HLA antigens in multiple sclerosis amongst Indians.

The infrequency of multiple sclerosis in India may have genetic implications. We found (a) the HLA-A3 and HLA-B7 haplotypes amongst Indians to be lower than those reported in Caucasians, (b) no excess of HLA-A3 and HLA-B7 amongst our 27 multiple sclerosis patients compared to 330 controls; instead it was the reverse, (c) HLA-B12 as high as 74% in the "clinically definite" cases, against only 9% in controls, (d) a significant relative risk of MS amongst Indians with HLA-B12 haplotype. Attention is drawn to th higher incidence of MS amongst the small Parsee community and the high association of HLA-B12 in these patients.