ASSOCIATIONS BETWEEN HLA CLASS-II ALLELES IN A NORTH INDIAN POPULATION

The HLA DR and DQ class II genes are in strong linkage disequilibrium and recombinaton is quite rare. However, many different DR-DO haplotyp es appear to have developed during evolution, giving rise to a variety of combinations with different distributions in populations. In the p resent report, 138 subjects from North India were studied for the alle les of HLA-DRB1, DRB3, DRB5, DQB1 and DQA1 loci using PCR-oligotyping. The probable haplotypes were constructed based on two-locus associati ons observed in this population A frequent haplotype in this populatio n, DRB11501-DRB5*0101-DQA1*0103-DQB1*0601, has been reported very rar ely in other ethnic groups. Other DR2 haplotypes, like DRB11502-DRB5* 0102-DQA10103-DQB1*0601, earlier reported in Caucasians, Chinese and Latin Americans, and DRB11502-DRB5*0102-DQA1*0103-DQB1*0503, earlier reported in Gypsies, were also observed. A relatively rare haplotype i n Caucasians which was earlier reported in Gypsies from the Czech Repu blic, DRB11404-DRB3*0202-DQA1*0101-DQB1*0503, was observed frequently in Indians, suggesting the probable migration of Gypsies from India T he results suggest that the North Indian population contains a mixture of Caucasoid, Black and Chinese genes. Similarities with Gypsies and South-East Asian populations suggest the role of ancient migrations fr om India.