Genetic screening for human leukocyte antigen alleles prior to carbamazepine treatment

Abstract

We describe a 28-year-old Malaysian Australian man of Han Chinese descent with toxic epidermal necrolysis (TEN), occurring 2weeks after commencing carbamazepine. He was subsequently found to be positive for human leukocyte antigen (HLA)-B*1502. Carbamazepine-induced Stevens–Johnson syndrome/TEN is strongly associated with the HLA-B*1502 allele, which is highly prevalent in Han Chinese, Malay, Thai and Indian populations. Prospective screening for the allele may prevent this cutaneous adverse drug reaction from occurring, but many neurologists and other medical practitioners are still unaware of the medico-legal risks of prescribing carbamazepine in susceptible populations and the availability of HLA-B*1502 testing. Performing HLA-B*1502 genotyping and avoiding carbamazepine in at-risk individuals has been proven to decrease incidences of drug-induced TEN. This test is widely available at most large pathology services in Australia, with results available within 2weeks. The recommendation by regulatory bodies should be strengthened to ensure that the broad medical community is made more aware of this pertinent issue.