Valproic acid is often used in frontline to treat children with epilepsy. A mutation can cause slow metabolism and thus dosing has to be adjusted, since the patient can not methabolize right the drug for treatment.
– The clinical consequences of decreased CYP2C9 function were investigated in epileptic children. It has been established that valproic acid, one of the first choices of antiepileptic drugs, is metabolized primarily by CYP2C9 in pediatric patients. Identification of loss-of-function mutations in CYP2C9 may lead to false prediction of a patient’s valproate metabolizing capacity, since CYP2C9 expression highly influences blood concentrations of valproate.