Diversity of HLA-DQA1 gene in the Korean population.

Genotype of the human leukocyte antigen (HLA)-DQA1 locus was analyzed in Koreans (n= 467) using the 14th International Workshop protocol established to characterize the sequences of exons 1-4 of the gene. Unexpectedly, it appeared that the DQA1 (19 alleles) was more diverse than DQB1 (15 alleles) in the study population. DQA1010201, DQA10303, DQA10103, and DQA10302 appeared to be major alleles exhibiting more than 10%. Among six allele groups, DQA101-06, DQA101 showed highest diversity exhibiting seven different alleles. Analysis using maximum likelihood method showed numerous multi-locus HLA haplotypes. High relative linkage disequilibrium values (RLD) of the two-locus haplotypes and exclusive association of a specific DQA1 allele with a specific DRB1 and/or DQB1 alleles suggested tight linkage of DQA1 to DRB1 and DQB1. In HLA-matching process for hematopoietic stem cell transplantation, however, DQA1 typing would be informative for individuals carrying specific DRB1 allele (DRB10802, DRB11201, or DRB11403) that could be associated with multiple DQA1 alleles in the study population. Information obtained in this study will be useful in medical and forensic areas as well as in anthropology.