CYP4F2 rs35572951: What Your Genotype Means
The rs35572951 variant, often studied alongside the functional V433M change in the CYP4F2 gene, is a genetic marker associated with how the body processes vitamin K. Research indicates that variations in this gene can influence the maintenance dose of anticoagulants like warfarin, as the enzyme plays a key role in vitamin K metabolism.
What each genotype means
Typical vitamin K clearance
You carry two copies of the standard allele, corresponding to normal CYP4F2 enzyme levels and typical clearance of vitamin K. This genotype is associated with baseline or standard maintenance dose requirements for warfarin when compared to carriers of the variant allele. If you are prescribed warfarin or other anticoagulants, your healthcare provider will evaluate your complete genetic and clinical profile to establish the appropriate dosage.
Found in approximately 45% to 60% of individuals of European ancestry and is the predominant genotype across most African populations.
Moderately reduced vitamin K clearance
You carry one copy of the V433M (*3) variant, which is associated with moderately reduced CYP4F2 enzyme activity and slightly higher steady-state vitamin K levels. Clinical studies show that individuals with this genotype often require a modest increase in warfarin maintenance doses, typically around 5% to 10% higher than average, to achieve target anticoagulation. Discuss this result with your clinician or pharmacist to ensure appropriate monitoring if you are taking or starting warfarin.
Carried by approximately 35% to 45% of individuals of European ancestry and roughly 20% to 35% of individuals of East Asian ancestry.
Reduced vitamin K clearance
You carry two copies of the V433M (*3) variant, which results in substantially decreased CYP4F2 enzyme levels and slower breakdown of vitamin K. Research indicates that individuals with two variant alleles typically require an increased warfarin maintenance dose, often 10% to 20% higher than standard, to achieve effective anticoagulation. If you are taking warfarin or considering anticoagulation therapy, be sure to review your dosing and monitoring plan with your doctor or pharmacist.
Present in roughly 5% to 12% of individuals of European and East Asian ancestries, and is rare in populations of African descent.
Understanding the Variant and Its Location
The variant rs35572951 is located within the CYP4F2 gene, which provides instructions for making an enzyme belonging to the cytochrome P450 family. This gene is situated on chromosome 19. In the context of pharmacogenomics, this specific SNP is frequently analyzed in relation to the V433M polymorphism (also known as rs2108622 or the *3 allele). While rs35572951 is a distinct marker, it is often evaluated in studies investigating how genetic diversity in the CYP4F2 gene affects the metabolism of various compounds, including vitamin K and certain medications. Geneticists track these variants to understand how small changes in DNA sequence can lead to functional differences in enzyme activity, which may ultimately impact how individuals respond to therapeutic interventions.
The Role of the CYP4F2 Gene
The CYP4F2 gene encodes an enzyme that is primarily responsible for the omega-hydroxylation of arachidonic acid, which leads to the production of 20-HETE. This molecule is essential for regulating vascular tone and renal function. Beyond its role in blood pressure regulation, the CYP4F2 enzyme is also involved in the metabolism of vitamin K in the liver. Vitamin K is a critical cofactor for the activation of blood-clotting factors. By metabolizing vitamin K, the CYP4F2 enzyme helps regulate the availability of this vitamin, which in turn influences the body's coagulation pathways. When the function of this enzyme is altered by genetic variants, it can change the rate at which vitamin K is cleared from the system, potentially affecting the efficacy of anticoagulant medications that work by inhibiting the vitamin K cycle.
Research Associations and Evidence Strength
Research into CYP4F2 variants has primarily focused on their impact on warfarin dosing. Studies have consistently shown that individuals carrying certain variants, such as the V433M allele, may require higher maintenance doses of warfarin to achieve target anticoagulation levels compared to those without the variant. This is because the reduced enzyme activity leads to higher levels of vitamin K, which counteracts the effect of the medication. However, the evidence strength for specific SNPs like rs35572951 is often considered limited or context-dependent. Associations can vary significantly based on ancestry, with some studies showing strong correlations in European populations while finding little to no effect in others. It is important to note that these findings are statistical associations observed in clinical cohorts and do not account for all factors influencing drug response, such as diet, age, and other genetic markers like VKORC1 and CYP2C9.
What You Can and Cannot Do With This Information
Genetic information regarding CYP4F2 should be viewed as one piece of a much larger clinical puzzle. If you have received results regarding this variant, it is essential to understand that this information is not a medical diagnosis and cannot predict your exact response to any medication. You should never change your medication dosage or stop taking a prescribed treatment based on genetic test results without consulting your healthcare provider. Pharmacogenomic testing is intended to provide clinicians with additional data to help personalize treatment plans, but it must be interpreted alongside clinical factors, medical history, and other laboratory tests. Always discuss your genetic findings with your doctor or a clinical pharmacist who can help you understand how this information applies to your specific health situation and whether it is relevant to your current treatment.
How common is this variant?
The minor allele frequency for variants in the CYP4F2 gene varies significantly by ancestry, typically ranging from approximately 20% to 35% in European populations and appearing at different frequencies across global populations.
Frequently asked questions
Does this variant mean I will have a bad reaction to warfarin?
Not necessarily. This variant is associated with the dose required to reach a stable level of anticoagulation, not necessarily an adverse reaction. Your doctor will use your INR levels and other clinical factors to determine the safest and most effective dose for you.
Should I get tested for CYP4F2 before starting medication?
Routine testing for this variant is not universally required for all patients. Decisions about genetic testing are made by your healthcare provider based on clinical guidelines and your specific medical needs.
Can diet change the effect of this genetic variant?
Yes, because the CYP4F2 enzyme is involved in vitamin K metabolism, your dietary intake of vitamin K can influence your response to anticoagulants. It is important to maintain a consistent diet and discuss any major changes with your healthcare team.
Is this variant the only thing that determines my warfarin dose?
No. Warfarin dosing is complex and is influenced by many factors, including your age, weight, other medications you are taking, and other genetic variants like VKORC1 and CYP2C9. Genetic testing is only one tool used to help guide dosing.
Sources & further reading
Educational information only, last refreshed 10/10/2026. Not medical advice — these associations describe population statistics, not individual predictions.
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Functional CYP4F2 variant influencing vitamin K metabolism and clinical warfarin dose requirements.
Coding variant c.1297C>T (p.Arg433Trp) in CYP4F2. Note: The primary clinical variant for warfarin dosing in CYP4F2 is rs2108622 (c.1347C>T); rs72552769 is a distinct, rare variant.
The CYP4F2 V33M variant is associated with altered vitamin K metabolism and influences warfarin maintenance dose.