Blood Clotting Disorders You Can Inherit

Genetic defects can cause your blood to clot too much
Blood Clotting Disorders You Can Inherit

Relatively rare, but increasingly studied, blood clotting disorders present at birth can create problems throughout your life.

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These disorders usually cause blood clots in veins including deep vein thrombosis (DVT) of the arms or legs, pulmonary embolism, and blood clots in the brain, intestines and kidneys. They rarely cause blood clots in the arteries.

How clotting works

When you sustain an injury or cut, important components in your blood such as platelets and plasma including fibrinogen and other factors help to stop blood loss. They do this by thickening up the blood and forming a clot.

However, the blood shouldn’t clot when it’s just moving through the body. If blood tends to clot too much, it is referred to as a hypercoagulable state. The term thrombophilia describes a hypercoagulable state when it is due to the presence of abnormal clotting factors in the blood. These abnormal clotting factors may be due to inherited or acquired conditions.

Top inherited clotting disorders

John Bartholomew, MD, Section Head of Vascular Medicine and Director of the Thrombosis Center at Cleveland Clinic, says there are two common genetic causes of excessive clotting and several others that are identified less frequently.

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Dr. Bartholomew says, “We are now looking closely at the specific causes behind clotting disorders, and our ever-increasing knowledge of genetics allows us to differentiate one disease from another, to identify the cause behind the symptoms.”

Though all occur rarely, Factor V Leiden and prothrombin gene mutation occur most often. Less common are: antithrombin, protein C and protein S deficiencies.

  1. Factor V Leiden: In Factor V Leiden, the normal checks and controls on a blood clotting substance known as Factor V are inactivated. In this particular case, genetic flaws inhibit a protein that normally keeps Factor V under control. As a result, blood clotting lasts longer than normal. Between 3 -8 percent of the population with European ancestry carries the gene mutation associated with the disorder.
  2. Prothrombin gene mutation: Patients with this disorder have a genetic defect that results in an overabundance of a blood clotting protein called prothrombin (also called Factor II). About 2 percent of Caucasians have some form of this disorder, which most often causes clots in the veins.
  3. Antithrombin deficiency (formerly called Antithrombin III) Protein C and Protein S deficiencies: These 3 are much less common (each found in less than 1% of the population in general). Clinical symptoms develop in early adulthood although patients with these disorders remain at risk for blood clots throughout their lifetime.

An acquired disorder

According to Dr. Bartholomew, “One of the most concerning thrombophilia disorders is the antiphospholipid syndrome.” It is an acquired condition, meaning it is not inherited. It is not clear why some people develop this condition, but it has been associated with infections, cancer, medications and some rheumatological conditions such as systemic lupus erythematosus.

In this complex syndrome, the body attacks substances called phospholipids that play a vital role in the integrity of cell wall membranes. As a result, blood cells degrade and then cause repeated clotting (thrombosis) in both the veins and arteries. This disorder can impact multiple systems in the body.

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Even if you have a blood clotting disorder, you most likely will only need treatment when a blood clot develops. Anticoagulant drugs help prevent additional clots because they decrease the blood’s ability to coagulate. These drugs include:

  • Warfarin (Coumadin®)
  • Heparin
  • Low-molecular weight heparin
  • Fondaparinux (Arixtra®)

There are a number of newer blood thinning drugs approved by the FDA and available for use. These include: dabigatran (Pradaxa®), rivaroxaban (Xarelto®) and apixaban (Eliquis®).

Your doctor will talk to you about the benefits and risks of these medications. This information, along with your diagnosis, will help determine the type of medication you will take, how long you will need to take it, and the type of follow-up monitoring you need.

As with any medication, it is important to know how and when to take it according to your doctor’s guidelines. It’s also important to have frequent blood tests that your doctor orders.

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