Hemochromatosis gene variants in three different ethnic populations: Effects of admixture for screening programs

Genetic testing for hemochromatosis may have important implications for dia gnosis and screening of the disease. However, the relative importance of mu tations in the gene for hereditary hemochromatosis, HFE, may vary among pop ulations, when the mutant allele frequencies and their penetrance in a part icular genetic and environmental background are taken into account. We pres ent data on the allele and genotype frequencies and population structure of two HFE genetic variants in three different ethnic groups from a highly mi xed urban population (Sao Paulo, Brazil). Allele frequencies for both the C 282Y and H63D HFE mutations showed significant differences among the studie d populations (for the C282Y mutation, Euro-Brazilian 3.7%, admired 0.7%, A fro-Brazilian 0.5%; and for the H63D mutation, Euro-Brazilian 20.3%, admire d 13.0%, Afro-Brazilian 6.4). The data substantiate a European origin for t hese mutations. Furthermore, they provide a basis for a more rational strat egic planning of population screening programs for the disease.