What genetic testing must be performed on Asian patients before starting Carbamazepine?

Carbamazepine is a medication commonly used to treat epilepsy and certain mood disorders, but it has been associated with serious adverse reactions, particularly in certain populations. Specifically, the HLA-B*1502 allele is a genetic variant that significantly increases the risk of developing severe skin reactions, such as Stevens-Johnson syndrome and toxic epidermal necrolysis, in patients of Asian descent.

Before initiating treatment with Carbamazepine, testing for the presence of the HLA-B1502 allele becomes crucial because individuals who carry this allele are at a higher risk for these potentially life-threatening conditions. Therefore, screening for HLA-B1502 prior to treatment is a recommended safety measure to help prevent adverse drug reactions in these patients.

The other options, while they may have their own clinical importance, do not specifically relate to the risk associated with Carbamazepine use in Asian patients. For instance, blood type does not influence how Carbamazepine is metabolized or its side effect profile, and checking A1C levels or Vitamin D levels serves different purposes unrelated to the risks posed by Carbamazepine therapy. Thus, HLA-B*1502 testing is the essential genetic test that should be performed before starting Carbamazep