Both Susie, the mother of our Tester, and Susie’s sister Barbara are still candidates to have an unknown child based on DNA, or one of their children possibly having an unknown child.

Of course, we still have one more sister, Elsie, and those three silent brothers sitting over there. It’s much easier for a male to have an unknown child than a female. By unknown, in this situation, I mean truly unknown, not hidden.

What’s Needed?

Of course, what we really need is tests from each of Susie’s siblings, but that’s not going to happen. What can we potentially do with what we have, how, and why?

Our Tester can refine these results in a number of ways.

Talk to living siblings or other family members and tactfully ask what they know about the four women during their reproductive years. Were they missing, off at school, visiting “aunts” in another location, separated from a spouse, etc.?
Check to see if Sarah shared her ethnicity results (View match, then click on “Ethnicity.”) If Sarah has a significant ethnicity that is impossible to confuse, this might be significant. For example, if Sarah is 50% Korean, and one of Susie’s brothers served in Korea, that makes him a prime candidate.
If possible, ask John, David, Jim, Ginger, Barbara, and Elsie to take DNA tests themselves. The best test is ALWAYS the oldest generation because their DNA is not yet divided in subsequent generations.
If that’s not possible, find a child or grandchild of Elsie, Jim, and John to test.
The Tester needs to find out how closely David’s son, Gary matches Sarah, then perform the same analysis that we stepped through above.
Ask Ginger’s son, Jacob to see if Sarah also shares matches with the closest family members of the known father of Ginger’s children. One of Ginger’s children could have had an unknown child. This is unlikely, based on what we’ve already determined about Sarah’s match level to Jacob, but it’s worth asking.
Ask Barbara’s granddaughter, Mary, to see if she and Sarah share matches with the closest family members of the known father of Barbara’s children. This scenario is much more likely.
If the answer is yes to either of the last two questions, we have identified which line Sarah descends from, because she can only descend from both Barbara AND the father of her children if Sarah descends from that couple.
If the answer is no, we’ve only eliminated full siblings to Ginger and Barbara’s children, not half-siblings.
If our Tester can make contact with Gary, ask him if he and Sarah share matches with David’s wife’s line. One of David’s children could have an unknown child.
If our Tester can actually make contact with Sarah, and if Sarah is willing and interested, our Tester can create a list of people to look for in her matches – for example, the spouses’ lines of all of Susie’s siblings. If Sarah matches NONE of the spouses’ lines, then one of Susie’s siblings (our Tester’s aunts/uncles,) or Susie’s mother, has an unknown child. However, if Sarah is a novice tester or genealogist, she might well be quite overwhelmed with understanding how to perform these searches. She may already be overwhelmed by discovering that she doesn’t match who she expected to match. Or, she may already know the answer to this question.
It would be easier if Sarah granted our Tester access to her DNA results to sort through all of these possibilities, but that’s not something I would expect a stranger to do, especially if this result is something Sarah wasn’t expecting.

I wrote instructions for providing access to DNA results in the article, How to Share DNA Results and Tree Access at Ancestry.

_____________________________________________________________

Follow DNAexplain on Facebook, here or follow me on Twitter, here.

Share the Love!

You’re always welcome to forward articles or links to friends and share on social media.

If you haven’t already subscribed (it’s free,) you can receive an email whenever I publish by clicking the “follow” button on the main blog page, here.

You Can Help Keep This Blog Free

Thank you so much.

DNA Purchases and Free Uploads

FamilyTreeDNA – Y, mitochondrial and autosomal DNA testing
MyHeritage DNA – Autosomal DNA test
MyHeritage FREE DNA file upload – Upload your DNA file from other vendors free
AncestryDNA – Autosomal DNA test
23andMe Ancestry – Autosomal DNA only, no Health
23andMe Ancestry Plus Health

Genealogy Products and Services

MyHeritage FREE Tree Builder – Genealogy software for your computer
MyHeritage Subscription with Free Trial
Legacy Family Tree Webinars – Genealogy and DNA classes, subscription-based, some free
Legacy Family Tree Software – Genealogy software for your computer
Newspapers.com – Search newspapers for your ancestors
NewspaperArchive – Search different newspapers for your ancestors

My Book

DNA for Native American Genealogy – by Roberta Estes, for those ordering the e-book from anyplace, or paperback within the United States
DNA for Native American Genealogy – for those ordering the paperback outside the US

Genealogy Books

Genealogical.com – Lots of wonderful genealogy research books

Genealogy Research

Legacy Tree Genealogists – Professional genealogy research

DNA: In Search of…Full and Half-Siblings

Posted on August 29, 2022 by Roberta Estes

This is the fifth article in our series of articles about searching for unknown close family members, specifically; parents, grandparents, or siblings. However, these same techniques can be applied by genealogists to identify ancestors further back in time as well.

I introduced the “In Search of” series in the article, DNA: In Search of…New Series Launches.
In the second article, DNA: In Search of…What Do You Mean I’m Not Related to My Family? – and What Comes Next? we discussed the discovery that something was amiss when you don’t match a family member that you expect to match, then how to make sure a vial or upload mix-up didn’t happen. Next, I covered the basics of the four kinds of DNA tests you’ll be able to use to solve your mystery.
In the third article, In Search of…Vendor Features, Strengths, and Testing Strategies, we discussed testing goals and strategies, including testing with and uploading to multiple autosomal DNA vendors, Y DNA, and mitochondrial DNA testing. We reviewed the vendor’s strengths and the benefits of combining vendor information and resources.
In the fourth article, DNA: In Search of…Signs of Endogamy, we discussed the signs of endogamy and various ways to determine if you or your recent ancestors descend from an endogamous population.

Please note that if a family member has tested and you do NOT see their results, ask them to verify that they have chosen to allow matching and for other people to view them in their match list. That process varies at different vendors.

You can also ask if they can see you in their results.

All Parties Need to Test

Searching for unknown siblings isn’t exactly searching, because to find them, they, themselves, or their descendant(s) must have taken a DNA test at the same vendor where you tested or uploaded a DNA file.

You may know through any variety of methods that they exist, or might exist, but if they don’t take a DNA test, you can’t find them using DNA. This might sound obvious, but I see people commenting and not realizing that the other sibling(s) must test too – and they may not have.

My first questions when someone comments in this vein are:

Whether or not they are positive their sibling actually tested, meaning actually sent the test in to the vendor, and it was received by the testing company. You’d be surprised how many tests are living in permanent residence on someone’s countertop until it gets pushed into the drawer and forgotten about.
If the person has confirmed that their sibling has results posted. They may have returned their test, but the results aren’t ready yet or there was a problem.
AND that both people have authorized matching and sharing of results. Don’t hesitate to reach out to your vendor’s customer care if you need help with this.

Sibling Scenarios

The most common sibling scenarios are when one of two things happens:

A known sibling tests, only to discover that they don’t match you in the full sibling range, or not at all, when you expected they would
You discover a surprise match in the full or half-sibling range

Let’s talk about these scenarios and how to determine:

If someone is a sibling
If they are a full or half-sibling
If a half-sibling, if they descend from your mother or father

As with everything else genetic, we’ll be gathering and analyzing different pieces of evidence along the way.

Full and Half-Siblings

Just to make sure we are all on the same page:

A full sibling is someone who shares both parents with you.
A half-sibling is someone who shares one parent with you, but not the other parent.
A step-sibling is someone who shares no biological parents with you. This situation occurs when your parent marries their parent, after you are both born, and their parent becomes your step-parent. You share neither of your biological parents with a step-sibling, so you share no DNA and will not show up on each other’s match lists.
A three-quarters sibling is someone with whom you share one parent, but two siblings are the other parent. For example, you share the same mother, but one brother fathered you, and your father’s brother fathered your sibling. Yes, this can get very messy and is almost impossible for a non-professional to sort through, if even then. (This is not a solicitation. I do not take private clients.) We will not be addressing this situation specifically.

Caution

With any search for unknown relatives, you have no way of knowing what you will find.

In one’s mind, there are happy reunions, but you may experience something entirely different. Humans are human. Their stories are not always happy or rosy. They may have made mistakes they regret. Or they may have no regrets about anything.

Your sibling may not know about you or the situation under which you, or they, were born. Some women were victims of assault and violence, which is both humiliating and embarrassing. I wrote about difficult situations, here.

Your sibling or close family member may not be receptive to either you, your message, or even your existence. Just be prepared, because the seeking journey may not be pain-free for you or others, and may not culminate with or include happy reunions.

On the other hand, it may.

Please step back and ponder a bit about the journey you are about to undertake and the possible people that may be affected, and how. This box, once opened, cannot be closed again. Be sure you are prepared.

On the other hand, sometimes that box lid pops off, and the information simply falls in your lap one day when you open your match list, and you find yourself sitting there, in shock, staring at a match, trying to figure out what it all means.

Congratulations, You Have a Sibling!

This might not be exactly what runs through your mind when you see that you have a very close match that you weren’t expecting.

The first two things I recommend when making this sort of discovery, after a few deep breaths, a walk, and a cup of tea, are:

Viewing what the vendor says
Using the DNAPainter Shared cM Relationship Chart

Let’s start with DNAPainter.

DNAPainter

DNAPainter provides a relationship chart, here, based on the values from the Shared cM Project.

You can either enter a cM amount or a percentage of shared DNA. I prefer the cM amount, but it doesn’t really matter.

I’ll enter 2241 cM from a known half-sibling match. To enter a percent, click on the green “enter %.”

As you can see, statistically speaking, this person is slightly more likely to be a half-sibling than they are to be a full sibling. In reality, they could be either.

Looking at the chart below, DNAPainter highlights the possible relationships from the perspective of “Self.”

