Four “founding mothers“ of Ashkenazi Jews

Four “founding mothers” who lived in Europe a thousand years ago were the ancestors of two fifths of all Ashkenazi (European origin) Jews. This is the conclusion of a team of researchers at the Technion&;Israel Institute of Technology, Haifa, after they compared DNA sequences from nearly 2000 Jews with those of 11 500 non–Jewish people in 67 different populations around the world. The remaining 60% were found to have much more heterogeneous genetic origins. The team, led by doctoral student, Doron Behar, and his supervisor, Professor Karl Skorecki of the Technion’s medical faculty and Rambam Medical Centre in Haifa, published their findings online ahead of print publication in the American Journal of Human Genetics on 11 January (). The article will appear in print in the March edition. Professor Skorecki, a nephrologist who also conducts genetic research, is known for his 1997 discovery of DNA marker evidence showing that most modern day Jewish men of the paternally inherited priestly caste (the Kohanim) are descendants of a single common male ancestor. The latest discovery, which will be followed by genetic studies of the Druze minority in Israel and other communities, has important implications beyond its inherent historical interest, said Professor Skorecki, as it adds to understanding of the mechanisms of genetic health and disease in different populations around the world. Because of its relative isolation over many centuries the Ashkenazi population, which accounts for most of the world’s Jews today, is also known to have accumulated some 20 recessive hereditary disorders (such as Tay–Sachs disease) that are rarely found in other populations. The team, which studied mitochondrial DNA (mtDNA) passed on solely by mothers to their children, found evidence of shared maternal ancestry of Ashkenazi and non–Ashkenazi Jews, a finding showing a shared ancestral pool that is consistent with previous studies that were based on the Y chromosome. This evidence pointed to a similar pattern of shared paternal ancestry of Jewish populations around the world originating in the Middle East. They concluded that the four founding types of mtDNA—likely to be of Middle Eastern origin—underwent a major overall expansion in Europe over the last thousand years. The “four founding mothers,” he added, “are from lineages that originate long before the launching of the Jewish people some 3400 years ago. They probably came from a large Middle Eastern gene pool. “As consistent with the Bible, in which the founding Jews were Abraham, Isaac, and Jacob and his sons, and the matriarchs were ‘imported’ from non–Jewish peoples and then converted, the haplotypes of contemporary Jewish men are much less varied.”