DNA: In Search of…Full and Half-Siblings

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

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

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

All Parties Need to Test

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

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

My first questions when someone comments in this vein are:

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

Sibling Scenarios

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

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

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

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

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

Full and Half-Siblings

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

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

Caution

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

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

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

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

On the other hand, it may.

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

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

Congratulations, You Have a Sibling!

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

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

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

Let’s start with DNAPainter.

DNAPainter

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

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

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

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

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

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

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

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

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

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

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

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

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

Relationship Probability Calculator

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

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

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

Vendors

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

Sibling Matches at Ancestry

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

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

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

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

Ancestry never stipulates full or half.

The following relationship is a half-sibling at Ancestry.

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

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

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

Sibling Matches at 23andMe

23andMe does identify full versus half-siblings.

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

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

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

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

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

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

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

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

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

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

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

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

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

Total Shared DNA Fully Identical DNA from Both Parents
Full Siblings ~50% ~25%
Half Siblings ~25% 0
  • Full siblings are expected to share about 50% of the same DNA. In other words, their DNA will match at that location. That’s all the green boxed locations, above.
  • Full siblings are expected to share about 25% of the same DNA from BOTH parents at the same location on BOTH copies of their chromosomes. These are fully identical regions and are boxed in purple, above.

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

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

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

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

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

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

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

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

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

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

GEDMatch shows both half and fully identical regions.

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

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

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

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

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

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

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

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

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

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

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

Sibling Matches at FamilyTreeDNA

FamilyTreeDNA does identify full siblings.

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

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

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

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

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

Sibling Matches at MyHeritage

MyHeritage indicates brother or sister for full siblings

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

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

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

View Close Known Relationships

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

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

Let’s start with the simplest situation first.

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

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

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

Here’s an example.

Close Relationships at FamilyTreeDNA

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

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

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

Now let’s make this a little more difficult.

No Parents, No Problem

Let’s say neither of your parents has tested.

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

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

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

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

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

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

Close Relationships at Ancestry

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

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

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

Close Relationships at MyHeritage

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

Now, THIS is interesting.

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

Close Relationships at 23andMe

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

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

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

More Tools Are Available

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

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

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

X Matching

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

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

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

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

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

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

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

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

Men pass no X chromosome to sons.

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

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

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

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

The full siblings, Melody, and Cinderella:

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Here’s a summary chart for sibling X matching.

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

Here’s the information presented in a different way.

DOES match X summary:

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

Does NOT match X summary:

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

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

X Matching at FamilyTreeDNA

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

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

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

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

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

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

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

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

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

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

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

Y DNA and Mitochondrial DNA

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

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

Y DNA

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

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

Y DNA at FamilyTreeDNA

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Y DNA at 23andMe

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

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

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

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

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

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

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

Mitochondrial DNA

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

Mitochondrial DNA at 23andMe

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

Mitochondrial DNA at FamilyTreeDNA

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

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

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

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

I wrote about heteroplasmies, here.

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

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

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

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

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

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

Sibling Summary and Checklist

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

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

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

Additional Resources

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

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

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

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

Strategy

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

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

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

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

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

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

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

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

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

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

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Top Ten RootsTech 2022 DNA Sessions + All DNA Session Links

The official dates of RootsTech 2022 were March 3-5, but the sessions and content in the vendor booths are still available. I’ve compiled a list of the sessions focused on DNA, with web links on the RootsTech YouTube channel

YouTube reports the number of views, so I was able to compile that information as of March 8, 2022.

I do want to explain a couple of things to add context to the numbers.

Most speakers recorded their sessions, but a few offered live sessions which were recorded, then posted later for participants to view. However, there have been glitches in that process. While the sessions were anticipated to be available an hour or so later, that didn’t quite happen, and a couple still aren’t posted. I’m sure the presenters are distressed by this, so be sure to watch those when they are up and running.

The Zoom rooms where participants gathered for the live sessions were restricted to 500 attendees. The YouTube number of views does not include the number of live viewers, so you’ll need to add an additional number, up to 500.

When you see a number before the session name, whether recorded or live, that means that the session is part of a series. RootsTech required speakers to divide longer sessions into a series of shorter sessions no longer than 15-20 minutes each. The goal was for viewers to be able to watch the sessions one after the other, as one class, or separately, and still make sense of the content. Let’s just say this was the most challenging thing I’ve ever done as a presenter.

For recorded series sessions, these are posted as 1, 2 and 3, as you can see below with Diahan Southard’s sessions. However, with my live session series, that didn’t happen. It looks like my sessions are a series, but when you watch them, parts 1, 2 and 3 are recorded and presented as one session. Personally, I’m fine with this, because I think the information makes a lot more sense this way. However, it makes comparisons difficult.

This was only the second year for RootsTech to be virtual and the conference is absolutely HUGE, so live and learn. Next year will be smoother and hopefully, at least partially in-person too.

When I “arrived” to present my live session, “Associating Autosomal DNA Segments With Ancestors,” my lovely moderator, Rhett, told me that they were going to livestream my session to the RootsTech page on Facebook as well because they realized that the 500 Zoom seat limit had been a problem the day before with some popular sessions. I have about 9000 views for that session and more than 7,400 of them are on the RootsTech Facebook page – and that was WITHOUT any advance notice or advertising. I know that the Zoom room was full in addition. I felt kind of strange about including my results in the top ten because I had that advantage, but I didn’t know quite how to otherwise count my session. As it turns out, all sessions with more than 1000 views made it into the top ten so mine would have been there one way or another. A big thank you to everyone who watched!

