The Challenges of Jewish DNA testing

By Kitty Munson Cooper
Blogging at

23 pairs of chromosomes

Image of painted (SKY) chromosomes - Courtesy of DeWitt Stetten, Jr., Museum of Medical Research

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 Test if you are Jewish?


  • Family Tree DNA * is the only place for Y testing, has projects, but the smallest database, however many jewish testers, cheek swab
  • 23andme gives health results and top level haplogroups
  • MyHeritage * has more European testers and connects to trees
  • is least likely to have matches for recent immigrants but has the largest database and best tree matching for now

* takes transfers

Diagrams from the NIH

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

Sample Y DNA STR results for 37 markers

Jewish E haplogroup Family Tree DNA project

A project at Family Tree DNA for Jewish Y markers

Mitochondria under a microscope

Near Eastern origin mtDNA Haplogroups:
K1a9 and N1b2


others are H variations, possibly European


Your autosomal DNA results are about 700,00 lines of data in a spreadsheet

Inheritance from 8 g-grandparents,
courtesy of Angie Bush

Admixture of a 100% Ashkenazi person from

Aunt Shaindel is found!

Lara is collecting Ashkenazi data and her preliminary 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

Kitty's Guidelines for Jewish DNA Matches worth following up on

  • At least one segment > 20 cM
  • Another segment > 10 cM
  • Several more good sized segments

Enter the cMs and get probable relationships

Israel Pickholtz documents his extensive family DNA project

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