Genetic diversity of HLA system in three populations from Sonora, Mexico: Ciudad Obregón, Hermosillo and rural Sonora.

We studied HLA class I (HLA-A, -B) and class II (HLA-DRB1, -DQB1) alleles by PCR-SSP based typing in 439 Mexicans from the state of Sonora living in Ciudad Obregón (N = 143), Hermosillo (N = 99), and rural communities (N = 197) to obtain information regarding allelic and haplotypic frequencies. We find that the 13 most frequent haplotypes for the state of Sonora include nine Native American, three European and one Asian haplotypes. Admixture estimates revealed that the main genetic components in the state of Sonora are European (51.25 ± 2.90% by ML; 37.70% of European haplotypes) and Native American (43.35 ± 2.57% by ML; 39.64% of Native American haplotypes), while the African genetic component was less apparent (5.39 ± 2.54% by ML; 11.04% of African haplotypes).