Bernard-Soulier Syndrome

What is Bernard-Soulier syndrome?

Bernard-Soulier Syndome (also called Giant Platelet Syndrome) is a disorder of platelet function. Glycoproteins are one of the many proteins that help platelets work well to plug holes in damaged blood vessels and start the process of making a blood clot. Glycoproteins can serve as a bridge that connects platelets to each other. This way, platelets can stick together to form a plug to stop bleeding.

Patients with Bernard-Soulier syndrome have a defective or absent glycoprotein called GP Ib/IX/V. Platelets may be abnormally large, they may not stick to each other, or there may not be enough platelets. This means platelets cannot form a plug to stop bleeding.

What causes it?

Bernard-Soulier syndrome is inherited from both parents and can occur in both men and women. The prevalence of Bernard-Soulier syndrome is not well known.

What are the symptoms?

The symptoms of Bernard-Soulier syndrome include:

  • Easy bruising
  • Bleeding from the nose or gums
  • In women, heavy menstrual bleeding or bleeding related to childbirth
  • Excessive bleeding after surgery or injury
  • Swelling, pain, or warmth around a joint
  • Inability to straighten or bend a joint normally
  • Headache or neck ache
  • Drowsiness or loss of consciousness
  • Sensitivity to light
  • Upset stomach
  • Vomit that is black and syrupy or bright red
  • Red- or black-colored stool

How is it diagnosed?

Diagnosis of disorders where platelets aren’t functioning normally is more complicated than diagnosis of clotting factor deficiencies. Screening blood tests that evaluate clotting factors may be normal. As a screening test, the number of platelets might be lower than normal, and when using a microscope they may look larger than normal.

The bleeding time test (not commonly used anymore), which looks at the time it takes for a very small cut to stop bleeding, will be long in patients with Bernard-Soulier Syndrome. Other platelet function screening tests may show a delayed time to make a platelet clump or plug.

A set of very specific tests that specialized laboratories and hematology specialists can do to further evaluate the specific platelet disorder can be done. One is called aggregation, where a fresh (not frozen) blood sample is examined to see which chemicals stimulate blood clotting. In Bernard-Soulier Syndrome, platelets only clump together normally in the presence of ristocetin. A second confirmatory test called flow cytometry looks at the specific glyoproteins on the surface of the platelets. GP Ib/IX/V is not detectable on platelets in patients with Bernard-Soulier Syndrome.

How is it treated?

Patients with platelet function disorders like Bernard-Soulier may need to have treatment in addition to local (eg. pressure, bandages) and topical therapies for severe bleeding episodes. They may also need treatment during dental or surgical procedures or after injuries or accidents.

Platelets and other agents may be incorporated into treatment. Bernard-Soulier syndrome patients given platelets containing normal glycoproteins can develop reactions since these patients don’t have these proteins. This could result in antibodies or a decreased response to platelets.

Excessive menstrual bleeding in women with platelet disorders may be controlled with hormonal contraceptives (birth control pills), intra-uterine devices (IUDs), or antifibrinolytic drugs.

In patients who bleed enough to have anemia (low blood counts), iron replacement may be recommended.

People with platelet function disorders should not take any products that impact blood clotting or platelet function. These include nonsteriodal anti-inflammatory drugs like ibuprofen or naproxen, aspirin, and blood thinners.