Quebec platelet disorder | |
---|---|
Other names | Factor V Quebec |
Autosomal dominant is the manner of inheritance of this condition |
Quebec platelet disorder (QPD) is a rare autosomal dominant bleeding disorder first described in a family from the province of Quebec, Canada. [1] [2] The disorder is characterized by large amounts of the fibrinolytic enzyme urokinase-type plasminogen activator (uPA) in platelets. [3] This causes accelerated fibrinolysis ( blood clot breakdown) which can result in bleeding. [2]
Individuals with QPD are at risk for experiencing a number of bleeding symptoms, including joint bleeds, hematuria, and large bruising. [4]
The disorder is characterized by large amounts of uPA in platelets. [3] Consequently, stored platelet plasminogen is converted to plasmin, which is thought to play a role in degrading a number of proteins stored in platelet α-granules. [5] These proteins include platelet factor V, von Willebrand factor, fibrinogen, thrombospondin-1, and osteonectin. [3] There is also a quantitative deficiency in the platelet protein multimerin 1 ( MMRN1). Furthermore, upon QPD platelet activation, uPA can be released into forming clots and accelerate clot lysis, resulting in delayed-onset bleeding (12-24hrs after injury). [6]
In 2010, the genetic cause of QPD was determined as a mutation involving an extra copy of the gene encoding uPA. [7] The mutation causes overproduction of uPA, an enzyme that accelerates blood clot breakdown. [2]
Genetic testing is the only way to definitively diagnose QPD, as most other tests cannot confirm this diagnosis. [8] Methods include polymerase chain reaction or Southern blotting for the genetic sequence, or assays for platelet uPA levels or platelet granules. [8]
Bleeding episodes are treated using antifibrinolytic medication, particularly tranexamic acid, to prevent fibrinolysis. [8]
The discovery was made by a team of doctors at McMaster University led by Dr. Catherine Hayward, a hematologist. [9]
Quebec platelet disorder | |
---|---|
Other names | Factor V Quebec |
Autosomal dominant is the manner of inheritance of this condition |
Quebec platelet disorder (QPD) is a rare autosomal dominant bleeding disorder first described in a family from the province of Quebec, Canada. [1] [2] The disorder is characterized by large amounts of the fibrinolytic enzyme urokinase-type plasminogen activator (uPA) in platelets. [3] This causes accelerated fibrinolysis ( blood clot breakdown) which can result in bleeding. [2]
Individuals with QPD are at risk for experiencing a number of bleeding symptoms, including joint bleeds, hematuria, and large bruising. [4]
The disorder is characterized by large amounts of uPA in platelets. [3] Consequently, stored platelet plasminogen is converted to plasmin, which is thought to play a role in degrading a number of proteins stored in platelet α-granules. [5] These proteins include platelet factor V, von Willebrand factor, fibrinogen, thrombospondin-1, and osteonectin. [3] There is also a quantitative deficiency in the platelet protein multimerin 1 ( MMRN1). Furthermore, upon QPD platelet activation, uPA can be released into forming clots and accelerate clot lysis, resulting in delayed-onset bleeding (12-24hrs after injury). [6]
In 2010, the genetic cause of QPD was determined as a mutation involving an extra copy of the gene encoding uPA. [7] The mutation causes overproduction of uPA, an enzyme that accelerates blood clot breakdown. [2]
Genetic testing is the only way to definitively diagnose QPD, as most other tests cannot confirm this diagnosis. [8] Methods include polymerase chain reaction or Southern blotting for the genetic sequence, or assays for platelet uPA levels or platelet granules. [8]
Bleeding episodes are treated using antifibrinolytic medication, particularly tranexamic acid, to prevent fibrinolysis. [8]
The discovery was made by a team of doctors at McMaster University led by Dr. Catherine Hayward, a hematologist. [9]