Congenital platelet function defects

Definition

Congenital (present at birth) platelet function defects are disorders of the platelets, the blood cells essential for the coagulation of the blood.

Causes, incidence, and risk factors

Congenital platelet function defects are bleeding disorders characterized by abnormal platelet function in spite of normal platelet counts. There is usually a family history of a bleeding disorder consisting of prolonged bleeding or easy bruising.

Bernard-Soulier syndrome is a congenital disorder where the platelets lack receptors to adhere to the walls of the blood vessels. Bleeding may be severe with this disorder.

Glanzmann's thrombasthenia is a condition caused by lack of a protein required for platelet aggregation (clumping). This disorder may cause mucosal and postoperative bleeding, which may be severe.

Storage pool disease is a mild bleeding disorder that causes bruising. The risk factor is a family history of a bleeding disorder.

Symptoms

• Nosebleeds
• Intraoperative and postoperative bleeding
• Easy bruising
• Prolonged bleeding with superficial injuries
• Menstrual periods, abnormal
• Bleeding gums

Signs and tests

• CBC that may reveal normal, or occasionally low, platelet count
• Prolonged bleeding time
• Platelet aggregation test
• Normal PT, PTT

Treatment

There is no specific treatment for these disorders. All people with bleeding disorders should avoid taking aspirin because it is known to prolong bleeding time -- the time it takes to form clotting mechanisms in the blood. Platelet transfusions may be administered when patients have severe bleeding.

Expectations (prognosis)

Treatment can usually control the bleeding, but these are lifelong conditions for which there is no cure. Precautions to avoid catastrophic bleeding should be taken.

Complications

• Severe bleeding
• Iron deficiency anemia in menstruating women

Calling your health care provider

Call your health care provider if bleeding or bruising of an unknown cause is present, or if bleeding does not respond to the usual method of control.

Prevention

Laboratory studies can detect the defective gene responsible for these platelet disorders. Genetic counseling may be of value to couples with a family history of any of these disorders who are planning children in the future.

Illustrations

Blood clot formation

Blood clots

Page Content:

Storage pool disease; Glanzmann's thrombasthenia; Bernard-Soulier syndrome; Platelet function defects - congenital ; bernard soulier syndrome; glanzmanns thrombasthenia