Which allele increases the risk of Stevens-Johnson syndrome when taking carbamazepine?

The correct answer is HLA-B15:02, as this specific allele is strongly associated with an increased risk of developing Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis in individuals who are prescribed carbamazepine. HLA-B15:02 is predominantly found in certain ethnic groups, most notably individuals of Asian descent, and its presence necessitates caution when considering treatment with carbamazepine due to the heightened risk of these severe skin reactions.

When patients possess this allele, their immune response may be abnormally activated by the drug, leading to a hypersensitivity reaction that manifests as SJS, characterized by extensive skin blistering and detachment, along with mucosal involvement. Genetic testing for HLA-B*15:02 is recommended before starting carbamazepine in populations at risk to prevent these serious adverse reactions.

In contrast to HLA-B15:02, other alleles such as HLA-DRB1, HLA-A02:01, and HLA-C*06:02 do not have the same established connection to carbamazepine-induced Stevens-Johnson syndrome. While they may be related to various other conditions or reactions, they lack the specific correlation that H