IMMUNOGLOBULIN ALLOTYPES AND ESTIMATION OF GENETIC ADMIXTURE AMONG POPULATIONS OF KINNAUR DISTRICT, HIMACHAL-PRADESH, INDIA

Four regional populations of the Kanet (Puh, Kalpa, Sangla, and Nachar ) and an endogamous group of Koli from Kinnaur District, Himachal Prad esh, India, were studied to determine the extent of genetic variation of immunoglobulin allotypes (GM, KM, and AM) and the genetic contribut ion from ancestral populations of Tibet and northwest India. Haplotype GMA G showed a higher frequency in the Kanet (40-60%)-a frequency th at is more comparable to Asian populations-whereas in the Koli a lower frequency was observed, which is nearer the values for populations fr om northwest India. The IG haplotype data suggest that the Kanet popul ation of Kinnaur District and the northeastern population of Nepal hav e different European origins than the more central population of India , represented by a sample from Delhi. The present results suggest that the populations of Kinnaur District are of admired origin with contri butions of Tibetan genes of 87.3%, 51.3%, 49.9%, 40.0%, and 9.5% in th e Puh, Kalpa, Sangla, and Nachar Kanet and the Koli, respectively. The genetic distance obtained from 19 loci (9 blood groups, 8 biochemical markers, GM, and KM) showed an inverse relationship between the dista nce of the hybrid population from the parental gene pool. The Puh Kane t, nearest the Tibetan border, had the highest proportion of Tibetan g enes but showed the lowest genetic distance with Tibetans. As the geog raphic distance of the other regional populations of the Kanet increas es from the border of Tibet, genetic distance compared with the parent al Tibetan population increases and the proportion of Tibetan admixtur e decreases. In the Kinnaur District admixture seems to contribute lar gely to the present-day observed high level of genetic differentiation .