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von Willebrand's Disease
von Willebrand's Disease (vWD) is a bleeding disorder that is named after Erik Adolf von Willebrand, a Finnish pediatrician (1870-1949). He first described the disease in 1926, differentiating it from another type of bleeding disorder, Haemophilia.
vWD is the most common hereditary coagulation abnormality described in humans. It arises from a quallitative or quantitative deficiency of von Willebrand factor (vWF), a multimeric protien that is required for platelet adhesion. It is known to affect humans and, in veterinary medicine, dogs. There are inherited and acquired forms of vWD. There are three hereditary types of vWD described - type 1, type 2 and type 3. Most cases are hereditary, but acquired forms of vWD have been described. The International Society on Thrombosis and Haemostasis's (ISTH) classification depends on the definition of quallitative and quantitative defects.
In humans, the incidence of vWD is roughly about 1 in 100 individuals. Because most forms are rather mild, they are detected more often in women, whose bleeding tendency shows during menstruation. Many vWD patients suffer from chronic bleeding, with symptoms surfacing as easy bruising, frequent nose bleeds, heavy menstruation, heavy beleeding from cuts or injury, and heavy bleeding during dental surgery.
Haemophilia (also Hemophilia)
Hemophilia is a disorder of blood-clotting protiens in humans. There are 3 types of Hemophilia, A, B (also known as Christmas Disease) & C. Hemophilia leads to a severely increased risk of bleeding from common injuries. The sites of bleeding are joints, muscles, digestive tract, and brain.
Haemophilia A (also spelled Hemophilia A or Hæmophilia A) is a blood clotting disorder caused by a mutation of the factor VIII gene, leading to a deficiency in Factor VIII. It is the most common hemophilia. Inheritance is X-linked recessive; hence, males are affected while females are carriers or very rarely display a mild phenotype. 1 in 10,000 males are affected.
Haemophilia B (also spelled Hemophilia B or Hæmophilia B) is a blood clotting disorder caused by a mutation of the Factor IX gene. It is the second most common form of haemophilia, rarer than haemophilia A. It is sometimes called Christmas disease after Stephen Christmas, the first patient described with this disease. In addition, the first report of its identification was published in the Christmas edition of the British Medical Journal.
Haemophilia C is a mild form of hemophilia affecting both sexes that predominantly occurs in Jews of Ashkenazi descent. It is due to deficiency of coagulation factor XI. It can be distinguished from haemophilia A and B as it does not lead to bleeding into the joints. |
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