description | Protein which, if defective, causes Bernard Soulier syndrome (BSS), a familial coagulation disorder characterized by a prolonged bleeding time, unusually large platelets, and impaired prothrombin consumption BSS is caused by a genetic deficiency in platelet membrane glycoprotein Ib alpha chain and platelet glycoprotein IX, where platelets aggregate normally but do not stick to collagen of the sub- endothelial membrane |