The disorder is characterized by large amounts of the fibrinolytic enzyme urokinase-type plasminogen activator (u-PA) in platelets.[5] 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.[6] These proteins include platelet factor V, Von Willebrand factor, fibrinogen, thrombospondin-1, and osteonectin.[5] There is also a quantitative deficiency in the platelet protein multimerin 1 (MMRN1).