The Challenges of Jewish

DNA testing: a Q & A

Questions people hope to answer with DNA are:


Where are my ancestors from?

Do I have any unknown relatives out there?

Am I related to ... those other ENGELs (or Schwartz or other family name)? Ethnicity

Ethnicity Estimates for half Galician half Polish Jewish Person Estimate Ethnicity

Ethnicity Estimates for half Galician half Polish Jewish Person Estimate

Ethnicity Estimates for half Galician half Polish Jewish Person estimate for the same person: left tested there, right uploaded

We Found South African 3rd cousins with DNA!

The "G" trick

The cousin level = the number of "G"s , else the greats plus one

If you are in different generations take the shorter path and the other is removed by the generation difference

Three types of personal DNA tests

Y test for father's father's line

mtDNA for mother's mother's line

Autosomal DNA test for all your ancestors

Where to do an Autosomal DNA Test if you are Jewish?

My recommendation:

Test at 23andme and then upload those results elsewhere, that gets you high level haplogroups and some health results

  • Upload those results to Family Tree DNA, MyHeritage, & GEDmatch

If you can afford it also test at 

  • Problem: Ancestry removes population specific segments giving better matches but it is least likely to have matches for recent immigrants. It has the largest database and good tree matching.

If you can afford it also do Y testing of your male line(s) at Family Tree DNA. Start with the 37 marker STR test.

SNP - Single Nucleotide Polymorphism

a DNA mutation where a single letter chang3s


STRs are short tandem repeats


An extra copy is made of a sequence of DNA

An extra copy is made of a sequence of DNA

An extra copy is made of a sequence of DNA

An extra copy is made of a sequence of DNA


An extra copy is made of a sequence of DNA


2 Types of Y DNA Tests

Deep ancestry - haplogroup

More recent ancestry - surname studies

Y Haplogroups from SNPs

Jewish Y Haplogroups: J1c3, J2a Cohanim
R1a1 most Levites
E1a1 is frequent
Others: various J subgroups, T1, and E1b

Mitochondria under a microscope

Near Eastern origin mtDNA Haplogroups:
K1a9 and N1b2


others are H variations, possibly European


The problem with Jewish Autosomal DNA matching is that we are all related!

MyHeritage Matches for our Galician and Polish Jewish person

You do not need to look at all those matches!


Start with the low hanging fruit, "extended family" estimated 3rd cousins or closer and large segments

Kitty's Guidelines for Jewish DNA Matches worth following up on: sort by LARGEST SEGMENT if you can

  • At least one segment > 20 cM
  • Another segment > 10 cM
  • Several more good sized segments
  • Review what Gil Bardige said in his DNA session 1396 with Adam

blogger Lara Diamond is collecting Ashkenazi data and her most recent report is here:

Close relationships are within the normal range but at the high end, the average is about 100-200 cM larger than the norm

Match to a maternal side Ashkenazi 3rd cousin

Comparison to a paternal side Norwegian 3rd cousin

Enter the cMs and get probable relationships

but for Jewish matches further away than 2nd cousins,

remove 10%

Clustering tools often create one big blob for Ashkenazi Jews - this one used the range 90-250 to get past that

has not yet been useful

Israel Pickholtz documents his extensive family DNA project in his book

Getting New Cousins to Respond to You

  • Have a family tree online
  • Upload friendly picture of yourself
  • Include details of who matches whom (they may have multiple kits)
  • Offer them information when you write to them

Do not be disheartened by lack of responses, some rarely log in 

One other reason to test DNA is if you are adopted or have an unknown father. These cases are very difficult in Jewish DNA, you need 2nd cousin matches to solve them

There is lots more information on my blog about Jewish DNA for example, read

The Challenges of Jewish DNA testing

By Kitty Cooper

The Challenges of Jewish DNA testing

Working with DNA testing presents unique challenges to the Jewish genealogical community due to the close relatedness of their DNA and the lack of deep family trees. Short presentation for the IAJGS Ask the DNA Experts Q&A session

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