DNA Inherited from Grandparents and Great-Grandparents

Philip Gammon, our statistician friend has been working with crossover simulations again in order to tell us what we might expect relative to how much DNA we actually inherit from grandparents and great-grandparents.

We know that on average, we’re going to inherit 25% of our DNA from each grandparent – but we also know in reality that’s not what happens. We get more or less than exactly 25% from each person in a grandparent pair. It’s the total of the DNA of both grandparents that adds up to 50% for the couple.

How does this work, and does it make a difference whether we inherit our grandparent’s DNA through males or females?

Philip has answers for us as a result of his simulations.

DNA Inheritance from Grandparents

Philip Gammon:

When we consider the DNA that we inherit from our ancestors the only quantity that we can be certain of is that we receive half of our autosomal DNA from each parent. This is delivered to us in the form of the 22 segments (i.e. chromosomes) provided by our mothers in the ova and the 22 segments/chromosomes provided by our fathers in the sperm cell. Beyond parent-child relationships we tend to talk about averages. For instance, we receive an average of one quarter of our DNA from each of our four grandparents and an average of one-eighth of our DNA from each of our eight great-grandparents etc.

These figures vary because our parents didn’t necessarily pass on to us equal portions of the DNA that they received from their parents. The level of variation is driven by the number (and location) of crossover events that occur when the ova and the sperm cells are created.

The statistics relevant to the recombination process were discussed in detail in a previous article (Crossovers: Frequency and Inheritance Statistics – Male Versus Female Matters). With the availability these days of abundant real data from direct-to-consumer genetic testing companies (such as the 23andMe data utilised by Campbell et. al. in their paper titled “Escape from crossover interference increases with maternal age”) we can use this information as a basis for simulations that accurately mimic the crossover process. From these simulations we can measure the amount of variation that is expected to be observed in the proportions of DNA inherited from our ancestors. This is precisely what I have done in simulations run on my GAT-C model.

Before looking at the simulation results let’s anticipate what we expect to see. The previous article on crossover statistics revealed that there are an average of about 42 crossovers in female meiosis and about 27 in male meiosis. So, on the set of 22 chromosomes received from our mothers there will have been an average of 42 crossover locations where there was a switch between DNA she inherited from one parent to the other. That means that the DNA we inherit from our maternal grandparents typically comes in about 64 segments, but it won’t necessarily be 32 segments from each maternal grandparent. Chromosomes that experienced an odd number of crossovers contain an even number of segments (half originating from the grandmother, the other half from the grandfather) but chromosomes with an even number of crossovers (or zero!) have an odd number of segments so on these chromosomes you must receive one more segment from one grandparent than the other. And of course not all segments are the same size either. A single crossover occurring close to one end of the chromosome results in a small segment from one grandparent and a large segment from the other. All up there are quite a few sources of variation that can affect the amount of DNA inherited from grandparents. The only certainty here is that the amount inherited from the two maternal grandparents must add to 50%. If you inherit more than the average of 25% from one maternal grandparent that must be offset by inheriting less than 25% from the other maternal grandparent.

Gammon grandparents maternal percent.png

The above chart shows the results of 100,000 simulation runs. Excluding the bottom and top 1% of results, 98% of people will receive between 18.7% and 31.3% of their DNA from a maternal grandparent. The more darkly shaded region in the centre shows the people who receive a fairly even split of between 24% and 26% from the maternal grandparents. Only 28.8% of people are in this region and the remainder receive a less even contribution.

On the set of 22 chromosomes received from fathers there will have been an average of around 27 crossovers so the DNA received from the paternal grandparents has only been split into around 49 segments. It’s the same amount of DNA as received from mothers but just in larger chunks of the grandparent’s DNA. This creates greater opportunity for the father to pass on unequal amounts of DNA from the two grandparents so it would be expected that results from paternal inheritance will show more variation than from maternal inheritance.

Gammon grandparents paternal percent.png

The above chart shows the results of 100,000 simulated paternal inheritance events. They are more spread out than the maternal events with the middle 98% of people receiving between 16.7% and 33.3% of their DNA from a paternal grandparent. Only 21.9% of people receive a fairly even split of between 24% and 26% from each paternal grandparent as shown by the more darkly shaded region in the centre.

Gammon grandparents percent cM.png

To help with the comparison between maternal and paternal inheritance from grandparents the two distributions have been overlayed on the same scale in the chart above. And what are the chances of receiving a fairly even split of grandparents DNA from both your mother and your father? Only 6.3% of people can be expected to inherit an amount of between 24% and 26% of their DNA from all four grandparents.

Now I’ll extend the simulations out to the next generation and examine the variation in proportions of DNA inherited from the eight great-grandparents. There are effectively four groups of great-grandparents:

  • Mother’s maternal grandparents
  • Mother’s paternal grandparents
  • Father’s maternal grandparents
  • Father’s paternal grandparents

The DNA from group 1 has passed to you via two maternal recombination events, from your mother’s mother to your mother, then from your mother to you. On average there would have been 42 crossovers in each of these recombination events. Group 4 comprised two paternal recombination events averaging only 27 crossovers in each. The average amount of DNA received along each path is the same but along the group 1 path it would comprise of more numerous smaller segments than the group 4 path. Groups 2 and 3 would be somewhere between, both consisting of one maternal and one paternal recombination event.

Gammon greatgrandparents percent cM.png

The above chart shows the variation in the amount of DNA received from members of the four groups of great-grandparents. 25,000 simulations were performed. The average amount from any great-grandparent is 12.5% but there can be considerably more variation in the amount received from the father’s paternal grandparents than from the mother’s maternal grandparents. Groups 2 and 3 are between these two extremes and are equivalent. It doesn’t matter whether a paternal recombination follows a maternal one or vice versa – the end result is that both paths consist of the same average number of crossovers.

The table below shows the range in the amount of DNA that people receive from their great-grandparents. The bottom and top 1% of outcomes have been excluded. Note that these are based on a total of 3,418 cM for the 22 autosomes which is the length observed in the Campbell et. al. study. The average of 12.5% of total DNA is 854.5 cM:

Group 1st percentile 99th percentile
Mother’s maternal grandparents 522 cM 1219 cM
Mother’s paternal grandparents 475 cM 1282 cM
Father’s maternal grandparents 475 cM 1281 cM
Father’s paternal grandparents 426 cM 1349 cM

As a matter of interest, in each of the 25,000 simulations the amount of DNA received from the eight great-grandparents were sorted into order from the highest cM to the lowest cM. The averages of each of these eight amounts were then calculated and the results are below:

Gammon greatgrandparents average cM.png

On average, a person receives 1,129 cM from the great-grandparent that they inherited the most of their DNA from and only 600 cM from the great-grandparent that they received the least of their DNA from. But none of us are the result of 25,000 trials – we are each the product of recombination events that occurred once only. The above chart shows the average or typical variation in the amount of DNA received from the eight great-grandparents. Half of people will have experienced more variation than shown above and half of people will have experienced less variation.

Could you have received the same amount of DNA from all eight grandparents? Of course, it is possible, but it turns out that it is extremely unlikely. The average is 12.5% (854.5 cM) so anything between 12% (820.4 cM) and 13% (888.7 cM) could be considered as being close to this figure. The results reveal that this did not occur in any of the 25,000 simulations. Not one person received amounts between 12% and 13% from all eight great-grandparents.

Widening the criteria, I observe that there were 13 instances in the 25,000 simulations where people received between 11.5% and 13.5% of their DNA from all eight great-grandparents. That is still an extremely rare occurrence. Expanding the range further to between 11% and 14% saw a total of 126 instances, but this still only represents about half a percent of all observations. I think that we just have to face the fact that unless we are an extremely rare individual then we will not have inherited close to equal amounts of DNA from our eight great-grandparents.

Now, back to Roberta.

Thanks Philip.

Now we see why we might not inherit the same amount of DNA from our grandparents and great-grandparents.

We Don’t Have Equal Numbers of Matches on Tree Branches

This also might explain, at least in part, why people don’t have the same number of DNA matches on each branch of their tree.

Of course, other reasons include:

  • Uneven family sizes
  • Fewer or more cousins testing on different branches
  • Recent immigration meaning there are few people available to test
  • Family from a region where DNA testing and/or genealogy is not popular
  • Endogamy which dramatically increases the number of people you will match

Real Life Example

In our real-life example, two grandchildren are fortunate to have three grandparents and one great-grandparent available for matching.

For comparison purposes, let’s take a look at how many matches each grandchild has in common with their grandparents and great-grandparent.

The line of descent is as follows:

Gammon line of descent.png

Both end of line testers are female children.

The transmission path from their great-grandmother is:

  • Female to their paternal grandmother
  • Female to their father
  • Male to female tester

The transmission path from their maternal grandfather is:

  • Male to their mother
  • Female to female tester

The transmission path from their maternal grandmother is:

  • Female to their mother
  • Female to female tester

This first chart shows the number of common matches.

Matches Grand 1 Grand 2 GGF GGM Grand 3 Grand 4
Female 1 absent 1061 absent 238 529 1306
Female 2 absent 1225 absent 431 700 1064

It’s interesting that the matches in just 3 generations to the great-grandmother vary by 55%. The second tester has almost twice as many matches in common with her great-great-grandmother as she does the first tester. There a difference in the earlier generation, meaning matches to Grand 2, but only about 23%. That difference increased significantly in one generation.

The second chart shows the total number of matching cM with the matching family member.

Total cM Grand 1 Grand 2 GGF GGM Grand 3 Grand 4
Female 1 absent 1688 absent 713 1601 1818
Female 2 absent 1750 absent 852 1901 1511

We can see that the amount of DNA inherited from a grandparent does correlate with the number of matches to that grandparents. The more DNA shared, of course the better the chances of sharing that DNA with another person. However, multiple factors may be involved with why some people have more or fewer matches.

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Y DNA: Part 1 – Overview

This is Part 1 of a series about Y DNA and how to use it successfully for genealogy.

If you’re in need of a brief DNA testing overview, please read 4 Kinds of DNA for Genetic Genealogy.

Y DNA testing has so much to offer. In this overview article, I’m touching briefly on each of the major functions and features of Y DNA testing. Following articles in this series will focus on how to utilize each tool for genealogy and harvesting every snippet of information available.

If you have Y DNA results, you can sign on to your account at Family Tree DNA and follow along. Throughout these articles, we’ll step through every tab and function, how to use them, and what they mean to you.

What is Y DNA and Why Do I Care?

Y DNA is what makes males, well, male.

The 23rd pair of human chromosomes consists of an X and a Y chromosome.

Female children inherit an X from both parents.

Male children inherit an X chromosome from their mother, but a Y from their father.

Generally, the Y chromosome follows the male surname line, so Estes males pass their Estes Y chromosome to their sons.

When adoptions occur, of course the surname of record does not match the biological surname associated with the Y chromosome – which is exactly why male adoptees take Y DNA tests.

Inheritance Path

In the example below, you can see that the light blue Y chromosome is passed from father to son to son to son to the male child in the current generation.

Y overview inheritance path

Click to enlarge

The dark blue maternal great-grandfather in this example also passes his Y chromosome to his son, but it stops there since the next generation in this tree is a female.

The light blue son at the bottom inherits a Y chromosome from his father, from ancestors all the way up that light blue line – along with his surname. The daughter doesn’t receive a Y chromosome nor do any females.

If you’re a male, you can test your own Y DNA of course.

If you’re a female, like the daughter, above, you must find a male in the line you seek to test. In this case, the brother, father, grandfather, paternal uncles and so forth represent her father’s Y DNA.

If you want information from any of the Y chromosome lineages in this chart that you don’t personally carry, you must find a male descended directly patrilineally from that line to test. It’s generally fairly easy to identify those people, because they will also carry the relevant surname. There are several examples in the article, Concepts – Who to Test for Your Father’s DNA.

Every Y DNA line has its own unique story for genealogists to harvest – assuming we can find an appropriate candidate for testing or find someone who has already tested. We’ll talk about how to see if your line may have already tested in the Projects section later in this article.

Why Y DNA Works

Y DNA is inherited from the patrilineal line directly. Unlike autosomal DNA, there is no genetic contribution from any females.

This uniquely male inheritance path allows us to use Y DNA for matching to other males beginning with the first generation, the father, then reaching back many generations providing a way to view our ancestral heritage beyond the line-in-the-sand boundary of surnames.

