Genetic polymorphisms can affect an individual's response to the pharmacological agents. Warfarin has a narrow therapeutic range and dose arrangement may vary from individual to individual. An insufficient dose may fail to prevent thromboembolism and overdose may increase the risk of bleeding. Increasing evidence suggests that genetic variation of CYP2C9 and VKORC1 greatly influences effective warfarin dosing (1). In the present case report, frequently occurring warfarin toxicity was caused by a genetic mutation in the patient with mitral valve replacement.
Keywords: warfarin, genetic, CYP2C9, VKORC1