Summary about Disease
Factor V Leiden thrombophilia is an inherited blood-clotting disorder caused by a mutation in the Factor V gene. This mutation makes Factor V resistant to inactivation by activated protein C (APC), which normally helps prevent excessive blood clotting. As a result, individuals with Factor V Leiden have an increased risk of developing abnormal blood clots, usually in the deep veins (deep vein thrombosis or DVT) or the lungs (pulmonary embolism or PE). Many people with Factor V Leiden never develop clots, while others may experience recurrent episodes. The risk of clotting is increased when combined with other risk factors.
Symptoms
Many individuals with Factor V Leiden are asymptomatic and never experience any symptoms. However, if a blood clot develops, symptoms will depend on the location of the clot. Common symptoms include:
Deep Vein Thrombosis (DVT): Pain, swelling, redness, and warmth in the affected leg (usually the calf or thigh).
Pulmonary Embolism (PE): Sudden shortness of breath, chest pain (often sharp and stabbing), rapid heartbeat, coughing up blood, lightheadedness, or fainting.
Less common sites: Clots can sometimes occur in other areas, such as the veins in the abdomen (portal or mesenteric vein thrombosis) or the brain (cerebral venous thrombosis). Symptoms will vary accordingly.
Causes
Factor V Leiden thrombophilia is caused by a specific genetic mutation in the Factor V gene (F5 gene). This mutation results in an altered Factor V protein that is resistant to inactivation by activated protein C (APC). People inherit the gene from one or both parents.
Inheritance: The condition is inherited in an autosomal manner. If you inherit one copy of the gene (heterozygous), your risk of developing blood clots is increased. If you inherit two copies of the gene (homozygous), your risk is higher still.
Medicine Used
The primary medications used to manage Factor V Leiden thrombophilia focus on preventing and treating blood clots.
Anticoagulants (Blood Thinners): These medications reduce the blood's ability to clot. Common anticoagulants include:
Warfarin (Coumadin): An oral anticoagulant that requires regular blood monitoring (INR).
Heparin (Unfractionated Heparin or Low Molecular Weight Heparins like Enoxaparin/Lovenox): Often used initially to treat acute clots. Low molecular weight heparins are administered via subcutaneous injection.
Direct Oral Anticoagulants (DOACs) like Rivaroxaban (Xarelto), Apixaban (Eliquis), Edoxaban (Savaysa), and Dabigatran (Pradaxa): These newer anticoagulants do not require routine blood monitoring.
Antiplatelet Medications: Medications like aspirin may be used in some cases, but are generally not the primary treatment for Factor V Leiden-related clotting.
Is Communicable
No, Factor V Leiden thrombophilia is not communicable. It is a genetic condition inherited from one or both parents, not an infectious disease.
Precautions
Individuals with Factor V Leiden can take precautions to minimize their risk of developing blood clots:
Maintain a healthy weight: Obesity is a risk factor for blood clots.
Stay active: Regular exercise improves circulation.
Avoid prolonged immobility: During long periods of sitting (e.g., long flights or car rides), get up and walk around regularly. Consider wearing compression stockings.
Stay hydrated: Dehydration can increase the risk of clotting.
Inform healthcare providers: Tell doctors and dentists about your Factor V Leiden status before any surgery, medical procedures, or when starting new medications.
Consider prophylactic anticoagulation in high-risk situations: Talk to your doctor about whether you need blood thinners during pregnancy, after surgery, or during prolonged immobility.
Smoking Cessation: Smoking increases the risk of blood clots.
How long does an outbreak last?
Factor V Leiden is a genetic predisposition, not an "outbreak." If a blood clot develops, the duration of treatment with anticoagulants varies depending on the situation:
First-time DVT/PE due to a reversible risk factor (e.g., surgery): Typically treated with anticoagulants for 3-6 months.
First-time unprovoked DVT/PE (no identifiable risk factor) or Factor V Leiden diagnosed alongside a clot: Longer-term anticoagulation may be considered, sometimes lifelong.
Recurrent DVT/PE: Often requires lifelong anticoagulation.
The course of treatment should always be determined by a healthcare professional.
How is it diagnosed?
Diagnosis of Factor V Leiden involves blood tests:
Factor V Leiden Genetic Test: This test detects the specific mutation in the Factor V gene.
Activated Protein C (APC) Resistance Assay: This test measures how well a patient's blood responds to activated protein C. If resistance is found, genetic testing for Factor V Leiden is usually performed.
Testing for blood clots: In someone who has a suspected DVT or PE, imaging tests such as ultrasound (for DVT) or CT scan (for PE) are performed to confirm the diagnosis.
Timeline of Symptoms
Factor V Leiden itself does not have a timeline of symptoms. Symptoms only occur if a blood clot develops. If a clot forms, the timeline of symptoms depends on the location and severity of the clot.
DVT: Symptoms usually develop gradually over a few days.
PE: Symptoms can develop suddenly and can be life-threatening.
Important Considerations
Pregnancy: Factor V Leiden increases the risk of blood clots during pregnancy and the postpartum period. Close monitoring and potentially prophylactic anticoagulation are often recommended.
Hormone Therapy: Estrogen-containing birth control pills or hormone replacement therapy can further increase the risk of blood clots in women with Factor V Leiden. Alternative contraception options should be considered.
Family History: If you have a family history of blood clots or Factor V Leiden, you should consider getting tested.
Individual Risk Assessment: The overall risk of developing blood clots in someone with Factor V Leiden depends on multiple factors, including whether they are heterozygous or homozygous for the mutation, the presence of other risk factors, and their lifestyle. Management should be individualized based on a thorough risk assessment by a healthcare professional.