In other words, because Y DNA is not mixed with any DNA from the mothers, it’s very nearly identical to our patrilineal ancestors’ Y DNA – meaning it matches that of the father, and grandfather, reaching back many generations.

Some people, especially new autosomal testers, believe that Y DNA is ONLY useful for deep ancestry and not for genealogy. That’s ENTIRELY mistaken. Y DNA is extremely important in confirming descent from known ancestors. In fact, without Y DNA, you can’t tell the difference with autosomal testing between a child born to a male and a child born to the female of a couple. I wrote about that hereNo one wants to spend years barking up the wrong tree.

Y DNA testing is also the single best way to push the Y DNA genealogy back further in time. It can and does identify the geographic source, overseas, of the DNA lineage, through matches to other testers as well as haplogroup matches. These are things autosomal DNA simply cannot accomplish.

In fact, Y DNA did exactly that for my own Speak(es) line, connecting us genetically to the Speak family from Downham, Lancashire, England which then facilitated discovering the actual baptism document of our immigrant ancestor. Finding our English geographic source had eluded researchers for decades. A year later, a group of 20+ descendants visited Downham and stood in that very church.

Speak Family at St Mary Whalley

There simply is no better success story.

Migration Path Identified

Not only can Y DNA confirm recent ancestors and find ones more distant, by tracing a series of mutations, we can track our ancestor over time beginning with Y Line Adam, born in Africa tens of thousands of years ago to that church in an ancestral country and then to where we are today.

Y overview migration path.png

Mutations Happen

If mutations never occurred, the Y DNA of all males would be identical and therefore not useful for us to use for genealogy or to peer back in time beyond the advent of surnames.

Mutations do occur, just not on any schedule. This means that it’s difficult to predict how long ago we shared a common ancestor with someone else based solely on Y DNA mutations – although some types of mutations are better predictors than others.

A mutation might occur between a male and his father, or there might be no mutations for hundreds or even, potentially, thousands of years – depending on the marker type.

For example, in the Estes DNA project, one group of men have no STR (short tandem repeat) mutations in 8 generations. Others have several in the same number of generations.

Part of the success of matching genealogically with Y DNA testing has to do with:

  • The type of markers tested
  • The number of markers tested – testing fewer marker locations results in matches that are much less specific and therefore less relevant.
  • The luck of whether anyone else from your line has tested

The best results are between men who have taken the Big Y-700 test which provides for the largest number of STR markers and all SNPs (single nucleotide polymorphisms) , both previously known and discovered individually during that person’s Big Y test result.

Let’s take a look at the two different kinds of Y DNA markers and their mutations.

Two Kinds of Mutations

Y DNA can be tested for two different kinds of mutations, STR (short tandem repeat) markers and SNPs (single nucleotide polymorphisms.)

All DNA is comprised of four different nucleotides, abbreviated by A, C, G and T.

  1. A=adenine
  2. C=cytosine
  3. G=guanine
  4. T=thymine

When mutations take place, they can take the form of three types of mutations:

  • A deletion occurs when a nucleotide, or multiple nucleotides, fail to copy during reproduction. Therefore, that location or locations are then blank, with no DNA at that location permanently.
  • A replacement occurs when a nucleotide is replaced or swapped out with a different nucleotide. For example, an A could be replaced with one of the other nucleotides, and so forth.
  • An insertion occurs when a nucleotide or a group of nucleotides is duplicated and inserted between existing nucleotides.

Let’s look at how this actually works.

Indel example 1

Here’s an example segment of DNA.

A deletion would occur if the leading A (or a series of nucleotides) were simply gone.

Indel example 3

A replacement would occur if the first A above were to change to T or G or C as in the example below:

Indel example 2

A replacement is a SNP mutation.

An insertion would be where DNA is inserted between existing nucleotide locations.

STR example

Note the extra red CTs that have been inserted. Specifically, 4 extra CTs, for a total of 5 sets of CT. This is the definition of a STR, a short tandem repeat mutation.

STR markers, known as short tandem repeats, accrue what are similar to copy machine errors. This occurs when a specific segment of Y DNA gets repeated several times in a row. In other words, the copy machine gets stuck.

STR Markers

We purchase STR Y DNA tests from Family Tree DNA grouped into panels that include a specific number of markers.

Y overview STR results

Example of 37 marker results – click to enlarge

These panels consist of the following number of marker locations:

  • 12 markers (now obsolete)
  • 25 markers (now obsolete)
  • 37 markers
  • 67 markers (replaced by 111)
  • 111 markers
  • 500 markers bundled as part of the now-obsolete Big Y-500
  • 700 markers bundled with the Big Y-700

The more markers purchased, the more data points to be compared, and the more relevant and convincing the results.

What Matches See

The STR matches and SNP matches look different on the tester’s results page.

Y overview matches

Click to enlarge

People whom you match on STR panels can see that you do match, if you’ve opted-in to matching, but they can’t see specific differences or mutations. They see the name you’ve entered for yourself, your earliest known ancestor and your match can send e-mail to you. Aside from that, they can’t see your results or mutations unless you’ve joined a public project.

Y overview project

Click to enlarge

Within projects, participant names cannot be listed publicly. In other words, your matches can’t tell that it’s you unless you tell them your kit number or they recognize your earliest known ancestor on the project page and you are the only person with that ancestor.

The Big Y-700 test tests all STR markers in addition to scanning the entire Y chromosome for all SNP (haplogroup defining) mutations. They have the STR matches page like everyone else, but they also have an additional Big Ypage.

People who have taken the Big Y test see a different view of matches on their Big Y matches tab. This is true for either the original Big Y, Big Y-500 which includes a minimum of 500 STR markers or the current Big Y-700 test which includes a minimum of 700 STR markers. (You can always upgrade to the Big Y-700 from earlier tests.)

Y overview Big Y.png

For SNP markers only, above, Big Y matches can see who they match and the SNPs they do and don’t match with that person in common.

For STR markers available only under the Big Y umbrella, meaning above 111 markers, results are displayed under the Y DNA Matches tab in the Big Y STR Differences column, below.

Y overview Big Y STRs

Click to enlarge

You can easily see that only one man on this match list has also taken the Big Y test, and he had 2 differences out of 440 markers. That’s in addition to 2 differences in the first 111 markers, for a total of 4 differences (mutations) in 551 markers.

Researching Without Testing

The great news is that even if you’ve just ordered your test and are waiting for results, you can research and join projects now.

For that matter, you can research using public projects without testing by going to the main Family Tree DNA webpage, scroll down and simply entering the surname of interest into the search box.

New dashboard surname search

You’ll be directed to surname projects where you can view ancestors and results of anonymized project members.

Give it a try to see what comes up for your surnames of interest.

Project Results

Projects at Family Tree DNA provide testers with access to volunteer administrators who help users with various types of information. Administrators also cluster users in projects that are meaningful to their research.

Most Y DNA testers immediately join their surname project.

Using the Estes surname project as an example, you can see that I’ve grouped the project members in ways I feel will be helpful to their genealogy.

Y overview Estes project.png

The Paternal Ancestor Names are particularly helpful to testers as well as people who are interested in testing in order to determine whether or not they are descended from a specific line.

It’s very useful to be able to discern if someone from your line has already tested – because it provides someone for you to match against, or not, as the case may be.

Y overview hap C project.png

The haplogroup C-P39 Y DNA project is shown above with the Paternal Ancestor Name as provided by testers that reflects Native American and First Nations ancestors.

Another important project feature is the project map function, allowing testers in a specific haplogroup (C-P39 below) to view the locations of the earliest known ancestors of other members of the same haplogroup – whether project members match each other or not. Your Native ancestors traveled with theirs and descended from a common ancestor. Cool, huh!

Y overview C map.png

What’s the story associated with the pin distribution of the C-P39 project, above? I wish we knew, and we may someday as research progresses. Whatever it is, it’s probably important genealogically.

Another type of project to join is a geographical or interest group project.

The Acadian AmerIndian Project welcomes descendants who have tested the Y, autosomal and/or mitochondrial DNA of the various Acadian families which includes French and English settlers along with First Nations indigenous ancestors.

Y overview Acadian.png

The map below shows the distribution of Y DNA members of the Acadian Amerindian project diaspora before and after Le Grand Dérangement” that scattered their descendants to the winds.

Y overview Acadian map.png

The pins on the Acadian Amerindian project map above are color coded by haplogroup.

Projects such as this facilitate genealogists discovering the haplogroup and related information about their direct line ancestor without personally testing.

Y overview Doucet.png

For example, if Germain Doucet born about 1641, part of the mustard-colored group above, is my ancestor, by viewing and/or joining this project, I can obtain this information about my ancestor. Project members can see more than casual browsers, because some testers only choose to display results to other project members and some projects are private, with results only displayed to project members. Many surname projects accept descendants who don’t carry the surname itself.

I obviously can’t personally test for Germain Doucet’s Y DNA myself, but thankfully, others who do descend patrilineally from Germain Doucet have been generous enough to test and share by joining this project.

Furthermore, I can contact the tester through the project administrator(s) and gain a great cousin with potentially LOTS of information.

Just think how useful Y DNA would be to genealogists if everyone tested!

Finding Projects to Join

I encourage all testers to join appropriate haplogroup projects. Often, more than one haplogroup project exists for each Y DNA letter, such as C or R. Generally, there are many subgroups for each core haplogroup and you may want to join more than one depending on your results.

I encourage testers to browse the selections and join other interest projects. For example, there are projects such as the Anabaptist Project which focuses on an endogamous religious sect, French-Swiss which is regional, or the American Indian project for people researching Native ancestry, in addition to relevant surname and haplogroup project(s). There are more than 10,000 total (well-organized) projects to choose from.

Your project selections may be a huge benefit to someone else as well as to your own research. Y DNA testing and matching is your best bet for jumping the pond and finding connections overseas.

How to Join Projects

Sign on to your personal page at Family Tree DNA and click on myProjects at the top, then on “Join A Project.”

Mitochondrial DNA join a project

Next, you’ll see a list of projects in which your surname appears. These may or may not be relevant for you.

Y overview project list

Click to enlarge

You can search by surname.

Y overview surname search.png

More importantly, you can browse in any number of sections.

Y-overview-project-categories.png

For Y DNA, I would suggest specifically surnames, of course, Y DNA haplogroups along with Y DNA Geographical Projects, and Dual Geographical Projects.

Y overview haplogroup alpha

Click to enlarge

When you find a project of interest, click to read the description written by the volunteer administrators to see if it’s a good fit for you, then click through to join.

Next Article in the Series

Of course, you’re probably wondering what all of those numbers in your results and shown in projects mean. The next article in a couple weeks will address the meaning of STR marker results.

Testing

If you haven’t yet Y DNA tested and you want to know what secrets your Y DNA holds, you can order your Y DNA test here.

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Disclosure

I receive a small contribution when you click on some (but not all) of the links to vendors in my articles. This does NOT increase the price you pay but helps me to keep the lights on and this informational blog free for everyone. Please click on the links in the articles or to the vendors below if you are purchasing products or DNA testing.

Thank you so much.

DNA Purchases and Free Transfers

Genealogy Services

Genealogy Research

2019: The Year and Decade of Change

2019 ends both a year and a decade. In the genealogy and genetic genealogy world, the overwhelmingly appropriate word to define both is “change.”

Everything has changed.

Millions more records are online now than ever before, both through the Big 3, being FamilySearch, MyHeritage and Ancestry, but also through multitudes of other sites preserving our history. Everyplace from National Archives to individual blogs celebrating history and ancestors.

All you need to do is google to find more than ever before.

I don’t know about you, but I’ve made more progress in the past decade that in all of the previous ones combined.

Just Beginning?

If you’re just beginning with genetic genealogy, welcome! I wrote this article just for you to see what to expect when your DNA results are returned.

If you’ve been working with genetic genealogy results for some time, or would like a great review of the landscape, let’s take this opportunity to take a look at how far we’ve come in the past year and decade.

It’s been quite a ride!

What Has Changed?

EVERYTHING

Literally.

A decade ago, we had Y and mitochondrial DNA, but just the beginning of the autosomal revolution in the genetic genealogy space.

In 2010, Family Tree DNA had been in business for a decade and offered both Y and mitochondrial DNA testing.

Ancestry offered a similar Y and mtDNA product, but not entirely the same markers, nor full sequence mitochondrial. Ancestry subsequently discontinued that testing and destroyed the matching database. Ancestry bought the Sorenson database that included Y, mitochondrial and autosomal, then destroyed that data base too.

