FVL & F2 gene mutation
By Russell Browne (Dip. Adv. Nut.) · Specialist in Genetic Nutrition & Methylation Protocols
Factor V Leiden (FVL) and Prothrombin (F2) are inherited clotting variants, and unlike many variants discussed on this site, they carry genuine clinical relevance for blood-clot risk. This one deserves a medically grounded approach.
What these genes do
The F5 gene (which carries the Factor V Leiden variant) and the F2 gene (which carries the Prothrombin G20210A variant) affect proteins involved in blood clotting. Certain variants are associated with a somewhat greater tendency for the blood to clot — a state referred to as thrombophilia.
FVL, F2 and clotting risk
These variants are associated with an increased risk of venous blood clots (such as deep vein thrombosis or pulmonary embolism). Crucially, most people who carry them never have a clot. The risk rises mainly in combination with other factors — surgery, prolonged immobility, pregnancy, and oestrogen-containing medications such as some contraceptives or HRT. Because of this, these variants matter most around those specific situations, and they are properly evaluated and managed by a doctor — not from a consumer report.
New to all this? Start with the overview
Bad Genes – The Genetic Advantage by Russell Browne is a plain-English tour of the common gene variants that most influence health — the ideal companion to your variant report, and a great place to see how the individual genes fit together.
What the research shows
Factor V Leiden and Prothrombin G20210A are well established in the medical literature as associated with increased venous-thrombosis risk, while the absolute risk for any individual remains modest and is strongly influenced by other factors. Reference.
Our approach in practice
We route anything clotting-related to medical care. This is not something to interpret or act on from a consumer report. A doctor can advise on appropriate testing and on sensible precautions in the situations that genuinely matter — particularly before surgery, during pregnancy, or when considering hormone-containing medications.
How to find your FVL & F2 result
Your existing 23andMe or AncestryDNA raw data file may include FVL & F2 markers, and a variant report can show what is present. For FVL & F2 specifically, please treat this as a starting point only — not a diagnosis. Because clotting variants matter around surgery, pregnancy, and hormone use, they should be discussed with a doctor. Any FVL & F2-related finding should be confirmed and interpreted through proper medical testing and a qualified doctor.
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Important medical note
This page is educational and is not medical advice, a diagnosis, or a treatment plan. Unlike many variants discussed on this site, FVL & F2 can carry genuine clinical relevance, and a consumer genetic report is not a diagnosis. These variants raise clotting risk mainly alongside surgery, pregnancy, immobility, and oestrogen-containing medications; most carriers never have a clot. If a clotting variant is relevant to you, discuss it with your doctor — especially in those situations. Please do not make medical decisions based on a consumer genetic report; seek proper testing and guidance from a qualified doctor.
About the Author
Russell Browne (Dip. Adv. Nut.)
Specialist in Genetic Nutrition & Methylation Protocols
Russell Browne is a qualified practitioner of Advanced Nutrition, Advanced Herbalism, and Homeopathy, with a specialized clinical focus on genetic nutrition, methylation pathways, and detoxification. With years of dedicated clinical experience helping patients decode complex chronic health issues, Russell is also the author of How to Treat Your MTHFR Gene Mutations the Right Way – The Genetic Advantage and several works on genetic wellness. He is committed to bridging the gap between complex genetic data and practical, root-cause clinical care.
Read Russell’s Full Professional Profile & Clinical Credentials
View Published Genetic Health Literature & Books
If you suspect you may have symptoms related to the FVL and or F2 gene mutations or you want to prevent a blood clot, the first thing to do is get your ancestry raw data and upload it to our app, this will show your FVL and F2 genes and provide the status of the mutations.
Once you confirm if you have FVL and or F2 mutations the best thing you can do is work with a practitioner who understand epigenetics and nutrigenomics via a consultation here.