POPULATION-GENETICS OF THE HRAS1 MINISATELLITE LOCUS

Several years ago it was reported that rare HRAS1 VNTR alleles occurre d more frequently in U.S. Caucasian cancer patients than in unaffected controls. Such an association, in theory, could be caused by undetect ed population heterogeneity. Also, in a study clearly relevant to this issue, it was recently reported that significant deviations from Hard y-Weinberg equilibrium exist at this locus in a sample of U.S. Caucasi ans. These considerations motivate our population genetic analysis of the HRAS1 locus. From published studies of the HRAS1 VNTR locus, which classified alleles into types, we found only small differences in the allele frequency distributions of samples from various European natio ns, although there were larger differences among ethnic groups (Africa n American, Caucasian, and Oriental). In an analysis of variation of r are-allele frequencies among samples from four European nations, most of the variance was attributable to molecular methodology, and very li ttle of the variance was accounted for by nationality. In addition, we showed that mixture of European subpopulations should result in only minor deviations from expected genotype proportions in a Caucasian dat abase and demonstrated that there was no significant deviation from Ha rdy-Weinberg equilibrium in our HRAS1 data.