A Study on Polymorphisms and Common and Well-Documented Alleles of HLA-DPA1 and-DPB1 in Southern Chinese Han Population

Abstract

Objective To explore the polymorphisms of human leukocyte antigen (HLA)-DPA1 and-DPB1,and determine the common and well-documented (CWD) alleles in southern Chinese Han population.Methods From February 2010 to September 2011,a total of 1 730 cases of peripheral blood samples from unrelated healthy voluntary blood donors of Chinese Han population in Shenzhen blood center,were collected in this study by compater random number table.All these samples were subjected to HLA-DPA1 and-DPB1 sequencing-based typing at exon 2 in both directions.In-house group specific primers were designed and utilized to identify the ambiguous allele combinations.Products of sequencing reactions subjected to sequence cleaning by EtOH/ethylene diamine tetraacetic acid (EDTA) method.The purified products were run electrophoresis on the ABI 3730 DNA sequencer,then obtained sequences were imported into the Assign 3.5 software,and the HLA-DPA1 and-DPB1 allelic genotype were assigned.Results In 1 730 unrelated healthy southern Chinese Han individuals,a total of 7 HLA-DPA1 alleles were identified,including 5 common alleles of which the frequencies were more than 0.1％.Frequencies of each common allele were 54.65％ of DPA1 * 02 ∶ 02,31.24％ of * 01 ∶ 03,10.26％ of * 02 ∶ 01,3.64％ of * 04 ∶ 01,and 0.12％ of * 01 ∶ 04.Two rare novel alleles were observed in less than 3 times.Thirty three HLA-DPB1 alleles including 20 common alleles with a frequency more than 0.1％,and 2 well-documented alleles with a frequency less than 0.1％ but were detected more than 3 times and 11 rare alleles of which two were novel alleles were determined.Conclusions Technique for simultaneous HLA-DPA1 and-DPB1 sequencebased typing at exon 2 and assay for determining ambiguous allele combinations using the in-house group specific primers have been established in this study.The information of allele frequencies and CWD alleles for HLA-DPA1 and-DPB1 in southern Chinese Han population were obtained. Key words: Human leukocyte antigens; Sequencing-based typing; Group specific primer; Common and well-documented alleles