Novel HLA-A and HLA-B alleles in South American Indians

The human leukocyte antigen (HLA) complex includes the most polymorphic genes in humans. More than 600 allelic variants have been described in different populations. The HLA-B locus has contributed the largest number of alleles. Although Native American populations display a restricted number of HLA-alleles, many novel HLA class I alleles have been identified in indigenous communities of Central and South America. We have studied 248 unrelated individuals from three tribes of North-East Argentina and one from South-West Brazil, as well as 80 related individuals from the Brazilian tribe. In the course of this work, we found 8 new B-locus alleles and 2 novel A-locus alleles in these populations. Here we report the nucleotide sequences of A*0219, A*0222, B*3519, B*3520, B*3521, B*3912, B*4009 and B*4803 and we show their relationship with similar alleles. The new alleles B*35092 and B*3518 have been described by us in a previous paper. The possible mechanisms that may have produced these alleles over evolutionary time are discussed.