The average of all the self-reported relationships is shown, on top, so 2613 for a full sibling. The range is shown below, so 1613-3488 for a full sibling.

In this case, there are several possibilities for two people who share 2241 cM of DNA.

I happen to know that these two people are half-siblings, but if I didn’t, it would be impossible to tell from this information alone.

The cM range for full siblings is 1613-3488, and the cM range for half-siblings is 1160-2436.

The lower part of the matching range, from 1160-1613 cM is only found in half-siblings.
The portion of the range from 1613-2436 cM can be either half or full siblings.
The upper part of the range, from 2436-3488 cM is only found in full siblings.

If your results fall into the center portion of the range, you’re going to need to utilize other tools. Fortunately, we have several.

If you’ve discovered something unexpected, you’ll want to verify using these tools, regardless. Use every tool available. Ranges are not foolproof, and the upper and lower 10% of the responses were removed as outliers. You can read more about the shared cM Project, here and here.

Furthermore, people may be reporting some half-sibling relationships as full sibling relationships, because they don’t expect to be half-siblings, so the ranges may be somewhat “off.”

Relationship Probability Calculator

Third-party matching database, GEDmatch, provides a Relationship Probability Calculator tool that is based on statistical probability methods without compiled user input. Both tools are free, and while I haven’t compared every value, both seem to be reasonably accurate, although they do vary somewhat, especially at the outer ends of the ranges.

When dealing with sibling matches, if you are in all four databases, GEDmatch is a secondary resource, but I will include GEDmatch when they have a unique tool as well as in the summary table. Some of your matches may be willing to upload to GEDmatch if the vendor where you match doesn’t provide everything you need and GEDmatch has a supplemental offering.

Next, let’s look at what the vendors say about sibling matches.

Vendors

Each of the major vendors reports sibling relationships in a slightly different way.

Sibling Matches at Ancestry

Ancestry reports sibling relationships as Sister or Brother, but they don’t say half or full.

If you click on the cM portion of the link, you’ll see additional detail, below

Ancestry tells you that the possible relationships are 100% “Sibling.” The only way to discern the difference between full and half is by what’s next.

If the ONLY relationship shown is Sibling at 100%, that can be interpreted to mean this person is a full sibling, and that a half-sibling or other relationship is NOT a possibility.

Ancestry never stipulates full or half.

The following relationship is a half-sibling at Ancestry.

Ancestry identifies that possible range of relationships as “Close Family to First Cousin” because of the overlaps we saw in the DNAPainter chart.

Clicking through shows that there is a range of possible relationships, and Ancestry is 100% sure the relationship is one of those.

DNAPainter agrees with Ancestry except includes the full-sibling relationship as a possibility for 1826 cM.

Sibling Matches at 23andMe

23andMe does identify full versus half-siblings.

DNAPainter disagrees with 23andMe and claims that anyone who shares 46.2% of their DNA is a parent/child.

However, look at the fine print. 23andMe counts differently than any of the other vendors, and DNAPainter relies on the Shared cM Project, which relies on testers entering known relationship matching information. Therefore, at any other vendor, DNAPainter is probably exactly right.

Before we understand how 23andMe counts, we need to understand about half versus fully identical segments.

To determine half or full siblings, 23andMe compares two things:

The amount of shared matching DNA between two people
Fully Identical Regions (FIR) of DNA compared to Half Identical Regions (HIR) of DNA to determine if any of your DNA is fully identical, meaning some pieces of you and your sibling’s DNA is exactly the same on both your maternal and paternal chromosomes.

Here’s an example on any chromosome – I’ve randomly selected chromosome 12. Which chromosome doesn’t matter, except for the X, which is different.

Your match isn’t broken out by maternal and paternal sides. You would simply see, on the chromosome browser, that you and your sibling match at these locations, above.

In reality, though, you have two copies of each chromosome, one from Mom and one from Dad, and so does your sibling.

In this example, Mom’s chromosome is visualized on top, and Dad’s is on the bottom, below, but as a tester, you don’t know that. All you know is that you match your sibling on all of those blue areas, above.

However, what’s actually happening in this example is that you are matching your sibling on parts of your mother’s chromosome and parts of your father’s chromosome, shown above as green areas

23andMe looks at both copies of your chromosome, the one you inherited from Mom, on top, and Dad, on the bottom, to see if you match your sibling on BOTH your mother’s and your father’s chromosomes in that location.

I’ve boxed the green matching areas in purple where you match your sibling fully, on both parents’ chromosomes.

If you and your sibling share both parents, you will share significant amounts of the same DNA on both copies of the same chromosomes, meaning maternal and paternal. In other words, full siblings share some purple fully identical regions (FIR) of DNA with each other, while half-siblings do not (unless they are also otherwise related) because half-siblings only share one parent with each other. Their DNA can’t be fully identical because they have a different parent that contributed the other copy of their chromosome.

	Total Shared DNA	Fully Identical DNA from Both Parents
Full Siblings	~50%	~25%
Half Siblings	~25%	0

Full siblings are expected to share about 50% of the same DNA. In other words, their DNA will match at that location. That’s all the green boxed locations, above.
Full siblings are expected to share about 25% of the same DNA from BOTH parents at the same location on BOTH copies of their chromosomes. These are fully identical regions and are boxed in purple, above.

You’ll find fully identical segments about 25% of the time in full siblings, but you won’t find fully identical segments in half-siblings. Please note that there are exceptions for ¾ siblings and endogamous populations.

You can view each match at 23andMe to see if you have any completely identical regions, shown in dark purple in the top comparison of full siblings. Half siblings are shown in the second example, with less total matching DNA and no FIR or completely identical regions.

Please note that your matching amount of DNA will probably be higher at 23andMe than at other companies because:

23andMe includes the X chromosome in the match totals
23andMe counts fully identical matching regions twice. For full siblings, that’s an additional 25%

Therefore, a full sibling with an X match will have a higher total cM at 23andMe than the same siblings elsewhere because not only is the X added into the total, the FIR match region is added a second time too.

Fully Identical Regions (FIR) and Half Identical Regions (HIR) at GEDmatch

At GEDMatch, you can compare two people to each other, with an option to display the matching information and a painted graphic for each chromosome that includes FIR and HIR.

If you need to know if you and a match share fully identical regions and you haven’t tested at 23andMe, you can both upload your DNA data file to GEDmatch and use their One to One Autosomal DNA Comparison.

On the following page, simply enter both kit numbers and accept the defaults, making sure you have selected one of the graphics options.

While GEDmatch doesn’t specifically tell you whether someone is a full or half sibling, you can garner additional information about the relationship based on the graphic at GEDmatch.

GEDMatch shows both half and fully identical regions.

The above match is between two full siblings using a 7 cM threshold. The blue on the bottom bar indicates a match of 7 cM or larger. Black means no match.

The green regions in the top bar indicate places where these two people carry the same DNA on both copies of their chromosome 1. This means that both people inherited the same DNA from BOTH parents on the green segments.

In the yellow regions, the siblings inherited the same DNA from ONE parent, but different DNA in that region from the other parent. They do match each other, just on one of their chromosomes, not both.

Without a tool like this to differentiate between HIR and FIR, you can’t tell if you’re matching someone on one copy of your chromosome, or on both copies.

In the areas marked with red on top, which corresponds to the black on the bottom band, these two siblings don’t match each other because they inherited different DNA from both parents in that region. The yellow in that region is too scattered to be significant.

Full siblings generally share a significant amount of FIR, or fully identical regions of DNA – about 25%.

Half siblings will share NO significant amount of FIR, although some will be FIR on very small, scattered green segments simply by chance, as you can see in the example, below.

This half-sibling match shares no segments large enough to be a match (7 cM) in the black section. In the blue matching section, only a few small green fragments of DNA match fully, which, based on the rest of that matching segment, must be identical by chance or misreads. There are no significant contiguous segments of fully identical DNA.

When dealing with full or half-siblings, you’re not interested in small, scattered segments of fully identical regions, like those green snippets on chromosome 6, but in large contiguous sections of matching DNA like the chromosome 1 example.

GEDmatch can help when you match when a vendor does not provide FIR/HIR information, and you need additional assistance.

Next, let’s look at full and half-siblings at FamilyTreeDNA

Sibling Matches at FamilyTreeDNA

FamilyTreeDNA does identify full siblings.

Relationships other than full siblings are indicated by a range. The two individuals below are both half-sibling matches to the tester.

The full range when mousing over the relationship ranges is shown below.

DNAPainter agrees except also gives full siblings as an option for the two half-siblings.

FamilyTreeDNA also tells you if you have an X match and the size of your X match.

We will talk about X matching in a minute, which, when dealing with sibling identification, can turn out to be very important.

Sibling Matches at MyHeritage

MyHeritage indicates brother or sister for full siblings

MyHeritage provides other “Estimated relationships” for matches too small to be full siblings.

DNAPainter’s chart agrees with this classification, except adds additional relationship possibilities.

Be sure to review all of the information provided by each vendor for close relationships.

View Close Known Relationships

The next easiest step to take is to compare your full or half-sibling match to known close family members from your maternal and paternal sides, respectively. The closer the family members, the better.

It’s often not possible to determine if someone is a half sibling or a full sibling by centiMorgans (cMs) alone, especially if you’re searching for unknown family members.

Let’s start with the simplest situation first.

Let’s say both of your parents have tested, and of course, you match both of them as parents.

Your new “very close match” is in the sibling range.

The first thing to do at each vendor is to utilize that vendor’s shared matches tool and see whether your new match matches one parent, or both.

Here’s an example.

Close Relationships at FamilyTreeDNA

This person has a full sibling match, but let’s say they don’t know who this is and wants to see if their new sibling matches one or both of their parents.

