HLA antigens in South India: I. Major groups of Tamil Nadu.

HLA-A, B profile of 385 normal healthy individuals living in Tamil Nadu, India was studied by microlymphocytotoxicity testing. Antigen, gene and haplotype frequencies of this population were calculated and compared to those already available in the literature. The sample was further divided into four major groups and the frequencies calculated. Genetic distances between the various major groups were also calculated: the analyses suggest that these different groups may differ by origin. The study further reveals that in any HLA genetic and disease association studies in India, one should give due consideration to the caste system of the sample studied.