Platelets are small, irregularly shaped blood cell pieces that play an important role in clotting blood. When an injury occurs and a blood clot is needed, the platelets activate and help plug the site of the injury. They attract other proteins needed in the clotting process and they help to form a stable clot. There are several ways or reasons that platelets may not work properly.
The specific problem may result in rare platelet disorders, such as:
A very rare platelet disorder that causes a deficiency of glycoprotein lb, the receptor for vWF, which is important in clot formation. A person with BSS can bleed for a very long time before a clot forms. In fact, it may take more than 20 minutes for the bleeding to stop from even a small cut.
An extremely rare bleeding disorder in which the platelets lack glycoprotein IIb/IIIa, the binding sites for vWF, on the surface. In people with GT, platelets do not adhere or stick to each other as they should. Bleeding continues significantly longer than normal.
A name given to several rare disorders in which the platelet granules, involved in platelet signaling, are affected. Chemicals inside the granules are pushed out (called secretion) into the bloodstream, signaling other platelets to the plug. In SPD, a certain type of granule in the platelets may be missing or be abnormal.
Causes are generally divided into those involving decreased production of platelets and those involving increased destruction or loss of platelets.