Select the match by checking the box to the left of the match name, then click on the little two-person icon at far right, which shows “In Common” matches

You can see on the resulting shared match list that both of the tester’s parents are shown on the shared match list.

Now let’s make this a little more difficult.

No Parents, No Problem

Let’s say neither of your parents has tested.

If you know who your family is and can identify your matches, you can see if the sibling you match matches other close relatives on both or either side of your family.

You’ll want to view shared matches with your closest known match on both sides of your tree, beginning with the closest first. Aunts, uncles, first cousins, etc.

You will match all of your family members through second cousins, and 90% of your third cousins. You can view additional relationship percentages in the article, How Much of Them is in You?.

I recommend, for this matching purpose, to utilize 2^nd cousins and closer. That way you know for sure if you don’t share them as a match with your sibling, it’s because the sibling is not related on that side of the family, not because they simply don’t share any DNA due to their distance.

In this example, you have three sibling matches. Based on your and their matches to the same known first and second cousins, you can see that:

Sibling 1 is your full sibling, because you both match the same maternal and paternal first and second cousins
Sibling 2 is your paternal half-sibling because you both match paternal second cousins and closer, but not maternal cousins.
Sibling 3 is your maternal half-sibling because you both match maternal second cousins and closer, but not paternal cousins.

Close Relationships at Ancestry

Neither of my parents have tested, but my first cousin on my mother’s side has. Let’s say I have a suspected sibling or half-sibling match, so I click on the match’s name, then on Shared Matches.

Sure enough, my new match also matches my first cousin that I’ve labeled as “on my mother’s side.”

If my new match in the sibling range also matches my second cousins or closer on my father’s side, the new match is a full sibling, not a half-sibling.

Close Relationships at MyHeritage

Comparing my closest match provided a real surprise. I wonder if I’ve found a half-sibling to my mother.

Now, THIS is interesting.

Hmmm. More research is needed, beginning with the age of my match. MyHeritage provides ages if the MyHeritage member authorizes that information to be shared.

Close Relationships at 23andMe

Under DNA Relatives, click on your suspected sibling match, then scroll down and select “Find Relatives in Common.”

The Relatives in Common list shows people that match both of you.

The first common match is very close and a similar relationship to my closest match on my father’s side. This would be expected of a sibling. I have no common matches with this match to anyone on my mother’s side, so they are only related on my father’s side. Therefore they are a paternal half-sibling, not a full sibling.

More Tools Are Available

Hopefully, by now, you’ve been able to determine if your mystery match is a sibling, and if so, if they are a half or full sibling, and through which parent.

We have some additional tools that are relevant and can be very informative in some circumstances. I suggest utilizing these tools, even if you think you know the answer.

In this type of situation, there’s no such thing as too much information.

X Matching

X matching, or lack thereof, may help you determine how you are related to someone.

There are two types of autosomal DNA. The X chromosome versus chromosomes 1-22. The X chromosome (number 23) has a unique inheritance path that distinguishes it from your other chromosomes.

The X chromosome inheritance path also differs between men and women.

Here’s my pedigree chart in fan form, highlighting the ancestors who may have contributed a portion of their X chromosome to me. In the closest generation, this shows that I inherited an X chromosome from both of my parents, and who in each of their lines could have contributed an X to them.

The white or uncolored positions, meaning ancestors, cannot contribute any portion of an X chromosome to me based on how the X chromosome is inherited.

You’ll notice that my father inherited none of his X chromosome from any of his paternal ancestors, so of course, I can’t inherit what he didn’t inherit. There are a very limited number of ancestors on my father’s side whom I can inherit any portion of an X chromosome from.

Men receive their Y chromosome from their fathers, so men ONLY receive an X chromosome from their mother.

Therefore, men MUST pass their mother’s X chromosome on to their female offspring because they don’t have any other copy of the X chromosome to pass on.

Men pass no X chromosome to sons.

We don’t need to worry about a full fan chart when dealing with siblings and half-siblings.

We only need to be concerned with the testers plus one generation (parents) when utilizing the X chromosome in sibling situations.

These two female Disney Princesses, above, are full siblings, and both inherited an X chromosome from BOTH their mother and father. However, their father only has one X (red) chromosome to give them, so the two females MUST match on the entire red X chromosome from their father.

Their mother has two X chromosomes, green and black, to contribute – one from each of her parents.

The full siblings, Melody, and Cinderella:

May have inherited some portion of the same green and black X chromosomes from their mother, so they are partial matches on their mother’s X chromosome.
May have inherited the exact same full X chromosome from their mother (both inherited the entire green or both inherited the entire black), so they match fully on their mother’s X chromosome.
May have inherited the opposite X from different maternal grandparents. One inherited the entire green X and one inherited the entire black X, so they don’t match on their mother’s X chromosome.

Now, let’s look at Cinderella, who matches Henry.

This female and male full sibling match can’t share an X chromosome on the father’s side, because the male’s father doesn’t contribute an X chromosome to him. The son, Henry, inherited a Y chromosome instead from his father, which is what made them males.

Therefore, if a male and female match on the X chromosome, it MUST be through HIS mother, but could be through either of her parents. In a sibling situation, an X match between a male and female always indicates the mother.

In the example above, the two people share both of their mother’s X chromosomes, so are definitely (at least) maternally related. They could be full siblings, but we can’t determine that by the X chromosome in this situation, with males.

However, if the male matches the female on HER father’s X chromosome, there a different message, example below.

You can see that the male is related to the female on her father’s side, where she inherited the entire magenta X chromosome. The male inherited a portion of the magenta X chromosome from his mother, so these two people do have an X match. However, he matches on his mother’s side, and she matches on her father’s side, so that’s clearly not the same parent.

These people CAN NOT be full siblings because they don’t match on HER mother’s side too, which would also be his mother’s side if they were full siblings.
They cannot be maternal half-siblings because their X DNA only matches on her father’s side, but they wouldn’t know that unless she knew which side was which based on share matches.
They cannot be paternal half-siblings because he does not have an X chromosome from his father.

They could, however, be uncle/aunt-niece/nephew or first cousins on his mother’s side and her father’s side. (Yes, you’re definitely going to have to read this again if you ever need male-female X matching.)

Now, let’s look at X chromosome matching between two males. It’s a lot less complicated and much more succinct.

Neither male has inherited an X chromosome from their father, so if two males DO match on the X, it MUST be through their mother. In terms of siblings, this would mean they share the same mother.

However, there is one slight twist. In the above example, you can see that the men inherited a different proportion of the green and black X chromosomes from their common mother. However, it is possible that the mother could contribute her entire green X chromosome to one son, Justin in this example, and her entire black X chromosome to Henry.

Therefore, even though Henry and Justin DO share a mother, their X chromosome would NOT match in this scenario. This is rare but does occasionally happen.

Based on the above examples, the X chromosome may be relevant in the identification of full or half siblings based on the sexes of the two people who otherwise match at a level indicating a full or half-sibling relationship.

Here’s a summary chart for sibling X matching.

X Match	Female	Male
Female	Will match on shared father’s full X chromosome, mother’s X is the same rules as chromosomes 1-22	Match through male’s mother, but either of female’s parents. If the X match is not through the female’s mother, they are not full siblings nor maternal half-siblings. They cannot have an X match through the male’s father. They are either full or half-siblings through their mother if they match on both of their mother’s side. If they match on his mother’s side, and her father’s side, they are not siblings but could be otherwise closely related.
Male	Match through male’s mother, but either of female’s parents. If the X match is not through the female’s mother, they are not full siblings nor maternal half-siblings. They cannot have an X match through the male’s father. They are either full or half-siblings through their mother if they match on both or their mother’s side. If they match on his mother’s side, and her father’s side, they are not siblings but could be otherwise closely related.	Both males are related on their mother’s side – either full or half-siblings.

Here’s the information presented in a different way.

DOES match X summary:

If a male DOES match a female on the X, he IS related to her through HIS mother’s side, but could match her on her mother or father’s side. If their match is not through her mother, then they are not full siblings nor maternal half-siblings. They cannot match through his father, so they cannot be paternal half-siblings.
If a female DOES match a female on the X, they could be related on either side and could be full or half-siblings.
If a male DOES match a male on the X, they ARE both related through their mother. They may also be related on their father’s side, but the X does not inform us of that.

Does NOT match X summary:

If a male does NOT match a female on the X, they are NOT related through HIS mother and are neither full siblings nor maternal half-siblings. Since a male does not have an X chromosome from his father, they cannot be paternal half-siblings based on an X match.
If a male does NOT match a male, they do NOT share a mother.
If a female does NOT match another female on the X, they are NOT full siblings and are NOT half-siblings on their paternal side. Their father only has one X chromosome, and he would have given the same X to both daughters.

Of the four autosomal vendors, only 23andMe and FamilyTreeDNA report X chromosome results and matching, although the other two vendors, MyHeritage and Ancestry, include the X in their DNA download file so you can find X matches with those files at either FamilyTreeDNA or GEDMatch if your match has or will upload their file to either of those vendors. I wrote step-by-step detailed download/upload instructions, here.

X Matching at FamilyTreeDNA

In this example from FamilyTreeDNA, the female tester has discovered two half-sibling matches, both through her father. In the first scenario, she matches a female on the full X chromosome (181 cM). She and her half-sibling MUST share their father’s entire X chromosome because he only had one X, from his mother, to contribute to both of his daughters.

In the second match to a male half-sibling, our female tester shares NO X match because her father did not contribute an X chromosome to his son.

If we didn’t know which parents these half-sibling matches were through, we can infer from the X matching alone that the male is probably NOT through the mother.

Then by comparing shared matches with each sibling, Advanced Matches, or viewing the match Matrix, we can determine if the siblings match each other and are from the same or different sides of the family.

