Factor V Leiden Mutation Test | London Blood Tests

Detect inherited clotting risk with our Factor V Leiden genetic blood test for £198. UKAS-accredited testing and optional GP consultation.

The Factor V Leiden Mutation Test is a genetic blood test used to identify an inherited risk of abnormal blood clotting (thrombophilia). It detects the Factor V Leiden mutation, a common cause of deep vein thrombosis (DVT) and pulmonary embolism (PE). Testing is performed in a UKAS-accredited laboratory, with an optional GP consultationfor interpretation.

What is the Factor V Leiden Blood Test?

Factor V is a clotting protein that plays a critical role in the blood coagulation cascade. The Factor V Leiden mutationcauses resistance to activated protein C (APC) — a natural anticoagulant — leading to a higher tendency for blood clot formation.

This mutation is inherited and lifelong. Individuals may carry:

• One copy (heterozygous) – moderately increased clot risk

• Two copies (homozygous) – significantly increased clot risk (less common)

Factor V Leiden is the most common inherited thrombophilia in people of European ancestry and is frequently tested in individuals with unexplained clots or strong family history of thrombosis.

At London Blood Tests, this mutation is detected using validated molecular genetic techniques aligned with UK haematology standards.

Benefits of the Factor V Leiden Test

1. Identifies Inherited Thrombophilia
   Confirms whether you carry a genetic mutation associated with increased clot risk.

2. Explains Unprovoked Blood Clots
   Helps identify the cause of DVT or PE without obvious triggers.

3. Supports Pregnancy Risk Assessment
   Relevant for recurrent miscarriage, placental complications, and pregnancy-related thrombosis.

4. Guides Preventive Care Decisions
   Results may influence anticoagulation use during surgery, pregnancy, or prolonged travel.

5. Informs Family Screening
   First-degree relatives may consider testing if the mutation is detected.

6. One-Time Lifetime Test
   As a genetic test, it only needs to be performed once.

7. Optional GP Consultation for Interpretation
   Results can be reviewed with a GP to explain risks and preventive strategies.

Why Do I Need a Factor V Leiden Blood Test?

You may benefit from this test if you:

• Have had an unexplained deep vein thrombosis or pulmonary embolism

• Developed blood clots at a young age

• Have a strong family history of blood clots

• Experienced recurrent miscarriage or pregnancy complications

• Are considering hormonal contraception or HRT

• Are planning major surgery or prolonged immobilisation

Common symptoms of blood clots include:

• Swelling, pain, or redness in one leg

• Warmth over the affected area

• Sudden shortness of breath

• Chest pain

• Rapid heartbeat

Early identification allows personalised risk management and informed medical decisions.

How the Test Works

In-Clinic Testing at London Blood Tests

1. Book Your Appointment

   • Book online or by phone at your chosen clinic.

   • No fasting required.

2. Pre-Test Review

   • Inform the clinician of any personal or family history of clotting.

3. Sample Collection

   • A trained phlebotomist collects a venous blood sample.

   • Takes approximately 5–10 minutes.

4. Laboratory Genetic Analysis

   • Sample analysed in a UKAS-accredited laboratory using molecular techniques.

5. Quality Control

   • Results undergo strict verification and validation.

6. Results Delivery

   • Results typically available within 10–14 business days.

7. Optional GP Consultation

   • Review implications, prevention strategies, and next steps with a GP.

At-Home Blood Draw (Home or Hotel Phlebotomy – UK-Wide)

1. Book Your Visit

   • Arrange a phlebotomist home or hotel visit at a convenient time.

2. Professional Collection

   • Certified phlebotomist collects your blood sample safely.

3. Secure Transport

   • Sample couriered the same day to the laboratory.

4. Laboratory Testing

   • Genetic analysis identical to clinic testing.

5. Results & Follow-Up

   • Results delivered online, with optional GP review.

Your Factor V Leiden Test Results – Explained

Results are reported as mutation detected or not detected.

Possible outcomes:

• No mutation detected: normal Factor V gene

• Heterozygous mutation: one copy detected – increased clot risk

• Homozygous mutation: two copies detected – high clot risk

Interpretation notes:

• Carrying the mutation does not guarantee a clot will occur

• Risk increases with additional factors such as smoking, pregnancy, surgery, or oestrogen therapy

• Results should be considered alongside other thrombophilia markers if indicated.