Polymorphism distribution of Int13, Int22, and St14 VNTRs in a Mexican population and their application in carrier diagnosis of hemophilia A.

Variable nucleotide tandem repeats (VNTR) Int13, Int22, and St14 were analyzed to determine polymorphic distribution in normal individuals from Mexico's central region and their efficacy in detecting hemophilia A carriers. Polymerase chain reaction (PCR) was carried out on 166 X chromosomes from unrelated Mexicans, and the same method was applied to detect carriers in hemophilia A families. Screening revealed the existence of at least eight different alleles for Int13, 4 alleles for Int22, and 10 alleles for St14.