Distribution of Alleles and Haplotypes in Qatari: Recommendation for Establishing Pharmacogenomic Markers Screening for Drug Hypersensitivity.

Human leukocyte antigen (HLA) proteins are present at the cellular surface of antigen-presenting cells and play a crucial role in the adaptive immune response. Class I genes, specifically certain alleles, are associated with adverse drug reactions (ADRs) and are used as pharmacogenetic markers. Although ADRs are a common causes of hospitalization and mortality, the data on the prevalence of pharmacogenetics markers in Arab countries are scarce. In this study, we investigated the frequencies of major pharmacogenomics markers in the Qatari population. Next-generation sequencing data from 1,098 Qatari individuals were employed for typing using HLA-HD version 1.4.0 and IPD-IMGT/HLA database. In addition, pharmacogenetics markers were obtained from the HLA Adverse Drug Reaction Database. In total, 469 major pharmacogenetic markers were identified, with *51:01 being the most frequent pharmacogenetic marker (26.67%) in the Qatari population. Moreover, *51:01 is associated with phenytoin- and clindamycin-induced ADRs. The second most frequent pharmacogenetic marker was the *58:01 allele (6.56%), which is associated with allopurinol-induced ADRs. The third most frequent pharmacogenetic marker was the *44:03 allele, which is associated with phenytoin-induced ADRs. The establishment of a pharmacogenetics screening program in Qatar for cost effective interventions aimed at preventing drug-induced hypersensitivity can be aided by the highly prevalent pharmacogenetic markers detected here.