Bernard-Soulier Syndrome is a severe bleeding disorder. Bernard and Soulier described this condition in 1948 when they identified a young man with a bleeding problem. This patient had a prolonged bleeding time, a low platelet count and large platelets. These features are the hallmark of the condition. Since the original condition was described a large number of patients have been identified with the syndrome. Although it is not exactly clear how many patients suffer from the illness, it is thought to occur in about 1 in a million patients. The purpose of this web-site is to gather information on the syndrome and to facilitate physicians in making the diagnosis and informing patients on the current status of research in the area.
Platelets are particles that circulate in the blood. Their primary role is to cause clotting. When a platelet meets a damaged blood vessel, it tries to correct this damage by clotting. Bernard-Soulier platelets are missing a part of the platelet that is involved in the initial steps of a platelet forming a clot and consequently patients with the syndrome have bleeding problems.
The problems Bernard-Soulier patients face are exemplified in the original description of the young man described by Bernard & Soulier. The patient suffered from bleeding problems from early childhood. For example following a tooth extraction he had prolonged bleeding. He bled into his spinal cord and had bruising to his eye following an accident. The patient died when he had a brain haemorrhage following a fight.
The disease usually occurs in an autosomal recessive manner. This means that each parent has one copy of the gene and when the child inherits the abnormal gene from the mother and father the illness is present. There are a number of rare exceptions to this. The disease can occur in association with some syndromes associated with chromosomal abnormalities or can occur in an autosomal dominant manner. This means that rarely the disease can be inherited from just one parent who carries the gene for the abnormality.
The cause of the problem has been identified as due to an abnormality on the glycoprotein Ib-IX-V complex on platelets. This is the receptor that causes platelets to stick. When this receptor is absent, platelets cannot stick.
The glycoprotein Ib-IX-V complex (abbreviated to GPIb) is four proteins that stick out of the surface of the platelet, the four proteins are termed GPIb alpha, GPIb beta, GPIb-IX and GPV. The subunit GPIb alpha binds to a protein called von Willebrand factor and this starts the clotting process. If the protein von Willebrand factor is absent or abnormal this also leads to a bleeding problem. The exact roles of GPIb beta, IX and V are not clear, but they seem to function to support the role of GPIb alpha.
The diagnosis is made in the standard manner that a physician makes a diagnosis. By taking the patients history, doing a physical exam and laboratory tests. The physician will ask specific questions about bleeding and about bleeding illness in the family. Since the illness may occur in the offspring of closely related family members the physician may take a detailed family history. The patient will be examined for signs of bleeding. Finally the physician will order a number of laboratory tests that can be performed in most good laboratories which will suggest the disorder. The disorder is usually confirmed in a specialist laboratory with specific interests in this illness.
The first step in treatment is helping the patient understand the illness. This web site is to assist in patient education. For example patients should not take drugs such as aspirin which can interfere with their platelet function. Dental hygiene is a critical issue. In women heavy periods can result in low iron and this must be treated. Bleeding episodes that are severe usually require transfusion of blood and or platelets.
In the last few years several investigators in many different countries have identified and characterised new mutations, which cause the syndrome. These studies help us to understand the structure and function of the receptor. On the basis of these studies new therapies may well be designed which can facilitate the treatment and diagnosis of the illness. Other investigators are looking at the possibility of taking a small number of blood cells from the patient and transforming them into normal platelets. These studies are exciting and offer tremendous hope for the future treatment of the illness.
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