Molecular diversity of HLA-A*02 in Asian Indians: predominance of A*0211.

The North Indians are considered predominantly Caucasoid with an admixture of genes from the Mongoloid and Aryan races. The present study was undertaken to investigate the genetic diversity of HLA-A*02 in the North Indian population and determine the frequency distribution of its molecular subtypes at the population level. The study revealed a high occurrence of A*0211 (33.8%) in this population along with increased frequencies of the common Oriental alleles, A*0206 (7.5%) and A*0207 (32.5%) and also of HLA-A*0205 (15%) commonly observed in negroid populations. HLA-A*0211 has only been reported with very low frequencies among the Ticuna Jews, Thai population, and Colombian Blacks in the malaria endemic areas of Africa. Significantly, we observed an unexpectedly low frequency of A*0201 (3.8%) in contrast to its distribution in Western Caucasians in whom it constitutes 95% of the HLA-A2 repertoire. Prevalence of HLA-A*0211 at very high frequencies among North Indians may be a consequence of the founder effect, racial admixture or selection pressure due to environmental factors in this population.