I hope that the RootsTech team notices that the most viewed session is the one that was NOT constrained by the 500-seat limited AND was live-streamed on Facebook. Seems like this might be a great way to increase session views for everyone next year. Hint, hint!!!

I also want to say a huge thank you to all of the presenters for producing outstanding content. The sessions were challenging to find, plus RootsTech is always hectic, even virtually. So, I know a LOT of people will want to view these informative sessions, now that you know where to look and have more time. Please remember to “like” the session on YouTube as a way of thanking your presenter.

With 140 DNA-focused sessions available, you can watch a new session, and put it to use, every other day for the next year! How fun is that! You can use this article as your own playlist.

Please feel free to share this article with your friends and genealogy groups so everyone can learn more about using DNA for genealogy.

Ok, let’s look at the top 10. Drum roll please…

Top 10 Most Viewed RootsTech Sessions

Session Title Presenter YouTube Link Views
1 1. Associating Autosomal DNA Segments With Ancestors Roberta Estes (live) https://www.youtube.com/watch?v=_IHSCkNnX48

 

~9000: 1019 + 500 live viewers + 7,400+ Facebook
2 1. What to Do with Your DNA Test Results in 2022 (part 1 of 3) Diahan Southard https://www.youtube.com/watch?v=FENAKAYLXX4 7428
3 Who Is FamilyTreeDNA? FamilyTreeDNA – Bennett Greenspan https://www.youtube.com/watch?v=MHFtwoatJ-A 2946
4 2. What to Do with Your DNA Test Results in 2022 (part 2 of 3) Diahan Southard https://www.youtube.com/watch?v=mIllhtONhlI 2448
5 Latest DNA Painter Releases DNAPainter Jonny Perl (live) https://www.youtube.com/watch?v=iLBThU8l33o 2230 + live viewers
6 DNA Painter Introduction DNAPainter – Jonny Perl https://www.youtube.com/watch?v=Rpe5LMPNmf0 1983
7 3. What to Do with Your DNA Test Results in 2022 (part 3 of 3) Diahan Southard https://www.youtube.com/watch?v=hemY5TuLmGI 1780
8 The Tree of Mankind Age Estimates Paul Maier https://www.youtube.com/watch?v=jjkL8PWAEwk 1638
9 A Sneak Peek at FamilyTreeDNA Coming Attractions FamilyTreeDNA (live) https://www.youtube.com/watch?v=K9sKqNScvnE 1270 + live viewers

 

10 Extending Time Horizons with DNA Rob Spencer (live) https://www.youtube.com/watch?v=wppXD1Zz2sQ 1037 + live viewers

 

All DNA-Focused Sessions

I know you’ll find LOTS of goodies here. Which ones are your favorites?

  Session Presenter YouTube Link Views
1 Estimating Relationships by Combining DNA from Multiple Siblings Amy Williams https://www.youtube.com/watch?v=xs1U0ohpKSA 201
2 Overview of HAPI-DNA.org Amy Williams https://www.youtube.com/watch?v=FjNiJgWaBeQ 126
3 How do AncestryDNA® Communities help tell your story? | Ancestry® Ancestry https://www.youtube.com/watch?v=EQNpUxonQO4 183

 

4 AncestryDNA® 201 Ancestry – Crista Cowan https://www.youtube.com/watch?v=lbqpnXloM5s

 

494
5 Genealogy in a Minute: Increase Discoveries by Attaching AncestryDNA® Results to Family Tree Ancestry – Crista Cowan https://www.youtube.com/watch?v=iAqwSCO8Pvw 369
6 AncestryDNA® 101: Beginner’s Guide to AncestryDNA® | Ancestry® Ancestry – Lisa Elzey https://www.youtube.com/watch?v=-N2usCR86sY 909
7 Hidden in Plain Sight: Free People of Color in Your Family Tree Cheri Daniels https://www.youtube.com/watch?v=FUOcdhO3uDM 179
8 Finding Relatives to Prevent Hereditary Cancer ConnectMyVariant – Dr. Brian Shirts https://www.youtube.com/watch?v=LpwLGgEp2IE 63
9 Piling on the chromosomes Debbie Kennett https://www.youtube.com/watch?v=e14lMsS3rcY 465
10 Linking Families With Rare Genetic Condition Using Genealogy Deborah Neklason https://www.youtube.com/watch?v=b94lUfeAw9k 43
11 1. What to Do with Your DNA Test Results in 2022 Diahan Southard https://www.youtube.com/watch?v=FENAKAYLXX4 7428
12 1. What to Do with Your DNA Test Results in 2022 Diahan Southard https://www.youtube.com/watch?v=hemY5TuLmGI 1780
13 2. What to Do with Your DNA Test Results in 2022 Diahan Southard https://www.youtube.com/watch?v=mIllhtONhlI 2448
14 DNA Testing For Family History Diahan Southard https://www.youtube.com/watch?v=kCLuOCC924s 84

 