23andMe was founded in 2006 and began autosomal testing in 2007 for health and genealogy. Genealogists piled on that bandwagon.

Family Tree DNA added autosomal to their menu in 2010, but Ancestry didn’t offer an autosomal product until 2012 and MyHeritage not until 2016. Both Ancestry and MyHeritage have launched massive marketing and ad campaigns to help people figure out “who they are,” and who their ancestors were too.

Family Tree DNA

2019 FTDNA

Family Tree DNA had a banner year with the Big Y-700 product, adding over 211,000 Y DNA SNPs in 2019 alone to total more than 438,000 by year end, many of which became newly defined haplogroups. You can read more here. Additionally, Family Tree DNA introduced the Block Tree and public Y and public mitochondrial DNA trees.

Anyone who ignores Y DNA testing does so at their own peril. Information produced by Y DNA testing (and for that matter, mitochondrial too) cannot be obtained any other way. I wrote about utilizing mitochondrial DNA here and a series about how to utilize Y DNA begins in a few days.

Family Tree DNA remains the premier commercial testing company to offer high resolution and full sequence testing and matching, which of course is the key to finding genealogy solutions.

In the autosomal space, Family Tree DNA is the only testing company to provide Phased Family Matching which uses your matches on both sides of your tree, assuming you link 3rd cousins or closer, to assign other testers to specific parental sides of your tree.

Family Tree DNA accepts free uploads from other testing companies with the unlock for advanced features only $19. You can read about that here and here.

MyHeritage

MyHeritage, the DNA testing dark horse, has come from behind from their late entry into the field in 2016 with focused Europeans ads and the purchase of Promethease in 2019. Their database stands at 3.7 million, not as many as either Ancestry or 23andMe, but for many people, including me – MyHeritage is much more useful, especially for my European lines. Not only is MyHeritage a genealogy company, piloted by Gilad Japhet, a passionate genealogist, but they have introduced easy-to-use advanced tools for consumers during 2019 to take the functionality lead in autosomal DNA.

2019 MyHeritage.png

You can read more about MyHeritage and their 2019 accomplishments, here.

As far as I’m concerned, the MyHeritage bases-loaded 4-product “Home Run” makes MyHeritage the best solution for genetic genealogy via either testing or transfer:

  • Triangulation – shows testers where 3 or more people match each other. You can read more, here.
  • Tree Matching – SmartMatching for both DNA testers and those who have not DNA tested
  • Theories of Family Relativity – a wonderful new tool introduced in February. You can read more here.
  • AutoClusters – Integrated cluster technology helps you to visualize which groups of people match each other.

One of their best features, Theories of Family Relativity connects the dots between people you DNA match with disparate trees and other documents, such as census. This helps you and others break down long-standing brick walls. You can read more, here.

MyHeritage encourages uploads from other testing companies with basic functions such as matching for free. Advanced features cost either a one-time unlock fee of $29 or are included with a full subscription which you can try for free, here. You can read about what is free and what isn’t, here.

You can develop a testing and upload strategy along with finding instructions for how to upload here and here.

23andMe

Today, 23andMe is best known for health, having recovered after having had their wings clipped a few years back by the FDA. They were the first to offer Health results, leveraging the genealogy marketspace to attract testers, but have recently been eclipsed by both Family Tree DNA with their high end full Exome Tovana test and MyHeritage with their Health upgrade which provides more information than 23andMe along with free genetic counseling if appropriate. Both the Family Tree DNA and MyHeritage tests are medically supervised, so can deliver more results.

23andMe has never fully embraced genetic genealogy by adding the ability to upload and compare trees. In 2019, they introduced a beta function to attempt to create a genetic tree on your behalf based on how your matches match you and each other.

2019 23andMe.png

These trees aren’t accurate today, nor are they deep, but they are a beginning – especially considering that they are not based on existing trees. You can read more here.

The best 23andMe feature for genealogy, as far as I’m concerned, is their ethnicity along with the fact that they actually provide testers with the locations of their ethnicity segments which can help testers immensely, especially with minority ancestry matching. You can read about how to do this for yourself, here.

23andMe generally does not allow uploads, probably because they need people to test on their custom-designed medical chip. Very rarely, once that I know of in 2018, they do allow uploads – but in the past, uploaders do not receive all of the genealogy features and benefits of testing.

You can however, download your DNA file from 23andMe and upload elsewhere, with instructions here.

Ancestry

Ancestry is widely known for their ethnicity ads which are extremely effective in recruiting new testers. That’s the great news. The results are frustrating to seasoned genealogists who get to deal with the fallout of confused people trying to figure out why their results don’t match their expectations and family stories. That’s the not-so-great news.

However, with more than 15 million testers, many of whom DO have genealogy trees, a serious genealogist can’t *NOT* test at Ancestry. Testers do need to be aware that not all features are available to DNA testers who don’t also subscribe to Ancestry’s genealogy subscriptions. For example, you can’t see your matches’ trees beyond a 5 generation preview without a subscription. You can read more about what you do and don’t receive, here.

Ancestry is the only one of the major companies that doesn’t provide a chromosome browser, despite pleas for years to do so, but they do provide ThruLines that show you other testers who match your DNA and show a common ancestor with you in their trees.

2019 Ancestry.png

ThruLines will also link partial trees – showing you ancestral descendants from the perspective of the ancestor in question, shown above. You can read about ThruLines, here.

Of course, without a chromosome browser, this match is only as good as the associated trees, and there is no way to prove the genealogical connection. It’s possible to all be wrong together, or to be related to some people through a completely different ancestor. Third party tools like Genetic Affairs and cluster technology help resolve these types of issues. You can read more, here.

You can’t upload DNA files from other testing companies to Ancestry, probably due to their custom medical chip. You can download your file from Ancestry and upload to other locations, with instructions here.

Selling Customers’ DNA

Neither Family Tree DNA, MyHeritage nor Gedmatch sell, lease or otherwise share their customers’ DNA, and all three state (minimally) they will not in the future without prior authorization.

All companies utilize their customers’ DNA internally to enhance and improve their products. That’s perfectly normal.

Both Ancestry and 23andMe sell consumers DNA to both known and unknown partners if customers opt-in to additional research. That’s the purpose of all those questions.

If you do agree or opt-in, and for those who tested prior to when the opt-in began, consumers don’t know who their DNA has been sold to, where it is or for what purposes it’s being utilized. Although anonymized (pseudonymized) before sale, autosomal results can easily be identified to the originating tester (if someone were inclined to do so) as demonstrated by adoptees identifying parents and law enforcement identifying both long deceased remains and criminal perpetrators of violent crimes. You can read more about re-identification here, although keep in mind that the re-identification frequency (%) would be much higher now than it was in 2018.

People are widely split on this issue. Whatever you decide, to opt-in or not, just be sure to do your homework first.

Always read the terms and conditions fully and carefully of anything having to do with genetics.

Genealogy

The bottom line to genetic genealogy is the genealogy aspect. Genealogists want to confirm ancestors and discover more about those ancestors. Some information can only be discovered via DNA testing today, distant Native heritage, for example, breaking through brick walls.

This technology, as it has advanced and more people have tested, has been a godsend for genealogists. The same techniques have allowed other people to locate unknown parents, grandparents and close relatives.

Adoptees

Not only are genealogists identifying people long in the past that are their ancestors, but adoptees and those seeking unknown parents are making discoveries much closer to home. MyHeritage has twice provided thousands of free DNA tests via their DNAQuest program to adoptees seeking their biological family with some amazing results.

The difference between genealogy, which looks back in time several generations, and parent or grand-parent searches is that unknown-parent searches use matches to come forward in time to identify parents, not backwards in time to identify distant ancestors in common.

Adoptee matching is about identifying descendants in common. According to Erlich et al in an October 2018 paper, here, about 60% of people with European ancestry could be identified. With the database growth since that time, that percentage has risen, I’m sure.

You can read more about the adoption search technique and how it is used, here.

Adoptee searches have spawned their own subculture of sorts, with researchers and search angels that specialize in making these connections. Do be aware that while many reunions are joyful, not all discoveries are positively received and the revelations can be traumatic for all parties involved.

There’s ying and yang involved, of course, and the exact same techniques used for identifying biological parents are also used to identify cold-case deceased victims of crime as well as violent criminals, meaning rapists and murderers.

Crimes Solved

The use of genetic genealogy and adoptee search techniques for identifying skeletal remains of crime victims, as well as identifying criminals in order that they can be arrested and removed from the population has resulted in a huge chasm and division in the genetic genealogy community.

These same issues have become popular topics in the press, often authored by people who have no experience in this field, don’t understand how these techniques are applied or function and/or are more interested in a sensational story than in the truth. The word click-bait springs to mind although certainly doesn’t apply equally to all.

Some testers are adamantly pro-usage of their DNA in order to identify victims and apprehend violent criminals. Other testers, not so much and some, on the other end of the spectrum are vehemently opposed. This is a highly personal topic with extremely strong emotions on both sides.

The first such case was the Golden State Killer, which has been followed in the past 18 months or so by another 100+ solved cases.

Regardless of whether or not people want their own DNA to be utilized to identify these criminals and victims, providing closure for families, I suspect the one thing we can all agree on is that we are grateful that these violent criminals no longer live among us and are no longer preying on innocent victims.

I wrote about the Golden State Killer, here, as well as other articles here, here, here and here.

In the genealogy community, various vendors have adopted quite different strategies relating to these kinds of searches, as follows:

  • Ancestry, 23andMe and MyHeritage – have committed to fight all access attempts by law enforcement, including court ordered subpoenas.
  • MyHeritage, Family Tree DNA and GedMatch allow uploads, so forensic kits, meaning kits from deceased remains or rape kits could be uploaded to search for matches, the same as any other kit. Law Enforcement uploads violate the MyHeritage terms of service. Both Family Tree DNA and GEDmatch have special law enforcement procedures in place. All three companies have measures in place to attempt to detect unauthorized forensic uploads.
  • Family Tree DNA has provided a specific Law Enforcement protocol and guidelines for forensic uploads, here. All EU customers were opted out earlier in 2019, but all new or existing non-EU customers need to opt out if they do not want their DNA results available for matching to law enforcement kits.
  • GEDmatch was recently sold to Verogen, a DNA forensics company, with information, here. Currently GEDMatch customers are opted-out of matching for law enforcement kits, but can opt-in. Verogen, upon purchase of GEDmatch, required all users to read the terms and conditions and either accept the terms or delete their kits. Users can also delete their kits or turn off/on law enforcement matching at any time.

New Concerns

Concerns in late 2019 have focused on the potential misuse of genetic matching to potentially target subsets of individuals by despotic regimes such as has been done by China to the Uighurs.

You can read about potential risks here, here and here, along with a recent DoD memo here.

Some issues spelled out in the papers can be resolved by vendors agreeing to cryptographically sign their files when customers download. Of course, this would require that everyone, meaning all vendors, play nice in the sandbox. So far, that hasn’t happened although I would expect that the vendors accepting uploads would welcome cryptographic signatures. That pretty much leaves Ancestry and 23andMe. I hope they will step up to the plate for the good of the industry as a whole.

Relative to the concerns voiced in the papers and by the DoD, I do not wish to understate any risks. There ARE certainly risks of family members being identified via DNA testing, which is, after all, the initial purpose even though the current (and future) uses were not foreseen initially.

In most cases, the cow has already left that barn. Even if someone new chooses not to test, the critical threshold is now past to prevent identification of individuals, at least within the US and/or European diaspora communities.

I do have concerns:

  • Websites where the owners are not known in the genealogical community could be collecting uploads for clandestine purposes. “Free” sites are extremely attractive to novices who tend to forget that if you’re not paying for the product, you ARE the product. Please be very cognizant and leery. Actually, just say no unless you’re positive.
  • Fearmongering and click-bait articles in general will prevent and are already causing knee-jerk reactions, causing potential testers to reject DNA testing outright, without doing any research or reading terms and conditions.
  • That Ancestry and 23andMe, the two major vendors who don’t accept uploads will refuse to add crypto-signatures to protect their customers who download files.

Every person needs to carefully make their own decisions about DNA testing and participating in sharing through third party sites.

Health

Not surprisingly, the DNA testing market space has cooled a bit this past year. This slowdown is likely due to a number of factors such as negative press and the fact that perhaps the genealogical market is becoming somewhat saturated. Although, I suspect that when vendors announce major new tools, their DNA kit sales spike accordingly.

