DESCRIPTION OF A NOVEL HLA-B35 (B-ASTERISK-3514) ALLELE FOUND IN A MEXICAN FAMILY OF NAHUA AZTEC DESCENT

A new allele, HLA-B3514, has been found in a Mexican family from Nahu a descent. Its exon 2 is identical to that of B3501 allele, but exon 3 bears a S-base difference at codons 152 and 156, which results in Va l --> Glu and Leu --> Trp changes, respectively, in the corresponding HLA molecule at the peptide-binding site. These substitutions may have originated from a DNA stretch donation from an allele belonging of th e B15 group, enabling HLA-B3514 to cope with the presentation of a ne w set of antigenic peptides. The high frequency of serologic B35 in Am erindians, together with the variety of B35 alleles detected by DNA se quencing in these populations, suggest that: a frequent B35 subtype wa s present in the founder population and that several B35 subtypes may have been recently generated, probably due to the abrupt arrival of ne w pathogens following European invasions.