Carrier detection of hemophilia A in a Mexican population by two Bcl I polymorphisms.

The frequency of alleles, intragenic (intron 18) and extragenic (DXS52) Bcl I RFLPs was investigated in a sample of the Mexican population. Altogether 33 X chromosomes at R8c locus and 30 at DXS52 locus were studied. The allele frequencies found at the F8c locus were similar to those reported in the majority of other populations. The observed heterozygosity for the intragenic and extragenic markers were 0.57 and 0.64, respectively. By using these two RFLPs 15 females at risk in five independent families with hemophilia A were investigated; ten of them could be identified and five excluded as carriers.