von Willebrand’s Disease (vWD)²

von Willebrand’s Disease (vWD) is the most common inherited bleeding disorder. Less severe and less well-known than hemophilia, it was first recognized in 1926 by Finnish physician Erik von Willebrand. vWD affects an early step in clot formation when the protein helps platelets adhere to the site of an injury and form a platelet plug. In Type 1 vWD, the most common form of the disease, the blood doesn't make enough protein. In Type 2 vWD, the protein doesn't function properly. In Type 3 vWD, there is a complete absence of protein. This is the rarest form of vWD since it must be inherited from both parents, whereas the other types of von Willebrand’s disease only have to be inherited by one parent.

Symptoms: Most people with vWD do not bleed into joints and muscles, but bleed from mucous membranes, including those of the mouth, nose, intestine, and uterus.

Congenital Platelet Function Defects³

These rare disorders are present at birth and characterized by prolonged bleeding time despite normal platelet counts. These disorders differ from each other in subtle ways. In Bernard-Soulier Syndrome, platelets are unable to undergo normal adhesion (stick to blood vessel walls), leading to potentially severe bleeding. In Glanzmann's Thrombasthenia, platelets fail to undergo normal aggregation (stick to other platelets) and are unable to form a plug at the injury site, resulting in potentially severe bleeding from mucous membranes and postoperative bleeding.

Both of these disorders are often first recognized during childhood, due to frequent bruising, nose bleeds, excessive bleeding in the mouth and gums, and even gastrointestinal bleeding. Women may experience heavy or prolonged menstrual bleeding. Other congenital platelet function defects include Gray Platelet Syndrome (in which a lack of important proteins within the platelet slows adhesion, aggregation and vessel repair) and Dense Granule Deficiency (in which a lack of storage sites for substances needed for normal platelet function slows platelet activation and blood vessel constriction).

Idiopathic Thrombocytopenic Purpura (ITP)*

This bleeding disorder occurs when the body mistakenly produces antibodies that destroy platelets. Acute ITP generally lasts 6 months and is more common in children. Chronic ITP is longer lasting (6 months or longer), mostly affects adults and affects women more frequently than men. In many cases, it resolves itself over time.

Symptoms: Bleeding under the skin, easy bruising, excessive menstrual bleeding, and bleeding in the gastrointestinal tract.

* For more detailed information, please refer to http://www.emedicine.com/med/topic987.htm or http://www.nhlbi.nih.gov/health/dci/Diseases/Itp/ITP_WhatIs.html.

Primary Thrombocythemia*⁴

Also known as essential thrombocytosis, this disorder involves overproduction of platelet cells without a recognizable cause. Red and white blood cells may also be affected. The disease occurs primarily in people over age 50.

Symptoms: Some patients may have no symptoms, others may have blood clots and bleeding.

* For more detailed information, please refer to http://www.nhlbi.nih.gov/health/dci/Diseases/Itp/ITP_WhatIs.html.

Thrombotic Thrombocytopenic Purpura (TTP)*⁵

Also known as Moschcowitz's Disease, TTP is a bleeding disorder characterized by low levels of platelets and red blood cells, along with neurological abnormalities. TTP can be inherited or acquired later in life. The disease occurs most often in adults and afflicts slightly more women than men. The acquired form is associated with viral and HIV infections. The cause is unknown, but the development of antibodies is thought to be involved.

Symptoms: Bleeding beneath the skin or in mucous membranes which leads to bruising or the appearance of purplish, rash-like areas, fever, fatigue, and low amount of urine can occur. Headaches, slurred speech, disorientation, and other neurological symptoms are common.

* For more detailed information, please refer to http://www.emedicine.com/med/topic987.htm.