HLA-B*15:02 Genotyping

​Local and International data strongly support an association between the presence of HLA-B*15:02 allele and the development of carbamazepine (CBZ)-induced Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN). The Ministry of Health (MOH) announced in April 2013, that the genotyping for the HLA-B*15:02 allele prior to the initiation of carbamazepine (CBZ) therapy in new patients of Asian ancestry had become the standard of care. This is to mitigate the risks of patients developing CBZ-induced Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN), which are associated with significant mortality as well as long-term morbidity.

CBZ should not be prescribed prior to the return of HLA-B*15:02 test results, and the use of CBZ tested positive for HLA-B*15:02 allele should be avoided.

In addition, the presence of the HLA-B*15:02 allele may be a risk factor for the development of SJS/TEN in patients taking other anti-epileptic drugs that have an aromatic ring structure such as phenytoin, lamotrigine, and oxcarbazepine.

​5 mL of blood in EDTA (lavender top) tube.

​As a one-time screening for the presence of HLA-B*15:02 allele for all patients where CBZ therapy is being considered, for example, in all newly diagnosed epilepsy patients. 

​Refrigerate sample at 2-8°C until transfer to laboratory. Do not freeze. Sample should reach the laboratory as soon as possible preferably within 6 hours after collection. 

Commercial real-time PCR assay

Positive, Negative or Inconclusive

1-5 calendar days

​Monday and Thursday (except public holidays)