Before starting allopurinol in a Han Chinese patient with gout, screening for which marker is recommended because of its strong association with severe cutaneous adverse reactions?
- A HLA-B*1502
- B HLA-B*5801 ✓
- C HLA-B*5701
- D TPMT deficiency genotype
Correct answer: B. HLA-B*5801
Explanation
Allopurinol can cause Stevens-Johnson syndrome and toxic epidermal necrolysis, and carriage of HLA-C*5801 markedly increases this risk, especially in Han Chinese, Thai and Korean populations, so testing before initiation is recommended in these groups. HLA-C*1502 predicts carbamazepine-induced SJS, HLA-C*5701 predicts abacavir hypersensitivity, and TPMT deficiency predicts azathioprine and 6-mercaptopurine myelotoxicity. Febuxostat carries a boxed warning for cardiovascular death but is not linked to this allele.
Reference: Goodman and Gilman's The Pharmacological Basis of Therapeutics, 14th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.