Pharmacogenomics with allopurinol causing DRESS includes which association in Chinese patients?

• A. HLA-B*58:01 in Chinese patients
• B. HLA-B*27:05 in Japanese patients
• C. HLA-DRB1*04:01 in Caucasians
• D. HLA-A*01:01 in Africans

Answer: (A)

Genetic variation in HLA genes can shape how the immune system reacts to drugs, leading to hypersensitivity reactions like DRESS. For allopurinol, the strongest and most consistent association is with HLA-B58:01 in Chinese patients. Carriers of this allele have a markedly higher risk of developing DRESS when exposed to allopurinol, which is why this particular genotype is a key predictor in this population. The other allele–population pairings listed do not have a established link with allopurinol-induced DRESS in those groups, so they’re not the predictive association here. This is the reason the correct match is HLA-B58:01 in Chinese patients, reflecting how pharmacogenomics guides safer prescribing in specific populations.