CLASS-I HLA ANTIGENS IN 2 LONG-SEPARATED POPULATIONS - MELANESIANS AND SOUTH-AMERINDS

Class I HLA antigens have been compared in 5,835 Melanesians of Papua New Guinea and 2,028 Amerindians of South America. The sample includes 50 PNGMel ethnolinguistic groups and 22 SAmInd groups. Both carry 15 serologically defined antigens and an undefined C allele. Except for A 2 in Papua New Guinea and Cw1 in South America, these antigens are wid ely distributed in their respective populations. Nine (A2 and A24, B39 , B60 and B62, and Cw1, Cw3, Cw4, and Cw7) are common to both, This co mmonality suggests that these two populations derive from an ancestral population with less polymorphism than modern East Asians. In both po pulations several theoretically possible haplotypes were absent, and o ther haplotypes were in positive disequilibrium in both. The parallels in disequilibria suggest that haplotypes are subject to selective for ces acting on the level of allelic interaction. Based on three locus h aplotype frequencies, the PNGMel groups form five clusters with intern ally typical linguistic and geographic characteristics and a miscellan eous category, but SAmInd groups show no cluster. (C) 1995 Wiley-Liss, Inc.