Under Additional Tests and Tools, Advanced Matching, FamilyTreeDNA provides an additional tool that can show only X matches combined with relationships.

Of course, you’ll need to view shared matches to see which people match the mother and/or match the father.

To see who matches each other, you’ll need to use the Matrix tool.

At FamilyTreeDNA, the Matrix, located under Autosomal DNA Results and Tools, allows you to select your matches to see if they also match each other. If you have known half-siblings, or close relatives, this is another way to view relationships.

Here’s an example using my father and two paternal half-siblings. We can see that the half-siblings also match each other, so they are (at least) half-siblings on the paternal side too.

If they also matched my mother, we would be full siblings, of course.

Next, let’s use Y DNA and mitochondrial DNA.

Y DNA and Mitochondrial DNA

In addition to autosomal DNA, we can utilize Y DNA and mitochondrial DNA (mtDNA) in some cases to identify siblings or to narrow or eliminate relationship possibilities.

Given that Y DNA and mitochondrial DNA both have distinctive inheritance paths, full and half-siblings will, or will not, match under various circumstances.

Y DNA

Y DNA is passed intact from father to son, meaning it’s not admixed with any of the mother’s DNA. Daughters do not inherit Y DNA from their father, so Y DNA is only useful for male-to-male comparisons.

Two types of Y DNA are used for genealogy, STR markers for matching, and haplogroups, and both are equally powerful in slightly different ways.

Y DNA at FamilyTreeDNA

Men can order either 37 or 111 STR marker tests, or the BIg Y which provides more than 700 markers and more. FamilyTreeDNA is the only one of the vendors to offer Y DNA testing that includes STR markers and matching between men.

Men who order these tests will be compared for matching on either 37, 111 or 700 STR markers in addition to SNP markers used for haplogroup identification and assignment.

Fathers will certainly match their sons, and paternal line brothers will match each other, but they will also match people more distantly related.

However, if two men are NOT either full or half siblings on the paternal side, they won’t match at 111 markers.

If two men DON’T match, especially at high marker levels, they likely aren’t siblings. The word “likely” is in there because, very occasionally, a large deletion occurs that prevents STR matching, especially at lower levels.

Additionally, men who take the 37 or 111 marker test also receive an estimated haplogroup at a high level for free, without any additional testing.

However, if men take the Big Y-700 test, they not only will (or won’t) match on up to 700 STR markers, they will also receive a VERY refined haplogroup via SNP marker testing that is often even more sensitive in terms of matching than STR markers. Between these two types of markers, Y DNA testing can place men very granularly in relation to other men.

Men can match in two ways on Y DNA, and the results are very enlightening.

If two men match on BOTH their most refined haplogroup (Big Y test) AND STR markers, they could certainly be siblings or father/son. They could also be related on the same line for another reason, such as known or unknown cousins or closer relationships like uncle/nephew. Of course, Y DNA, in addition to autosomal matching, is a powerful combination.

Conversely, if two men don’t have a similar or close haplogroup, they are not a father and son or paternal line siblings.

FamilyTreeDNA offers both inexpensive entry-level testing (37 and 111 markers) and highly refined advanced testing of most of the Y chromosome (Big Y-700), so haplogroup assignments can vary widely based on the test you take. This makes haplogroup matching and interpretation a bit more complex.

For example, haplogroups R-M269 and I-BY14000 are not related in thousands of years. One is haplogroup R, and one is haplogroup I – completely different branches of the Y DNA tree. These two men won’t match on STR markers or their haplogroup.

However, because FamilyTreeDNA provides over 50,000 different haplogroups, or tree branches, for Big Y testers, and they provide VERY granular matching, two father/son or sibling males who have BOTH tested at the Big Y-700 level will have either the exact same haplogroup, or at most, one branch difference on the tree if a mutation occurred between father and son.

If both men have NOT tested at the Big Y-700 level, their haplogroups will be on the same branch. For example, a man who has only taken a 37/111 marker STR test may be estimated at R-M269, which is certainly accurate as far as it goes.

His sibling who has taken a Big Y test will be many branches further downstream on the tree – but on the same large haplogroup R-M269 branch. It’s essential to pay attention to which tests a Y DNA match has taken when analyzing the match.

The beauty of the two kinds of tests is that even if one haplogroup is very general due to no Big Y test, their STR markers should still match. It’s just that sometimes this means that one hand is tied behind your back.

Y DNA matching alone can eliminate the possibility of a direct paternal line connection, but it cannot prove siblingship or paternity alone – not without additional information.

The Advanced Matching tool will provide a list of matches in all categories selected – in this case, both the 111 markers and the Family Finder test. You can see that one of these men is the father of the tester, and one is the full sibling.

You can view haplogroup assignments on the public Y DNA tree, here. I wrote about using the public tree, here.

In addition, recently, FamilyTreeDNA launched the new Y DNA Discover tool, which explains more about haplogroups, including their ages and other fun facts like migration paths along with notable and ancient connections. I wrote about using the Discover tool, here.

Y DNA at 23andMe

Testers receive a base haplogroup with their autosomal test. 23andMe tests a limited number of Y DNA SNP locations, but they don’t test many, and they don’t test STR markers, so there is no Y DNA matching and no refined haplogroups.

You can view the haplogroups of your matches. If your male sibling match does NOT share the same haplogroup, the two men are not paternal line siblings. If two men DO share the same haplogroup, they MIGHT be paternal siblings. They also might not.

Again, autosomal close matching plus haplogroup comparisons include or exclude paternal side siblings for males.

Paternal side siblings at 23andMe share the same haplogroup, but so do many other people. These two men could be siblings. The haplogroups don’t exclude that possibility. If the haplogroups were different, that would exclude being either full or paternal half-siblings.

Men can also compare their mitochondrial DNA to eliminate a maternal relationship.

These men are not full siblings or maternal half-siblings. We know, unquestionably, because their mitochondrial haplogroups don’t match.

23andMe also constructs a genetic tree, but often struggles with close relative placement, especially when half-relationships are involved. I do not recommend relying on the genetic tree in this circumstance.

Mitochondrial DNA

Mitochondrial DNA is passed from mothers to all of their children, but only females pass it on. If two people, males or females, don’t match on their mitochondrial DNA test, with a couple of possible exceptions, they are NOT full siblings, and they are NOT maternal half-siblings.

Mitochondrial DNA at 23andMe

23andMe provides limited, base mitochondrial haplogroups, but no matching. If two people don’t have the same haplogroup at 23andMe, they aren’t full or maternal siblings, as illustrated above.

Mitochondrial DNA at FamilyTreeDNA

FamilyTreeDNA provides both mitochondrial matching AND a much more refined haplogroup. The full sequence test (mtFull), the only version sold today, is essential for reliable comparisons.

Full siblings or maternal half-siblings will always share the same haplogroup, regardless of their sex.

Generally, a full sibling or maternal half-sibling match will match exactly at the full mitochondrial sequence (FMS) level with a genetic distance of zero, meaning fully matching and no mismatching mutations.

There are rare instances where maternal siblings or even mothers and children do not match exactly, meaning they have a genetic distance of greater than 0, because of a mutation called a heteroplasmy.

I wrote about heteroplasmies, here.

Like Y DNA, mitochondrial DNA cannot identify a sibling or parental relationship without additional evidence, but it can exclude one, and it can also provide much-needed evidence in conjunction with autosomal matching. The great news is that unlike Y DNA, everyone has mitochondrial DNA and it comes directly from their mother.

Once again, FamilyTreeDNA’s Advanced Matching tool provides a list of people who match you on both your mitochondrial DNA test and the Family Finder autosomal test, including transfers/uploads, and provides a relationship.

You can see that our tester matches both a full sibling and their mother. Of course, a parent/child match could mean that our tester is a female and one of her children, of either sex, has tested.

Below is an example of a parent-child match that has experienced a heteroplasmy.

Based on the comparison of both the mitochondrial DNA test, plus the autosomal Family Finder test, you can verify that this is a close family relationship.

You can also eliminate potential relationships based on the mitochondrial DNA inheritance path. The mitochondrial DNA of full siblings and maternal half-siblings will always match at the full sequence and haplogroup level, and paternal half-siblings will never match. If paternal half-siblings do match, it’s happenstance or because of a different reason.

Sibling Summary and Checklist

I’ve created a quick reference checklist for you to use when attempting to determine whether or not a match is a sibling, and, if so, whether they are half or full siblings. Of course, these tools are in addition to the DNAPainter Shared cM Tool and GEDmatch’s Relationship Predictor Calculator.

	FamilyTreeDNA	Ancestry	23andMe	MyHeritage	GEDmatch
Matching	Yes	Yes	Yes	Yes	Yes
Shared Matches	Yes – In Common With	Yes – Shared Matches	Yes – Relatives in Common	Yes – Review DNA Match	Yes – People who match both or 1 of 2 kits
Relationship Between Shared Matches	No	No	No	Yes, under shared match	No
Matches Match Each Other*	Yes, Matrix	No	Yes, under “View DNA details,” then, “compare with more relatives”	Partly, through triangulation	Yes, can match any kits
Full Siblings	Yes	Sibling, implies full	Yes	Brother, Sister, means full	No
Half Siblings	Sibling, Uncle/Aunt-Niece/Nephew, Grandparent-Grandchild	Close Family – 1C	Yes	Half sibling, aunt/uncle-niece-nephew	No
Fully Identical Regions (FIR)	No	No	Yes	No	Yes
Half Identical Regions (HIR)	No	No	Yes	No	Yes
X matching	Yes	No	Yes	No	Yes
Unusual Reporting or Anomalies	No	No, Timber is not used on close relationships	X match added into total, FIR added twice	No	Matching amount can vary from vendors
Y DNA	Yes, STRs, refined haplogroups, matching	No	High-level haplogroup only, no matching	No	No, only if tester enters haplogroup manually
Mitochondrial DNA	Yes, full sequence, matching, refined haplogroup	No	High-level haplogroup only, no matching	No	No, only if tester enters haplogroup manually
Combined Tools (Autosomal, X, Y, mtDNA)	Yes	No	No	No	No

*Autoclusters through Genetic Affairs show cluster relationships of matches to the tester and to each other, but not all matches are included, including close matches. While this is a great tool, it’s not relevant for determining close and sibling relationships. See the article, AutoClustering by Genetic Affairs, here.