15 Understanding Your DNA Ethnicity Estimate at 23andMe Diana Elder

 

https://www.youtube.com/watch?v=xT1OtyvbVHE 66
16 Understanding Your Ethnicity Estimate at FamilyTreeDNA Diana Elder https://www.youtube.com/watch?v=XosjViloVE0 73
17 DNA Monkey Wrenches DNA Monkey Wrenches https://www.youtube.com/watch?v=Thv79pmII5M 245
18 Advanced Features in your Ancestral Tree and Fan Chart DNAPainter – Jonny Perl https://www.youtube.com/watch?v=4u5Vf13ZoAc 425
19 DNA Painter Introduction DNAPainter – Jonny Perl https://www.youtube.com/watch?v=Rpe5LMPNmf0 1983
20 Getting Segment Data from 23andMe DNA Matches DNAPainter – Jonny Perl https://www.youtube.com/watch?v=8EBRI85P3KQ 134
21 Getting segment data from FamilyTreeDNA DNA matches DNAPainter – Jonny Perl https://www.youtube.com/watch?v=rWnxK86a12U 169
22 Getting segment data from Gedmatch DNA matches DNAPainter – Jonny Perl https://www.youtube.com/watch?v=WF11HEL8Apk 163
23 Getting segment data from Geneanet DNA Matches DNAPainter – Jonny Perl https://www.youtube.com/watch?v=eclj8Ap0uK4 38
24 Getting segment data from MyHeritage DNA matches DNAPainter – Jonny Perl https://www.youtube.com/watch?v=9rGwOtqbg5E 160
25 Inferred Chromosome Mapping: Maximize your DNA Matches DNAPainter – Jonny Perl https://www.youtube.com/watch?v=tzd5arHkv64 688
26 Keeping track of your genetic family tree in a fan chart DNAPainter – Jonny Perl https://www.youtube.com/watch?v=W3Hcno7en94 806

 

27 Mapping a DNA Match in a Chromosome Map DNAPainter – Jonny Perl https://www.youtube.com/watch?v=A61zQFBWaiY 423
28 Setting up an Ancestral Tree and Fan Chart and Exploring Tree Completeness DNAPainter – Jonny Perl https://www.youtube.com/watch?v=lkJp5Xk1thg 77
29 Using the Shared cM Project Tool to Evaluate DNA Matches DNAPainter – Jonny Perl https://www.youtube.com/watch?v=vxhn9l3Dxg4 763
30 Your First Chromosome Map: Using your DNA Matches to Link Segments to Ancestors DNAPainter – Jonny Perl https://www.youtube.com/watch?v=tzd5arHkv64 688
31 DNA Painter for absolute beginners DNAPainter (Jonny Perl) https://www.youtube.com/watch?v=JwUWW4WHwhk 1196
32 Latest DNA Painter Releases DNAPainter (live) https://www.youtube.com/watch?v=iLBThU8l33o 2230 + live viewers
33 Unraveling your genealogy with DNA segment networks using AutoSegment from Genetic Affairs Evert-Jan Blom https://www.youtube.com/watch?v=rVpsJSqOJZI

 

162
34 Unraveling your genealogy with genetic networks using AutoCluster Evert-Jan Blom https://www.youtube.com/watch?v=ZTKSz_X7_zs 201

 

 

35 Unraveling your genealogy with reconstructed trees using AutoTree & AutoKinship from Genetic Affairs Evert-Jan Blom https://www.youtube.com/watch?v=OmDQoAn9tVw 143
36 Research Like a Pro with DNA – A Genealogist’s Guide to Finding and Confirming Ancestors with DNA Family Locket Genealogists https://www.youtube.com/watch?v=NYpLscJJQyk 183
37 How to Interpret a DNA Network Graph Family Locket Genealogists – Diana Elder https://www.youtube.com/watch?v=i83WRl1uLWY 393
38 Find and Confirm Ancestors with DNA Evidence Family Locket Genealogists – Nicole Dyer https://www.youtube.com/watch?v=DGLpV3aNuZI 144
39 How To Make A DNA Network Graph Family Locket Genealogists – Nicole Dyer https://www.youtube.com/watch?v=MLm_dVK2kAA 201
40 Create A Family Tree With Your DNA Matches-Use Lucidchart To Create A Picture Worth A Thousand Words Family Locket Genealogists – Robin Wirthlin https://www.youtube.com/watch?v=RlRIzcW-JI4 270
41 Charting Companion 7 – DNA Edition Family Tree Maker https://www.youtube.com/watch?v=k2r9rkk22nU 316

 

42 Family Finder Chromosome Browser: How to Use FamilyTreeDNA https://www.youtube.com/watch?v=w0_tgopBn_o 750

 

 

43 FamilyTreeDNA: 22 Years of Breaking Down Brick Walls FamilyTreeDNA https://www.familysearch.org/rootstech/session/familytreedna-22-years-of-breaking-down-brick-walls Not available
44 Review of Autosomal DNA, Y-DNA, & mtDNA FamilyTreeDNA  – Janine Cloud https://www.youtube.com/watch?v=EJoQVKxgaVY 77
45 Who Is FamilyTreeDNA? FamilyTreeDNA – Bennett Greenspan https://www.youtube.com/watch?v=MHFtwoatJ-A 2946
46 Part 1: How to Interpret Y-DNA Results, A Walk Through the Big Y FamilyTreeDNA – Casimir Roman https://www.youtube.com/watch?v=ra1cjGgvhRw 684

 

47 Part 2: How to Interpret Y-DNA Results, A Walk Through the Big Y FamilyTreeDNA – Casimir Roman https://www.youtube.com/watch?v=CgqcjBD6N8Y

