HLA genes in Chimila Amerindians (Colombia), the Peopling of America and Medical implications

Our aim is to study the HLA-A, -B, -C, -DRB1 and -DQB1 gene frequencies in the Chimila Amerindian (Colombia) ethnic group. Results are compared with other World populations in order to obtain information about Chimila and Amerindian Health promotion, Amerindian origins and America peopling. Written consent was obtained from Chimila subjects to be included in this study. Peripheral blood was drawn and HLA DNA genotyping was carried out by standard methods. Analyses of Chimila relatedness with other Amerindians and worldwide populations was performed with a standard NJ dendrogram and correspondence analyses methodology. Chimila HLA gene profile showed to be related to that of other Amerindians groups. New complete HLA extended haplotypes were obtained. Some of them are described for the first time. Also, specific genealogical comparisons were done between Chimila Amerindians and Pacific Islanders by using specific HLA alleles. Our conclusions are: 1) These new data and HLA extended haplotypes are useful for present and future Chimila Preventive Medicine (HLA linked diseases), HLA Pharmacogenomics and transplantation regional programs, 2) Classical accepted origin of America peopling should be revised: Pacific (Asian and Austronesian) and Atlantic (European) populations gene exchange may have occurred before 1492 AD. This is confirmed by our present studies using HLA autosomic genetic markers. 3) Genetic HLA Amerindian profile is separated from that of other World populations. Keywords : America peopling, Amerindians, Anthropology, Chimila, Epidemiology, HLA and Transplantation.