Mendelian diseases among Roman Jews: implications for the origins of disease alleles.

The Roman Jewish community has been historically continuous in Rome since pre-Christian times and may have been progenitor to the Ashkenazi Jewish community. Despite a history of endogamy over the past 2000 yr, the historical record suggests that there was admixture with Ashkenazi and Sephardic Jews during the Middle Ages. To determine whether Roman and Ashkenazi Jews shared common signature mutations, we tested a group of 107 Roman Jews, representing 176 haploid sets of chromosomes.