Giant Platelet Syndrome




The Bernard-Soulier Syndrome (BSS)  or giant platelet syndrome is a rare inherited bleeding disorder caused by abnormal platelets and subsequent abnormal clotting. It is one of the giant platelet syndromes. This syndrome was originally described in 1948 by two physicians who were treating a patient with a bleeding problem. They discovered that this patient had a prolonged bleeding time, fewer platelets, and larger platelets than the normal individual. Since then, the platelet abnormality has been described and determined to be due to the platelets lacking the ability to stick adequately to injured blood-vessel walls. This is a crucial aspect of the process of forming a blood clot, and as a result of this problem, there is abnormal bleeding.


  • Excessive bleeding following injury
  • Frequent nosebleeds
  • Heavy menstrual flow
  • Easy bruising
  • Low-healing bruises


Bernard-Soulier syndrome is a rare inherited disease and is transmitted in an autosomal recessive pattern. This means that both parents must carry a gene for the Bernard-Soulier syndrome and transmit that gene to the child for the child to have the disease. The prevalence is believed to be less than one in 1 million individuals. The molecular basis is now known and is due to a defect in the platelet glycoprotein complex 1b-IX-V.


Patients are often diagnosed with BSS after seeking medical attention following prolonged or reoccurring bleeding episodes. Some infants are diagnosed after excessive bleeding following circumcision. Other children and adults may be diagnosed after bleeding excessively following trauma or tooth extraction. Very frequently there is a history of another family member with similar symptoms, and the physician evaluating the patient will often document a detailed family history to assist in the diagnosis.


There is no specific treatment for Bernard-Soulier syndrome. Patients should avoid any drugs which may interfere with clot formation, such as aspirin, ibuprofen, and naproxen. Severe bleeding episodes may require platelet and blood transfusions. Recombinant clotting factors and a coagulation drug known as DDAVP may also be of short-term benefit in selected patients. Affected individuals should avoid participation in contact sports. Iron supplements are often recommended to patients with the disease to help minimize the anemia often observed in patients with frequent blood loss.