Apo E allele frequencies in younger (age 42-50) vs older (age 65-90) women.

Allelic variation at the apolipoprotein E (Apo E) structural locus has been shown to influence concentrations of total cholesterol and low density lipoprotein cholesterol (LDL-C). Apo E has six phenotypes resulting from three common alleles at this locus. The epsilon 2 allele is associated with lower LDL-C and the epsilon 4 allele with higher LDL-C. In the current study, we compared the epsilon allele distribution in two cohorts of white women recruited from population based listing of southwestern Pennsylvania. The "younger" cohort consisted of 473 women, age 42-50; the "older" cohort, 870 women, age 65-90. A comparison of the overall distribution of allele frequencies in the two cohorts was significantly different. The allele frequency of epsilon 4 was lower in the older cohort (0.098 vs. 0.122, P = 0.08) and the epsilon 2 allele frequency was higher (0.084 vs. 0.059, P = 0.05) in the older cohort. These observations are consistent with the hypothesis that there may be a selection against individuals with the epsilon 4 allele. However, future research is needed to confirm this observation and to compare survival in individuals by their epsilon allele.