Genetic Genealogy and the Ashkenazi Problem

Today is National DNA Day. DNA testing has become increasingly popular for genealogy purposes, and the Jewish community is no exception to this trend. This is clear from this year's IAJGS conference on Jewish Genealogy, which is boasting in-depth DNA workshops and has more than 20 lectures related to DNA on its schedule.

But DNA testing for genealogy purposes poses a special problem for Jews, often called the Ashkenazi Problem: Jews tend to marry Jews, and Jews who do not marry Jews tend to drop out of the Jewish community, and we have been doing that for so long in such a small population that we all tend to have a lot of DNA in common. The technical term for this is "endogamy," or in other words, inbreeding.  As a result, one study found that the average Jewish DNA tester matched 54% of all testers with any Jewish heritage! Compare this with gentile testers, who matched less than 1% of all testers with gentile ancestry.

But if you are Jewish and interested in DNA testing, don't give up hope! It is possible to make real connections with real relatives through DNA testing. One of my great-grandfathers (Joseph Spigler) had seven siblings, four of whom married and had children, and I have successfully identified DNA matches from three of his siblings! Although two of those matches did not appear until six months after I took my test, and I have had less success so far on other branches. DNA testing can be particularly valuable if you are from a family separated by the Holocaust (discussed further below) or by adoption (discussed further below). But you have to come into it with proper expectations, and you have to meet your relatives halfway if you expect to have any success. 

The first thing to keep in mind is: DNA testing will not magically build a family tree for you. Ancestry.com is clearly aware of this, because their advertisements for DNA testing emphasize identifying your ethnicity, not identifying ancestors. If all four of your grandparents are Ashkenazim (Jew whose ancestors came from Central or Eastern Europe), Ancestry's ethnicity piece will only tell you that you are 93-98% European Jewish with trace amounts of other things. If you are not Jewish but you have reason to suspect that, like former Secretary of State Madeleine Albright, you or one of your ancestors converted to survive the Holocaust, this will very definitely show it. If you were adopted and have reason to believe one or both of your birth parents was Jewish, ethnicity will certainly show it. If you have a family story about a relatively recent intermarriage, this might also confirm it for you.  But other than that, basic ethnicity isn't going to tell an Ashkenazi anything useful. So what else can DNA testing do for you?

DNA testing can put you in touch with distant cousins who share parts of your DNA. Those cousins might know more about your shared ancestry than you do, or they might work with you to find more information about your shared ancestors, or they might simply fill in information about descendants of your ancestors, which I have always said is the more rewarding way to do your genealogy: when you trace the descendants of your ancestors, you get a lot more results, and those results are cousins you never knew instead of European gravestones.

But as I said above, Jewish DNA testers are going to have a lot of matches, so you will need to do some work to review these many matches and figure out which ones are real, and you'll have to meet your cousins halfway if you expect to make any matches.

Jewish DNA test results have a very low signal-to-noise ratio: you will have a lot of matches, and not a lot of them will be related within the genealogical range (closely enough that you can identify the common ancestor). You need to identify that common ancestor if you want to know whether your nearest common ancestor is closer than our fathers Abraham, Isaac and Jacob.  The only way you are going to be able to make that connection is if both you and your DNA match have done enough research to build a tree that contains a common match, or at least a match with a shared surname and region so that you know there is probably a connection and you can work together to find that common ancestor.

I had my DNA tested through Ancestry.com because Ancestry has been a genealogical research tool for a very long time, with integrated family tree building long before anyone thought about DNA testing. Lots of people already had family trees there before they started DNA testing. And Ancestry has a nice feature that gives you "hints" if the family tree connected to your DNA test has someone in common with one of your DNA hits, so you'll really want to build out that tree as much as you can before you take that DNA test, and you'll want to make it publicly available so your matches can see that you match. (a little more about other DNA testing options below)

Unfortunately, what I found was that a lot of my hits had no family tree at all (perhaps they expected DNA to magically build a tree) or they had a tree that was so limited as to be useless (only a handful of ancestors mostly marked Private), or they had a tree that was locked down so I couldn't see it. Some of them had perfectly good trees that were not properly linked to the DNA test, so you should click through on those people with "no family tree" and see if there is an unlinked tree that is useful to you. One of my three Spigler cousins had an unlinked tree that matched us up; I never would have found that connection if I hadn't clicked through.

