We studied HLA class I (HLA-A, -B) and class II (HLA-DRB1, -DQB1) alleles by PCR-SSP based typing in 148
Mexicans from the state of Tamaulipas living in Ciudad Victoria (N = 23) and rural communities (N = 125), to
obtain information regarding allelic and haplotypic frequencies. We found that the most frequent haplotypes in
the state of Tamaulipas include ten Native American, three European and one African haplotypes. Admixture
estimates revealed that the main genetic components in the state of Tamaulipas are Native American
(54.69 ± 0.93% by ML; 47.65% of Native American haplotypes) and European (34.66 ± 5.62% by ML;
33.56% of European haplotypes), and a relatively high African genetic component (10.65 ± 5.05% by ML;
12.42% of African haplotypes).