Factor V Leiden

1 What is Factor V Leiden?

Factor V Leiden is a genetic disease in which there is a mutation in the factor V, one of the clotting factors.

This disease increases the frequency of developing abnormal clots that could block small vessels and thus inhibit blood flow to certain vital organs like the brain, heart and kidneys. However,clots are never formed in most people with factor V Leiden.

It usually affects women more than it affects men.

Treatment involves giving anticoagulants which dissolve clots and decrease the formation of new clots.

2 Symptoms

Because clots don't develop in most people, symptoms of factor V Leiden may not develop.

Symptoms in those who clots form depend on the size and location of the clot.Small clots usually cause no damage and can be dissolved without administration of anticoagulants.However, larger clots that are found in the vessels leading to the brain, heart or kidneys can be fatal.

The following symptoms can occur in people with factor V Leiden:

  • If the clot is in a deep vein usually in the legs- pain, swelling of the legs, ankles and feet, redness and warmness of the skin of the leg.
  • If the clot is within the skin- warmness of the skin, tenderness, pain and redness of the area affected. 
  • If the clot travels to the lungs - shortness of breath, chest pain especially when breathing in, coughing with blood and tachycardia (rapid heart beat).

3 Causes

Factor V Leiden thrombophilia is caused by a specific mutation in the Factor V gene.

Under normal conditions blood clots are formed to stop bleeding when there is injury to a blood vessel. After the clots have been formed they are later destroyed by anticoagulants within the blood.

Factor V is also destroyed by anti-clotting factors that prevents the formation of unnecessary clots.However, in factor V Leiden, clots form even when there is no injury to the vessels and because there is a mutation in factor V, anti-clotting factors fail to destroy factor V. These clots are usually formed in the veins because the flow of blood is slower than in arteries.

Factor V Leiden is a hereditary disorder that can be passed from parents to their children.

People with factor V Leiden can either be heterozygous meaning they inherited it from one parent and have only one defective gene or homozygous meaning they inherited it from both parents and have two defective genes. Homozygous individuals are at an increased risk of developing clots as compared to heterozygous individuals.

4 Making a Diagnosis

If your doctor suspects factor V Leiden, he/she may ask about your family history and look for possible thrombotic diseases in the past to make a diagnosis.

Blood tests are performed to verify the diagnosis of factor V Leiden.

These tests include:

  • Activated protein C test in which protein C,
  • An anti-clotting protein is added to blood to check for a mutation in favtor V
  • A genetic test.

A genetic test is used to confirm the results of activated protein C resistance test.

5 Treatment

Anti-coagulants which dissolve clots and prevent the formation of new clots are the recommended treatment for factor V Leiden. This is only required in people who develop clots since if anti-coagulants are given to people who don't develop clots they could provoke bleeding.

A combination of heparin and warfarin are given initially and the duration of the treatment depends on the severity of thrombosis.

  • Heparin is injected directly into a vein and works more faster than warfarin.
  • Warfarin is taken orally. Unlike heparin, warfarin is not recommended for pregnant women since it can cause birth defects.

Themost common side effect of both drugs is bleeding.

Other drugs that can be taken orally include:

  • Dabigatran
  • Rivaroxaban
  • Aixaban

They can also cause bleeding that is difficult to reverse.

6 Lifestyle and Coping

Lifestyle modifications are necessary in order to cope with factor V Leiden.

Avoiding the following activities can reduce the risk of the formation of clots:

  • Staying in a sitting or standing position for long periods of time
  • Prolonged bed rest especially during an illness or paralyis
  • Having an injury or surgery
  • Being obese or overweight
  • Smoking
  • Using contraceptives or estrogen replacement therapy.

If you are taking anti-coagulants for factor V Leiden, you can prevent bleeding by:

  • Avoiding sports that could lead to physical injury
  • Using a soft toothbrush and waxed floss
  • Avoiding shaving cuts by using an electfric razor
  • Being careful when using sharp objects like knives

7 Risks and Complications

There are several risks and complications associated with factor V Leiden.

Because factor V Leiden is a hereditary disease, having a family member with this disease increases your chance of having it. It also affects causacians more than any other race.

Complications of factor V Leiden are due to the formation of blood clots that may impair the normal flow of blood to certain organs.

Some of the complications include: deep vein thrombosis that can lead to pulmonary and pulmonary embolism.

  • Pulmonary embolisms is usually caused by deep vein thrombosis. When a thrombus is formed in a deep vein of the leg, it can travel to the heart and from there to the vessels of the lungs. This embolism eventually blocks the small vessels of the lung and can make breathing difficult and painful.
  • Another potetially letghal complication is an increased risk of miscarriage and complications during pregnancy.An example of a complication during pregancy is preeclampsia which is an increases in blood pressure that is caused by pregnancy.
  • Other complications associated with pregancy include slow fetal growth and detachment of the placenta from the uterine wall. Therefore, pregnant women with factor V Leiden should be carefully monitored to prevent these complications.