ABSTRACT
A member of a new HLA-A locus family, HLA-A*8001, has been characterized from 3 African-American individuals expressing a unique HLA-A serologic specificity. The HLA-A*8001 sequence is most closely related to alleles of the HLA-A1/3/11 family, although it also contains residues characteristic of the HLA-A2/28, -A9, -A10, and -A19 families. More importantly, the HLA-A*8001 sequence contains four unique nonsynonymous (amino acid replacing) nucleotide substitutions absent from all other primate A locus alleles. In addition, five other nucleotide substitutions, four nonsynonymous and one synonymous (silent), observed only in non-human primate A locus alleles were found. Neighbor-joining tree analysis of HLA-A*8001 supports the notion that the HLA-A*8001 allele is a member of a new HLA-A locus family which was derived from the ancestral A3 lineage but diverged early in the evolution of the HLA-A locus.
