CYP4F2 rs3093105: What Your Genotype Means
The rs3093105 variant is a genetic polymorphism located within the CYP4F2 gene, which encodes an enzyme involved in the metabolism of vitamin K. Research has investigated this variant for its statistical association with the maintenance dose of warfarin, an anticoagulant medication.
What each genotype means
Typical enzyme function
You carry two copies of the standard A allele for rs3093105 in the CYP4F2 gene. In pharmacogenomic research, this baseline genotype is associated with normal CYP4F2 enzymatic activity in vitamin K clearance and baseline required warfarin dosages. Always consult your healthcare provider or pharmacist regarding any anticoagulant therapy, as dosing is guided by multiple genetic and clinical factors.
Found in approximately 40% to 55% of individuals of European and East Asian ancestry.
Intermediate dose requirement
You carry one copy of the C variant allele (corresponding to c.34T>G or p.W12G on the reverse strand, historically cataloged in the CYP4F2*2 or *4 star alleles). Research shows this variant has limited but observed associations with modestly altered vitamin K metabolism and slightly higher warfarin dose requirements compared to the AA genotype. Discuss any anticoagulant dosing decisions directly with your physician or pharmacist.
Carried by roughly 35% to 45% of people in European and East Asian populations.
Potentially higher dose requirement
You carry two copies of the C variant allele for rs3093105 in the CYP4F2 gene. Published studies report that individuals homozygous for this change may have decreased enzyme activity for certain substrates and statistically require slightly higher daily maintenance doses of warfarin. Because this variant accounts for only a minor fraction of overall dose variability, never alter medication dosing without consulting your doctor or pharmacist.
Carried by about 5% to 15% of individuals in European and East Asian cohorts.
Understanding the rs3093105 Variant
The rs3093105 variant is a single nucleotide polymorphism (SNP) situated within the CYP4F2 gene. In genetics, a SNP represents a variation at a single position in the DNA sequence among individuals. This specific variant has been identified and cataloged in public databases, allowing researchers to study its distribution and potential functional impact. While many SNPs have no observable effect on health or physiology, researchers focus on those that may alter protein function or gene expression. The rs3093105 variant is of interest in the field of pharmacogenomics, which examines how an individual's genetic makeup influences their response to specific medications. By studying where this SNP sits in the genome, scientists can better understand the biological pathways that might be affected by its presence.
The Role of the CYP4F2 Gene
The CYP4F2 gene provides instructions for making an enzyme that belongs to the cytochrome P450 family. This enzyme plays a critical role in the metabolism of various compounds, including vitamin K. Vitamin K is essential for the body's blood-clotting process. Because warfarin works by inhibiting the recycling of vitamin K to prevent blood clots, enzymes that regulate vitamin K levels, such as those produced by CYP4F2, are biologically relevant to how the body processes the drug. Variations in the CYP4F2 gene may lead to differences in the activity or efficiency of this enzyme. When the enzyme's function is altered, it can theoretically influence the amount of vitamin K available, which in turn may affect the stability of the anticoagulant effect provided by warfarin therapy.
Research and Clinical Associations
Scientific research has explored the association between CYP4F2 variants and warfarin dose requirements. While variants like rs2108622 are frequently cited in major pharmacogenomic studies, rs3093105 has also been investigated as part of the broader genetic landscape of warfarin metabolism. Studies have generally found that genetic factors, including those in CYP4F2, VKORC1, and CYP2C9, contribute to the variability in the dose of warfarin required to achieve a therapeutic effect. However, the evidence strength for any single variant's impact can be limited, and results often vary across different ethnic populations. It is important to note that warfarin dosing is complex and influenced by many factors, including age, body weight, diet, and other medications. Consequently, genetic testing for this variant is not a standalone tool for determining clinical treatment.
Interpreting Your Results
If you have information regarding your genotype for rs3093105, it is essential to understand that this data does not constitute a medical diagnosis or a prescription instruction. Pharmacogenomic associations are statistical observations made across large groups of people and may not accurately predict an individual's specific response to a medication. You should never change your medication dosage or stop taking a prescribed drug based on genetic test results without consulting your healthcare provider. A doctor or pharmacist is the only person qualified to interpret how your genetic information, combined with your clinical history and current health status, should influence your treatment plan. Always discuss any concerns about your medication or genetic findings with your clinical team to ensure your care is managed safely and effectively.
How common is this variant?
The minor allele frequency for variants in the CYP4F2 gene typically ranges between 25% and 35% across various European and Asian populations.
Frequently asked questions
Does my CYP4F2 genotype mean I need a different warfarin dose?
Genetic variants are only one of many factors that influence warfarin dosing. Your doctor considers your age, weight, diet, and other medications alongside genetic information to determine the appropriate dose.
Should I get tested for CYP4F2 variants before starting warfarin?
Clinical guidelines vary regarding routine genetic testing for warfarin. You should discuss with your healthcare provider whether such testing is appropriate or beneficial for your specific clinical situation.
Is rs3093105 the same as other CYP4F2 variants?
No, rs3093105 is a specific SNP within the CYP4F2 gene. Other variants, such as rs2108622, are also studied in the context of warfarin metabolism, but they are distinct genetic markers.
Can I change my warfarin dose based on my genotype?
No. You must never change your medication dosage without direct instruction from your prescribing physician. Adjusting warfarin doses without medical supervision can lead to serious health risks, including bleeding or clotting.
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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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.
This variant (V433M, *3 allele) decreases vitamin K metabolism, typically requiring an increased maintenance dose of warfarin to achieve target anticoagulation.
The CYP4F2 V33M variant is associated with altered vitamin K metabolism and influences warfarin maintenance dose.