Distribution of plasma alpha-1-B-glycoprotein (A1BG) polymorphism in several populations of the Indian subcontinent.

The distribution of plasma alpha 1B-glycoprotein (A1BG) was determined by a two-dimensional electrophoresis (agarose-polyacrylamide gel) followed by protein staining in a group of 1099 individuals from 11 populations of the Indian subcontinent. The sample comprised 454 from several tribes of Arunachal Pradesh; 76 Bengali Hundus and 88 Bengali Muslims; 179 Tamil Hindus from Singapore and 107 from India; 81 Tamil Muslims, 48 Sinhalese from Sri Lanka and 66 North Indians. Three common A1BG phenotypes (1-1, 1-2 and 2-2) were observed in this study. One each of a new allele (A1BG7) in heterozygous form (1-7) was detected respectively among Tamil Hindus of India and Singapore. The phenotypic distribution of A1BG alleles was at Hardy-Weinberg equilibrium in all the populations. The frequency of A1BG2 was in general lower in the Mongoloid tribes of Arunachal Pradesh (0.043-0.104) and North Indians (0.068) compared to that in other Indian populations (0.130-0.171) and Sinhalese (0.208).