Look at it this way, do you know any serious genealogists who haven’t DNA tested? Most are in all of the major databases, meaning Ancestry, 23andMe, FamilyTreeDNA, MyHeritage and GedMatch.

All of the testing companies mentioned above (except GEDmatch who is not a testing company) now have a Health offering, designed to offer existing and new customers additional value for their DNA testing dollar.

23andMe separated their genealogy and health offering years ago. Ancestry and MyHeritage now offer a Health upgrade. For existing customers, FamilyTreeDNA offers the Cadillac of health tests through Tovana.

I would guess it goes without saying here that if you really don’t want to know about potential health issues, don’t purchase these tests. The flip side is, of course, that most of the time, a genetic predisposition is nothing more and not a death sentence.

From my own perspective, I found the health tests to be informative, actionable and in some cases, they have been lifesaving for friends.

Whoever knew genealogy might save your life.

Innovative Third-Party Tools

Tools, and fads, come and go.

In the genetic genealogy space, over the years, tools have burst on the scene to disappear a few months later. However, the last few years have been won by third party tools developed by well-known and respected community members who have created tools to assist other genealogists.

As we close this decade, these are my picks of the tools that I use almost daily, have proven to be the most useful genealogically and that I feel I just “couldn’t live without.”

And yes, before you ask, some of these have a bit of a learning curve, but if you are serious about genealogy, these are all well worthwhile:

  • GedMatch – offers a wife variety of tools including triangulation, half versus fully identical segments and the ability to see who your matches also match. One of the tools I utilize regularly is segment search to see who else matches me on a specific segment, attached to an ancestor I’m researching. GedMatch, started by genealogists, has lasted more than a decade prior to the sale in December 2019.
  • Genetic Affairs – a barn-burning newcomer developed by Evert-Jan Blom in 2018 wins this years’ “Best” award from me. Genetic Affairs offers clustering, tree building between your matches even when YOU don’t have a tree. You can read more here.

2019 genetic affairs.png

Just today, Genetic Affairs released a new cluster interface with DNAPainter, example shown above.

  • DNAPainter – THE chromosome painter created by Jonny Perl just gets better and better, having added pedigree tree construction this year and other abilities. I wrote a composite instructional article, here.
  • DNAGedcom.com and Genetic.Families, affiliated with DNAAdoption.org – Rob Warthen in collaboration with others provides tools like clustering combined with triangulation. My favorite feature is the gathering of all direct ancestors of my matches’ trees at the various vendors where I’ve DNA tested which allows me to search for common surnames and locations, providing invaluable hints not otherwise available.

Promising Newcomer

  • MitoYDNA – a non-profit newcomer by folks affiliated with DNAAdoption and DNAGedcom is designed to replace YSearch and MitoSearch, both felled by the GDPR ax in 2018. This website allows people to upload their Y and mitochondrial DNA results and compare the values to each other, not just for matching, which you can do at Family Tree DNA, but also to see the values that do and don’t match and how they differ. I’ll be taking MitoYDNA for a test drive after the first of the year and will share the results with you.

The Future

What does the future hold? I almost hesitate to guess.

  • Artificial Intelligence Pedigree Chart – I think that in the not-too-distant future we’ll see the ability to provide testers with a “one and done” pedigree chart. In other words, you will test and receive at least some portion of your genealogy all tidily presented, red ribbon untied and scroll rolled out in front of you like you’re the guest on one of those genealogy TV shows.

Except it’s not a show and is a result of DNA testing, segment triangulation, trees and other tools which narrow your ancestors to only a few select possibilities.

Notice I said, “the ability to.” Just because we have the ability doesn’t mean a vendor will implement this functionality. In fact, just think about the massive businesses built upon the fact that we, as genealogists, have to SEARCH incessantly for these elusive answers. Would it be in the best interest of these companies to just GIVE you those answers when you test?

If not, then these types of answers will rest with third parties. However, there’s a hitch. Vendors generally don’t welcome third parties offering advanced tools and therefore block those tools, even though they are being used BY the customer or with their explicit authorization to massage their own data.

On the other hand, as a genealogist, I would welcome this feature with open arms – because as far as I’m concerned, the identification of that ancestor is just the first step. I get to know them by fleshing out their bones by utilizing those research records.

In fact, I’m willing to pony up to the table and I promise, oh-so-faithfully, to maintain my subscription lifelong if one of those vendors will just test me. Please, please, oh pretty-please put me to the test!

I guess you know what my New Year’s Wish is for this and upcoming years now too😊

What About You?

What do you think the high points of 2019 have been?

How about the decade?

What do you think the future holds?

Do you care to make any predictions?

Are you planning to focus on any particular goal or genealogy problem in 2020?

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Disclosure

I receive a small contribution when you click on some of the links to vendors in my articles. This does NOT increase the price you pay but helps me to keep the lights on and this informational blog free for everyone. Please click on the links in the articles or to the vendors below if you are purchasing products or DNA testing.

Thank you so much.

DNA Purchases and Free Transfers

Genealogy Products and Services

Genealogy Research

Fun DNA Stuff

  • Celebrate DNA – customized DNA themed t-shirts, bags and other items

Big Y News and Stats + Sale

I must admit – this past January when FamilyTreeDNA announced the Big Y-700, an upgrade from the Big Y-500 product, I was skeptical. I wondered how much benefit testers would really see – but I was game to purchase a couple upgrades – and I did. Then, when the results came back, I purchased more!

I’m very pleased to announce that I’m no longer skeptical. I’m a believer.

The Big Y-700 has produced amazing results – and now FamilyTreeDNA has decoupled the price of the BAM file in addition to announcing substantial sale prices for their Thanksgiving Sale.

I’m going to discuss sale pricing for products other than the Big Y in a separate article because I’d like to focus on the progress that has been made on the phylogenetic tree (and in my own family history) as a result of the Big Y-700 this year.

Big Y Pricing Structure Change

FamilyTreeDNA recently anounced some product structure changes.

The Big Y-700 price has been permanently dropped by $100 by decoupling the BAM file download from the price of the test itself. This accomplishes multiple things:

  • The majority of testers don’t want or need the BAM file, so the price of the test has been dropped by $100 permanently in order to be able to price the Big Y-700 more attractively to encourage more testers. That’s good for all of us!!!
  • For people who ordered the Big Y-700 since November 1, 2019 (when the sale prices began) who do want the BAM file, they can purchase the BAM file separately through the “Add Ons and Upgrades” page, via the “Upgrades” tab for $100 after their test results are returned. There will also be a link on the Big Y-700 results page. The total net price for those testers is exactly the same, but it represents a $100 permanent price drop for everyone else.
  • This BAM file decoupling reduces the initial cost of the Big Y-700 test itself, and everyone still has the option of purchasing the BAM file later, which will make the Big Y-700 test more affordable. Additionally, it allows the tester who wants the BAM file to divide the purchase into two pieces, which will help as well.
  • The current sale price for the Big Y-700 for the tester who has taken NO PREVIOUS Y DNA testing is now just $399, formerly $649. That’s an amazing price drop, about 40%, in the 9 months since the Big Y-700 was introduced!
  • Upgrade pricing is available too, further down in this article.
  • If you order an upgrade from any earlier Big Y to the Big Y-700, you receive an upgraded BAM file because you already paid for the BAM file when you ordered your initial Big Y test.
  • The VCF file is still available for download at no additional cost with any Big Y test.
  • There is no change in the BAM file availability for current customers. Everyone who ordered before November 1, 2019 will be able to download their BAM file as always.

The above changes are permanent, except for the sale price.

2019 has been a Banner Year

I know how successful the Big Y-700 has been for kits and projects that I manage, but how successful has it been overall, in a scientific sense?

I asked FamilyTreeDNA for some stats about the number of SNPs discovered and the number of branches added to the Y phylotree.

Drum roll please…

Branches Added This Year Total Tree Branches Variants Added to Tree This Year Total Variants Added to Tree
2018 6,259 17,958 60,468 132.634
2019 4,394 22.352 32,193 164,827

The tests completed in 2019 are only representative for 10 months, through October, and not the entire year.

Haplotree Branches

Not every SNP discovered results in a new branch being added to the haplotree, but many do. This chart shows the number of actual branches added in 2018 and 2019 to date.

Big Y 700 haplotree branches.png

These stats, provided by FamilyTreeDNA, show the totals in the bottom row, which is a cumulative branch number total, not a monthly total. At the end of October 2019, the total number of individual branches were 22,352.

Big Y 700 haplotree branches small.png

This chart, above, shows some of the smaller haplogroups.

Big Y 700 haplotree branches large.png

This chart shows the larger haplogroups, including massive haplogroup R.

Haplotree Variants

The number of variants listed below is the number of SNPs that have been discovered, named and placed on the tree. You’ll notice that these numbers are a lot larger than the number of branches, above. That’s because roughly 168,000 of these are equivalent SNPs, meaning they don’t further branch the tree – at least not yet. These 168K variants are the candidates to be new branches as more people test and the tree can be further split.

Big Y 700 variants.png

These numbers also don’t include Private Variants, meaning SNPs that have not yet been named.

If you see Private Variants listed in your Big Y results, when enough people have tested positive for the same variant, and it makes sense, the variants will be given a SNP name and placed on the tree.

Big Y 700 variants small.png

The smaller haplogroups variants again, above, followed by the larger, below.

Big Y 700 variants large.png

Upgrades from the Big Y, or Big Y-500 to Big Y-700

Based on what I see in projects, roughly one third of the Big Y and Big Y-500 tests have upgraded to the Big Y-700.

For my Estes line, I wondered how much value the Big Y-700 upgrade would convey, if any, but I’m extremely glad I upgraded several kits. As a result of the Big Y-700, we’ve further divided the sons of Abraham, born in 1747. This granularity wasn’t accomplished by STR testing and wasn’t accomplished by the Big Y or Big Y-500 testing alone – although all of these together are building blocks. I’m ECSTATIC since it’s my own ancestral line that has the new lineage defining SNP.

Big Y 700 Estes.png

Every Estes man descended from Robert born in 1555 has R-BY482.

The sons of the immigrant, Abraham, through his father, Silvester, all have BY490, but the descendants of Silvester’s brother, Robert, do not.

Moses, son of Abraham has ZS3700, but the rest of Abraham’s sons don’t.

Then, someplace in the line of kit 831469, between Moses born in 1711 and the present-day tester, we find a new SNP, BY154784.

Big Y 700 Estes block tree.png

Looking at the block tree, we see the various SNPs that are entirely Estes, except for one gentleman who does not carry the Estes surname. I wrote about the Block Tree, here.

Without Big Y testing, none of these SNPs would have been found, meaning we could never have split these lines genealogically.

Every kit I’ve reviewed carries SNPs that the Big Y-700 has been able to discern that weren’t discovered previously.

Every. Single. One.

Now, even someone who hasn’t tested Y DNA before can get the whole enchilada – meaning 700+ STRs, testing for all previously discovered SNPs, and new branch defining SNPs, like my Estes men – for $399.

If a new Estes tester takes this test, without knowing anything about his genealogy, I can tell him a great deal about where to look for his lineage in the Estes tree.

Reduced Prices

FamilyTreeDNA has made purchasing the Big Y-700 outright, or upgrading, EXTREMELY attractive.

Test Price
Big Y-700 purchase with no previous Y DNA test

 

$399
Y-12 upgrade to Big Y-700 $359
Y-25 upgrade to Big Y-700 $349
Y-37 upgrade to Big Y-700 $319
Y-67 upgrade to Big Y-700 $259
Y-111 upgrade to Big Y-700 $229
Big Y or Big Y-500 upgrade to Big Y-700 $189

Note that the upgrades include all of the STR markers as yet untested. For example, the 12-marker to Big Y-700 includes all of the STRs between 25 and 111, in addition to the Big Y-700 itself. The Big Y-700 includes:

  • All of the already discovered SNPs, called Named Variants, extending your haplogroup all the way to the leaf at the end of your branch
  • Personal and previously undiscovered SNPs called Private Variants
  • All of the untested STR markers inclusive through 111 markers
  • A minimum of a total of 700 STR markers, including markers above 111 that are only available through Big Y-700 testing

With the refinements in the Big Y test over the past few years, and months, the Big Y is increasingly important to genealogy – equally or more so than traditional STR testing. In part, because SNPs are not prone to back mutations, and are therefore more stable than STR markers. Taken together, STRs and SNPs are extremely informative, helping to break down ancestral brick walls for people whose genealogy may not reach far back in time – and even those who do.