Additional Resources

Some of you may be wondering how endogamy affects sibling numbers.

Endogamy makes almost everything a little more complex. I wrote about endogamy and various ways to determine if you have an endogamous heritage, here.

Please note that half-siblings with high cM matches also fall into the range of full siblings (1613-3488), with or without endogamy. This may be, but is not always, especially pronounced in endogamous groups.

As another resource, I wrote an earlier article, Full or Half Siblings, here, that includes some different examples.

Strategy

You have a lot of quills in your quiver now, and I wish you the best if you’re trying to unravel a siblingship mystery.

You may not know who your biological family is, or maybe your sibling doesn’t know who their family is, but perhaps your close relatives know who their family is and can help. Remember, the situation that has revealed itself may be a shock to everyone involved.

Above all, be kind and take things slow. If your unexpected sibling match becomes frightened or overwhelmed, they may simply check out and either delete their DNA results altogether or block you. They may have that reaction before you have a chance to do anything.

Because of that possibility, I recommend performing your analysis quickly, along with taking relevant screenshots before reaching out so you will at least have that much information to work with, just in case things go belly up.

When you’re ready to make contact, I suggest beginning by sending a friendly, short, message saying that you’ve noticed that you have a close match (don’t say sibling) and asking what they know about their family genealogy – maybe ask who their grandparents are or if they have family living in the area where you live. I recommend including a little bit of information about yourself, such as where you were born and are from.

I also refrain from using the word adoption (or similar) in the beginning or giving too much detailed information, because it sometimes frightens people, especially if they know or discover that there’s a painful or embarrassing family situation.

And, please, never, ever assume the worst of anyone or their motives. They may be sitting at their keyboard with the same shocked look on their face as you – especially if they have, or had, no idea. They may need space and time to reach a place of acceptance. There’s just nothing more emotionally boat-capsizing in your life than discovering intimate and personal details about your parents, one or both, especially if that discovery is disappointing and image-altering.

Or, conversely, your sibling may have been hoping and waiting just for you!

Take a deep breath and let me know how it goes!

Please feel free to share this article with anyone who could benefit.

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In Search of…Vendor Features, Strengths, and Testing Strategies

Posted on July 29, 2022 by Roberta Estes

This is the third in our series of articles about searching for unknown close family members, specifically; parents, grandparents, or siblings. However, these same techniques can be applied to ancestors further back in time too.

I introduced the series in the article, DNA: In Search of…New Series Launches.
In the second article, DNA: In Search of…What Do You Mean I’m Not Related to My Family? – and What Comes Next?, we discussed the discovery that something was amiss, then how to make sure a vial or upload mix-up didn’t happen. That was followed by the basics of the four kinds of DNA tests you’ll be able to use to solve your mystery.

In this article, we are going to discuss your goals and why testing or uploading to multiple vendors is advantageous – even if you could potentially solve the initial mystery at one vendor. Of course, the vendor you test with first might not be the vendor where the mystery will be solved, and data from multiple vendors might just be the combination you need.

Testing Strategy – You Might Get Lucky

I recommended in the first article that you go ahead and test at the different vendors.

Some people asked why, and specifically, why you wouldn’t just test at one vendor with the largest database first, then proceed to the others if you needed to.

That’s a great question, and I want to discuss the pros and cons in this article more specifically.

Clearly, that is one strategy, but the approach you select might differ based on a variety of considerations:

You may only be interested in obtaining the name of the person you are seeking – or – you may be interested in finding out as much as possible.
You may find that your best match at one company is decidedly unhelpful, and may even block you or your efforts, while someone elsewhere may be exactly the opposite.
Solving your mystery may be difficult and painful at one vendor, but the answer may be infinitely easier at a different vendor where the answer may literally be waiting.
There may not be enough, or the right information, or matches, at any one vendor, but the puzzle may be solvable by combining information from multiple vendors and tests. Every little bit helps.
You may have a sense of urgency, especially if you hope to meet the person and you’re searching for parents, siblings or grandparents who may be aging.
You may be cost-sensitive and cannot afford more than one test at a time. Fortunately, our upload strategy helps with that too. Also, watch for vendor sales or bundles.

From the time you order your DNA test, it will be about 6-8 weeks, give or take a week or two in either direction, before you receive results.

When those results arrive, you might get lucky, and the answer you seek is immediately evident with no additional work and just waiting for you at the first testing company.

If that’s the case, you got lucky and hit the jackpot. If you’re searching for both parents, that means you still have one parent to go.

Unidentified grandparents can be a little more difficult, because there are four of them to sort between.

If you discover a sibling or half-sibling, you still need to figure out who your common parent is. Sometimes X, Y, and mitochondrial DNA provides an immediate answer and is invaluable in these situations.

It’s more likely that you’ll find a group of somewhat more distant relatives. You may be able to figure out who your common grandparents or great-grandparents are, but not your parent(s) initially. Often, the closer generation or two is actually the most difficult because you’re dealing with contemporary records which are not publicly available, fewer descendants, and the topic may be very uncomfortable for some people. It’s also complicated because you’re often not dealing with “full” relationships, but “half,” as in half-sibling, half-niece, half-1C, etc.

You may spend a substantial amount of time trying to solve this puzzle at the first vendor before ordering your next test.

That second test will also take about 6-8 weeks, give or take. I recommend that you order the first two autosomal tests, now.

Order Your First Two Autosomal Tests

The two testing companies with the largest autosomal databases for comparison, Ancestry, and 23andMe, DO NOT accept DNA file uploads from other companies, so you’ll need to test with each individually.

Fortunately, you CAN transfer your autosomal DNA tests to both MyHeritage and FamilyTreeDNA, for free.

You will have different matches at each company. Some people will be far more responsive and helpful than others.

I recommend that you go ahead and order both the Ancestry and 23andMe tests initially, then upload the first one that comes back with results to both FamilyTreeDNA and MyHeritage. Complete, step-by-step download/upload instructions can be found here.

You can also upload your DNA file to a fifth company, Living DNA, but they are significantly smaller and heavily focused on England and Great Britain. However, if that’s where you’re searching, this might be where you find important matches.

You can also upload to GEDMatch, a popular third-party database, but since you’re going to be in the databases of the four major testing companies, there is little to be gained at GEDMatch in terms of people who have not tested at one of the major companies. Do NOT upload to GEDMatch INSTEAD of testing or uploading to the four major sites, as GEDMatch only has a small fraction of the testers in each of the vendor databases.

What GEDMatch does offer is a chromosome browser – something that Ancestry does NOT offer, along with other clustering tools which you may find useful. I recommend GEDMatch in addition to the others, if needed or desired.

Ordering Y and Mitochondrial DNA Tests

We reviewed the basics of the different kinds of DNA, here.

Some people have asked why, if autosomal DNA shows relatives on all of your lines, would one would want to order specific tests that focus on just one line?

It just so happens that the two lines that Y and mitochondrial DNA test ARE the two lines you’re seeking – direct maternal – your mother (and her mother), and direct paternal, your father (and his father.)

These two tests are different kinds of DNA tests, testing a different type of DNA, and provide very focused information, and matches, not available from autosomal DNA tests.

For men, Y DNA can reveal your father’s surname, which can be an invaluable clue in narrowing paternal candidates. Knowing that my brother’s Y DNA matched several men with the surname of Priest made me jump for joy when he matched a woman of that same last name at another vendor.

Here’s a quote from one of the members of a Y DNA project where I’m the volunteer administrator:

“Thank you for your help understanding and using all 4 kinds of my DNA results. By piecing the parts together, I identified my father. Specifically, without Y DNA testing, and the Big Y test, I would not have figured out my parental connection, and then that my paternal line had been assigned to the wrong family. STR testing gave me the correct surname, but the Big Y test showed me exactly where I fit, and disproved that other line. I’m now in touch with my father, and we both know who our relatives are – two things that would have never happened otherwise.”

If you fall into the category of, “I want to know everything I can now,” then order both Y and mitochondrial DNA tests initially, along with those two autosomal tests.

You will need to order Y (males only) and mitochondrial DNA tests separately from the autosomal Family Finder test, although you should order on the same account as your Family Finder test at FamilyTreeDNA.

If you take the Family Finder autosomal test at FamilyTreeDNA or upload your autosomal results from another vendor, you can simply select to add the Y and mitochondrial DNA tests to your account, and they will send you a swab kit.

Conversely, you can order either a Y or mitochondrial DNA test, and then add a Family Finder or upload a DNA file if you’ve already taken an autosomal DNA test to that account too. Note – these might not be current prices – check here for sales.

You will want all 3 of your tests on the same account so that you can use the Advanced Matches feature.

Using Advanced Matches, you’ll be able to view people who match you on combinations of multiple kinds of tests.

For example, if you’re a male, you can see if your Y DNA matches also match you on the Family Finder autosomal test, and if so, how closely?

Here’s an example.

In this case, I requested matches to men with 111 markers who also match the tester on the Family Finder test. I discovered both a father and a full sibling, plus a few more distant matches. There were ten total combined matches to work with, but I’ve only shown five for illustration purposes.

