A Genetic Cause of Increased Clotting Risk

Prothrombin 20210 Mutation, also called Factor II Mutation is a genetic condition that causes an increase in likelihood of your blood forming dangerous blood clots.

All individuals make the prothrombin (also called factor two) protein that helps blood clot. However, there are certain individuals who have a DNA mutation in the gene used to make prothrombin (also called prothrombin G20210A or the factor II (two) mutation). They are said to have an inherited thrombophilia (clotting disorder) called prothrombin G20210A. When this occurs, they make too much of the prothrombin protein.

Prothrombin G20210A and the tendency to develop blood clots

  • Normally, the prothrombin protein is produced to help the blood clot, and is produced in greater amounts after a blood vessel is damaged.
  • People who have a mutation in the prothrombin gene produce more prothrombin protein than is normal.  Since there is more of the prothrombin protein in the blood, this increases the tendency to form clots.

Testing for prothrombin G20210A

Prothrombin testing is done by taking a blood sample, and using a genetic test to look at the prothrombin gene.

  • The DNA is isolated from blood cells and the prothrombin gene is examined to see if there is a mutation in the DNA code. If a gene change is found (the 20210st letter is changed from a G to an A), then the person has a prothrombin (or factor II) mutation.

Prevalence of prothrombin G20210A

A change in the prothrombin gene is present in 2-4% (or 1 in 50 to 1 in 25) of Caucasians, and is more common in individuals of European ancestry. In the United States, approximately 0.4% (about 1 in 250) of African Americans also have the mutation. Prothrombin G20210A mutation is rare in other groups.

If you have Prothombin G20210A mutation, you need to be aware of the symptoms of DVTs so you can seek medical attention.

If you have a Deep Vein Thrombosis or DVT (leg or arm clot), you will notice:

  • Pain or tenderness in your arm or leg with one or more of the following:
    • Swelling
    • Red or purple skin color
    • Warm to the touch

If a piece of a DVT breaks off and travels to the lung, it can cause a lung clot. We call this a pulmonary embolism or PE. A PE can be a life threatening medical emergency. You need to seek immediate medical attention if you have symptoms of a PE.

If you have a Pulmonary Embolism or PE (lung clot), you may experience:

  • Hard to breath or shortness of breath
  • Chest pain
  • Rapid or racing heart beat
  • Fainting or passing out
  • Coughing up blood

You can read more about Prothrombin G20210A (Factor II Mutation) at the links below:

Prothrombin 20210 Mutation (Factor II Mutation) (2004) By Elizabeth A. Varga, MS and Stephan Moll, M

Cardiology Patient Page Circulation, American Heart Association Journal

Key points discussed:

  • Understanding blood clotting
  • Prothrombin/prothrombin genetic mutation
  • How Does One get the prothrombin mutation
  • Diagnosing prothrombin mutations
  • Implications of the prothrombin mutation
  • Treatment of prothrombin mutation
  • Implications for Women
  • Testing family members
  • Minimizing risks

Prothrombin-Related Thrombophilia (2011) Jody L Kujovich, MD

GeneReviews™ [Internet] University of Washington

Key points discussed: 

  • Disease characteristics
  • Diagnosing
  • Treatment and management
  • Risks (including pregnancy) and prevention of complications
  • Extensive genetics information with genotype/phenotype correlations
  • Genetic testing
  • Genetic counseling
  • Other genetic blood clotting disorders that can occur with Prothrombin G20210A (Factor II Mutation)

Factor II  (2013)  Robert A Schwartz, MD, MPH & Emmanuel C Besa, MD

Key points discussed:

  • In-depth genetics of Factor II
  • Signs & Symptoms
  • Acquired & inherited Factor II
  • Diagnosis
  • Lab tests
  • Treatment
  • Medication

You can read about people who have had Prothrombin G20210A (Factor II Mutation) and Blood Clots in their own voices:

Patient Stories of Prothrombin G20210A (Factor II Mutation)