Be aware that the relationship level that the DNA test predicts is merely an estimate, and not necessarily accurate. People may be more closely or distantly related than the test suggests. A 2^nd cousin once removed (grandson of my great-grandfather) showed up as relatively low probability 4^th cousin. On the other hand, a high probability third cousin… we still haven't quite figured out how he's related. His great-grandfather was my 2g-grandmother's immigration contact, so we think they might be siblings (making us 2nd cousins once removed), but the parent names he has for that great-grandfather don't match the parent names I have for my 2g-grandmother. Are they siblings? Cousins? Not a clue.

For me, though, it is the challenge of the puzzle that makes genealogy so much fun, and DNA testing puts more puzzle pieces on the table for me to play with.

DNA Testing for Families of Holocaust Survivors

DNA testing is particularly valuable for the families of Holocaust survivors, and I highly recommend it if your family tree has been shattered  in this way. The Holocaust separated families, and many of them did not know whether their relatives survived or where they ended up. In my own family, one of my grandfather's siblings fled Germany to Holland to avoid the Holocaust and survived in hiding. They lost touch with the family and did not know that anyone had survived, though they got back in touch after the war. Many families were not so lucky, and never knew whether their relatives survived. Newspapers at the time were filled with personal ads seeking missing relatives, but name changes and lack of knowledge of where people lived made this very difficult and often unsuccessful.

DNA testing can reconnect these broken families if both sides have their DNA tested. These tend to be relatively close relatives, so their DNA results are not distorted as much by all the background noise, and they often know their family tree far enough back (or at least their family tree is recent enough to be researchable) to identify the common ancestor.

The most famous of these success stories is Menachem Bender, who was separated from his identical twin brother in Mengele's experiments and never saw him again but thinks he survived. He hasn't found his brother yet, but DNA testing and genealogical research put him in touch with a first cousin, daughter of his mother's sister, who had pictures of the parents he lost in the Holocaust.

Another story tells of a woman who made a DNA connection with a descendant of the aunt of her Holocaust survivor grandfather. He always knew that he had an aunt in America, but had no idea where or what her married name was. DNA answered the question, and put her in touch with many cousins.

DNA Testing for Adoptees

DNA testing for adoptees is a way to make a connection with birth relatives, though it can be very challenging because of the lack of information. Adoptees generally do not even know the names of their birth parents (though you should really check your states laws, because some states have opened records in recent years, check here: http://bastards.org/local/).

If your birth parents have had a DNA test and you have a DNA test, there will be a clear match. You may also get good matches with close relatives, such as half-siblings or aunts and uncles, but these results are somewhat less obvious and the birth relative you match may not know that you exist, which makes it hard to tell what you have. DNA tests do not tell you whether you match on the maternal side or the paternal side.

There are many adoption DNA search success stories floating around out there, but not all adoption DNA tests are successes, and some of them take a lot of time. Here are a few cases I personally know of with varying degrees of success:

In one case, a (Jewish) man was surprised to find a DNA match that was a better match than his own grandson was. The younger man said that he was adopted and was looking for his birth parents, but he had no idea who they were. The older man knew nothing about any child of the family that was given up for adoption. Eventually, the older man got his brother to admit that the brother had fathered a child given up for adoption around the time that the younger man was born. The older man was the adoptee's uncle and had successfully identified the adoptee's birth father, so that one is a success story!

In another case, an (interfaith) adoptee had a "1^st or 2^nd cousin" hit. The person's name was not displayed and the person had no family tree online. This adoptee was already in contact with her birth relatives, and had done some genealogy to know who was in her birth family, but couldn't figure out who this person was. She contacted the person administering his DNA test without mentioning the adoption aspect, and it took quite a while before she got any response. Before she heard back, she determined through her own research who he was based on the name of the person administering the test and the initials used for his online name: he was the son of her (gentile) birth father's much older half-sister, a sister who had died before the adoptee was even born, when the match was in his early teens. The DNA match was a half-cousin, and he eventually responded, but he didn't even know that his mother had brothers, let alone that one of the brothers had fathered a child given up for adoption! If the adoptee hadn't already known who her birth relatives were, this would have been of no use whatsoever to identify her birth relatives.

