Analysis of factor VIII gene polymorphisms in Brazilian blacks reveals further differences in the black population.

We report here the analysis of four intragenic (BclI, HindIII, XbaI, and BglI) and two extragenic (MspI and TaqI/St14) polymorphisms associated with the factor VIII gene in the Brazilian Black population. No difference was observed for the allelic frequencies of the BclI, HindIII, and BglI polymorphisms when we compared our results with those reported for North American Blacks. For the first time, the XbaI and MspI polymorphisms were investigated in a Black population. Interestingly, the XbaI polymorphism is almost monomorphic for the Brazilian Black population, differing in this respect from all other populations studied thus far. The MspI polymorphism presents inverse allelic frequencies for the Brazilian Blacks when compared with Caucasians, as observed for the BclI and HindIII polymorphisms. Analysis of the TaqI/St14 multiallelic system revealed five novel alleles (ranging from 5.8 to 11.0 kb) which may represent unique alleles for the Black population. The results show that analysis of factor VIII gene polymorphisms and haplotypes may be successfully used for investigating interrelationships between human populations. The results also allow definition of a strategy for carrier detection and prenatal diagnosis of hemophilia A in this population based on analysis of factor VIII gene polymorphisms, which is considered an alternative approach for those families where identification of gene mutation is not feasible.