Classical hemophilia of due to absence of

Plasma factor VIII-vWF complex is made up of two proteins. One, which is required for the activator of factor X in the intrinsic coagulation pathway, is called factor VIII procoagulant protein, or factor VIII. Deficiency of factor VIII gives rise to hemophilia A. factor VIII is associated noncovalently with a much larger protein, vWF, that forms high – molecular-weight multimers of sizes that range as high as 20 megadaltons. vWF is found normally in the plasma (in association with factor VIII), in platelet granules, in endothelial cells in unusual cytoplasmic vesicles called Weibel-palade bodies, and in the subendothelium, where it binds to collagen.