Allele and Haplotype Frequencies in High-Resolution Typing of Human Leukocyte Antigen -A, -B, -C, -DRB1, -DQB1 and -DPB1 in Thai Voluntary Stem Cell Donors

Abstract

The HLA allele and haplotype frequencies were calculated from 110,007 voluntary donors with HLA high-resolution typing and 263,542 voluntary donors with medium to high-resolution typing. This is the first study of a large samples with high-resolution HLA typing in Thai population. The frequencies of HLA-A, -B, -C, -DRB1, -DQB1 and -DPB1 alleles and haplotypes were calculated from typing by next generation sequencing (NGS). A total number of G groups for HLA-A, -B, -C, -DRB1, -DQB1 and -DPB1 were 44, 83, 38, 42, 16 and 39, respectively. A total number of 2-field single allele for HLA-A, -B, -C, -DRB1, -DQB1 and -DPB1 were 142, 196, 122, 122, 71, and 124, respectively. The variety of each HLA alleles in the Thais ranging from 1.86% to 5.58% of the total alleles in IMGT/HLA database. The frequencies of allele following common, intermediate and well-documented (CIWD) groups for HLA-A, -B, -C, -DRB1, -DQB1 and -DPB1 were 104, 155, 87, 98, 48 and 96, respectively. The alleles with frequency greater than 5% were A*02:03, A*11:01, A*33:03, A*02:07, A*24:02, A*24:07, B*46:01, B*15:02, B*44:03, C*01:02, C*07:02, C*03:04, C*08:01, DRB1*12:02, DRB1*14:54 and DQB1*03:03. The haplotypes with frequency greater than 10% were A*33:03∼C*03:02∼B*58:01∼DRB1*03:01∼DQB1*02:01, A*02:07∼C*01:02∼B*46:01∼DRB1*09:01∼DQB1*03:03,A*33:03∼C*07:01:01G∼B*44:03∼DRB1*07:01∼DQB1*02:01:01G and A*11:01∼C*08:01∼ B*15:02∼DRB1*12:02∼ DQB1*03:01. These findings enable the registry to predict the opportunity to find good matched organ and stem cell donors for the patient with rare HLA typing.

Keywords: Allele frequency; Haplotype frequency; High-resolution typing; Human leukocyte antigen (HLA).