Additional sequence analysis outside exon 2 clarifies DRB1*12 and DRB1*14 allelic frequencies in Koreans

Polymorphisms Outside exon 2 of the DRB1 coding region exhibit increased ambiguities in allele assignments in typing laboratories analyzing the exon 2 sequence alone. This study investigated the frequencies of alleles in DRB1*120101/1206/1210 and DRB1*140101/1454 groups by DNA sequencing of exons I and/or 3 and examined their associations with class 11 alleles at adjacent loci in Koreans. Of 103 individuals, 97 were DRB1*120101 and 6 were DRB1*1210. None Carried DRB1*1206, an allele initially characterized from a Korean individual. Association of DRB1*120101 with various DRB3, DQA1. and DQB1 alleles was reflected in 11 different four-locus haplotypes. In contrast, DRB1*1210 was exclusively associated with DRB3*020201, DQA1*0505, and DQB1*0301. All 97 DRB1*140101/1454 samples were DRB1*1454. DRB1*1454 was strongly associated with DRB3*020201, DQA1*010401, and two different DQB1 alleles (*0502, *0503). Continuous updating of HLA high-resolution typing information will be useful in the development of typing and matching strategies for hematopoietic stem cell transplantation. (C) 2009 American Society for Histocompatibility and Immunogenetics. Published by Elsevier Inc. All rights reserved.