 

259
48 Big Y-700: A Brief Overview FamilyTreeDNA – Janine Cloud https://www.youtube.com/watch?v=IefUipZcLCQ 96
49 Mitochondrial DNA & The Million Mito Project FamilyTreeDNA – Janine Cloud https://www.youtube.com/watch?v=5Zppv2uAa6I 179
50 Mitochondrial DNA: What is a Heteroplasmy FamilyTreeDNA – Janine Cloud https://www.youtube.com/watch?v=ZeGTyUDKySk 57
51 Y-DNA Big Y: A Lifetime Analysis FamilyTreeDNA – Janine Cloud https://www.youtube.com/watch?v=E6NEU92rpiM 154
52 Y-DNA: How SNPs Are Added to the Y Haplotree FamilyTreeDNA – Janine Cloud https://www.youtube.com/watch?v=CGQaYcroRwY 220
53 Family Finder myOrigins: Beginner’s Guide FamilyTreeDNA – Katy Rowe https://www.youtube.com/watch?v=VrJNpSv8nlA 88
54 Mitochondrial DNA: Matches Map & Results for mtDNA FamilyTreeDNA – Katy Rowe https://www.youtube.com/watch?v=YtA1j01MOvs 190
55 Mitochondrial DNA: mtDNA Mutations Explained FamilyTreeDNA – Katy Rowe https://www.youtube.com/watch?v=awPs0cmZApE 340

 

56 Y-DNA: Haplotree and SNPs Page Overview FamilyTreeDNA – Katy Rowe https://www.youtube.com/watch?v=FOuVhoMD-hw 432
57 Y-DNA: Understanding the Y-STR Results Page FamilyTreeDNA – Katy Rowe https://www.youtube.com/watch?v=gCeZz1rQplI 148
58 Y-DNA: What Is Genetic Distance? FamilyTreeDNA – Katy Rowe https://www.youtube.com/watch?v=qJ6wY6ILhfg 149
59 DNA Tools: myOrigins 3.0 Explained, Part 1 FamilyTreeDNA – Paul Maier https://www.youtube.com/watch?v=ACgY3F4-w78 74

 

60 DNA Tools: myOrigins 3.0 Explained, Part 2 FamilyTreeDNA – Paul Maier https://www.youtube.com/watch?v=h7qU36bIFg0 50
61 DNA Tools: myOrigins 3.0 Explained, Part 3 FamilyTreeDNA – Paul Maier https://www.youtube.com/watch?v=SWlGPm8BGyU 36
62 African American Genealogy Research Tips FamilyTreeDNA – Sherman McRae https://www.youtube.com/watch?v=XdbkM58rXIQ 153

 

63 Connecting With My Ancestors Through Y-DNA FamilyTreeDNA – Sherman McRae https://www.youtube.com/watch?v=xbo1XnLkuQU 200
64 Join The Million Mito Project FamilyTreeDNA (Join link) https://www.familysearch.org/rootstech/session/join-the-million-mito-project link
65 View the World’s Largest mtDNA Haplotree FamilyTreeDNA (Link to mtDNA tree) https://www.familytreedna.com/public/mt-dna-haplotree/L n/a
66 View the World’s Largest Y Haplotree FamilyTreeDNA (Link to Y tree) https://www.familytreedna.com/public/y-dna-haplotree/A link
67 A Sneak Peek at FamilyTreeDNA Coming Attractions FamilyTreeDNA (live) https://www.youtube.com/watch?v=K9sKqNScvnE 1270 + live viewers

 

68 DNA Upload: How to Transfer Your Autosomal DNA Data FamilyTreeDNA -Katy Rowe https://www.youtube.com/watch?v=CS-rH_HrGlo 303
69 Family Finder myOrigins: How to Compare Origins With Your DNA Matches FamilyTreeDNA -Katy Rowe https://www.youtube.com/watch?v=7mBmWhM4j9Y 145
70 Join Group Projects at FamilyTreeDNA FamilyTreeDNA link to learning center article) https://www.familysearch.org/rootstech/session/join-group-projects-at-familytreedna link

 

71 Product Demo – Unraveling your genealogy with reconstructed trees using AutoKinship GEDmatch https://www.youtube.com/watch?v=R7_W0FM5U7c 803
72 Towards a Genetic Genealogy Driven Irish Reference Genome Gerard Corcoran https://www.youtube.com/watch?v=6Kx8qeNiVmo 155

 

73 Discovering Biological Origins in Chile With DNA: Simple Triangulation Gonzalo Alexis Luengo Orellana https://www.youtube.com/watch?v=WcVby54Uigc 40
74 Cousin Lynne: An Adoption Story International Association of Jewish Genealogical Societies https://www.youtube.com/watch?v=AptMcV4_B4o 111
75 Using DNA Testing to Uncover Native Ancestry Janine Cloud https://www.youtube.com/watch?v=edzebJXepMA 205
76 1. Forensic Genetic Genealogy Jarrett Ross https://www.youtube.com/watch?v=0euIDZTmx5g 58
77 Reunited and it Feels so Good Jennifer Mendelsohn https://www.youtube.com/watch?v=X-hxjm7grBE 57

 

