DNA test #dna

Hanna Grossman

I have done an Ancestry autosomal test and gotten my results.

They include two 2nd cousins whom I know.

And very many 2-3 cousins , none of whose names I recognize, and none of whom have matching names in their (very minimal) connected trees.

How can I proceed to find out any more about how these matches may be related? #dna

Hanna Grossman, Arlington VA

Adam Turner

First off: if you are Ashkenazi, at least a few of those who appear in "2nd-3rd cousins," especially those near the bottom of that list, are unlikely to be your real cousins. See Jennifer Mendelson's article for a cogent explanation why: https://medium.com/@CleverTitleTK/no-you-dont-really-have-7-900-4th-cousins-some-dna-basics-for-those-with-jewish-heritage-857f873399ff

(It is possible, though much less likely, that someone who has a stronger match and shows up in the "1st-2nd cousins" section will also not be your genuine cousin. The rest of my post is premised on the assumption that they probably are indeed your genuine cousin.)

There are a number of ways to figure out how names in your AncestryDNA list who you don't recognize are related to you. Here are a few:

1. Contact the person directly, using the "Message" button in AncestryDNA, and ask them.* Not everyone will respond, but many will!

2. Ask around. See if your known relatives who you are in touch with have heard of this person before. 

3. Do traditional research like you would for any other name you don't recognize; see if you can identify who this person is, where they came from, who their family members are, etc. Even if the person didn't link their results to a tree in Ancestry, you can often figure out quite a bit based on their name alone.

4. Use the Shared Matches tab on their Ancestry profile to narrow things down. If you already know that 6 people on your mother's side of your family match you on AncestryDNA and 4 people on your father's side match you on AncestryDNA, how many of those people match this mystery person whom you don't recognize? If they match all of your known paternal cousins while appearing to match none of your known maternal cousins, that is a pretty decent hint that this person is likeliest to be another paternal cousin of yours. 

5. Convince more of your relatives to also take AncestryDNA tests to see how they match the mystery person. Expensive, but might be worth it to figure out if you really have a long-lost close cousin!

*If your family is close, and you would know who all your first and second cousins are (yet can't figure out the connection to this person despite AncestryDNA saying they are your first cousin), it's probably a good idea to proceed gently when communicating with this mystery person. There is always a possibility that one of your aunts, uncles, or close cousins has a secret, like giving up a baby for adoption or having a child out of wedlock, and that even the child has no idea that one or both of the people who raised them are not their biological parents.

Good luck!

Adam Turner

Jill Whitehead

Most testing companies are optimistic in their assessment of cousinship, and they usually give a range e.g. 2nd to 5th cousin . In reality the 3rd cousin is likely a 4th or 5th cousin or more. You can can have very many 3rd, 4th and 5th cousins, and probably very few of them are close relations to you that could be traced.  As so many Jews are interrelated, this makes cousinships seems closer than they really are e.g. so many 1st cousin, uncle-niece etc relationships in closed communities over time - this is called endogamy. Most people of Jewish origin share at least one chromosome segment, but this could go way back into the depth of time to your deep ancestry, and will have no meaning for tracing recent relations.  

The 2019 issue of Shemot, the journal of the Jewish Genealogical Society of Great Britain, is a DNA special that explains all these matters. Most of the companies also have information about these matters. Ancestry is the weakest, as it does not give the same full information as FTDNA, 23andMe and MyHeritage, which are all much better on Jewish genetics than Ancestry.

Jill Whitehead, Surrey, UK


Here are a few more tips:

  1. Ancestry DNA now gives you the number of centimorgans (cMs) in the largest segment you share with a DNA match.  Unfortunately, it does not appear right in your list of matches, but you'll see it when you click on the person's name.  I've been entering the info on the largest segment in the "notes" field for each person right on the list of DNA matches.  Focus on individuals for whom the largest segment is >20... or even better, >30 cM.  
  2. One disadvantage of Ancestry DNA is that they don't show you the number of cM for each segment like MyHeritage and FTDNA do.  Upload your Ancestry DNA to those sites to find more DNA matches; in the process, you'll be able to "fish in all ponds" and find more matches.  It's worth it to pay the one-time fee of $20-$30 to access DNA tools on MyHeritage and FTDNA, like a Chromosome Browser.
  3. Join the Facebook group Jewish DNA for Genetic Genealogy and Family Research.  You'll learn a lot there.  Be sure to check out the files section!
Good luck!

Ellen Morosoff Pemrick

Sarah L Meyer

I have a non-Jewish friend who had a "second" cousin at Ancestry - whom he did not recognize.  Both were from England.  Both had very well done paper trails. He did recognize 4 surnames in his match's surname list.  They emailed.  They learned that they were 8th cousins in 4 distinct ways.  No computer can distinguish between the situation of 8th cousin in 4 ways, 4th cousin in two different ways or second cousin in one way - based on total DNA.   You may well be fourth cousins in two different ways. - say on your mother's side and on your father's side.  I doubt that most of us have trees far enough back to be able to determine 8th cousins, but fourth cousins in two ways - that might be possible.

Sarah L Meyer
Georgetown TX
BIRGARDOVSKY, EDELBERG, HITE (CHAIT), PERCHIK Russia (southern Ukraine) and some Latvia or Lithuania