Lower frequency of Gaucher disease carriers among Tay-Sachs disease carriers.
The heterozygote frequency of Gaucher disease (GD) and Tay-Sachs disease (TSD) is distinctly high among Ashkenazi Jews (1:29 for TSD and 1:16 for GD). Two main theories have been suggested to explain this high occurrence: a founder effect with subsequent genetic drift, and a selective advantage of heterozygotes. We compared the frequency of the GD most common mutation (1226A-->G) among carriers of the common TSD mutation (+1277 TATC) with the frequency of this mutation in the general Ashkenazi population. The frequency of GD carriers among 308 TSD heterozygotes was 1:28 which is about half the expected (P = 0.03). These results indicate that carriers of both diseases do not possess additional evolutionary advantage over single mutation carriers. A reasonable interpretation of these findings is that one or both mutations have arisen relatively recently in different regions of Europe and have not yet reached genetic equilibrium.
Peleg
L
L
Genetic Institute, Sheba Medical Center, Tel Hashomer, Israel.
Frisch
A
A
Goldman
B
B
Karpaty
M
M
Narinsky
R
R
Bronstein
S
S
Frydman
M
M
D004252:DNA Mutational Analysis; D005776:Gaucher Disease / Q000235:genetics*; D005787:Gene Frequency; D006579:Heterozygote; D006801:Humans; D007585:Jews / Q000235:genetics*; D013661:Tay-Sachs Disease / Q000235:genetics*