CYP2C9*3 associated with PHT-induced SJS (OR: 10.41; 95% CI: 2.06–55.42; p = 0.0042).HLAB*13:01, HLAB*56:02/04 and CYP2C19*3 (OR: 13.29; p = 0.0001; OR: 56.23; p = 0.0007 and OR: 6.75; p = 0.0414, respectively). The gene discussed is CYP2C9; the disease is pulmonary hypertension, primary, 1.