This information is worth its weight in gold.

Is the Big Y Test Worth It?

People ask if the Big Y test is really worth the extra money.

The answer is, “it depends.”

If all you’re looking for are matching surnames, then the answer is probably no. A 37 or 111 marker test will probably suffice. Eventually, you’ll probably want to do the Big Y, though.

If you’re looking for exact placement on the tree, with an estimated distance to other men who have taken that test, then the answer is, “absolutely.” I wish the Big Y test had been available back when I was hunting for my brother’s biological family.

The Big Y test provides a VERY specific haplogroup and places you very accurately in your location on the Y DNA tree, along with other men of your line, assuming they have tested. You may find the surname, as well as being placed within a generation or a few of current in that family line.

Additionally, the Discover page provides estimates of how far in the past you share a common ancestor with other people that share the same haplogroup. This can be a HUGE boon to a male trying to figure out his surname line and how closely in time he’s related to his matches.

Big Y NPE Examples

Y DNA SNP mutations tested with the Big Y test accrue a mutation about every generation, or so. Sometimes we see mutations in every generation.

Here’s an example from my Campbell line. Haplogroups are listed in the top three rows.

I created this spreadsheet, but FamilyTreeDNA provides a block tree for Big Y testers. I’ve added the genealogy of the testers, with the various Big Y testers at the bottom and common ancestors above, in bold.

We have two red NPE lines showing. The MacFarlane tester matches M. Campbell VERY closely, and two Clark males match W. Campbell and other Campbells quite closely. We utilized autosomal plus the Y results to determine where the unknown parentage events occurred. Today, if you’re a Clark or MacFarlane male, or a male by any other surname who was fathered by a Y chromosome Campbell male (by any surname), you’ll know exactly where you fit in this group of testers on your direct paternal line.

Y DNA is important because men often match other men with the same surname, which is a HUGE clue, especially in combination with autosomal DNA results. I say “often,” because it’s possible that no one in your line has tested, or that your father’s surname is not his biological surname either.

Y and mitochondrial DNA matches can be HUGELY beneficial pieces of information either by confirming a close autosomal relationship on that line, or eliminating the possibility.

Lineage-Specific Population Information

In addition to matching other people, both Y and mitochondrial DNA tests provide you with lineage-specific population or “ethnicity” information for this specific line which helps you focus your research.

For example, if you view the Y DNA Haplogroup Origins shown for this tester, you’ll discover that these matches are Jewish.

The tester might not be Jewish on any other genealogical line, but they definitely have Jewish ancestry on their Y DNA, paternal, line.

The same holds true for mitochondrial DNA as well. The main difference with mitochondrial DNA is that the surname changes with each generation, haplogroups today (pre-Million Mito) are less specific, and fewer people have been tested.

Y and Mitochondrial DNA Benefits

Knowing your Y and mitochondrial DNA haplogroups not only arm you with information about yourself, they provide you with matching tools and an avenue to include or exclude people as your direct line paternal or maternal ancestors.

Your Y and mitochondrial DNA can also provide CRITICALLY IMPORTANT information about whether that direct line ancestor belonged to an endogamous population, and where they came from.

For example, both Jewish and Native populations are endogamous populations, meaning highly intermarried for many generations into the past.

Knowing that helps you adjust your autosomal relationship analysis.

Why Order Multiple Tests Initially Instead of Waiting?

If you’ve been adding elapsed time, two autosomal tests (Ancestry and 23andMe), two uploads (to FamilyTreeDNA and MyHeritage,) a Y DNA test, and a mitochondrial DNA test, if all purchased serially, one following the other, means you’ll be waiting approximately 6-8 months.

Do you want to wait 6-8 months for all of your results? Can you afford to?

Part of this answer has to do with what, exactly, you’re seeking, and how patient you are.

Only you can answer that question.

A Name or Information?

Are you seeking the name or identity of a person, or are you seeking information about that person?

Most people don’t just want to put a name to the person they are seeking – they want to learn about them and the rest of the family that door opens.

You will have different matches at each company. Even after you identify the person you seek, the people you match may have trees you can view, with family photos and other important information. (Remember, you can’t see living people in trees.) Your matches may have first-person information about your relative and may know them if they are living, or have known them.

Furthermore, you may have the opportunity to meet that person. Time delayed may not be able to be recovered or regained.

One cousin that I assisted discovered that his father had died just six weeks before he broke through that wall and made the connection.

Working with data from all vendors simultaneously will allow you to combine that data and utilize it together. Using your “best” matches at each company, augmented by X, Y, and/or mitochondrial DNA, can make MUCH shorter work of this search.

Your closest autosomal matches are the most important and insightful. In this series, I will be working with the top 15 autosomal results at each vendor, at least initially. This approach provides me with the best chance of meaningful close relationship discoveries.

Data and Vendor Results Integration

Here’s a table of my two closest maternal and paternal matches at the four major vendors. I can assign these to maternal or paternal sides, because I know the identity of my parents, and I know some of these people. If an adoptee was doing this, the top 4 could all be from one parent, which is why we work with the top 15 or so matches.

Vendor	Closest Maternal	Closest Paternal	Comments
Ancestry	1C, 1C1R	Half-1C, 2C	I recognized both of the maternal and neither of the paternal.
23andMe	2C, 2C	1C1R, half-gr-niece	Recognized both maternal, one paternal
MyHeritage	Mother uploaded, 1C	Half-niece, half-1C	Recognized both maternal, one paternal
FamilyTreeDNA	Mother tested, 1C1R	Parent/child, half-gr-niece uploaded	Recognized all 4

To be clear, I tested my mother’s mitochondrial DNA before she passed away, but because FamilyTreeDNA archives DNA samples for 25 years, as the owner/manager of her DNA kit, I was able to order the Family Finder test after she had passed away. Her tests are invaluable today.

Then, years later, I uploaded her results to MyHeritage.

If I was an adopted child searching for my mother, I would find her results in both databases today. She’ll never be at either 23andMe or Ancestry because she passed away before she could test there and they don’t accept uploads.

Looking at the other vendors, my half-niece at MyHeritage is my paternal half-sibling’s daughter. My half-sibling is deceased, so this is as close as I’ll ever get to matching her.

At 23andMe, the half-great-niece is my half-siblings grandchild.

It’s interesting that I have no matches to descendants of my other half-sibling, who is also deceased. Maybe I should ask if any of his children or grandchildren have tested. Hmmmm…..

You can see that I stand a MUCH BETTER chance of figuring out close relatives using the combined closest matches of all four databases instead of the top matches from just one database. It doesn’t matter if the database is large if the right person or people didn’t test there.

Combine Resources

I’ll be providing analysis methodologies for working with results from all of the vendors together, just in case your answer is not immediately obvious. Taking multiple DNA tests facilitates using all of these tools immediately, not months later. Solving the puzzle sooner means you may not miss valuable opportunities.

You may also discover that the door slams shut with some people, or they may not respond to your queries, but another match may be unbelievably helpful. Don’t limit your possibilities.

Let’s take a look at the strengths of each vendor.

Vendor Strengths and Things to Know

Every vendor has product strengths and idiosyncracies that the others do not. All vendors provide matches and shared matches. Each vendor provides ethnicity tools which certainly can be useful, but the features differ and will be covered elsewhere.

Ancestry – Ancestry has the largest autosomal database and includes ThruLines, but no Y or mitochondrial DNA testing, no clusters, no chromosome browser, no triangulation, and no X chromosome matching or reporting. Ancestry provides genealogical records, advanced tools, and full tree access to your matches’ trees with an Ancestry subscription. Ancestry does not allow downloading your match list or segment match information, but the other vendors do.
23andMe – 23andMe has the second largest database. They provide triangulation and genetic trees that include your closest matches. Many people test at 23andMe for health and wellness information, so 23andMe has people in their database who are not specifically interested in genealogy and probably won’t have tested elsewhere, but may be invaluable to your search. 23andMe provides Y and mtDNA high-level haplogroups only, but no matching or other haplogroup information. If you purchase a new test or have a V5 ancestry+health current test, you can expand your matches from a limit of 1500 to about 5000 with an annual membership. For seeking close relatives, you don’t need those features, but you may want them for genealogy. 23andMe is the only vendor that limits their customers’ matches.
MyHeritage – MyHeritage has the third largest database that includes lots of European testers. MyHeritage provides triangulation, Theories of Family Relativity, and an integrated cluster tool* but does not report X matches and does not offer Y or mitochondrial DNA testing. MyHeritage accepts autosomal DNA file uploads from other testing companies for free and provides access to advanced DNA features for a one-time unlock fee. MyHeritage includes genealogical records and full feature access to advanced DNA tools with a Complete Subscription. (Free 15 days trial subscription, here.)
FamilyTreeDNA Family Finder (autosomal) – FamilyTreeDNA is the oldest DNA testing company, meaning their database includes people who initially tested 20+ years ago and have since passed away. This, in essence, gets you one generation further back in time, with the possibility of stronger matches. Their Family Matching feature buckets and triangulates your matches, assigning them to your maternal or paternal sides if you link known matches to their proper place in your tree, even if your parents have not tested. FamilyTreeDNA accepts uploads from other testing companies for free and provides advanced DNA features for a one time unlock fee.
FamilyTreeDNA – FamilyTreeDNA is the only company that offers both Y and mitochondrial DNA testing products that include matching, integration with autosomal test results, and other tools. These two tests are lineage-specific and don’t have to be sorted from your other ancestral lines.

I wrote about using Y DNA results, here.

I wrote about using mitochondrial DNA results, here.

