Bernard–Soulier syndrome (BSS), also called hemorrhagiparous thrombocytic dystrophy,[1] is a rare autosomal recessive coagulopathy (bleeding disorder) that causes a deficiency of glycoprotein Ib (GpIb), the receptor for von Willebrand factor, which is important in clot formation.
The incidence is estimated to be less than 1 in 1 million persons, based on cases reported from Europe, North America, and Japan.[2]
It is a Giant Platelet Syndrome that is characterized by abnormally large platelets.
Symptoms
As with other congenital platelet function defects, BSS often presents as a bleeding disorder with symptoms[3] of:
- Perioperative and postoperative bleeding
- Bleeding gums
- Easy bruising
- Heavy menstrual periods
- Epistaxis
- Abnormally prolonged bleeding from small injuries
Characteristics
Characterized by prolonged bleeding time, thrombocytopenia, increased megakaryocytes (bone marrow platelet progenitors), and decreased platelet survival, Bernard–Soulier syndrome is associated with quantitative or qualitative defects of the platelet glycopotein complex GPIb/V/IX. The degree of thrombocytopenia may be estimated incorrectly, due to the possibility that when the platelet count is performed with automatic counters, giant platelets (which may be as frequent as 70–80% in occasional patients) may reach the size of red blood cells and, as a consequence, are not recognized as platelets by the counters. BSS platelets do not aggregate to ristocetin, and this defect is not corrected by the addition of normal plasma, distinguishing it from von Willebrand disease. The platelet responses to physiologic agonists is normal, with the exception of low concentrations of thrombin. Bleeding events, which may be very severe, can be controlled by platelet transfusion. Most heterozygotes, with few exceptions, do not have a bleeding diathesis.
It presents as a bleeding disorder due to the inability of platelets to bind and aggregate at sites of vascular endothelial injury.[4]
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