Which genetic polymorphism would affect the warfarin dose requirement in a patient with a deep venous thrombosis?

The CYP2C9 polymorphism significantly impacts the metabolism of warfarin, a commonly used anticoagulant for conditions such as deep venous thrombosis. Warfarin is primarily metabolized by the CYP2C9 enzyme, and variations in the CYP2C9 gene can lead to different enzymatic activity levels among individuals. Those with certain polymorphisms may require lower doses of warfarin due to reduced enzyme activity, which can lead to an increased risk of bleeding if standard doses are administered.

Understanding the specific CYP2C9 genotype can help clinicians tailor warfarin dosing to achieve optimal therapeutic levels while minimizing adverse effects. This pharmacogenetic interaction is particularly relevant since individual responses to warfarin can vary widely due to genetic factors, emphasizing the importance of personalized medicine in anticoagulation therapy.

In contrast, polymorphisms in genes like SLCO1B1 and CYP2C19 do not have a significant direct impact on warfarin pharmacokinetics and pharmacodynamics. SLCO1B1 is more related to the transport of statins and other drugs, while CYP2C19 predominantly affects the metabolism of antiplatelet agents like clopidogrel. Thus, the focus on CYP2C9 highlights