RESUMEN
We studied HLA class I (HLA-A, -B) and class II (HLA-DRB1, -DQB1) alleles by PCR-SSP based typing in 250 Mexicans from the states of Baja California Norte and Baja California Sur living in Mexicali (Nâ¯=â¯100), La Paz (Nâ¯=â¯75), Tijuana (Nâ¯=â¯25) and rural communities (Nâ¯=â¯50) to obtain information regarding allelic and haplotypic frequencies. The most frequent haplotypes for the Baja California region include nine Native American and five European haplotypes. Admixture estimates revealed that the main genetic components are European (50.45⯱â¯1.84% by ML; 42.03% of European haplotypes) and Native American (43.72⯱â¯2.36% by ML; 40.24% of Native American haplotypes), while the African genetic component was less apparent (5.83⯱â¯0.98% by ML; 9.36% of African haplotypes).