The present invention provides a method of predicting the risk of a patient for developing adverse
drug reactions, particularly SJS or TEN. It was discovered that an HLA-B
allele, HLA-B* 1502, is associated with SJS / TEN that is induced by a variety of drugs. The correlation with HLA-B* 1502 is most significant for
carbamazepine-induced SJS / TEN, wherein all the patients tested have the HLA-B* 1502
allele. In addition, another HLA-B
allele, HLA-B*5801, is particularly associated with SJS / TEN induced by
allopurinol. Milder cutaneous reactions, such as maculopapular
rash,
erythema multiforme (EM), urticaria, and fixed
drug eruption, are particularly associated with a third allele, HLA-B *4601. For any of the alleles, genetic markers (e.g., HLA markers,
microsatellite, or
single nucleotide polymorphism markers) located between DRB1 and HLA-A region of the specific HLA-B
haplotype can also be used for the test.