Bernard-Soulier syndrome
Encyclopedia
Bernard–Soulier syndrome (BSS), also called hemorrhagiparous thrombocytic dystrophy, 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.
It is a Giant Platelet Syndrome that is characterized by abnormally large platelets.
, 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.
There are three forms:
.
Coagulopathy
Coagulopathy is a condition in which the blood’s ability to clot is impaired. This condition can cause prolonged or excessive bleeding, which may occur spontaneously or following an injury or medical and dental procedures.The normal clotting process depends on the interplay of various proteins in...
(bleeding disorder) that causes a deficiency of glycoprotein Ib
Glycoprotein Ib
Glycoprotein Ib , also known as CD42,is a component of the GPIb-V-IX complex on platelets. The GPIb-V-IX complex binds von Willebrand factor, allowing platelet adhesion and platelet plug formation at sites of vascular injury....
(GpIb), the receptor for von Willebrand factor
Von Willebrand factor
von Willebrand factor is a blood glycoprotein involved in hemostasis. It is deficient or defective in von Willebrand disease and is involved in a large number of other diseases, including thrombotic thrombocytopenic purpura, Heyde's syndrome, and possibly hemolytic-uremic syndrome...
, 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.
It is a Giant Platelet Syndrome that is characterized by abnormally large platelets.
Characteristics
Characterized by prolonged bleeding time, thrombocytopeniaThrombocytopenia
Thrombocytopenia is a relative decrease of platelets in blood.A normal human platelet count ranges from 150,000 to 450,000 platelets per microliter of blood. These limits are determined by the 2.5th lower and upper percentile, so values outside this range do not necessarily indicate disease...
, 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
Ristocetin
Ristocetin is an antibiotic, obtained from Amycolatopsis lurida, previously used to treat staphylococcal infections. It is no longer used clinically because it caused thrombocytopenia and platelet agglutination. It is now used solely to assay those functions in vitro in the diagnosis of conditions...
, and this defect is not corrected by the addition of normal plasma, distinguishing it from von Willebrand disease
Von Willebrand disease
von Willebrand disease is the most common hereditary coagulation abnormality described in humans, although it can also be acquired as a result of other medical conditions. It arises from a qualitative or quantitative deficiency of von Willebrand factor , a multimeric protein that is required for...
.
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
Bleeding diathesis
In medicine , bleeding diathesis is an unusual susceptibility to bleeding mostly due to hypocoagulability, in turn caused by a coagulopathy . Several types are distinguished, ranging from mild to lethal...
.
It presents as a bleeding disorder due to the inability of platelets to bind and aggregate at sites of vascular endothelial injury.
Genetics
- Type A - GP1BAGP1BAGlycoprotein Ib , alpha polypeptide also known as CD42b , is a human gene.-Interactions:GP1BA has been shown to interact with YWHAZ and FLNB.-Further reading:...
- Type B - GP1BBGP1BBGlycoprotein Ib , beta polypeptide also known as CD42c , is a human gene.-External links:...
- Type C - GP9Glycoprotein IXGlycoprotein IX also known as CD42a , is a human gene.-External links:...
Eponym
The syndrome is named after Dr. Jean Bernard and Jean Pierre SoulierJean Pierre Soulier
Jean Pierre Soulier was a French physician and haematologist. He was the General Director of Centre National de Transfusion Sanguine Paris and professor of haematology at the University of Paris, at the Necker Hospital for Sick Children.-References:*D. Menache-Aronson . . Journal of Thrombosis...
.
See also
- Gray platelet syndromeGray platelet syndromeGray platelet syndrome , or platelet alpha-granule deficiency, is a rare congenital bleeding disorder caused by a reduction or absence of alpha-granules in blood platelets, and the release of proteins normally contained in these granules into the marrow, causing myelofibrosis.GPS is primarily...
- Glanzmann's thrombastheniaGlanzmann's thrombastheniaGlanzmann's thrombasthenia is an abnormality of platelets. It is an extremely rare coagulopathy , in which the platelets lack glycoprotein IIb/IIIa...
- von Willebrand diseaseVon Willebrand diseasevon Willebrand disease is the most common hereditary coagulation abnormality described in humans, although it can also be acquired as a result of other medical conditions. It arises from a qualitative or quantitative deficiency of von Willebrand factor , a multimeric protein that is required for...
- May-Hegglin anomaly