If you are a male and have not Y DNA tested, there’s never been a better opportunity. If you are a female, find a male on a brick wall line and sponsor a scholarship.

Click here to order or upgrade!

______________________________________________________________

Disclosure

I receive a small contribution when you click on some of the links to vendors in my articles. This does NOT increase the price you pay but helps me to keep the lights on and this informational blog free for everyone. Please click on the links in the articles or to the vendors below if you are purchasing products or DNA testing.

Thank you so much.

DNA Purchases and Free Transfers

Genealogy Services

Genealogy Research

Duplicate Copies of Parental Chromosomes – Uniparental Disomy

Recently, three articles were been published that discuss a phenomenon where unsuspecting individuals have two copies one parent’s chromosome, and no copy of the other parent’s chromosome. This is called Uniparental Disomy.

Since then, online I’ve seen this phenomenon being offered as a reason for all kinds of things – which just isn’t the case.

I’m sure in part it’s because people either haven’t actually read the articles, or they don’t understand what’s being said.

I’m going to explain this briefly and then tell you how you can find out if this situation actually DOES apply to you.

Uniparental Disomy in Brief

Here are a few summary bullet points about uniparental disomy:

  • Uniparental disomy is found on ONLY ONE CHROMOSOME in roughly 1 in 2000 people in the reference samples utilized at 23andMe.
  • This is not a new discovery, per se. It was known and previously believed to occur in 1 of 3,500 births, but that frequency has been updated to 1 in 2,000 in the paper.
  • Uniparental disomy was found in 1 of 50,000 people on TWO CHROMOSOMES.
  • This is NOT the reason you have more maternal or paternal matches, in general. Legitimate reasons for more matches on one parent’s line include the fact that one family or another historically has more or fewer descendants, more or fewer dead ends, recent immigrants, ancestors from regions where DNA testing is not popular and/or endogamous populations.
  • The people included in the research were trios where the tester and their parents have all 3 tested.
  • Many/most people with uniparental disomy have no known health issues.
  • The testers have in some cases been associated with some conditions, as described in the paper and supplemental information.
  • Of the people who carry this condition, more people carry a double maternal chromosome than a double paternal chromosome.
  • Uniparental disomy occurs more on chromosome 16 than any other chromosome, twice as often as the second highest, chromosome 7, with 40 and 20 occurrences each, respectively. Chromosome 18 had none. No, no one knows why.
  • It’s not necessary for the entire chromosome to be duplicated. In some cases, only part of the chromosome is improperly combined.

Articles

This Atlantic article provides an overview:

This academic paper in Cell is referenced in The Atlantic article and is where the meat of the information is found. Be sure to look at the supplemental files too.

Much of the data for the article was from 23andMe who discussed this study in their blog here.

What About You?

Do you have a chromosome that has experienced uniparental disomy? Probably not, but there’s a very easy way for you to find out.

If you have a duplicate chromosome, or portion of a chromosome from one parent, the genetic genealogy “indicator” that you’ll see is called ROH, or Run of Homozygosity. This condition occurs in situations where you have a duplicate chromosome, or where your parents are related to each other

  1. The first question to ask yourself is whether or not your parents are related to each other. If so, you will have some ROH segments.
  2. The second question is whether you have an entire duplicated chromosome when your parents aren’t related.

In order to answer both questions, we use the tool at GedMatch called “Are your parents related?”

Are Your Parents Related to Each Other?

You’ll need to establish an account at GedMatch and upload your DNA results from one of the testing vendors.

Here are instructions for how to download from the various vendors:

Using the “Are your parents related” Tool

To use this tool at GedMatch, after your uploaded kit is finished processing, click on “Are your parents related?” and enter the kit number of the person you want to evaluate. I’m assuming for this discussion that person is you.

Parents related.png

Normally, we use this tool to determine if someone’s parents are related to each other. We find this occurring in endogamous populations or where cousins married in the past few generations, as happened rather routinely in history.

In those situations, across all of a person’s chromosomes (not just one), we find relatively small segments of common DNA inherited by the person on both their maternal and paternal copies of each chromosome.

Parents are related.png

These matching areas are called ROH or “runs of homozygosity” meaning that the DNA is identical on both chromosomes for short segments, as shown above in the regions where the top bars are solid green and the bottom bar is solid blue.

The legend for reading the graphic is shown below.

Parents related legend.png

The chromosomes of a person whose parents are not related is shown below. Notice that there are no significant green bars on top, and no blue bars on the bottom.

Parents not related.png

Simple chance alone is responsible for tiny segments that are identical, like those tiny green slivers, but not larger segments over 7cM as shown in the first example and marked by blue on the bottom.

For someone that has a fully duplicated chromosome, meaning uniparental disomy, we see something different.

A Duplicate Chromosome

For someone that has a duplicate parental chromosome, all of their chromosomes look normal except that one entire chromosome, or a very large segment, is entirely identical.

Below is an example of a person whose chromosome 7 is duplicated. The rest of this person’s chromosomes looked like the image above with only tiny green slivers.

Parents uniparental disomy.png

If you have a duplicate chromosome, you’re rare, one in every 2,000 people in the populations studied.

If you have two identical chromosomes, you’re hen’s teeth rare – 1 in 50,000.

If you have uniparental disomy, you probably have no idea. You can also experience uniparental disomy when most of, but not all of a single chromosome is duplicated.

If you have duplicate parental chromosomes, you’ll match people on both sides of your family normally on all of your OTHER non-duplicate chromosomes. On your duplicate chromosome, you’ll only match people from the parent whose chromosome is duplicated.

In other words, this is NOT why you seem to be missing matches from one side of your family generally. You’ll need to look at other reasons to explain that.

If you have a duplicate chromosome, or large segment of a duplicate chromosome, leave a comment.

______________________________________________________________

Disclosure

I receive a small contribution when you click on some of the links to vendors in my articles. This does NOT increase the price you pay but helps me to keep the lights on and this informational blog free for everyone. Please click on the links in the articles or to the vendors below if you are purchasing products or DNA testing.

Thank you so much.

DNA Purchases and Free Transfers

Genealogy Services

Genealogy Research

 

 

Hit a Genetic Genealogy Home Run Using Your Double-Sided Two-Faced Chromosomes While Avoiding Imposters

Do you want to hit a home run with your DNA test, but find yourself a mite bewildered?

Yep, those matches can be somewhat confusing – especially if you don’t understand what’s going on. Do you have a nagging feeling that you might be missing something?

I’m going to explain chromosome matching, and its big sister, triangulation, step by step to remove any confusion, to help you sort through your matches and avoid imposters.

This article is one of the most challenging I’ve ever written – in part because it’s a concept that I’m so familiar with but can be, and is, misinterpreted so easily. I see mistakes and confusion daily, which means that resulting conclusions stand a good chance of being wrong.

I’ve tried to simplify these concepts by giving you easy-to-use memory tools.

There are three key phrases to remember, as memory-joggers when you work through your matches using a chromosome browser: double-sided, two faces and imposter. While these are “cute,” they are also quite useful.

When you’re having a confusing moment, think back to these memory-jogging key words and walk yourself through your matches using these steps.

These three concepts are the foundation of understanding your matches, accurately, as they pertain to your genealogy. Please feel free to share, link or forward this article to your friends and especially your family members (including distant cousins) who work with genetic genealogy. 

Now, it’s time to enjoy your double-sided, two-faced chromosomes and avoid those imposters:)

Are you ready? Grab a nice cup of coffee or tea and learn how to hit home runs!

Double-Sided – Yes, Really

Your chromosomes really are double sided, and two-faced too – and that’s a good thing!

However, it’s initially confusing because when we view our matches in a chromosome browser, it looks like we only have one “bar” or chromosome and our matches from both our maternal and paternal sides are both shown on our one single bar.

How can this be? We all have two copies of chromosome 1, one from each parent.

Chromosome 1 match.png

This is my chromosome 1, with my match showing in blue when compared to my chromosome, in gray, as the background.

However, I don’t know if this blue person matches me on my mother’s or father’s chromosome 1, both of which I inherited. It could be either. Or neither – meaning the dreaded imposter – especially that small blue piece at left.

What you’re seeing above is in essence both “sides” of my chromosome number 1, blended together, in one bar. That’s what I mean by double-sided.

There’s no way to tell which side or match is maternal and which is paternal without additional information – and misunderstanding leads to misinterpreting results.

Let’s straighten this out and talk about what matches do and don’t mean – and why they can be perplexing. Oh, and how to discover those imposters!

Your Three Matches

Let’s say you have three matches.

At Family Tree DNA, the example chromosome browser I’m using, or at any vendor with a chromosome browser, you select your matches which are viewed against your chromosomes. Your chromosomes are always the background, meaning in this case, the grey background.

Chromosome 1-4.png

  • This is NOT three copies each of your chromosomes 1, 2, 3 and 4.
  • This is NOT displaying your maternal and paternal copies of each chromosome pictured.
  • We CANNOT tell anything from this image alone relative to maternal and paternal side matches.
  • This IS showing three individual people matching you on your chromosome 1 and the same three people matching you in the same order on every chromosome in the picture.

Let’s look at what this means and why we want to utilize a chromosome browser.

I selected three matches that I know are not all related through the same parent so I can demonstrate how confusing matches can be sorted out. Throughout this article, I’ve tried to explain each concept in at least two ways.

Please note that I’m using only chromsomes 1-4 as examples, not because they are any more, or less, important than the other chromosomes, but because showing all 22 would not add any benefit to the discussion. The X chromosome has a separate inheritance path and I wrote about that here.

Let’s start with a basic question.

Why Would I Want to Use a Chromosome Browser?

Genealogists view matches on chromosome browsers because:

  • We want to see where our matches match us on our chromosomes
  • We’d like to identify our common ancestor with our match
  • We want to assign a matching segment to a specific ancestor or ancestral line, which confirmed those ancestors as ours
  • When multiple people match us on the same location on the chromosome browser, that’s a hint telling us that we need to scrutinize those matches more closely to determine if those people match us on our maternal or paternal side which is the first step in assigning that segment to an ancestor

Once we accurately assign a segment to an ancestor, when anyone else matches us (and those other people) on that same segment, we know which ancestral line they match through – which is a great head start in terms of identifying our common ancestor with our new match.

That’s a genetic genealogy home run!

Home Runs 

There are four bases in a genetic genealogy home run.

  1. Determine whether you actually match someone on the same segment
  2. Which is the first step in determining that you match a group of people on the same segment
  3. And that you descend from a common ancestor
  4. The fourth step, or the home run, is to determine which ancestor you have in common, assigning that segment to that ancestor

If you can’t see segment information, you can’t use a chromosome browser and you can’t confirm the match on that segment, nor can you assign that segment to a particular ancestor, or ancestral couple.

The entire purpose of genealogy is to identify and confirm ancestors. Genetic genealogy confirms the paper trail and breaks down even more brick walls.

But before you can do that, you have to understand what matches mean and how to use them.

The first step is to understand that our chromosomes are double-sided and you can’ t see both of your chromosomes at once!

Double Sided – You Can’t See Both of Your Chromosomes at Once

The confusing part of the chromosome browser is that it can only “see” your two chromosomes blended as one. They are both there, but you just can’t see them separately.

Here’s the important concept:

You have 2 copies of chromosomes 1 through 22 – one copy that you received from your mother and one from your father, but you can’t “see” them separately.

When your DNA is sequenced, your DNA from your parents’ chromosomes emerges as if it has been through a blender. Your mother’s chromosome 1 and your father’s chromosome 1 are blended together. That means that without additional information, the vendor can’t tell which matches are from your father’s side and which are from your mother’s side – and neither can you.

All the vendor can tell is that someone matches you on the blended version of your parents. This isn’t a negative reflection on the vendors, it’s just how the science works.

Chromosome 1.png

Applying this to chromosome 1, above, means that each segment from each person, the blue person, the red person and the teal person might match you on either one of your chromosomes – the paternal chromosome or the maternal chromosome – but because the DNA of your mother and father are blended – there’s no way without additional information to sort your chromosome 1 into a maternal and paternal “side.”

Hence, you’re viewing “one” copy of your combined chromosomes above, but it’s actually “two-sided” with both maternal and paternal matches displayed in the chromosome browser.

Parent-Child Matches

Let’s explain this another way.

