Major histocompatibility complex class II alleles in an Uygur population in the Silk Route of Northwest China

HLA class II (DRB1, DQA1, DQB1 and DPB1) genotyping was performed in 57 unrelated Uygur individuals inhabiting the northwestern China area by the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. Among 98 DRB1 alleles tested, 23 alleles were detected, and DRB1(*)0701 (16.7%) and DRB1(*)0301 (14.0%) were the most and the second most common alleles, respectively. In 8 DQA1 alleles detected, DQA1(*)05 (26.3%), DQA1(*)03 (21.9%) and DQA1(*)0201 (21.1%) were very frequent. Of 21 DQB1 alleles tested, 13 were observed. Among them, DQB1(*)02 was highly predominant with the gene frequency of 32.5%. Of 46 DPB1 alleles tested, 15 were detected, among which DPB1(*)0401 (31.6%) was the most frequent. Two haplotypes predominate clearly; DRB1(*)0701-DQA1(*)0201-DQB1(*)02 (15.5%) and DRB1(*)0301-DQA1(*)05-DQB1(*)02 (12.6%). The dendrogram constructed by the neighbour-joining (NJ) method based on the allele frequencies of the DRB1, DQA1, DQB1 and DPB1 genes of 13 representative populations all over the world suggested that Uygur belonged to the Asian group and lay at the closest genetic distance to a Kazak population inhabiting the same area.