Identification of Four Novel HLA-A Alleles from an East African Population by High-Resolution Sequence-Based Typing

Abstract

We report here four novel human leukocyte antigen (HLA)–A alleles identified among an East African population during sequence-based HLA-A typing. The novel alleles were confirmed by sequencing two separate polymerase chain reaction products and by molecular cloning and sequencing multiple clones. The new allele A*9202 is identical to A*0202 at exon 2 and exon 3 except for a single nucleotide difference at codon 43 (CGG→CAG), resulting in a coding change from Arginine to Glutamine. The second new allele has a synonymous change at codon 139 (GCA→GCG), that differentiates it from A*680101. The new allele has been named by the World Health Organization nomenclature committee as A*680105. The novel allele A*2630 is identical to A*2603 at exon 2 and exon 3 except for a nonsynonymous change at codon 90 (GAC→GCC), changed from Aspartic acid to Alanine. The fourth new allele is identical to A*290201 except for a single nucleotide difference at codon 138 (ATG→GTG), resulting in a coding change from Methionine to Valine. The new allele has been named by the World Health Organization nomenclature committee as A*2915. Identification of these novel HLA-A alleles reflects the genetic diversity of this East African population.