Prothrombin G20210A Mutation Test | London Blood Tests

Test for the Factor II Prothrombin G20210A mutation with our genetic blood test. UKAS-accredited testing and optional GP consultation.

The Factor II (Prothrombin) – G20210A Mutation Test is a genetic blood test used to identify an inherited risk of abnormal blood clotting (thrombophilia). It detects the G20210A mutation in the prothrombin gene, which increases the risk of deep vein thrombosis (DVT) and pulmonary embolism (PE). Testing is performed in a UKAS-accredited laboratory, with an optional GP consultation for result interpretation.

What is the Factor II Prothrombin G20210A Mutation Test?

Prothrombin (Factor II) is a clotting protein essential for normal blood coagulation. The G20210A mutation is a genetic variation in the prothrombin gene that leads to increased prothrombin levels, making the blood more prone to clotting.

This mutation is inherited and remains present for life. Individuals may carry:

• One copy (heterozygous) – moderately increased clot risk

• Two copies (homozygous) – significantly higher clot risk (rare)

The Factor II G20210A test is commonly ordered as part of a thrombophilia screen, especially in individuals with unexplained blood clots, pregnancy complications, or a strong family history of thrombosis.

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

Benefits of the Factor II G20210A Mutation Test

1. Identifies Inherited Clotting Risk
   Confirms whether you carry a genetic mutation linked to increased blood clot formation.

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

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

4. Guides Preventive Treatment Decisions
   Results may influence anticoagulation strategies during surgery, pregnancy, or long flights.

5. Informs Family Screening
   First-degree relatives may benefit from testing if a 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 discuss personal risk and preventive measures.

Why Do I Need a Factor II Mutation Blood Test?

You may benefit from this test if you:

• Have had an unexplained DVT or pulmonary embolism

• Developed blood clots at a young age

• Have a strong family history of thrombosis

• Experienced recurrent miscarriage or pregnancy complications

• Are considering hormonal contraception or HRT

• Are planning major surgery or prolonged immobilisation

Symptoms of blood clots may include:

• Swelling or pain in one leg

• Warmth or redness of the skin

• Sudden shortness of breath

• Chest pain

• Rapid heartbeat

Identifying inherited thrombophilia allows proactive risk management and informed clinical decisions.

How the Test Works

In-Clinic Testing at London Blood Tests

1. Book Your Appointment

   • Book online or by phone at your preferred clinic.

   • No fasting required.

2. Pre-Test Review

   • Inform the clinician about clotting history or family history.

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 genetic 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

   • Discuss implications, prevention strategies, and next steps.

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 same day to the laboratory.

4. Laboratory Testing

   • Genetic analysis identical to clinic testing.

5. Results & Follow-Up

   • Results delivered online, GP review optional.

Your Factor II Prothrombin Test Results – Explained

Results are reported as mutation detected or not detected.

Possible outcomes:

• No mutation detected: normal prothrombin gene

• Heterozygous mutation: one copy detected – increased clot risk

• Homozygous mutation: two copies detected – high clot risk (rare)

Interpretation notes:

• Carrying the mutation does not guarantee a clot will occur

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

• Results should be interpreted alongside other thrombophilia tests if indicated.