Frequency and haplotype association of HLA-DQB1∗03:19 in Saudi Arabian population

Abstract

Background The relatively new HLA-antigen DQB1∗0319 allele was identified in 2006 and included as common allele in the updated common and well documented allele (CWD) list. HLA-DQB1∗03:19 allele differs from DQB1∗03:01allele at nucleotide position 554 (CT) in Exon 2, which results in Thr to Ile amino acid exchange. This allele shows a strong association with DRB1∗11:02. Rare association with DRB1∗13:04 had been also reported. Objective To assess the frequency of DQB1∗03:19 allele in Saudi population we reviewed all HLA- typing results of our database (4000). The samples represent patients and corresponding donors referred to the only transplant center covering the largest province in Saudi Arabia during five years period. Methods Medium resolution typing for HLA-DRB1 and -DQB1 was performed by Luminex-based SSO method. Sequencing based typing (SBT) was performed by Atria Genetics HLA SBT kits and analyzed on ABI 3130 Genetic Analyzer using ASSIGN 3.6 software (Conexio Genomics). Results HLA DQA1∗05:05 -DQB1∗03:19 allele was observed in 124 (3%) individuals. The data showed that the majority of these DQB1∗03:19 samples (65%) were also positive for either, DRB1∗11:01 or DRB1∗11:02 and DRB3∗02:02 alleles, suggesting that the haplotype DRB1∗11:01/02, DRB3∗02:02, is the commonest haplotype having this antigen. The next common haplotype was DQB1∗03:19, DRB1∗08:04 (15%), followed by DQB1∗03:19, DRB1∗07:03 (11%) followed by DQB1∗03:19, DRB1∗03:01 (9%). Conclusion Our data suggests that DQB1∗03:19 is observed frequently in Saudi population and the commonest haplotype reported is in agreement with the known DRB1∗11:01/02 association, however unusual association with DRB1∗08:04 or 07:03 or 03:01 probably is unique to our population.