Prospective screening for HLA-B*5701 decreases or abolishes abacavir hypersensitivity reaction. In Caucasians, the HLA complex protein 5 gene (HCP5) rs2395029(G) allele is in complete linkage disequilibrium (LD) with HLA-B*5701 (r(2) = 1).
Aim: To assess the frequency of HLA-B*5701 and its LD with HCP5 rs2395029(G) allele, to extend our knowledge of genetic variants that are of critical relevance for the development of pharmacogenetics in Mexico.
Materials & methods: We genotyped 300 Mexican Mestizos from the Mexican Genome Diversity Project. HLA-B*5701 genotyping was performed using a DNA sequencing method. HCP5 rs2395029 was genotyped using a custom TaqMan(®) SNP genotyping assay and confirmed by direct sequencing. Genotypes for 14 SNPs in the HCP5 region were retrieved from the Mexican Genome Diversity Project database for LD analysis.
Results: HLA-B*5701 carrier frequency was 2% and the allelic frequency was 0.010. Haplotype analysis revealed that HLA-B*5701 and the HCP5 rs2395029(G) allele are in complete LD (r(2) = 1) in this Mexican Mestizos sample.
Conclusion: It is feasible to have a pharmacogenetic program based on HCP5 rs2395029 genotyping as a screening tool with confirmation of HLA-B*5701 carriage by sequenciation, to prevent abacavir hypersensitivity reaction in Mexican patients before initiating abacavir therapy.