RESUMO
America first inhabitants and peopling are still debated. In order to increase knowledge about these questions, we have aimed to detect HLA genes of an Amerindian secluded community: Jaidukama, who lives in North Colombia Equatorial forest. HLA genotyping and extended haplotype calculations were carried out in 39 healthy individuals belonging to 13 families. HLA frequencies were compared to other Amerindians and worldwide populations by calculating genetic distances, relatedness dendrograms and correspondence analyses. Only four DRB1 alleles were found (*0404, *0407, *1402 and *1602); however a total of 17 Amerindian different extended class I-class II HLA haplotypes were directly counted from the family studies, nine of them were specific of Jaidukamas. Some of the alleles or group of alleles within an extended haplotype (i.e. DQB1-DRB1) were also found in Asians and Pacific Islanders, further supporting existence of Asian and Pacific gene flow with Amerindians or a common founder effect. It is further supported that HLA extended haplotypes vary faster than alleles in populations. It is concluded that this unique model of Amerindian secluded families study suggests that rapid HLA haplotype variation may be more important than allele variation for survival (starting immune responses). This work may also be useful for future transplant programs in the area.