In a third case, a (gentile) adoptee had a DNA test hoping to learn about her birth family. She had a lot of distant cousin hits email her initially, but nothing remotely close and she was frustrated with it and thought it might have been a waste of time. About a year after her test, the DNA service told her that she had a close hit and suggested that it was a grandson. She was amused by the notion (she has no children or grandchildren), but I pointed out that a grandparent/grandchild relationship shares the same amount of DNA as a half-sibling relationship (https://isogg.org/wiki/Autosomal_DNA_statistics#Table), and that this is probably a child of a birth parent. She got in touch with him, but I haven't heard anything since then, so I'm not sure whether this is a success story. It is, at the very least, a story that it may take time for success and you should not expect to have success the first day you spit in a cup.

And in a last, a sad unsuccessful case, a (Jewish) adoptee had learned who her birth parents were but they had died by the time the records were opened and she really knew nothing about them. She did a DNA test hoping to contact some birth relatives and learn more. Sadly, the adoptee died without ever making contact with a birth relative, but a friend maintains the DNA account hoping that someday a contact will be made.

Other DNA Tests and Tools

I also had my DNA tested through Family Tree DNA (FTDNA), but was somewhat less satisfied with the results. Family trees are largely nonexistent there, so it is hard to see how you are related to people. They do give you the ability to post family surnames and locations, and many people do that, which could be helpful. And they give you more, better information about your DNA match results: how many cM of DNA are shared, what the largest shared segment is (which can be very useful for Jewish DNA because larger segments are better hits), whether the person matches on the X chromosome (which, if a match, gives a hint of where the connection lies). They also have a nice chromosome browser tool that lets you see where in the DNA you match. This can be particularly useful once you've confirmed the relationship of one match: if you match two people in the same location for a significant stretch, it is more likely that the three of you share the same ancestor, so the third person is probably connected in the same branch where you are connected to the known relative. It takes some time and effort to work this out, but it can be worth it.

I also uploaded one of my existing DNA tests to the new My Heritage DNA service. Like Ancestry.com, they started as a family tree research service and have the ability to load family trees, which again, is likely to help you identify genuine matches. Like FTDNA, they tell you how many cM of DNA you share, over how many segments, and what the largest segment was. I think My Heritage may be filtering out the smaller segments that tend to be background noise, because one of my Spigler cousins showed up as a match on Ancestry, FTDNA and My Heritage, and had LESS cM shared with me on My Heritage than on the other two (and keep in mind: I uploaded that My Heritage data from a test result that said I had more cM in common). I gather that My Heritage is an Israeli company, so they may have more awareness than others of the problems in Jewish DNA research and may be addressing that.

My Heritage is not the only service that lets you upload existing test results for free or for a discount price. This will increase the number of people you are compared to, which gives you a better chance of finding a match.

You may also want to upload your results to GEDMatch, a free service that lets you upload DNA test results from various services and compare them with others using many useful tools, including ones that break things down by chromosome like FTDNA (some tools require a small charge). You can also upload your family tree (GEDCOM) and compare to ones on their site or search ones on their site. You can search for people who match your DNA who have a GEDCOM, and when you look at descendants on a GEDCOM, it will show you who has a DNA test.

Links for More Information

• Differences in Autosomal DNA Characteristics between Jewish and Non-Jewish Populations - This is a very informative scientific article examining the statistical difficulties of Jewish DNA testing. 
• Using Ashkenazi Jewish DNA to Find Family A more informal blog entry discussing much of the same, and also talking about the Holocaust survivor who sought his lost twin brother with DNA.
• Autosomal DNA statistics This is a good breakdown of what you would expect to see in the DNA shared by non-endogamous populations. It says nothing about the effect that Jewish endogamy has on these percentages, but it is worth knowing.