Which of the following statement is not true about Von willebrand disease?
Laboratory findings of Von willebrand disease

Platelet count : Normal 
Bleeding time : Prolonged
Clotting time : Prolonged
Prothrombin time : Normal
VWF is synthesized by endothelial cells and megakonjocytes
VWF maybe located in the plasma and subendothelial tissue
VWF causes platelet adhesion and prevents degradation of factor VIII in plasma
Deficiency of VWF causes prolonged prothrombin time