Abacavir (ABC) is a NRTI (nucleoside reverse transcriptase inhibitor) antiretroviral drug has potent antiviral activity against HIV infection. Abacavir can cause a severe hypersensitivity reaction (ABC-HSR) in about 5–8% of persons living with HIV (PLHIV) and varies in severity and clinical manifestation indicative of multiorgan involvement, including fever, skin rash, constitutional, gastrointestinal tract, and respiratory symptoms. According to pharmacogenetic studies, development of abacavir hypersensitivity reaction is strongly associated with the HLA-B*57:01 allele. ABC-HSR is reduced or eliminated by prospective HLA-B*57:01 screening. Therefore, HLA-B*57:01 genotyping is required prior to the prescription of ABC. The sequence-specific oligonucleotide probes (SSOP) reverse hybridization method, followed by Sanger sequencing, is routinely used in laboratory. This method is both time-consuming and costly. HCP5 rs2395029 is localized within the MHC class I region, was found to be in complete linkage disequilibrium with HLA-B*57:01. In this review, we examine the prevalence of HLA-B*57:01, available diagnostic techniques, and its linkage disequilibrium (LD) with the HCP5 rs2395029 (G) allele in various ethnic groups around the world.