Distribution of HLA-DQA1, -DQB1 and -DRB1 genes and haplotypes in Han, Uyghur, Kazakh and Hui populations inhabiting Xinjiang Uyghur Autonomous Region, China.

Genetic polymorphisms of human leucocyte antigen (HLA)-DRB1, -DQA1 and -DQB1 among four main ethnic groups including Han (n = 70), Uyghur (n = 71), Kazakh (n = 52) and Hui (n = 40) subjects from Xinjiang Uyghur Autonomous Region were investigated using a polymerase chain reaction-sequence-based typing (PCR-SBT). In total, 32 HLA-DRB1 alleles, eight HLA-DQA1 alleles and 14 HLA-DQB1 alleles were identified. The most predominant HLA-DRB1, -DQA1 and -DQB1 alleles were DRB115:01 (12.50%), DQA101:02 (21.43%) and DQB103:01 (19.29%) in Han; DRB107:01 (18.48%), DQA105:01/03/05 (24.65%) and DQB102:01/02 (31.69%) in Uyghur; and DRB113:01 (13.64%), DQA105:01/03/05 (28.85%) and DQB102:01/02 (27.88%) in Kazakh, respectively. In Hui, DRB107:01, DRB111:01 and DRB114:01 were the most dominant alleles with the same frequency of 11.8%, while the predominant DQA1 and DQB1 alleles were DQA103:01/02/03 (23.75%) and DQB102:01/02 (16.25%), respectively. In addition, the most common two-locus haplotypes were DQA105:01/03/5-DQB103:01 (10.0%) in Han; DQA102:01-DQB102:01/02 (18.31%) in Uyghur; DQA105:01/03/05-DQB102:01/02 (15.38%) in Kazakh; and DQA103:01/02/03-DQB103:03 (11.25%) in Hui. The phylogenetic dendrograms constructed based on the allele frequencies of HLA-DRB1, -DQA1 and -DQB1 in 13 populations (e.g. Asian, Central Asian and European) revealed that the Han and Hui populations were clustered together and closest to Han population from China, while the Kazakh and Uyghur populations were closest to each other and two ethnic groups were clustered together with Central Asian and European populations.