NEW YORK (GenomeWeb News) – Most Jewish populations appear to be genetically related to a subset of non-Jewish Middle Eastern populations, according to a paper appearing online today in Nature.
An international research team led by investigators in Israel and Estonia genotyped individuals from more than a dozen Jewish communities around the world, comparing their genetic profiles with those of dozens more non-Jewish populations. In the process, they found evidence that most modern Jewish populations appear to have descended from ancient Hebrew or Israelite populations in an eastern Mediterranean region known as Levant.
"These results cast light on the variegated genetic architecture of the Middle East, and trace the origins of most Jewish Diaspora communities to the Levant," senior author Richard Villems, head of the University of Tartu's evolutionary biology department, and his co-authors wrote.
Villems and his co-workers used Illumina 610K or 660K bead arrays to genotype DNA isolated from blood or spit samples from 121 Jewish individuals from 14 populations.
After doing quality control step and accounting for linkage disequilibrium, the team was left with data on 226,839 autonomous SNPs, which they integrated with Y-chromosome data for 8,000 individuals and mitochondrial DNA findings on 14,000 individuals, both generated through previous studies.
These samples were then compared with data on 1,166 non-Jewish individuals from 69 Old World populations. The researchers also included Illumina 650K array data on non-Jewish populations from the Human Genome Diversity Panel in their analysis.
The researchers reported that the Ashkenazi, Caucasus, Middle Eastern, North African, and Sephardi Jewish populations clustered with non-Jewish populations in the Middle East, particularly Druze and Cypriot groups, suggesting a "close relationship between most contemporary Jews and non-Jewish populations from Levant."
Within this large Jewish cluster, the team found three Jewish sub-groups: one representing Ashkenazi and North African Sephardi Jewish populations, another representing Jewish communities in the Caucasus and Middle East, and a third representing a Yemenite Jewish group.
In contrast to the pattern observed for most of the Jewish populations, though, the team found that Jewish individuals tested in Ethiopia and India were more closely clustered with the non-Jewish populations living near them in these regions.
"Strong similarities to their neighboring host populations may have resulted from one or more of the following: large-scale introgression, asymmetrical sex-biased gene flow, or religious and cultural diffusion during the process of becoming one of the many and varied Jewish communities," the researchers wrote.
Overall though, the team says their results are consistent with the notion that modern Jewish populations are descendants of ancient Hebrew populations originating in and around Israel that migrated from this region to other parts of the world.
"This inference underscores the significant genetic continuity that exists among most Jewish communities and contemporary non-Jewish Levantine populations," Villems and his colleagues wrote, "despite their long-term residence in diverse regions remote from the Levant and isolation from one another."
Just last week, a team of scientists reported on Jewish genetic patterns in the American Journal of Human Genetics. That study suggested that Jewish populations from around the world appear to remain genetically related to one another.