78 Genealogical Research and DNA Testing: The Perfect Companions Kimberly Brown https://www.youtube.com/watch?v=X82jA3xUVXk 80
79 Finding a Jewish Sperm Donor Kitty Munson Cooper https://www.youtube.com/watch?v=iKRjFfNcpug 164
80 Using DNA in South African Genealogy Linda Farrell https://www.youtube.com/watch?v=HXkbBWmORM0 141
81 Using DNA Group Projects In Your Family History Research Mags Gaulden https://www.youtube.com/watch?v=0tX7QDib4Cw 165
82 2. The Expansion of Genealogy Into Forensics Marybeth Sciaretta https://www.youtube.com/watch?v=HcEO-rMe3Xo 35

 

83 DNA Interest Groups That Keep ’em Coming Back McKell Keeney (live) https://www.youtube.com/watch?v=HFwpmtA_QbE 180 plus live viewers
84 Searching for Close Relatives with Your DNA Results Mckell Keeney (live) https://www.familysearch.org/rootstech/session/searching-for-close-relatives-with-your-dna-results Not yet available
85 Top Ten Reasons To DNA Test For Family History Michelle Leonard https://www.youtube.com/watch?v=1B9hEeu_dic 181
86 Top Tips For Identifying DNA Matches Michelle Leonard https://www.youtube.com/watch?v=-3Oay_btNAI 306
87 Maximising Messages Michelle Patient https://www.youtube.com/watch?v=4TRmn0qzHik 442
88 How to Filter and Sort Your DNA Matches MyHeritage https://www.youtube.com/watch?v=fmIgamFDvc8 88
89 How to Get Started with Your DNA Matches MyHeritage https://www.youtube.com/watch?v=JPOzhTxhU0E 447

 

90 How to Track DNA Kits in MyHeritage` MyHeritage https://www.youtube.com/watch?v=2W0zBbkBJ5w 28

 

91 How to Upload Your DNA Data to MyHeritage MyHeritage https://www.youtube.com/watch?v=nJ4RoZOQafY 82
92 How to Use Genetic Groups MyHeritage https://www.youtube.com/watch?v=PtDAUHN-3-4 62
My Story: Hope MyHeritage https://www.youtube.com/watch?v=qjyggKZEXYA 133
93 MyHeritage Keynote, RootsTech 2022 MyHeritage https://www.familysearch.org/rootstech/session/myheritage-keynote-rootstech-2022 Not available
94 Using Labels to Name Your DNA Match List MyHeritage https://www.youtube.com/watch?v=enJjdw1xlsk 139

 

95 An Introduction to DNA on MyHeritage MyHeritage – Daniel Horowitz https://www.youtube.com/watch?v=1I6LHezMkgc 60
96 Using MyHeritage’s Advanced DNA Tools to Shed Light on Your DNA Matches MyHeritage – Daniel Horowitz https://www.youtube.com/watch?v=Pez46Xw20b4 110
97 You’ve Got DNA Matches! Now What? MyHeritage – Daniel Horowitz https://www.youtube.com/watch?v=gl3UVksA-2E 260
98 My Story: Lizzie and Ayla MyHeritage – Elizbeth Shaltz https://www.youtube.com/watch?v=NQv6C8G39Kw 147
99 My Story: Fernando and Iwen MyHeritage – Fernando Hermansson https://www.youtube.com/watch?v=98-AR0M7fFE 165

 

100 Using the Autocluster and the Chromosome Browser to Explore Your DNA Matches MyHeritage – Gal Zruhen https://www.youtube.com/watch?v=a7aQbfP7lWU 115

 

101 My Story : Kara Ashby Utah Wedding MyHeritage – Kara Ashby https://www.youtube.com/watch?v=Qbr_gg1sDRo 200
102 When Harry Met Dotty – using DNA to break down brick walls Nick David Barratt https://www.youtube.com/watch?v=8SdnLuwWpJs 679
103 How to Add a DNA Match to Airtable Nicole Dyer https://www.youtube.com/watch?v=oKxizWIOKC0 161
104 How to Download DNA Match Lists with DNAGedcom Client Nicole Dyer https://www.youtube.com/watch?v=t9zTWnwl98E 124
105 How to Know if a Matching DNA Segment is Maternal or Paternal Nicole Dyer https://www.youtube.com/watch?v=-zd5iat7pmg 161
106 DNA Basics Part I Centimorgans and Family Relationships Origins International, Inc. dba Origins Genealogy https://www.youtube.com/watch?v=SI1yUdnSpHA 372
107 DNA Basics Part II Clustering and Connecting Your DNA Matches Origins International, Inc. dba Origins Genealogy https://www.youtube.com/watch?v=ECs4a1hwGcs 333
108 DNA Basics Part III Charting Your DNA Matches to Get Answers Origins International, Inc. dba Origins Genealogy https://www.youtube.com/watch?v=qzybjN0JBGY 270
109 2. Using Cluster Auto Painter Patricia Coleman https://www.youtube.com/watch?v=-nfLixwxKN4 691
110 3. Using Online Irish Records Patricia Coleman https://www.youtube.com/watch?v=mZsB0l4z4os 802
111 Exploring Different Types of Clusters Patricia Coleman https://www.youtube.com/watch?v=eEZBFPC8aL4 972

 

