HLA profile of the Mexican Mestizo population.

The HLA-A, B and C profile of 665 Mexican Mestizos was studied by microcytotoxicity testing for 30 HLA specificities. Antigen, gene and haplotype frequencies were calculated, and results were compared to those of the three other series of HLA profiles in Mexican Mestizos available in the literature: one from Mexico-City, one from Los Angeles, California, USA, and a recent one from San Antonio, Texas, USA. Comparing the antigen frequencies of our series with those of the other study from Mexico-City, significant differences were only found in three antigens of the HLA-B locus. On the other hand, comparison of either series from Mexico-city with the Los Angeles or the San Antonio studies yielded discrepancies in several specificities of both HLA-A and B loci, most notably the consistent absence of A25 in Mexican Mestizos living in Mexico-City. The presence of this specificity in the Mexican Mestizo Population living in these two American cities could have resulted from input of Caucasian and Black genes over several generations. Differences in haplotype frequency were observed comparing the two series from Mexico-City and the series from San Antonio. Comparison of haplotype frequency with the Los Angeles series was not possible.