HLA alleles play a critical role in drug hypersensitivity reactions. Some alleles are linked to severe reactions, such as Stevens-Johnson syndrome or toxic epidermal necrolysis, caused by drugs like carbamazepine and allopurinol. For example, the allele HLA-B*15:02 is associated with carbamazepine-induced hypersensitivity in certain Asian populations, highlighting the need for genetic screening before drug administration in susceptible groups.