*Third parties such as Genetic Affairs provide clustering tools for both 23andMe and FamilyTreeDNA. Clustering is integrated at MyHeritage. Ancestry does not provide a tool for nor allow third-party clustering. If the answer you seek isn’t immediately evident, Genetic Affairs clustering tools group people together who are related to each other, and you, and create both genetic and genealogical trees based on shared matches. You can read more about their tools, here.

Fish in all the Ponds and Use All the Bait Possible

Here’s the testing and upload strategy I recommend, based on the above discussion and considerations. The bottom line is this – if you want as much information as possible, as quickly as possible, order the four tests in red initially. Then transfer the first autosomal test results you receive to the two companies identified in blue. Optionally, GEDMatch may have tools you want to work with, but they aren’t a testing company.

What	When	Ancestry	23andMe	MyHeritage	FamilyTreeDNA
Order autosomal	Initially	X	X
Order Y 111 or Big-Y DNA test if male	Initially				X
Order mitochondrial DNA test	Initially if desired				X
Upload free autosomal	When Ancestry or 23andMe results are available			X	X
Unlock Advanced Tools	When you upload			$29	$19
Optional GEDMatch free upload	If desired, can subscribe for advanced tools

When you upload an autosomal DNA file to a vendor site, only upload one file per site, per tester. Otherwise, multiple tests simply glom up everyone’s match list with multiple matches to the same person.

Multiple vendor sites will hopefully provide multiple close matches, which increase your opportunity to discover INFORMATION about your family, not just the identity of the person you seek.

Or maybe you prefer to wait and order these DNA tests serially, waiting until one set of results is back and you’re finished working with them before ordering the next one. If so, that means you’re a MUCH more patient person than me. 😊

Our next article in this series will be about endogamy, how to know if it applies to you, and what that means to your search.

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You’re always welcome to forward articles or links to friends and share on social media.

If you haven’t already subscribed (it’s free,) you can receive an email whenever I publish by clicking the “follow” button on the main blog page, here.

You Can Help Keep This Blog Free

Thank you so much.

DNA Purchases and Free Uploads

FamilyTreeDNA – Y, mitochondrial, and autosomal DNA testing
MyHeritage DNA – Autosomal DNA test
MyHeritage FREE DNA file upload – Upload your DNA file from other vendors free
AncestryDNA – Autosomal DNA test
23andMe Ancestry – Autosomal DNA only, no Health
23andMe Ancestry Plus Health

Genealogy Products and Services

MyHeritage FREE Tree Builder – Genealogy software for your computer
MyHeritage Subscription with Free Trial
Legacy Family Tree Webinars – Genealogy and DNA classes, subscription-based, some free
Legacy Family Tree Software – Genealogy software for your computer
Newspapers.com – Search newspapers for your ancestors
NewspaperArchive – Search different newspapers for your ancestors

My Book

DNA for Native American Genealogy – by Roberta Estes, for those ordering the e-book from anyplace, or paperback within the United States
DNA for Native American Genealogy – for those ordering the paperback outside the US

Genealogy Books

Genealogical.com – Lots of wonderful genealogy research books

Genealogy Research

Legacy Tree Genealogists – Professional genealogy research

Ancestry Only Shows Shared Matches of 20 cM and Greater – What That Means & Why It Matters

Posted on May 12, 2022 by Roberta Estes

Recently, I’ve noticed an uptick in confused people who’ve taken Ancestry’s DNA test.

They are using shared matches, which is a great tool and exactly what they should be doing, but they become confused when no shared matches appear with some specific people.

This is especially perplexing when they know through information sharing or because they manage multiple DNA kits that those two people who both match them actually do share DNA and match each other, meaning they “should” appear on a shared match list. Or worse, yet, conflicting match information is displayed, with one person showing the shared match, but the other person reciprocally does not.

What gives?

That’s exactly what this article addresses. It’s not quite as simple as it sounds, but it’s certainly easier once you understand.

What Are Matches and Shared Matches?

Matches occur when two people match each other. From your perspective as a DNA tester, matches are people who have taken DNA tests and appear on your match list because you share some level of DNA equal to or greater than the match threshold of the vendor in question.

At Ancestry, that minimum matching threshold is 8 cM (centimorgans) of matching DNA.

Individual matches are always one-to-one. Your match list is a list of people who all match you.

So, you match person 1, and you match person 2, individually.

Your matches may or may not also match each other. If they do match each other in addition to matching you, that’s a shared match which is a hint as to a potential common ancestor between all three people.

Shared matches are a list of people who match you PLUS any one other match on your list. In other words, shared matches are three-way matches.

In the diagram above, you can see that you match Match 1 and you also match Match 2. In this case, Match 1 and Match 2 also match each other, so all three of you match each other, but not necessarily on the same segment. Therefore, you’re all three shared matches, as shown in the center of the three circles.

Viewing Shared Matches

To view a list of people who match you and Match 1, you would request shared matches with Match 1 by clicking on “View Match” or “Learn More” on your match list, then on “Shared Matches” on the next screen.

The resulting shared match list consist of people who match you AND Match 1, both. It’s easy to make assumptions about why you have shared matches, but don’t.

Shared Matches are Hints

A shared match CAN mean:

That all three people share a common ancestral line.
You share a common ancestor with Match 1 and Match 2, but Match 1 and 2 match each other because they share an entirely different ancestor.
You match Match 1 because you share DNA from Ancestor A and you match Match 2 because you share DNA from Ancestor B. Match 1 and 2 match each other either because they share one or both of those common ancestors.
Match 1 and Match 2 might match because Match 1 and Match 2 share an ancestor that isn’t related to you.
That one (or more) of the matches is identical by chance, meaning the DNA combined from two parents in a random way that just happens to match with someone else.

Shared matches are great hints to be sifted for relevance. The operative word here is hint.

What If We Don’t Have Shared Matches?

Conversely, NOT having a shared match doesn’t mean you don’t share a common ancestor.

Sorry about the triple negative. Let me say that another way, because this is important.

Even though you and someone else aren’t on a shared match list, you might still share DNA and you may share a common ancestor, whether you share their DNA or not.

Ancestry’s shared matches work differently than shared matches at other vendors. Before we discuss that, let’s talk about why shared matches are important.

Why Do Shared Matches Matter Anyway?

Matches and shared matches are how genealogists perform two critically important functions:

Verifying “known” ancestors. Sometimes paper trails aren’t accurate and certainly, neither are trees.
Identifying unknown ancestors. Looking for common families among shared DNA matches is a HUGE hint when tracking down those pesky unknown ancestors.

I wrote about shared matches, here, when Ancestry purged segments under 8 cM, but I think the message about the limitations of shared matches and how the process actually works deserves its own article, especially for new users. Shared matches and segment cM numbers can be quite confusing, but they don’t need to be.

I wrote an article titled DNA Beginnings: Matching at Ancestry and What It Means that includes lots of useful information.

Ok, now let’s look specifically at using shared matches and why sometimes shared matches just don’t seem to make sense.

Matches

By far, the majority of your matches at any vendor will be more distant matches. That’s because you have thousands of distant relatives, most of whom you don’t know (yet).

You’ll only have a few closer relatives.

At Ancestry, I have 102,000+ total matches, of which more than 97,000 are distant matches. Based on these numbers, keep in mind that about 95.74% of my matches are distant, meaning 20 cM or below, and yours probably are too. You’ll need that number later.

Note that 20 cM is Ancestry’s threshold between close matches and distant matches.

That’s about exactly where you’d expect, on average, to see a 20 cM match – generally at or further back than 4^th cousins. 20 cM is roughly the 4^th to 6^th cousin level.

Of course, you won’t match most of your 5^th cousins at all, yet you’ll match some with more than 20 cM. That’s just the roll of the genetic dice.

Closer ancestors (meaning closer matches) is also the area of genealogy where much of the lower-hanging fruit has been plucked.

In my case, the closest unknown ancestor in my tree occurs at the 6^th generation level and I have 5 or 6 missing sixth-generation ancestors – all females with no surnames. Two have no names at all.

Click to enlarge any image

How Much DNA Do Cousins Share?

One of my priorities as a genealogist is to identify those unknown people, which is why matches, and shared matching at that level are critical for me.

Ancestry tells me that this 20 cM match is likely my 4^th-6^th cousin.

At DNAPainter, in the Shared cM Tool, you can enter the total cM number of a match, which is the total amount of DNA that you share after Ancestry’s Timber algorithm has been applied. The range of relationship probabilities for 20 cM is shown below.

For a total match of 20 cM with another individual, several relationships ranging between half 3C2R/3C3R and 8^th cousins are the most probable relationships at 58%.

For the record, this is total cM, which does not necessarily mean one segment. Ancestry reports the number of segments, but Ancestry does not show you the segment locations, nor do they have a chromosome browser. Without a chromosome browser, you have no way of determining whether or not you match with shared matches on the same segment(s). In other words, there is no triangulation at Ancestry, meaning confirmation of a specific shared DNA segment descended from a common ancestor. You can find triangulation resources, here.

Close Matches

The best way to figure out how you are related to closer matches (assuming you don’t already know them and Ancestry has not found a common ancestor) is using shared matches. Hopefully, you will share matches with people you do know or with whom you’ve already identified your common ancestor.

One of my relatively close DNA matches at Ancestry is Lonnie. I don’t know Lonnie, but it looks like I should because he’s probably a 1st or 2nd cousin. We share 357 cM of DNA over 20 segments.

I thought I knew all of my 1^st and 2^nd cousins. Let’s see if I can figure out how I’m related to Lonnie.

By clicking on Lonnie’s name on my match list, then on Shared Matches, I can determine that Lonnie and I connect through my Estes and Vannoy lines based on who we both match, which means that our common ancestor is either my paternal grandfather or my great-grandparents, Lazarus Estes and Elizabeth Vannoy.