112 The Million Mito Project: Growing the Family Tree of Womankind Paul Maier https://www.youtube.com/watch?v=cpctoeKb0Kw 541
113 The Tree of Mankind Age Estimates Paul Maier https://www.youtube.com/watch?v=jjkL8PWAEwk 1638
114 Y-DNA and Mitochondrial DNA Testing Plans Paul Woodbury https://www.youtube.com/watch?v=akymSm0QKaY 168
115 Finding Biological Family Price Genealogy https://www.youtube.com/watch?v=4xh-r3hZ6Hw 137
116 What Y-DNA Testing Can Do for You Richard Hill https://www.youtube.com/watch?v=a094YhIY4HU 191
117 Extending Time Horizons with DNA Rob Spencer (live) https://www.youtube.com/watch?v=wppXD1Zz2sQ 1037 + live viewers
118 DNA for Native American Ancestry by Roberta Estes Roberta Estes https://www.youtube.com/watch?v=EbNyXCFfp4M 212
119 1. Associating Autosomal DNA Segments With Ancestors Roberta Estes (live) https://www.youtube.com/watch?v=_IHSCkNnX48

 

~9000: 1019 + 500 live viewers + 7,400+ Facebook
120 1. What Can I Do With Ancestral DNA Segments? Roberta Estes (live) https://www.youtube.com/watch?v=Suv3l4iZYAQ 325 plus live viewers

 

121 Native American DNA – Ancient and Contemporary Maps Roberta Estes (live) https://www.youtube.com/watch?v=dFTl2vXUz_0 212 plus 483 live viewers

 

122 How Can DNA Enhance My Family History Research? Robin Wirthlin https://www.youtube.com/watch?v=f3KKW-U2P6w 102
123 How to Analyze a DNA Match Robin Wirthlin https://www.youtube.com/watch?v=LTL8NbpROwM 367
124 1. Jewish Ethnicity & DNA: History, Migration, Genetics Schelly Talalay Dardashti https://www.youtube.com/watch?v=AIJyphGEZTA 82

 

125 2. Jewish Ethnicity & DNA: History, Migration, Genetics Schelly Talalay Dardashti https://www.youtube.com/watch?v=VM3MCYM0hkI 72
126 Ask us about DNA Talking Family History (live) https://www.youtube.com/watch?v=kv_RfR6OPpU 96 plus live viewers
127 1. An Introduction to Visual Phasing Tanner Blair Tolman https://www.youtube.com/watch?v=WNhErW5UVKU

 

183
128 2. An Introduction to Visual Phasing Tanner Blair Tolman https://www.youtube.com/watch?v=CRpQ8EVOShI 110

 

129 Common Problems When Doing Visual Phasing Tanner Blair Tolman https://www.youtube.com/watch?v=hzFxtBS5a8Y 68
130 Cross Visual Phasing to Go Back Another Generation Tanner Blair Tolman https://www.youtube.com/watch?v=MrrMqhfiwbs 64
131 DNA Basics Tanner Blair Tolman https://www.youtube.com/watch?v=OCMUz-kXNZc 155
132 DNA Painter and Visual Phasing Tanner Blair Tolman https://www.youtube.com/watch?v=2-eh1L4wOmQ 155
133 DNA Painter Part 2: Chromosome Mapping Tanner Blair Tolman https://www.youtube.com/watch?v=zgOJDRG7hJc 172
134 DNA Painter Part 3: The Inferred Segment Generator Tanner Blair Tolman https://www.youtube.com/watch?v=96ai8nM4lzo

 

100
135 DNA Painter Part 4: The Distinct Segment Generator Tanner Blair Tolman https://www.youtube.com/watch?v=Pu-WIEQ_8vc 83
136 DNA Painter Part 5: Ancestral Trees Tanner Blair Tolman https://www.youtube.com/watch?v=dkYDeFLduKA 73
137 Understanding Your DNA Ethnicity Results Tanner Blair Tolman https://www.youtube.com/watch?v=4tAd8jK6Bgw 518
138 What’s New at GEDmatch Tim Janzen https://www.youtube.com/watch?v=AjA59BG_cF4

 

515
139 What Does it Mean to Have Neanderthal Ancestry? Ugo Perego https://www.youtube.com/watch?v=DshCKDW07so 190
140 Big Y-700 Your DNA Guide https://www.youtube.com/watch?v=rIFC69qswiA 143
141 Next Steps with Your DNA Your DNA Guide – Diahan Southard (live) https://www.familysearch.org/rootstech/session/next-steps-with-your-dna Not yet available

Additions:

142  Adventures of an Amateur Genetic Genealogist – Geoff Nelson https://www.familysearch.org/rootstech/session/adventures-of-an-amateur-genetic-genealogist     291 views

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What is a Heteroplasmy and Why Do I Care?

Most people have never heard of a heteroplasmy – but you might have one.

You Might Have a Heteroplasmy If…

…You have no exact matches at the full sequence mitochondrial DNA level.

A heteroplasmy is one of the first things I think of when someone tells me they have no exact full sequence matches but several that are a genetic distance of 1, meaning one mutation difference.

That phenomenon usually means the tester has a rare mutation that no one else has, at least no one who has tested their mitochondrial DNA (yet) – and that mutation just might be a heteroplasmy.

Heteroplasmies are generally (but not always) quite recent mutations. Actually, heteroplasmies are mutations caught in the act of mutating – kind of like an insect in genetic amber – frozen in time in your generation.

By Anders L. Damgaard – http://www.amber-inclusions.dk – Baltic-amber-beetle CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=16792582

Let’s say you might have a heteroplasmy. Or maybe you want to see if you do. Even if YOU don’t have a heteroplasmy, other people’s heteroplasmies can and will affect matching.

