Allele and haplotype frequencies of human leukocyte antigen-A, -B, -C, -DRB1, and -DQB1 from sequence-based dna typing data in Koreans

Abstract

Background: Data on allele frequencies (AFs) and haplotype frequencies (HFs) of HLA-C and -DQB1 are limited in Koreans. We investigated AFs and HFs of HLA-A, -B, -C, -DRB1, and -DQB1 in Koreans by high-resolution sequence-based typing (SBT). Methods: Hematopoietic stem cells were obtained from 613 healthy, unrelated donors to analyze HLA-A, -B, -C, -DRB1, and -DQB1 genotypes by using AlleleSEQR HLA-A, -B, -C, -DRB1, and -DQB1 SBT kits (Abbott Molecular, USA), respectively. Alleles belonging to HLA-C∗07:01/07:06 group were further discriminated by using PCR-sequence specific primer analysis. AFs and HFs were calculated by direct counting and maximum likelihood method, respectively. Results: In all, 24 HLA-A, 46 HLA-B, 24 HLA-C, 29 HLA-DRB1, and 15 HLA-DQB1 al-leles were identified. AFs and HFs of HLA-A, -B, and -DRB1 were similar to those reported previously. For the HLA-C locus, C∗01:02 was the most common allele, followed by C∗03:03, C∗03:04, C∗14:02, C∗03:02, and C∗07:02 (AF ≥7%). AFs of C∗07:01 and C∗07:06 were 0.16% and 3.18%, respectively. For the HLA-DQB1 locus, DQB1∗03:01 was the most common allele, followed by DQB1∗03:03, ∗03:02, ∗06:01, ∗05:01, ∗04:01, and ∗06:02 (AF =7%). AFs of DQB1∗02:01 and DQB1∗02:02 were 2.12% and 6.69%, respectively. HFs of A∗33:03-C∗07:06 and C∗07:06-B∗44:03 were 3.09% and 3.10%, respectively, while those of DRB1∗07:01-DQB1∗02:02 and DRB1∗03:01-DQB1∗02:01 were 6.61% and 2.04%, respectively. Conclusions: This study reported AFs and HFs of HLA, including HLA-C and -DQB1, in Koreans by using high-resolution SBT. These data can be used to resolve ambiguous results of HLA typing for organ and hematopoietic stem cell transplantations.