Chromosome parent.png

The example above shows one of my parents matching me. Don’t be deceived by the color blue which is selected randomly. It could be either parent. We don’t know.

You can see that I match my parent on the entire length of chromosome 1, but there is no way for me to tell if I’m looking at my mother’s match or my father’s match, because both of my parents (and my children) will match me on exactly the same locations (all of them) on my chromosome 1.

Chromosome parent child.png

In fact, here is a combination of my children and my parents matching me on my chromosome 1.

To sort out who is matching on paternal and maternal chromosomes, or the double sides, I need more information. Let’s look at how inheritance works.

Stay with me!

Inheritance Example

Let’s take a look at how inheritance works visually, using an example segment on chromosome 1.

Chromosome inheritance.png

In the example above:

  • The first column shows addresses 1-10 on chromosome 1. In this illustration, we are only looking at positions, chromosome locations or addresses 1-10, but real chromosomes have tens of thousands of addresses. Think of your chromosome as a street with the same house numbers on both sides. One side is Mom’s and one side is Dad’s, but you can’t tell which is which by looking at the house numbers because the house numbers are identical on both sides of the street.
  • The DNA pieces, or nucleotides (T, A, C or G,) that you received from your Mom are shown in the column labeled Mom #1, meaning we’re looking at your mother’s pink chromosome #1 at addresses 1-10. In our example she has all As that live on her side of the street at addresses 1-10.
  • The DNA pieces that you received from your Dad are shown in the blue column and are all Cs living on his side of the street in locations 1-10.

In other words, the values that live in the Mom and Dad locations on your chromosome streets are different. Two different faces.

However, all that the laboratory equipment can see is that there are two values at address 1, A and C, in no particular order. The lab can’t tell which nucleotide came from which parent or which side of the street they live on.

The DNA sequencer knows that it found two values at each address, meaning that there are two DNA strands, but the output is jumbled, as shown in the First and Second read columns. The machine knows that you have an A and C at the first address, and a C and A at the second address, but it can’t put the sequence of all As together and the sequence of all Cs together. What the sequencer sees is entirely unordered.

This happens because your maternal and paternal DNA is mixed together during the extraction process.

Chromosome actual

Click to enlarge image.

Looking at the portion of chromosome 1 where the blue and teal people both match you – your actual blended values are shown overlayed on that segment, above. We don’t know why the blue and the teal people are matching you. They could be matching because they have all As (maternal), all Cs (paternal) or some combination of As and Cs (a false positive match that is identical by chance.)

There are only two ways to reassemble your nucleotides (T, A, C, and G) in order and then to identify the sides as maternal and paternal – phasing and matching.

As you read this next section, it does NOT mean that you must have a parent for a chromosome browser to be useful – but it does mean you need to understand these concepts.

There are two types of phasing.

Parental Phasing

  • Parental Phasing is when your DNA is compared against that of one or both parents and sorted based on that comparison.

Chromosome inheritance actual.png

Parental phasing requires that at least one parent’s DNA is available, has been sequenced and is available for matching.

In our example, Dad’s first 10 locations (that you inherited) on chromosome 1 are shown, at left, with your two values shown as the first and second reads. One of your read values came from your father and the other one came from your mother. In this case, the Cs came from your father. (I’m using A and C as examples, but the values could just as easily be T or G or any combination.)

When parental phasing occurs, the DNA of one of your parents is compared to yours. In this case, your Dad gave you a C in locations 1-10.

Now, the vendor can look at your DNA and assign your DNA to one parent or the other. There can be some complicating factors, like if both your parents have the same nucleotides, but let’s keep our example simple.

In our example above, you can see that I’ve colored portions of the first and second strands blue to represent that the C value at that address can be assigned through parental phasing to your father.

Conversely, because your mother’s DNA is NOT available in our example, we can’t compare your DNA to hers, but all is not lost. Because we know which nucleotides came from your father, the remaining nucleotides had to come from your mother. Hence, the As remain after the Cs are assigned to your father and belong to your mother. These remaining nucleotides can logically be recombined into your mother’s DNA – because we’ve subtracted Dad’s DNA.

I’ve reassembled Mom, in pink, at right.

Statistical/Academic Phasing

  • A second type of phasing uses something referred to as statistical or academic phasing.

Statistical phasing is less successful because it uses statistical calculations based on reference populations. In other words, it uses a “most likely” scenario.

By studying reference populations, we know scientifically that, generally, for our example addresses 1-10, we either see all As or all Cs grouped together.

Based on this knowledge, the Cs can then logically be grouped together on one “side” and As grouped together on the other “side,” but we still have no way to know which side is maternal or paternal for you. We only know that normally, in a specific population, we see all As or all Cs. After assigning strings or groups of nucleotides together, the algorithm then attempts to see which groups are found together, thereby assigning genetic “sides.” Assigning the wrong groups to the wrong side sometimes happens using statistical phasing and is called strand swap.

Once the DNA is assigned to physical “sides” without a parent or matching, we still can’t identify which side is paternal and which is maternal for you.

Statistical or academic phasing isn’t always accurate, in part because of the differences found in various reference populations and resulting admixture. Sometimes segments don’t match well with any population. As more people test and more reference populations become available, statistical/academic phasing improves. 23andMe uses academic phasing for ethnicity, resulting in a strand swap error for me. Ancestry uses academic phasing before matching.

By comparison to statistical or academic phasing, parental phasing with either or both parents is highly accurate which is why we test our parents and grandparents whenever possible. Even if the vendor doesn’t use our parents’ results, we certainly can!

If someone matches you and your parent too, you know that match is from that parent’s side of your tree.

Matching

The second methodology to sort your DNA into maternal and paternal sides is matching, either with or without your parents.

Matching to multiple known relatives on specific segments assigns those segments of your DNA to the common ancestor of those individuals.

In other words, when I match my first cousin, and our genealogy indicates that we share grandparents – assuming we match on the appropriate amount of DNA for the expected relationship – that match goes a long way to confirming our common ancestor(s).

The closer the relationship, the more comfortable we can be with the confirmation. For example, if you match someone at a parental level, they must be either your biological mother, father or child.

While parent, sibling and close relationships are relatively obvious, more distant relationships are not and can occur though unknown or multiple ancestors. In those cases, we need multiple matches through different children of that ancestor to reasonably confirm ancestral descent.

Ok, but how do we do that? Let’s start with some basics that can be confusing.

What are we really seeing when we look at a chromosome browser?

The Grey/Opaque Background is Your Chromosome

It’s important to realize that you will see as many images of your chromosome(s) as people you have selected to match against.

This means that if you’ve selected 3 people to match against your chromosomes, then you’ll see three images of your chromosome 1, three images of your chromosome 2, three images of your chromosome 3, three images of your chromosome 4, and so forth.

Remember, chromosomes are double-sided, so you don’t know whether these are maternal or paternal matches (or imposters.)

In the illustration below, I’ve selected three people to match against my chromosomes in the chromosome browser. One person is shown as a blue match, one as a red match, and one as a teal match. Where these three people match me on each chromosome is shown by the colored segments on the three separate images.

Chromosome 1.png

My chromosome 1 is shown above. These images are simply three people matching to my chromosome 1, stacked on top of each other, like cordwood.

The first image is for the blue person. The second image is for the red person. The third image is for the teal person.

If I selected another person, they would be assigned a different color (by the system) and a fourth stacked image would occur.

These stacked images of your chromosomes are NOT inherently maternal or paternal.

In other words, the blue person could match me maternally and the red person paternally, or any combination of maternal and paternal. Colors are not relevant – in other words colors are system assigned randomly.

Notice that portions of the blue and teal matches overlap at some of the same locations/addresses, which is immediately visible when using a chromosome browser. These areas of common matching are of particular interest.

Let’s look closer at how chromosome browser matching works.

What about those colorful bars?

Chromosome Browser Matching

When you look at your chromosome browser matches, you may see colored bars on several chromosomes. In the display for each chromosome, the same color will always be shown in the same order. Most people, unless very close relatives, won’t match you on every chromosome.

Below, we’re looking at three individuals matching on my chromosomes 1, 2, 3 and 4.

Chromosome browser.png

The blue person will be shown in location A on every chromosome at the top. You can see that the blue person does not match me on chromosome 2 but does match me on chromosomes 1, 3 and 4.

The red person will always be shown in the second position, B, on each chromosome. The red person does not match me on chromosomes 2 or 4.

The aqua person will always be shown in position C on each chromosome. The aqua person matches me on at least a small segment of chromosomes 1-4.

When you close the browser and select different people to match, the colors will change and the stacking order perhaps, but each person selected will always be consistently displayed in the same position on all of your chromosomes each time you view.

The Same Address – Stacked Matches

In the example above, we can see that several locations show stacked segments in the same location on the browser.

Chromosome browser locations.png

This means that on chromosome 1, the blue and green person both match me on at least part of the same addresses – the areas that overlap fully. Remember, we don’t know if that means the maternal side or the paternal side of the street. Each match could match on the same or different sides.

Said another way, blue could be maternal and teal could be paternal (or vice versa,) or both could be maternal or paternal. One or the other or both could be imposters, although with large segments that’s very unlikely.

On chromosome 4, blue and teal both match me on two common locations, but the teal person extends beyond the length of the matching blue segments.

Chromosome 3 is different because all three people match me at the same address. Even though the red and teal matching segments are longer, the shared portion of the segment between all three people, the length of the blue segment, is significant.

The fact that the stacked matches are in the same places on the chromosomes, directly above/below each other, DOES NOT mean the matches also match each other.

The only way to know whether these matches are both on one side of my tree is whether or not they match each other. Do they look the same or different? One face or two? We can’t tell from this view alone.

We need to evaluate!

Two Faces – Matching Can be Deceptive!

What do these matches mean? Let’s ask and answer a few questions.

  • Does a stacked match mean that one of these people match on my mother’s side and one on my father’s side?

They might, but stacked matches don’t MEAN that.

If one match is maternal, and one is paternal, they still appear at the same location on your chromosome browser because Mom and Dad each have a side of the street, meaning a chromosome that you inherited.

Remember in our example that even though they have the same street address, Dad has blue Cs and Mom has pink As living at that location. In other words, their faces look different. So unless Mom and Dad have the same DNA on that entire segment of addresses, 1-10, Mom and Dad won’t match each other.

Therefore, my maternal and paternal matches won’t match each other either on that segment either, unless:

  1. They are related to me through both of my parents and on that specific location.
  2. My mother and father are related to each other and their DNA is the same on that segment.
  3. There is significant endogamy that causes my parents to share DNA segments from their more distant ancestors, even though they are not related in the past few generations.
  4. The segments are small (segments less than 7cM are false matches roughly 50% of the time) and therefore the match is simply identical by chance. I wrote about that here. The chart showing valid cM match percentages is shown here, but to summarize, 7-8 cMs are valid roughly 46% of the time, 8-9 cM roughly 66%, 9-10 cM roughly 91%, 10-11 cM roughly 95, but 100 is not reached until about 20 cM and I have seen a few exceptions above that, especially when imputation is involved.

Chromosome inheritance match.png

In this inheritance example, we see that pink Match #1 is from Mom’s side and matches the DNA I inherited from pink Mom. Blue Match #2 is from Dad’s side and matches the DNA I inherited from blue Dad. But as you can see, Match #1 and Match #2 do not match each other.

Therefore, the address is only half the story (double-sided.)

What lives at the address is the other half. Mom and Dad have two separate faces!

Chromosome actual overlay

Click to enlarge image

Looking at our example of what our DNA in parental order really looks like on chromosome 1, we see that the blue person actually matches on my maternal side with all As, and the teal person on the paternal side with all Cs.

  • Does a stacked match on the chromosome browser mean that two people match each other?

Sometimes it happens, but not necessarily, as shown in our example above. The blue and teal person would not match each other. Remember, addresses (the street is double-sided) but the nucleotides that live at that address tell the real story. Think two different looking faces, Mom’s and Dad’s, peering out those windows.

If stacked matches match each other too – then they match me on the same parental side. If they don’t match each other, don’t be deceived just because they live at the same address. Remember – Mom’s and Dad’s two faces look different.

For example, if both the blue and teal person match me maternally, with all As, they would also match each other. The addresses match and the values that live at the address match too. They look exactly the same – so they both match me on either my maternal or paternal side – but it’s up to me to figure out which is which using genealogy.

Chromosome actual maternal.png

Click to enlarge image

When my matches do match each other on this segment, plus match me of course, it’s called triangulation.