Here’s everything you ever wanted to know about heteroplasmies but didn’t know to ask😊

Heteroplasmies are Fascinating

A heteroplasmy is actually quite interesting because it’s a genetic mutation in progress.

This means you have two versions of a DNA sequence showing in your mitochondrial DNA at a specific location.

Said another way, at a specific genetic location, you show both of two separate nucleotides. Amounts detected of a second nucleotide greater than 20% are considered a heteroplasmy. Amounts below 20% are ignored. Generally, within a few generations, the mutation will resolve in one direction or the other – although some heteroplasmies persist for several generations and can sometimes define family branches.

If you’d like to read more about mitochondrial DNA, I wrote a series of step-by-step articles and combined them into one resource page, here.

Show Me!

You can easily check to see if you have a heteroplasmy by signing on to your FamilyTreeDNA account. Hopefully, you’ve taken the full sequence test.

Today, new testers, thankfully, can only purchase full sequence tests, so HVR1 results don’t present quite the same challenges when combined with heteroplasmies as they used to. We’ll talk about that in a minute.

If you have only taken the HVR1 or HVR1+HVR2 “Plus” test, as opposed to the Full Sequence, you can upgrade by signing on here and clicking on the “Full” button on the Maternal Ancestry section of your personal page.

These buttons will be pink if you’ve taken that test already, and grey if you need to upgrade. If you have an account at FamilyTreeDNA, you can add a mitochondrial DNA test to that same account by clicking on “Add Ons and Upgrades” at the top of your personal page. You can order a test if you’re a new customer, here.

How Do I Know if I Have a Heteroplasmy?

Your mitochondrial DNA has a total of 16,569 locations that you can think of as addresses. If your DNA at those locations is normal, meaning no mutations, they won’t be listed in your results.

Mutations are shown in your mitochondrial DNA results by a different letter at the end of the location.

For example, here are my mutations for my HVR1 region. Each of these locations in the HVR1 region has a mutation.

For locations that are shown in your results, meaning those where you have a mutation, you’ll see, in order:

  • A letter, either T, A, C or G
  • The location number
  • A different letter, typically another one of T, A, C or G, but sometimes a small d

For the first mutation, C16069T, the location address is 16069, the normal value is C, the mutation that occurred is T.

Heteroplasmies are shown in your mitochondrial DNA results by letters other than T, A, C, G or d at the end of the location.

I don’t have any heteroplasmies, so I’m switching to the results of a cousin who has a heteroplasmic mutation at location T16362Y to use as an example. The trailing Y means they have a heteroplasmy at location 16362.

But first, what do those letters mean?

The Letters

The letters stand for the nucleotide bases that comprise DNA, as follows:

  • T – Thymine
  • A – Adenine
  • C – Cytosine
  • G – Guanine
  • d – a deletion has occurred. There is no nucleotide at this location.

For location T16362Y, the first letter, T, is the “normal” value found at this location. If a mutation has occurred, the second letter is the mutated value. Normally, this is one of the other nucleotides, A, C or G.

Any other letter after the location has a specific meaning; in this case, Y means that both a C and a T were found, per the chart below.

Note – if you have a small letter t, a, c or g, it’s not a heteroplasmy, and I wrote about small letters and what they mean in the article, Mitochondrial DNA Part 2: What Do Those Numbers Mean?

Check Your Results

On your FamilyTreeDNA personal page in the mtDNA section, click on the Mutations tab.

If you’ve taken the full sequence test, you’ll see Extra Mutations. You’re looking for any mutation that ends in any letter other than T, A, C, G or d.

If you haven’t taken the full sequence test, you don’t have “Extra” mutations listed, but you can still view your mutations for the HVR1 and HVR2 regions.

Look for any value that has any letter other than T, A, C, G or lower case d at the end of the location.

The Y tells us that this location is a heteroplasmy.

Heteroplasmy Matching

Ok, let’s look at a heteroplasmy mutation at location 16326. A heteroplasmy can occur at any mitochondrial location. I’ve selected this location because it occurs in the HVR1 region of the mitochondrial DNA, so even people who haven’t tested at the full sequence level will see results for this location. Plus, the location at which the heteroplasmy occurs affects matching in different ways.

Using the example of T16362Y, the Y tells us that both nucleotides C and T were found. This location should match against anyone carrying the following values in the same location:

  • Y (letter indicating a C/T heteroplasmy)
  • T (standard or normal value)
  • C (mutated value)

However, currently at Family Tree DNA, the heteroplasmy only counts as a match to anyone with a Y, the specific heteroplasmy indicator, and the “normal” value of T, but not the mutated value of C.

This table shows how heteroplasmies are counted at FamilyTreeDNA. For heteroplasmy T16362Y, based on the value your potential match has at this location, you either will or will not be considered a match at that location.

Scenario Other Person’s Value Your Result – T16362Y
1 T16362Y – heteroplasmy indicator Match to you at this location
2 T16362T – normal value, not a mutation Match to you at this location
3 T16362C – mutated value Not counted as match to you at this location
  • If your match has a value of Y, the heteroplasmic C/T value, they are counted as a match to you, so no problem.
  • If your match has a value of T, the normal value, this location won’t be shown on their mutation list at all. They WILL be counted as a match to you so there’s no issue.
  • If your match has a value of C, the mutated value, in my opinion they should also be counted as a match to you, but they aren’t today. The logic, I believe, was that the most likely value is the standard or normal value and that the mutated value is much less likely to be accurate. Regardless, I’ve requested this change and am hoping for a matching adjustment in a future release for heteroplasmies.

