Von Willebrand Disease

Von Willebrand disease is an inherited bleeding disorder. The disease is named after the doctor who discovered it, Erik von Willebrand. People born with the disease have one or both of the following:

• Low levels of a protein called von Willebrand factor that helps the blood to clot
• Von Willebrand factor that doesn’t work properly

When von Willebrand factor is missing or doesn’t work, it can cause prolonged bleeding after an injury or accident.

Types

Type 1
In type 1 von Willebrand disease, there is a low level of von Willebrand factor. The level of factor VIII may also be lower than normal. This is the mildest and most common form of the disease. About 3 out of 4 people diagnosed with von Willebrand disease have type 1.

Type 2
In type 2 von Willebrand disease, a defect in von Willebrand factor causes it to not work properly. Type 2 is divided into 2A, 2B, 2M, and 2N. Each is treated differently, so knowing the exact type is important.

Type 3
People with type 3 von Willebrand disease usually have no von Willebrand factor and very low factor VIII. Type 3 is severe and very rare.

Symptoms

The signs and symptoms depend on the type and severity of the disease. Some people have the gene for the disease but don’t have bleeding symptoms.

People with type 1 and type 2 von Willebrand disease may have the following mild-to-moderate bleeding symptoms:

• Easy bruising
• Nosebleeds
• Bleeding from the gums after a dental procedure
• Heavy menstrual bleeding in women
• Blood in their stools (from bleeding in the intestines or stomach)
• Blood in their urine (from bleeding in the kidneys or bladder)
• Excessive bleeding after a cut or other accident
• Excessive bleeding after surgery

Heavy menstrual bleeding is the most common symptom in women who have von Willebrand disease. If untreated, it can lead to iron-deficiency anemia. Doctors may test for von Willebrand disease in women who have unusually heavy menstrual bleeding. Some people may only be diagnosed after an episode of prolonged bleeding after an accident or surgery.

People with type 3 von Willebrand disease (rare and severe) are usually diagnosed in childhood. They may have:

• Any of the symptoms listed above.
• Severe bleeding episodes for no reason. These bleeding episodes can be life threatening if not treated immediately.
• Bleeding into soft tissues or joints, causing severe pain and swelling. Bleeding into the joints is called hemarthrosis.

Diagnosis

Von Willebrand disease is sometimes difficult to diagnose. Mild symptoms may be mistaken for other illnesses. Severe von Willebrand disease can cause significant bleeding problems during infancy. Because of this, people with severe von Willebrand disease are usually diagnosed during the first year of life. People who have milder forms of the disease may not have significant bleeding problems, or they may have mild bleeding symptoms. People with milder forms of von Willebrand disease may not be diagnosed until adulthood.

Your doctor will review your personal and family history for signs and symptoms that indicate a bleeding disorder, including von Willebrand disease. Your doctor also may order laboratory tests.

If your doctor thinks that you have von Willebrand disease, specific tests must be done because some people with a mild form of the disease (type 1) may have normal results on the usual tests for bleeding disorders. If you have bleeding symptoms, your doctor will order blood tests that specifically check:

• Your blood’s ability to clot
• The level of von Willebrand factor in your blood
• How well the von Willebrand factor works (the “activity?of the factor)

These tests may be repeated several times to confirm the diagnosis.

Your doctor will order a combination of blood tests to diagnose the disease. These tests may include:

• Von Willebrand factor antigen. This test measures the amount of von Willebrand factor in your blood.
• Ristocetin cofactor activity. This test shows how well the von Willebrand factor works.
• A test for factor VIII clotting activity. Some people with von Willebrand disease have low levels of factor VIII activity, while others have normal levels.
• Von Willebrand factor multimers. This test is used to evaluate abnormal results of the tests listed above, and it shows the makeup or structure of the von Willebrand factor. This test helps your doctor diagnose what type of von Willebrand disease you have.
• Platelet function test. This test measures how well your platelets and von Willebrand factor are working together.

Causes

Von Willebrand disease is usually inherited—that is, passed in the genes from parent to child. Genes are located in the cells of the body and control how the cells make proteins, such as von Willebrand factor. Each cell in the body has two copies of every gene (except some genes related to gender). You inherit one copy from your mother and one from your father.

In a person with von Willebrand disease, one or both of the genes that control the production of von Willebrand factor are defective. Type 1 and type 2 von Willebrand disease can develop if a person inherits one copy of the defective gene from one parent and a normal copy of the gene from the other. Type 1 and type 2 von Willebrand disease also can develop if the person inherits a defective copy of the gene from both parents. Type 3 von Willebrand disease develops only if a person inherits a defective von Willebrand gene from both parents.

In rare cases, von Willebrand disease isn’t inherited, but develops due to other reasons later in life. This is called acquired von Willebrand syndrome.

Reference:

National Heart, Lung, and Blood Institute, USA.