HLA-B ALLELES OF THE NAVAJO - NO EVIDENCE FOR RAPID EVOLUTION IN THE NADENE

New HLA-B locus alleles have been found in South American Amerindian p opulations but were largely absent in North American Amerindian tribes also descended from this first Paleo-Indian migration. We have now ex tended these studies to the Navajo, descendants of the second Nadene m igration. No new functional alleles were found at the B locus of this tribe. This limited study supports the notion that while new B locus v ariants are common in South American Amerindians, it is more difficult to find new B locus alleles in North American native peoples. Whether this dichotomy is due to differences in pathogen environment and/or p opulation structures between North and South America remains a subject of speculation.