Heteroplasmies do affect matching at the different levels.

Viewing Your Matches

Mitochondrial DNA, for testing purposes, is broken into three regions, HVR1 (hyper-variable region 1), HVR2 and the Coding Region.

At FamilyTreeDNA, you can view your matches at each level. The matches are cumulative, meaning that the HVR2 level includes the HVR1 level information, and the Coding Region level includes the HVR1 and HVR2 regions. That highest level which includes all three regions shows information from your entire your entire full mitochondrial DNA sequence.

Heteroplasmy Effects on Matching

If you otherwise match someone exactly, but one of you has a heteroplasmy and the other person carries the mutated value, you will be counted as a mismatch of 1 at the full sequence level.

A mismatch has different effects when it occurs in the HVR1, HVR2 or Coding Regions, respectively.

GD is an abbreviation for Genetic Distance which is how mutations are counted. A GD of 1 means the two people have one mutation difference between them.

In the following chart, the effects of you having a nonmatch, heteroplasmic or otherwise, in each of the regions is shown at each level. The region in which the mismatch occurs is shown in the first column, at left, and the effect the mismatch has on matching in each region is shown in columns 2-4.

The red sections are not counted as matches.

Mismatch Occurs in this Region HVR1 Level Match to Someone Else HVR2 Level Match to Someone Else Coding Region Level Match to Someone Else
HVR1 region nonmatch GD of 1 means no match GD of 1 means no match GD of 1 is a match
HVR2 region nonmatch Does not affect HVR1 – so you are a match GD of 1 means no match GD of 1 is a match
Coding Region nonmatch Does not affect HVR1 – so you are a match Does not affect HVR2 – so you are a match GD of 1 is a match

For purposes of this discussion, we’re assuming our two people being compared in the chart above match exactly on every other location so matching is not otherwise affected.

  • If your heteroplasmic nonmatch occurs in the HVR1 region – in other words, scenario 3 – you’ll fall into the HVR1 nonmatch row. That means you won’t be shown as a match at the HVR1 or HVR1+HVR2 levels, but you WILL be shown as a full sequence match.
  • If your heteroplasmic nonmatch is in the HVR2 region of addresses, it won’t affect your HVR1 matches, but it will affect your HVR2 and Coding Region matches. This means you will be shown as HVR1 match, not an HVR2 match, but will be a full sequence match.
  • If your heteroplasmic nonmatch is in the Coding Region, it won’t affect your HVR1 or HVR2 matches, but it will affect your Coding Region matches. However, it won’t preclude matches and you’ll be shown as a match in all three regions.

To be very clear, I have no issue with these match thresholds. It’s important to understand how this works, and therefore why heteroplasmic (and other) mismatches in specific regions affect our matches in the way they do.

Why Aren’t Mismatches of 1 Counted as Matches in the HVR1 or HVR2 Regions?

The match threshold at FamilyTreeDNA for the HVR1 and the HVR1+HVR2 regions, both small regions of about 1000 locations each, is that only an exact match is considered a match. Therefore, a heteroplasmic nonmatch in this region can really be confusing and sometimes misleading, especially if either or BOTH people have NOT tested at the full sequence level.

These are the match thresholds in effect today.

HVR1 GD or # of Mutations Allowed for a Match HVR2 GD or # of Mutations Allowed for a Match Coding Region GD or # of Mutations Allowed for a Match
0 – no mutations allowed 0 – no mutations allowed 3 mutations allowed

If both people match on either the heteroplasmy identified (Y in our case) or one person has the normal value – all is fine. But if one person has a heteroplasmy and the other has the mutated value – then a mismatch occurs. This is really only problematic when:

  • The heteroplasmy mismatch is in the HVR1 region and both people have only tested at that level, causing the two people to not match at all.
  • The heteroplasmy mismatch occurs in combination with other mutations that, cumulatively, push the two people over the GD 3 full sequence matching threshold.

The second scenario happens rarely, but I have seen situations where people don’t match their mothers, aunts, siblings, or other close relatives because of multiple heteroplasmic mutations occurring in different people.

And yes, this is hen’s teeth rare – but it does occasionally happen.

So, what’s the bottom line about heteroplasmies?

Heteroplasmy Bottom Line

  1. You can suspect a heteroplasmy if you have full sequence matches, but no exact matches.
  2. If you have a heteroplasmy in the HVR1 region, understand that you may not have many or any matches in the HVR1 and HVR2 regions. The remedy is to test at the full sequence level and check matches there.
  3. If you have a heteroplasmy and don’t match someone you expect to match – reach out to them and ask about their value at that specific location. If that location isn’t listed for them in their results, then they have no mutation there and your heteroplasmy is NOT the cause of you not matching with them.
  4. If you don’t match someone you expect to match, reach out to them and ask if THEY have any heteroplasmies. The easiest way to ask is, “Do you have any mutations listed that end with anything other than T, A, C, G or d?” Feel free to link to this article so that they’ll know where to look, and why you’re asking.

Do you have any heteroplasmies?

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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

Books

Genealogy Research