HLA-B and Stevens-Johnson syndrome: So far, the evidence for a clinical PGx effect on ADRs is probably best for non-dose-related hypersensitivity reactions, such as carbamazepine induced Stevens-Johnson syndrome in the carriers of the HLA-B*1502 allele [13], or abacavir-related hypersensitivity in the carriers of the HLA-B*5701 allele [14].