Prothrombin Gene Mutation

What is prothrombin gene mutation?

Prothrombin gene mutation (or Factor II mutation or Prothrombin G20210A) is an inherited condition that increases your predisposition to develop abnormal blood clots in the veins (deep vein thrombosis or DVT) and lungs (pulmonary embolism or PE). This happens because your body makes more of the Factor II (prothrombin) protein than you need for normal clot formation. Blood clots can cause serious problems in your body when they block blood flow, keeping oxygen from getting to your cells.

What’s the difference between homozygous and heterozygous prothrombin gene mutation?

You may inherit an abnormal Factor II gene from one or both parents. If you get the mutation from both of your parents, you are homozygous (you have two abnormal copies of the Factor II gene). If you get the mutation from one of your parents, you are heterozygous (you have only one abnormal copy of the Factor II gene, but the gene from your other parent is normal).

In heterozygous carriers of this mutation, the risk of developing a deep vein thrombosis or pulmonary embolism is about two to three in 1,000. That risk is several times higher in homozygous carriers.

Will I pass the prothrombin gene mutation on to my children?

If you are homozygous, you will pass the mutation on to your children.

If you are heterozygous, there’s a 50% chance that your children will get the mutation.

How common is prothrombin gene mutation?

About 1 in every 50 white people in Europe and North America has the heterozygous prothrombin gene mutation, making it the second most common inherited clotting disorder. Factor V Leiden is the most common one. About 1 of every 250 Black people in America has the prothrombin gene mutation.

How does prothrombin gene mutation affect my body?

You may have a higher risk of getting:

• Pulmonary embolism.
• Deep venous thrombosis (DVT).

Although the prothrombin gene mutation is the second most common inherited predisposition to a deep vein thrombosis or pulmonary embolism, it is the weakest of all inherited clotting disorders in terms of risk of causing abnormal blood clots. In addition, this mutation only increases the risk of vein clots (deep vein thrombosis or pulmonary embolism). It does not increase the risk of myocardial infarction (heart attacks) or arterial strokes.

What are the symptoms of prothrombin gene mutation?

The mutation does not cause any symptoms in and of itself. You probably won’t know you have prothrombin gene mutation unless you have a specific blood test if/after you develop a deep vein thrombosis or pulmonary embolism. The majority of people born with this mutation will not develop an abnormal blood clot in their lifetime.

Symptoms of deep vein thrombosis in your arm or leg include:

• Pain.
• Swelling.
• Skin that looks purple or red.
• Skin that feels warm.

Symptoms of a pulmonary embolism (located in your lung) include:

• Chest pain.
• Shortness of breath.
• Very fast heartbeat.
• Fainting.
• Cough with or without blood.

What causes prothrombin gene mutation?

It is a genetic mutation in your Factor II gene that makes it create too much prothrombin (coagulation factor II), and you end up with a higher risk of developing blood clots than someone with a normal prothrombin gene.

Other things can add to your blood clot risk, including:

• Smoking.
• Having surgery.
• Having obesity.
• Being pregnant.
• Taking birth control pills.
• Getting older.
• Taking hormone therapy.
• Being hospitalized for several days.
• Having a cast on your leg.
• Going on a long flight or a very long road trip.

How is prothrombin gene mutation diagnosed?

You’ll need a specific blood test to check for the prothrombin gene mutation. Your provider may think you have a clotting problem if you:

• Have had clots two or more different times in the past.
• Are young and healthy when you get a clot.
• Have a relative with clotting problems.

How is prothrombin gene mutation treated?

There is no specific treatment for the mutation itself. At this time, we can’t treat or change our genes.

But your provider can help you keep your blood from clotting too much. If you’re having a deep vein thrombosis or pulmonary embolism, your provider will typically treat you with anticoagulants (blood thinners) and occasionally with thrombolytic (“clot-busting”) medicines. In rare cases, you may need a catheter procedure or surgery to remove the bulk of the clots.

What medications/treatments are used for prothrombin gene mutation?

There is no specific treatment for the mutation itself.

If you develop a deep vein thrombosis or pulmonary embolism, your provider will prescribe an anticoagulant. The length of treatment may vary depending on your situation. Some people only need treatment for three months, but others will need blood thinner treatment indefinitely.

How do I take care of myself?

If you’re taking anticoagulants (blood thinners), be aware that you may bleed or bruise more easily, which is why it is very important to have regular follow-up medical appointments with your provider.

How soon after treatment will I feel better?

Symptoms of a deep vein thrombosis or pulmonary embolism typically start getting better soon after specific treatment is started. Symptoms may resolve within days or months, depending on the location and severity of your deep vein thrombosis or pulmonary embolism.

How can I prevent prothrombin gene mutation?

Because it’s an inherited condition, you can’t prevent the prothrombin gene mutation. However, you can reduce your risk of a deep vein thrombosis or pulmonary embolism if you:

• Lose weight (if you have overweight/obesity).
• Quit smoking.
• Exercise regularly for good circulation in the veins of your legs.

What can I expect if I have prothrombin gene mutation?

The majority of people who have the prothrombin gene mutation don’t get a dangerous blood clot and the mutation doesn’t cause deep vein thrombosis or pulmonary embolism in the vast majority of pregnancies.

How long does the prothrombin gene mutation last?

You’ll have the prothrombin gene mutation for life, since it’s part of your genetic makeup.

What is the outlook for prothrombin gene mutation?

You will most likely not have a dangerous blood clot, but your provider can provide counseling on how to reduce the risk of a deep vein thrombosis or pulmonary embolism.

How do I take care of myself with prothrombin gene mutation?

You may not need to do anything other than lead a healthy lifestyle to minimize the risk of a deep vein thrombosis or pulmonary embolism.

What is the effect of prothrombin gene mutation in pregnancy?

If you’ve had a deep vein thrombosis or pulmonary embolism before and know you have the prothrombin gene mutation, you may need a prescription for low-dose (preventive doses) of an injectable blood thinner (such as heparin or a low-molecular-weight heparin) during your pregnancy and for a few weeks after delivery. Both of those types of injectable blood thinners are safe for your baby.

But not everyone with the prothrombin gene mutation and a history of deep vein thrombosis or pulmonary embolism needs blood thinners during pregnancy. It depends on the specific details of the previous deep vein thrombosis or pulmonary embolism.

If you have the prothrombin gene mutation but never had a deep vein thrombosis or pulmonary embolism before, you will not need a blood thinner during or after pregnancy.

Can you donate blood if you have prothrombin gene mutation?

Yes, you may be able to donate blood if you’re not taking a blood thinner. The mutation in itself is not a reason to avoid donating blood, but you should not give blood if you are using an anticoagulant (blood thinner). Check with your provider.

When should I see my healthcare provider?

You should either contact your provider or go to the nearest Emergency Room if you think you’re having a deep vein thrombosis. If you have symptoms of a pulmonary embolism, you should go to the closest emergency room.

If you are already taking an anticoagulant, make sure you keep regular appointments with your provider.

What questions should I ask my doctor?

• Do I need to take an anticoagulant?
• How long do I need to take the anticoagulant?
• Did I get the mutation from both parents or just one?
• How frequently do I need to have checkups?

A note from Cleveland Clinic

A prothrombin gene mutation can raise your risk of getting a pulmonary embolism or deep venous thrombosis. You may never get a dangerous clot, but it’s helpful to know the warning signs in case you do. Talk to your provider to see if you should be taking a blood thinner. Keep going to your follow-up appointments with your provider, especially if you’re taking a blood thinner.