F5 rs6025: Understanding the Factor V Leiden Variant
The rs6025 variant in the F5 gene is a well-studied genetic change known as Factor V Leiden. It is associated with an increased risk of developing venous thromboembolism, a condition involving dangerous blood clots.
What each genotype means
Typical blood clotting risk
This genotype represents the common, non-mutated form of the Factor V gene. Individuals with this profile do not carry the Factor V Leiden mutation and therefore do not have the associated genetic predisposition to activated protein C resistance.
This is the most common genotype found in the vast majority of the global population.
Increased venous thrombosis risk
This genotype indicates you are heterozygous for the Factor V Leiden mutation, also known as R506Q or G1691A. Research shows this increases the relative risk of venous thromboembolism, though most individuals with this genotype never experience a blood clot. Please discuss your personal health history and any potential medication risks, such as those related to oral contraceptives, with your clinician.
Carried by roughly 3-5% of people of European ancestry; it is significantly less common in other populations.
High venous thrombosis risk
This genotype indicates you are homozygous for the Factor V Leiden mutation. This profile is associated with a significantly higher risk of venous thromboembolism compared to those without the mutation or those who are heterozygous. Because this increases the risk of blood clots, you should discuss your clinical risk profile and any necessary preventative measures with a healthcare professional.
This genotype is rare, occurring in approximately 1 in 5,000 individuals.
What is rs6025?
The variant rs6025 is a single nucleotide polymorphism (SNP) located within the F5 gene on chromosome 1. In this specific position, a guanine (G) is replaced by an adenine (A), which results in a change in the protein sequence. Specifically, this mutation causes an amino acid substitution where arginine is replaced by glutamine at position 506 of the Factor V protein. This change is famously referred to as the Factor V Leiden mutation. Because this variant alters the structure of a protein critical to the body's coagulation system, it has been the subject of extensive clinical research regarding its role in blood clotting disorders.
The Role of the F5 Gene
The F5 gene provides instructions for making a protein called coagulation Factor V. This protein plays a vital role in the complex process of blood clotting, which is the body's way of stopping bleeding after an injury. Under normal conditions, an activated protein called protein C acts as a natural 'brake' on the clotting process by breaking down Factor V. However, the Factor V Leiden mutation changes the shape of the Factor V protein at the exact site where protein C normally binds. Because of this structural change, the protein becomes resistant to being broken down by protein C. This resistance means the clotting process remains active for longer than it should, which can lead to an increased risk of forming abnormal blood clots.
Research and Clinical Associations
Research consistently associates the rs6025 variant with an increased risk of venous thromboembolism (VTE). Studies indicate that individuals who carry one copy of the variant (heterozygous) have a higher risk of clotting compared to non-carriers, while those with two copies (homozygous) face a significantly higher risk. The evidence for this association is considered strong in clinical literature. Furthermore, research has shown that the risk associated with this variant can be compounded by other factors, such as the use of hormonal contraceptives or the presence of active cancer. It is important to note that while the variant increases the statistical risk of clotting, it does not guarantee that an individual will experience a medical event. Clinical management of clotting risk is complex and depends on a variety of genetic and environmental factors.
Population Frequency
The prevalence of the rs6025 variant varies significantly across different ancestral groups. It is most commonly observed in populations of European descent, where the carrier frequency is estimated to be between 3% and 5%. In contrast, the variant is much rarer or virtually absent in many other global populations. Because of this distribution, genetic screening for Factor V Leiden is often prioritized in clinical settings for individuals of European ancestry who present with unexplained blood clots. Understanding these population-specific frequencies is essential for researchers and clinicians when interpreting the clinical significance of a genetic test result.
What You Can Do With This Information
Genetic information regarding rs6025 is a tool for understanding biological predispositions, not a medical diagnosis. If you have received information about your status for this variant, it is important to discuss the findings with a qualified healthcare provider or a genetic counselor. They can help you interpret the results in the context of your personal and family medical history. Never use genetic data to make independent decisions about your health, such as starting or stopping medications like hormonal contraceptives or blood thinners. Always consult with your clinician or pharmacist regarding any concerns about clotting risk or medication management. They are the only ones who can provide personalized medical advice based on your complete health profile.
How common is this variant?
The rs6025 variant is found in approximately 3-5% of individuals of European ancestry, while it is significantly less common in other global populations.
Frequently asked questions
What is Factor V Leiden?
Factor V Leiden is the name of the specific genetic mutation (rs6025) in the F5 gene. It causes the Factor V protein to be resistant to the body's natural anti-clotting mechanisms, potentially increasing the risk of blood clots.
Does having the rs6025 variant mean I will get a blood clot?
No, having the variant does not mean you will definitely develop a blood clot. It only indicates a higher statistical risk compared to the general population, and many people with the variant never experience a clotting event.
Should I get tested for Factor V Leiden?
Genetic testing for Factor V Leiden is typically recommended by doctors only for specific patients, such as those who have already had an unexplained blood clot or have a strong family history of clotting. You should discuss the necessity of testing with your healthcare provider.
How does Factor V Leiden affect medication use?
The presence of this variant can influence how a doctor manages your care, particularly regarding medications like hormonal contraceptives or surgery recovery. Always inform your doctor or pharmacist about your genetic status so they can provide appropriate guidance.
Sources & further reading
Educational information only, last refreshed 10/2/2026. Not medical advice — these associations describe population statistics, not individual predictions.
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