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.
Genetic Institute, Sheba Medical Center, Tel Hashomer, Israel.
L
L
Peleg
A
A
Frisch
B
B
Goldman
M
M
Karpaty
R
R
Narinsky
S
S
Bronstein
M
M
Frydman
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*