Is Tay-Sachs Disease Increasing?

TAY-SACHS disease, caused by a recessive autosomal gene, occurs approximately a hundred times more frequently in Jews from Central Europe (Ashkenazi) than in those from the Mediterranean Basin (Sephardic). Myrianthopoulos and Aronson1 proposed that the difference in gene frequency of the two populations is a consequence of simple heterozygote advantage in the Ashkenazi. Furthermore, they stated that this advantage probably arose fifty generations ago when there was a mass exodus of Jews after the Roman conquest of Jerusalem. The present gene frequencies in the two populations were given by Myrianthopoulos and Aronson as qASH = 0.0126 and qSEPH = 0.0013. This corresponds to q2ASH = 0.000158 and q2SEPH = 0.0000017 or approximately 158 Tay-Sachs births per million among the Ashkenazi Jews and 1.7 per million among the Sephardic Jews.