Medical genetics of Jews

The medical genetics of Jews have been studied to identify and prevent some rare genetic diseases that, while still rare, are more common than average among people of Jewish descent. There are several autosomal recessive genetic disorders that are more common than average in ethnically Jewish populations, particularly Ashkenazi Jews, because of relatively recent population bottlenecks and because of consanguineous marriage (marriage of second cousins or closer).^[1] These two phenomena reduce genetic diversity and raise the chance that two parents will carry a mutation in the same gene and pass on both mutations to a child.

The genetics of Ashkenazi Jews have been particularly well studied, because the phenomenon affects them the most. This has resulted in the discovery of many genetic disorders associated with this ethnic group.^[2] The medical genetics of Sephardic Jews and Mizrahi Jews are more complicated, because they are genetically more diverse, and therefore no genetic disorders are more common in these groups as a whole; instead, they tend to have the genetic diseases common in their various countries of origin.^[2][3]

Several organizations, such as Dor Yeshorim,^[4] offer screening for Ashkenazi genetic diseases, and these programs have done much, particularly by reducing the instance of Tay–Sachs disease.^[5]