You can see the notes I’ve made about these matches I share with Lonnie.

Viewing Lonnie’s unlinked tree verifies the ancestral line that shared matches suggest. An unlinked tree means that Lonnie has not linked his DNA test to himself in his tree. Since Ancestry doesn’t know who he is in the tree, they can’t find a common ancestor for me and Lonnie. However, I can by viewing his tree.

Our common ancestor is Lazarus Estes and his wife, Elizabeth Vannoy. Therefore, Lonnie is my 2^nd cousin.

That wasn’t difficult, in part because I had already worked on the genealogy of our common matches and Lonnie had a small unlinked tree where I could confirm our common ancestor.

Now let’s move to more distant, not-so-easy matches.

Distant Matches

I’ve spent a lot of time over the years identifying common ancestors with my matches.

When I make that connection, whether or not Ancestry has been able to identify our common ancestor, I make notes about common ancestors and anything else that seems relevant. Notes very conveniently show on my match list so I don’t need to open each match to see how we are related.

Ancestry does identify potential common ancestors using ThruLines. Note the word potential. Ancestry compares the trees of you and your matches searching for common ancestors and suggests connections. It’s up to you to verify. ThruLines are hints, not gospel. Additionally, you may have multiple ancestral links to your matches. Ancestry can only work with the fact that you have a DNA match with someone AND the user-provided trees of your matches.

Ancestry’s ThruLines only reach back a maximum of 7 generations to suggest common ancestors. At 7 generations distance, you’d be a 5^th cousin to a descendant who is also 7 generations downstream from that ancestor.

The information from DNAPainter, who utilizes the Shared CM Project compiled data shows that the most likely amount of shared DNA for 5^th cousins, is, you’ve guessed it – 20 cM.

Jacob Dobkins is my 7^th generation ancestor. I have ThruLines for him and his wife, but not for their parents who are one generation too distant for ThruLines. I’d LOVE to see Ancestry extend ThruLines another 2 or 3 generations.

ThruLines matches me with people who descend from Jacob through his other children. Other children are important because the only ancestors you share with those people are (presumably) that ancestral couple.

Matches with Jacob’s descendants range from 8 cM (the smallest amount Ancestry reports) to 32 cM.

Here’s an example.

Ancestry displays some shared matches with all of your matches, regardless of the size of your match to that person. However, Ancestry ONLY shows shared matches to a third person if you share more than 20 cM of DNA with that third person.

For example, I match KO with 8 cM of DNA. Ancestry shows my shared matches with KO, below.

I only have 3 shared matches with KO. I only match KO at 8 cM, but I match our shared matches at 39, 31 and 21 cM, respectively.

Ancestry does NOT show shared matches below 20 cM, so it’s unknown how many additional shared matches KO and I actually have if shared matches less than 20 cM were displayed.

Perspective is Critical

Whether you see a shared match or not is sometimes a matter of perspective, meaning which of two people you request shared matches with.

In this case, I requested shared matches with KO. I only share 8 cM of DNA with KO, but that doesn’t matter. The amount of DNA you share with the person you’re requesting shared matches with is irrelevant.

Ancestry’s Shared Matches with KO include Ker

I will see shared matches with KO to anyone we mutually share as matches above 20 cM, including Ker.

If I request shared matches with Ker, with whom I share 39 cM of DNA, I will see all of our mutual matches at 20 cM (or greater) of DNA. However, that does NOT include KO because I only share 8 cM of DNA with KO.

This restriction applies regardless of how much DNA KO and Ker share, which is an unknown to me of course.

Ancestry’s Shared Matches with Ker does NOT include KO

Nothing has changed between these matches, yet KO does not appear on my shared matches list with Ker when I request shared matches with Ker.

I still share 8 cM with KO and 39 cM with Ker. KO and Ker still both match each other. The only difference is that Ker shows up on my shared match list with KO because I share more than 20 cM with Ker. However, when I request a match list with Ker, KO does NOT appear because I only share 8 cM with KO.

This is the source of the confusion and often, why people disagree about shared matches. It’s kind of a “now you see it, now you don’t” situation.

If a person shows as a shared match depends on:

Whether the third person actually does share DNA with the tester and the person they’ve asked for shared matches with
Whether the third person shares 20 cM DNA or more with the tester, the person requesting the shared match list with one of their matches

Whether someone appears on a shared match list can literally be a matter of perspective unless the match and the shared matches all match the tester at 20 cM or larger.

Another Example

Let’s look at a larger match to a descendant of the same ancestor.

I share exactly 20 cM with Joyce, my 5C1R.

Viewing my shared matches with Joyce, I match 50 other people that she matches as well.

I only share 25 cM of DNA with the smallest match with Joyce. Apparently, there are no matches with Joyce with whom I share between 20 and 25 cM of DNA.

Bottom Line

Here’s the bottom line.

Ancestry NEVER shows any shared matches below 20 cM from the perspective of the tester, meaning people who match you and someone else, both.

If you recall our earlier math, that means that approximately 95.74% of my shared matches aren’t shown.

This puts shared matches in a different perspective because now I realize just how many matches I’m not seeing.

Why is This Confusing?

If you aren’t aware of this shared match limitation, and that a majority of your shared matches are actually below 20 cM, you may interpret shared match results to mean you actually DON’T share specific matches with that other person. That isn’t necessarily true, as we saw above with KO and Ker.

Furthermore, let’s say you manage your DNA kit plus 3 more, A, B and C. Because you manage all 4 kits, that means you can see the results for all 4 people.

A – 10 cM
B – 20 cM
C – 40 cM

From the perspective of YOUR kit, you will see some shared matches FOR all of those matches.

What you won’t see is shared matches if you don’t match the shared match (third person) at 20 cM or greater.

Always remember, shared match information at Ancestry is ALWAYS from the perspective of your DNA kit combined with the person with whom you request the match.

I’ve put this information in a grid because that’s how I make sense of things like this.

Here are your matches. When you click on shared matches with person A who you match at 10 cM, you’ll see both person B and person C as shared matches since you match both of those people at 20 cM or larger. You WILL see 20 cM shared matches, but you will not see 19 cM shared matches.

When you request shared matches for A, you will see both B and C.

When you request shared matches with kits B and C, you will not see A because you only match them at 10 cM.

However, from the perspective of DNA kits A, B and C, shared matches look different.

Let’s look at shared matches from the perspective of Kits A, B and C.

Kit A matches you, Kit B and C, but can only see Kit B as a shared match because matches with you and Kit C are under 20 cM.

Kit B doesn’t match C at all, so they clearly won’t have shared matches. However, they do match you and Kit A, both at 20 cM and over, so Kit B will see you as a shared match with Kit A, and Kit A as a shared match with you.

Kit C doesn’t match Kit B, so no shared matches with that person at all. Kit C does match you and Kit A. However, when Kit C clicks on shared matches for you, Kit A doesn’t show up because they only match Kit A on 9 cM. When Kit C clicks on Kit A for shared matches, you ARE listed as a shared match because you share 40 cM of DNA with Kit C.

There’s no way to discern whether two of your matches match each other unless they show as a match in the shared match tool. You can’t tell if their absence on the shared match list means they actually don’t match, or their shared match absence is because they match you at less than 20 cM.

Whew, that was a mouthful.

You may need to refer back to this from time to time if you’re confused by your shared matches at Ancestry.

If you need to remember rules, remember this.

You can obtain shared matches with yourself plus any match, regardless of how much or how little DNA you share with that one match. Prove this to yourself by finding a match under 20 cM, like my 8 cM match, and viewing your shared matches.
No one will show on a shared match list with another person unless they match you at 20 cM or greater. Prove this to yourself by viewing the smallest shared match with anyone.

Strategy

The takeaway of this is if you have a larger (20 cM or over) and smaller match (under 20 cM), always request shared matches from the perspective of the smaller match because the smaller match won’t show up as a shared match on any shared match list.

The only way you can see shared matches that includes people under 20 cM is to request to view shared matches with individual people who match you below 20 cM.

In my case, I will never see KO on any shared match list because I only match KO at 8 cM. However, I can request my shared matches with KO in which case I’ll see all 20 cM or greater shared matches with KO.

Alternatives

Every vendor provides a shared match feature, and each functions differently.

In the chart below, I’ve provided basic shared match information for each vendor.

If you’re interested in uploading your DNA file from Ancestry or another vendor, I’ve provided upload/download step-by-step instructions for each vendor, here.

_____________________________________________________________

Follow DNAexplain on Facebook, here or follow me on Twitter, here.

Share the Love!

You’re always welcome to forward articles or links to friends and share on social media.

If you haven’t already subscribed (it’s free,) you can receive an email whenever I publish by clicking the “follow” button on the main blog page, here.

You Can Help Keep This Blog Free

Thank you so much.

DNA Purchases and Free Uploads

FamilyTreeDNA – Y, mitochondrial and autosomal DNA testing
MyHeritage DNA – Autosomal DNA test
MyHeritage FREE DNA file upload – Upload your DNA file from other vendors free
AncestryDNA – Autosomal DNA test
23andMe Ancestry – Autosomal DNA only, no Health
23andMe Ancestry Plus Health

Genealogy Products and Services

MyHeritage FREE Tree Builder – Genealogy software for your computer
MyHeritage Subscription with Free Trial
Legacy Family Tree Webinars – Genealogy and DNA classes, subscription-based, some free
Legacy Family Tree Software – Genealogy software for your computer
Newspapers.com – Search newspapers for your ancestors
NewspaperArchive – Search different newspapers for your ancestors

My Book

DNA for Native American Genealogy – by Roberta Estes, for those ordering within the United States
DNA for Native American Genealogy – for those ordering outside the US

Genealogy Books