Analysis of the complete genomic sequence of HLA-A alleles in the Chinese Han population

To analyse the complete genomic sequences and investigate the intron polymorphism of the human leucocyte antigen (HLA)-A locus, the full-length nucleotide sequences of each major allelic group of HLA-A in the Chinese Han population were determined, including HLA-A*01, A*02, A*03, A*11, A*23, A*24, A*26, A*29, A*30, A*31, A*32, A*33, A*34, A*68, A*69. More than 3.0-kb DNA fragment of HLA-A locus was amplified from 5'-untranslated region to 3'-noncoding region for sequencing. Full-length sequences of the HLA-A alleles were determined using an ABI BigDye((R)) Terminator Cycle Sequencing kit and the HLA-A phylogenetic tree was analysed by dnaman software. Full-length nucleotide sequences of 15 HLA-A alleles (GenBank Accession numbers EU445470-EU445484) were obtained. HLA-A*110101, A*2301, A*300101, A*310102, A*330301, A*340101, A*680102 and A*6901 alleles were firstly reported for complete genomic sequences. Total 247 polymorphism positions were found in the complete genomic sequences of HLA-A alleles and a insertion of 17 nucleotides within intron 3 was observed in several allelic groups. According to the phylogenetic tree of the full-length nucleotide sequences, HLA-A locus was classified into seven major allelic lineages. In this study, complete genomic sequences of common HLA-A alleles were obtained and the data will help us understand the evolution of HLA-A.