A genetic profile of the South African Ashkenazi Jewish population.

The South African Ashkenazi Jewish population is described in terms of the prevailing frequencies of the genes at 25 red cell enzyme and serum protein loci and 4 placental enzyme loci. Variation was encountered in 23 of these systems. The Tay-Sachs allele which occurs at polymorphic frequencies in Ashkenazi populations was found at a frequency of 0.022, which suggests that approximately 1 baby with Tay-Sachs disease could be expected out of every 2,000 born in this community should preventive measures not be taken. The atypical serum pseudocholinesterase cholinesterase allele was encountered at a relatively low frequency and instances of scoline apnoea would be expected to occur only during approximately 1 out of every 10,000 surgical operations performed. A single case of glucose-6-phosphate dehydrogenase deficiency was discovered during the survey. In general, the allele frequencies in the systems studied do not differ radically from those of Ashkenazi populations living in other parts of the world. In accordance with other Ashkenazi populations, the frequencies of certain alleles in our samples provide support for the belief that the Ashkenazim have their origin in the Middle East.