Triangulation – Think of 3

If my two matches match each other on this segment, in addition to me, it’s called triangulation which is genealogically significant, assuming:

  1. That the triangulated people are not closely related. Triangulation with two siblings, for example, isn’t terribly significant because the common ancestor is only their parents. Same situation with a child and a parent.
  2. The triangulated segments are not small. Triangulation, like matching, on small segments can happen by chance.
  3. Enough people triangulate on the same segment that descends from a common ancestor to confirm the validity of the common ancestor’s identity, also confirming that the match is identical by descent, not identical by chance.

Chromosome inheritance triangulation.png

The key to determining whether my two matches both match me on my maternal side (above) or paternal side is whether they also match each other.

If so, assuming all three of the conditions above are true, we triangulate.

Next, let’s look at a three-person match on the same segment and how to determine if they triangulate.

Three Way Matching and Identifying Imposters

Chromosome 3 in our example is slightly different, because all three people match me on at least a portion of that segment, meaning at the same address. The red and teal segments line up directly under the blue segment – so the portion that I can potentially match identically to all 3 people is the length of the blue segment. It’s easy to get excited, but don’t get excited quite yet.

Chromosome 3 way match.png

Given that three people match me on the same street address/location, one of the following three situations must be true:

  • Situation 1- All three people match each other in addition to me, on that same segment, which means that all three of them match me on either the maternal or paternal side. This confirms that we are related on the same side, but not how or which side.

Chromosome paternal.png

In order to determine which side, maternal or paternal, I need to look at their and my genealogy. The blue arrows in these examples mean that I’ve determined these matches to all be on my father’s side utilizing a combination of genealogy plus DNA matching. If your parent is alive, this part is easy. If not, you’ll need to utilize common matching and/or triangulation with known relatives.

  • Situation 2 – Of these three people, Cheryl, the blue bar on top, matches me but does not match the other two. Charlene and David, the red and teal, match each other, plus me, but not Cheryl.

Chromosome maternal paternal.png

This means that at least either my maternal or paternal side is represented, given that Charlene and David also match each other. Until I can look at the identity of who matches, or their genealogy, I can’t tell which person or people descend from which side.

In this case, I’ve determined that Cheryl, my first cousin, with the pink arrow matches me on Mom’s side and Charlene and David, with the blue arrows, match me on Dad’s side. So both my maternal and paternal sides are represented – my maternal side with the pink arrow as well as my father’s side with the blue arrows.

If Cheryl was a more distant match, I would need additional triangulated matches to family members to confirm her match as legitimate and not a false positive or identical by chance.

  • Situation 3 – Of the three people, all three match me at the same addresses, but none of the three people match each other. How is this even possible?

Chromosome identical by chance.png

This situation seems very counter-intuitive since I have only 2 chromosomes, one from Mom and one from Dad – 2 sidesof the street. It is confusing until you realize that one match (Cheryl and me, pink arrow) would be maternal, one would be paternal (Charlene and me, blue arrow) and the third (David and me, red arrows) would have DNA that bounces back and forth between my maternal and paternal sides, meaning the match with David is identical by chance (IBC.)

This means the third person, David, would match me, but not the people that are actually maternal and paternal matches. Let’s take a look at how this works

Chromosome maternal paternal IBC.png

The addresses are the same, but the values that live at the addresses are not in this third scenario.

Maternal pink Match #1 is Cheryl, paternal blue Match #2 is Charlene.

In this example, Match #3, David, matches me because he has pink and blue at the same addresses that Mom and Dad have pink and blue, but he doesn’t have all pink (Mom) nor all blue (Dad), so he does NOT match either Cheryl or Charlene. This means that he is not a valid genealogical match – but is instead what is known as a false positive – identical by chance, not by descent. In essence, a wily genetic imposter waiting to fool unwary genealogists!

In his case, David is literally “two-faced” with parts of both values that live in the maternal house and the paternal house at those addresses. He is a “two-faced imposter” because he has elements of both but isn’t either maternal or paternal.

This is the perfect example of why matching and triangulating to known and confirmed family members is critical.

All three people, Cheryl, Charlene and David match me (double sided chromosomes), but none of them match each other (two legitimate faces – one from each parent’s side plus one imposter that doesn’t match either the legitimate maternal or paternal relatives on that segment.)

Remember Three Things

  1. Double-Sided – Mom and Dad both have the same addresses on both sides of each chromosome street.
  2. Two Legitimate Faces – The DNA values, nucleotides, will have a unique pattern for both your Mom and Dad (unless they are endogamous or related) and therefore, there are two legitimate matching patterns on each chromsome – one for Mom and one for Dad. Two legitimate and different faces peering out of the houses on Mom’s side and Dad’s side of the street.
  3. Two-Faced Imposters – those identical by chance matches which zig-zag back and forth between Mom and Dad’s DNA at any given address (segment), don’t match confirmed maternal and paternal relatives on the same segment, and are confusing imposters.

Are you ready to hit your home run?

What’s Next?

Now that we understand how matching and triangulation works and why, let’s put this to work at the vendors. Join me for my article in a few days, Triangulation in Action at Family Tree DNA, MyHeritage, 23andMe and GedMatch.

We will step through how triangulation works at each vendor. You’ll have matches at each vendor that you don’ t have elsewhere. If you haven’t transferred your DNA file yet, you still have time with the step by step instructions below:

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Disclosure

I receive a small contribution when you click on some of the links to vendors in my articles. This does NOT increase the price you pay but helps me to keep the lights on and this informational blog free for everyone. Please click on the links in the articles or to the vendors below if you are purchasing products or DNA testing.

Thank you so much.

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Genealogy Research

MyHeritage LIVE 2019 Day 2 and Party

Let’s start out with some trivia.

Did you know that the Hilton Amsterdam is the home of this famous photo?

MyHeritage Live Beatles

No, well me either. I’m glad someone told me on Sunday. Kind of explains the Beatles themed party Saturday evening.

MyHeritage Live Beatles suite

As for the Beatlemania party, I’ll save those photos for last😊

Please note that I’m still traveling and these photos are rather rough – so please keep that in mind.

MyHeritage LIVE Day 2

There was lots to see and do on Sunday – a DNA track, a genealogy track and also a hands-on lab series.

MyHeritage Live shoe

I floated between several sessions hoping to improve my search skills in the morning. It was difficult to choose, but fortunately, you don’t have to because they are all going to be available shortly at Legacy Tree Webinars.

MyHeritage Live Alon Carmel

I popped into The WorldWide DNA Web by Alon Carmel to learn a bit more about the upcoming ethnicity release.

I also attended Evaluating Your Smart Matches and Record Matches by James Tanner. My phone decided to misbehave and I don’t have any photos of this session. I had never heard James speak before and I encourage you to watch his session when the webinars become available.

I understand from others that his session in the afternoon, Developing Your Own Research Plan at MyHeritage, was excellent, especially for someone just starting out.

The session I found the most interesting from Day 2 of the #MyHeritageLIVE conference was the one dealing with the MyHeritage health test.

MyHeritage Live Yaniv Erlich

First, I found the scientific aspect fascinating as presented by Dr. Yaniv Erlich (PhD, not MD).

MyHeritage Live Gilad audience

Gilad Japhet, MyHeritage CEO, joined us in the audience.

MyHeritage Live vantage

As you probably know, MyHeritage added the Health test earlier this year. I ordered mine and have been waiting to finish writing the article until after this conference.

MyHeritage Live health summary 3

MyHeritage reports on 27 conditions, including 14 diseases and 13 carrier reports.

I feel it’s particularly important that in the US, the test is physician ordered. This means that when you order the test, you answer a few questions that are automatically submitted to PWNHealth where they are reviewed by a physician to determine if a genetic health test is appropriate for you.

The test is then run in a CLIA certified lab – meaning the test is a medical grade test.

Then, the results are reviewed by a physician. If your results are in the high risk range, a second test is performed using a different type of technology to verify the results before they are returned to you – at no charge to you.

If the results are in the high risk range and would be concerning, you are provided with a genetic counseling session – also at no charge.

I feel this is particularly important.

Yaniv provided additional detail which I will include in my upcoming article.

Yaniv said something that I think is particularly relevant – seeing the results in black and white sometimes encourages people to make decisions and act in a different way than simply hearing your physician say to live a healthy lifestyle during your yearly physical.

My Own Experience

I had not told anyone at MyHeritage about my own experience with genetic health testing before the MyHeritage LIVE conference.

The day before the MyHeritage Health Panel discussion, I decided that I was going to tell my own story during the session if the opportunity arose and it was appropriate. I think it’s important, not just to me, but perhaps to you too.

MyHeritage Live health panel

The health panel included Geoff Rasmussen as moderator, at left, Diahan Southard, me and Yaniv Erlich, left to right.

I’m not intimidated by much, but talking about your own health publicly can be daunting. People are very sensitive and often embarrassed by health topics, especially ones like type two diabetes and weight because they are sometimes viewed as character defects, not health issues. In any case, I was a bit nervous.

However, I decided when I launched my blog 7 years ago that I was going to be transparent. I really think stories like mine can help others.

I have two points to make.

  1. Genetics isn’t destiny.

With very few exceptions, genetics isn’t destiny. You may have a genetic predisposition for a disease, but you may also be able to mitigate that disease with lifestyle and environmental changes. You may want to monitor that aspect of your health more closely. You have choices.

Forewarned is forearmed.

  1. Knowledge is power.

My sister had breast cancer and underwent a radical mastectomy in 1988.

Several years ago, I took a medical genetics health test.

We thought my sister was cancer free and had dodged that bullet. She and her husband were traveling when I received a phone call from my brother-in-law that my sister had experienced a heart attack. She died the next day.

Some years ago, I took a direct-to-consumer medical test focused on health results to see if I too carried a predisposition for breast cancer. I was relieved to discover that I do not, BUT – I discovered something I didn’t expect. I carried an elevated risk for heart disease.

Not in the red (danger) range, but knowing that my sister died of a heart attack in addition to this elevated risk was enough to get my attention in a way that nothing else ever had before.

I knew I had to do something.

I was heavy.

So was my sister.

I was not able to lose weight and keep it off.

Neither was my sister.

I knew I had to do something about this, and I decided after much deliberation to have bariatric surgery to facilitate weight loss. If you’re thinking for one minute that I took the “easy way out,” you’re sorely mistaken. Regardless of the methodology, I was and remain successful and that’s all that matters.

Now, a decade later, I not only lost a significant amount of weight, I’ve kept it off. My BMI is normal, I’m not diabetic and I’m healthier and feel better than I did before the surgery.

My quality of life is greatly improved and the chances of me developing obesity-related diseased are greatly reduced – including heart disease and diabetes, although I don’t have an elevated genetic risk for that.

However, obesity itself is a risk factor for diabetes, without genetics. No risk factors also doesn’t mean you won’t get the disease. It only means there’s not a currently known genetic element.

Yaniv showed a chart that indicated that people at high risk of diabetes are more sensitive to high BMI. Furthermore, if you have high risk of either heart disease or diabetes, you need to and can minimize the risk of the other factor.

These predispositions are not a death sentence, BUT DOING NOTHING IS! Sooner than later.

I will be writing an article shorting detailing my results and including several slides from Yaniv’s session. I want to be sure I fully understand them before publication, so I’ll need to follow up with Yaniv before completing that article.

I know I had made the right decision for me, but seeing the actual data confirmed it.

Furthermore, it’s not just about me. I have a husband, two children and grandchildren and I want to spend as much quality time with them as possible in this lifetime.

There are two critical words there.

Quality and time.

I know that not everyone wants to know about their health predispositions. I understand and it’s a personal decision for everyone.

I hope you’ll consider health testing.

There are more perspectives than mine, and more topics were covered during the panel discussion – such as differing opinions as to whether children should be tested. I hope you’ll view the session when they become available through Legacy Tree Webinars. All panelists had important points worth considering and things I hadn’t thought about.

Party

Now for Beatlemania.

I’m actually not a big party person, but MyHeritage provided props for party-goers and everyone had fun. Some folks danced. Some hung out and others sat in the lobby chatting.

MyHeritage Live Jonny Perl and Evert-Jan Blom.png

Here are Jonny Perl (DNAPainter) and Evert-Jan Blom (Genetic Affairs) talking.

MyHeritage Live Jonny and EJ

And later at the party in their Beatlemania garb.

