What is Quebec platelet disorder? How do you make the diagnosis, and what is the management?¶
Answer: Quebec platelet disorder (QPD) is a rare autosomal dominant bleeding disorder. It is caused by a tandem duplication of PLAU (the urokinase plasminogen activator gene) on chromosome 10. This leads to a platelet-dependent gain-of-function defect, with multiple-fold expression of uPA in megakaryocytes and platelets — causing local plasmin-mediated degradation of α-granules and accelerated platelet-localized clot lysis.
- Presentation: the hallmark is delayed bleeding after trauma, surgery, or dental procedures. Patients may have mild thrombocytopenia. PFA is usually normal; aggregation may show reduced epinephrine response. Platelet morphology is usually normal.
- Diagnosis: genetic testing.
- Treatment: antifibrinolytic therapy is the treatment of choice and the only known effective treatment. Unlike other inherited platelet function disorders, platelet transfusions are ineffective, as they do not correct the localized defect.
Source: Quebec platelet disorder: update on pathogenesis, diagnosis, and treatment