Allele and Haplotype Frequencies of HLA-A, -B, -C, and -DRB1 Genes in 3,750 Cord Blood Units From a Kinh Vietnamese Population

Abstract

The frequencies and diversities of human leukocyte antigen (HLA) alleles and haplotypes are representative of ethnicities. Matching HLA alleles is essential for many clinical applications, including blood transfusion, stem cell transplantation, and tissue/organ transplantation. To date, the information about the frequencies and distributions of HLA alleles and haplotypes among the Kinh Vietnamese population is limited because of the small sample size. In this study, more than 3,750 cord blood units from individuals belonging to the Kinh Vietnamese population were genotyped using PCR sequence-specific oligonucleotide (PCR-SSO) for HLA testing. The results of the study demonstrated that the most frequently occurring HLA-A, -B, -C, and -DRB1 alleles were A*11:01 (25%), A*24:02 (12.3%), A*02:01 (11.2); A*03:03 (8.95%), A*02:03 (7.81%), A*29:01 (7.03%); B*15:02 (15.1%), B*46:01 (10.7%), B*58:01 (7.65%), B*38:02 (7.29%); C*08:01 (17.2), C*07:02 (16.2%), C*01:02 (15.2), C*03:02 (8.3%), C*15:05 (6.13); DRB1*12:02 (31.0%), DRB1*09:01 (10.47%), DRB1*15:02 (7.54%); DRB1*07:01 (6.68%), DRB1*10:01 (6.63%), respectively, with the highest allele diversity level observed in locus B (93 alleles). The most frequent haplotypes of two-locus combinations of HLA-A–B, HLA-A–C, HLA-A–DRB1, HLA-B–C, HLA-B–DRB1, and HLA-C–DRB1 haplotypes were A*11:01–B*15:02 (7.63%), A*11:01–C*08:01 (7.98%), A*11:01–DRB1*12:02 (10.56%), B*15:02–C*08:01 (14.0%), B*15:02–DRB1*12:02 (10.47%), and C*08:01–DRB1*12:02 (11.38%), respectively. In addition, the most frequent haplotypes of three- and four-locus sets of HLA-A–B–C, HLA-A–B–DRB1, HLA-A–C–DRB1, HLA-B–C–DRB1, and HLA-A–B–C–DRB1 were A*11:01–B*15:02–C*08:01 (7.57%), A*11:01–B*15:02–DRB1*12:02 (5.39%), A*11:01–C*08:01–DRB1*12:02 (5.54%), B*15:02–C*08:01–DRB1*12:02 (10.21%), and A*11:01–B*15:02–C*08:01–DRB1*12:02 (5.45%), respectively. This study provides critical information on the frequencies and distributions of HLA alleles and haplotypes in the Kinh Vietnamese population, accounting for more than 85% of Vietnamese citizens. It paves the way to establish an umbilical cord blood bank for cord blood transplantation programs in Vietnam.

Human Leukocyte Antigens and Sulfamethoxazole/Cotrimoxazole–Induced Severe Cutaneous Adverse Reactions

“…Finally, the significant associations found in the HLA-A*11:01, HLA-B*15:02, and HLA-C*08:01 alleles may reflect the linkage disequilibrium in Asian populations. The frequency of the HLA-A*11:01–B*15:02–C*08:01 haplotype was approximately 8% in Kinh Vietnamese populations, while HLA-A*11:01–B*15:02–C*08:01–DRB1*12:02–DQB1*03:01 was around 2% in Chinese populations . Therefore, the results of our study should be interpreted more conservatively.…”

“…3 To prevent double counting, we extracted the data for SMX from the study and integrated the results with data from other relevant studies. Finally, the significant associa- 34,35 Therefore, the results of our study should be interpreted more conservatively.…”

The pharmacogenomics of carbamazepine-induced cutaneous adverse drug reaction in the South of Vietnam

“…Comparatively, Do MD et al (Do et al, 2020) reported these two to be 7.92% and 9.41% respectively. Que TN et al (Que et al, 2022) also reported these two alleles to be 7.29% and 10.7% respectively.…”

“…The possible explanation may be due to the different regions or the small sample size, which can only reflect a part of the whole population. Interestingly enough, Que TN et al ( Que et al, 2022 ) reported a frequency of 15.11% of HLA-B*15:02 with a sample size of 3750 participants, who were recruited in Northern and North-central Vietnam ( Que et al, 2022 ). Besides, we found the frequencies of HLA-B*38:02 and *46:01 to be equally 10%.…”

Frequency and distribution of HLA‐DQB1 alleles from 2076 cord blood samples of the Vietnamese cohort

“…Clinically, cord blood samples were collected within 24 h of birth. Before storage, all cord blood samples were checked for the following parameters: no blood cluster or bizarre colours, mean corpuscular volume ≥ 95 fl, no abnormal haemoglobin confirmed by high performance liquid chromatography analysis, number of nucleated cells ≥ 10 9 cells/ml and negative for infectious pathogens, including hepatitis C virus, hepatitis B virus, human immunodeficiency virus, cytomegalovirus and bacteria (Que et al., 2022).…”