MyHeritage Live Geoff Rasmussen and Daniel Horowitz.png

Geoff Rasmussen of Legacy Tree Webinars and Daniel Horowitz of MyHeritage.

MyHeritage Live Marianne Melcherts

Marianne Melcherts of MyHeritage (who you can find in the MyHeritage Facebook Users’ Group) and me. Yes, we’re both Dutch or have Dutch heritage.

MyHeritage Live Marianne dutch field.png

Here – this is better!

MyHeritage Live Ran Snir

Cheese and tulips. Ran Snir of MyHeritage (right) and someone whose name escapes me at the moment. (Sorry.)

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Everyone was having so much fun! These lovely folks came from Texas.

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The folk dancers were amazing. Look at that lace cap.

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Even the dancers had fun.

What’s Next?

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Aaron Godfrey provided the closing session.

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This event was an amazing success. I can’t wait to see how many people tuned in by livestream.

MyHeritage Live Germany.png

Aaron had one more story for us.

MyHeritage Live Germany father.png

A 99 year old lady DNA tested to find her biological father and found a close match. There was a family rumor…

The family wanted to meet her.

MyHeritage Live reunion

On her birthday.

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At a surprise party!

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I swear, MyHeritage needs to start including boxes of tissues in the goody bags! Don’t wait to DNA test. You never know who’s waiting for you!

I hope you’ve enjoyed coming along with me to #MyHeritageLIVE 2019 in Amsterdam.

But wait – there’s one more announcement!

MyHeritage Live 2020.png

Yes, there is going to be a MyHeritage LIVE 2020.

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The plan is for Israel, although a date won’t be announced until a venue can be finalized.

Lots of conference attendees were very excited and already making plans to attend.

In closing, I hope you’ll do the following:

Start making at least tentative plans for Israel!

Have fun and enjoy your genealogy. More and more records are becoming available every single day and may hold gems for you.

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Disclosure

I receive a small contribution when you click on some of the links to vendors in my articles. This does NOT increase the price you pay but helps me to keep the lights on and this informational blog free for everyone. Please click on the links in the articles or to the vendors below if you are purchasing products or DNA testing.

Thank you so much.

DNA Purchases and Free Transfers

Genealogy Services

Genealogy Research

Mitochondrial DNA: Part 1 – Overview

This is Part 1 of a series about mitochondrial DNA, abbreviated as mtDNA, and how to use it successfully for genealogy.

What is Mitochondrial DNA and Why Do I Care?

Mitochondrial DNA.jpg

Mitochondrial DNA is different from nuclear, or autosomal, DNA. Nuclear DNA resides within the nucleus of a cell, while mitochondrial DNA resides outside the nucleus.

Mitochondrial DNA nucleus.png

Every cell has thousands of mitochondria while it only has one nucleus.

Mitochondrial DNA is a circular ring with 16,569 base pair locations. The biological purpose of mitochondria is to power the organism, converting chemical energy into a form that the cells can utilize.

Mitochondrial DNA is also different from autosomal DNA in how it is passed to offspring.

Inheritance Path

Mitochondrial DNA is unique because all people, males and females, inherit their mitochondrial DNA from their mothers, but only females pass it on to their children.

Y and mtDNA inheritance

The chart above illustrates which individuals in your tree inherit their mitochondrial DNA from whom.

Mitochondrial DNA inheritance.png

The daughter and son both inherit their mitochondrial DNA from their mother, who inherits hers from her mother, and so forth – on up the direct matrilineal line. You can read about the difference between matrilineal and maternal lines, here. In essence, maternal can be referring to anyone on your mother’s side of your tree, while matrilineal is your mother’s mother’s mother’s line ad infinitum.

However, every person in this tree carries mitochondrial DNA of specific ancestors.

Mitochondrial DNA inheritance 2.png

The red arrows show the inheritance path of mitochondrial DNA for individuals whose contributors are also in the tree.

The father of the children inherited his mitochondrial DNA from his magenta mother’s matrilineal line.

His father inherited his mitochondrial DNA from his lavender mother’s line.

The maternal grandfather in dark blue inherited his mitochondrial DNA from his red mother’s line.

Mitochondrial DNA inheritance 3.png

The gold arrows show that the contributors of these individuals are not shown on this tree, but they all inherited their mitochondrial DNA from their matrilineal lines as well.

When discussing mitochondrial DNA, we generally think in terms of ourselves, but the application of mitochondrial DNA to genealogy is as far reaching as all of our ancestors.

Each line has its own unique story for us to harvest – assuming we can find an appropriate candidate for testing or find someone who has already tested.

Why Mitochondrial DNA Works

Mitochondrial DNA is inherited from our matrilineal line directly, with no genetic contribution from any males. This inheritance path allows us to use mitochondrial DNA for matching to others reaching back generations as well as providing a way to view beyond the line-in-the-sand of surnames.

In other words, because mitochondrial DNA is not mixed with DNA from the fathers, it’s very nearly identical to our matrilineal ancestors’ mitochondrial DNA many generations ago.

In fact, by tracing a series of mutations, we can track our ancestor over time from mitochondrial Eve, born in Africa tens of thousands of years ago to where we are today.

Mutations Happen

If mutations never occurred, the mitochondrial DNA of all people would be identical and therefore not useful for us to use for genealogy or to peer back in time beyond the advent of surnames.

Mutations do occur, just not on any schedule. This means that it’s difficult to predict how long ago we shared a common ancestor with someone else based solely on mitochondrial DNA mutations.

There might be a mutation between us and our mother, or there might be no mutations for hundreds or even, potentially, thousands of years.

Part of the success of matching genealogically with mitochondrial DNA testing has to do with the regions tested.

Testing fewer locations results in matches that are much less relevant.

The Regions

Mitochondrial DNA is divided into 4 regions used for genealogy.

  • HVR1 – Hypervariable Region 1 – locations 16021-16569 (548 total locations)
  • HVR2 – Hypervariable Region 2 – locations 1-437 (437 locations)
  • HVR3 – Hypervariable Region 3 – locations 438-576 (138 locations)
  • Coding Region – the balance of the mitochondria (15,445 locations)

If you think of mitochondrial DNA as a clock face, the hypervariable regions span the time from approximately 11-1. The Coding Region is the balance.

Mitochondrial DNA loop.png

Family Tree DNA bundles the HVR3 region with the HVR2 region in their results. They test the entire D Loop, meaning a total of 1124 locations in their mtPlus product.

Matching at the HVR1 or HVR1 plus HVR2/3 levels alone can reach back thousands of years in time. I strongly encourage testers to test at the higher full sequence level with the mtFull product, allowing much more granular matching.

The HVR1, 2 and 3 regions are exactly as their name suggests – hypervariable – meaning that they mutate faster than the coding region.

The mtFull or full sequence test tests the entire mitochondria – all 16,569 locations.

Genealogists need a full sequence test in order to do two things:

  • Match with other testers reliably
  • Obtain a full haplogroup which acts as a periscope in time, allowing us to look much further back in time than autosomal and on one specific line. There’s no confusion as to which line the results came from with mitochondrial DNA.

If you’ve only taken the mtPlus test, don’t worry, you can sign on here and upgrade at any time to the mtFull.

Medical Information

The coding region carries most of the potentially medically relevant locations. Medical data is not provided in the results of the testing – only genealogically relevant information.

Family Tree DNA does provide for HVR1 and HVR2/3 results to be shown in projects that testers join, if testers so choose. Coding region results are never shared anyplace unless individual testers share them individually with each other.

I’m personally not concerned about this, but mitochondrial DNA testing has been occurring for 20+ years now and it was uncertain at that early date what medical information might be discovered in the coding region, so the decision to not share was made by Family Tree DNA at that time and remains in effect today.

Today, Family Tree DNA is the only vendor to test your full sequence mitochondrial DNA and provide matching. Therefore, all examples in this series utilize results and tools at Family Tree DNA.

So, what can people see of your actual results?

What Matches See

Mitochondrial DNA match view

You can click this image to enlarge.

People whom you match can see that you do match, but they can’t see any differences or mutations. They see the name you’ve entered, your earliest known ancestor and can send e-mail to you. Aside from that, they can’t see your results or mutations unless you’ve joined a project.

Within projects, participant names are never listed publicly. In other words, your matches can’t tell that it’s you unless they recognize your earliest known ancestor on the project list and you are the only person with that ancestor.

Don’t worry though, because only your HVR1 and HVR2 region results are listed in projects, as shown in the next section.

Benefits of Joining Projects

The great news is that even if you’ve just ordered your test and are waiting for results, you can research and join projects now.

Projects at Family Tree DNA provide testers with access to volunteer administrators to help as well as clustering users in projects that are meaningful to their research.

Mitochondrial DNA hap A project.png

The haplogroup A project is shown above with maternal earliest known ancestor (EKA) names as provided by testers.

Another important project feature is the project map function, allowing testers in a specific haplogroup to view the locations of the earliest known ancestors of other members of the same haplogroup – whether they match each other or not. Your ancestors traveled with theirs and descended from a common ancestor. Cool, huh!

Mitochondrial DNA hap A10 map.png

For example, here’s the haplogroup A10 cluster around Montreal. What’s the story associated with that distribution? Whatever it is, it’s probably important genealogically.

Mitochondrial DNA hap A5a1a1 map.png

Here’s haplogroup A5a1a1 in Japan.

Do you have clusters? You can see if you join relevant projects.

Another type of project to join is a geographical or interest group.

The Acadian AmerIndian Project welcomes descendants who have tested the Y, autosomal and/or mitochondrial DNA of the various Acadian families which includes French and English settlers along with First Nations indigenous ancestors.

Mitochondrial DNA Acadian Amerindian project.png

The map shows the distribution of the haplogroup A2f1a ancestors of various Acadian testers.

Mitochondrial DNA Acadian hap A2f1a map.png

Projects such as the Acadian AmerIndian Project facilitate genealogists discovering the haplogroup and information about their direct line ancestor without testing.

For example, if Anne Marie Rimbault, shown above, is my ancestor, by viewing and hopefully joining this project, I can harvest this information about my ancestor. I can’t personally test for her mitochondrial DNA myself, but thankfully, others who do descend matrilineally from Anne Marie have been generous enough to test and share.

Furthermore, I’ve contacted the tester through the project and gained a great cousin with LOTS of information.

Just think how useful mitochondrial DNA would be to genealogists if everyone tested!

Finding Projects to Join

I encourage all testers to join appropriate haplogroup projects. There may be more than one. For mitochondrial haplogroup J, there is only one project, but for those who carry haplogroup H, there is a haplogroup H project and many additional subgroup projects.

I also encourage you to browse the selections and join other interest projects. For example, there are projects such as Cumberland Gap which is regional, the American Indian project for people researching Native ancestry, in addition to your relevant haplogroup project(s).

When deciding which projects to join, don’t neglect your mitochondrial DNA. Your selection may be a huge benefit to someone else as well as to your own research.

How to Join Projects

Sign on to your personal page at Family Tree DNA and click on myProjects at the top, then on “Join A Project.”

mitochondrial dna project join.png

Next, you’ll see a list of projects in which your surname appears. These may or may not be relevant for you.

Mitochondrial project list

You can click to enlarge this image.

You can search by surname.

Mitochondrial project search.png

More importantly, you can browse in any number of sections.

Mitochondrial project browse.png

For mitochondrial DNA, I would suggest specifically mtDNA haplogroups, of course, along with mtDNA Geographical Projects, Dual Geographical Projects, and mtDNA lineage projects.

Surname projects are more challenging for mitochondrial DNA since the surname changes every generation.

When you find a project of interest, click to read the description written by the volunteer administrators to see if it’s a good fit for you, then click through to join.

Next Article in the Series

Of course, you’re probably wondering what all of those numbers in your results and shown in projects mean. The next article in about a week will address exactly that question.

Reference Articles

These articles may be of interest.

Mitochondrial DNA is often confused with X DNA, and they are not at all the same.

Mitochondrial DNA can quickly confirm or put to rest that Native American ancestor family story.

A great example of using mitochondrial DNA to break through a brick wall that would never have fallen otherwise!

If you haven’t yet tested, your can order your mtFull Sequence test today!

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Disclosure

I receive a small contribution when you click on some (but not all) of the links to vendors in my articles. This does NOT increase the price you pay but helps me to keep the lights on and this informational blog free for everyone. Please click on the links in the articles or to the vendors below if you are purchasing products or DNA testing.

Thank you so much.

DNA Purchases and Free Transfers

Genealogy Services

Genealogy Research