Von Willebrand Disorder
The most common bleeding disorder that affects women is Von Willebrand Disorder (vWD). This is also the most common type of bleeding disorder. It affects about 1% of the population. Unfortunately, bleeding symptoms are not always recognized as abnormal, so only a small number of affected individuals have been diagnosed.
vWD is not a single disorder, but a family of related disorders, all caused by a problem with the von Willebrand factor (VWF). This is a protein in blood which is necessary for proper blood coagulation, or clotting. All types of vWD are inherited in an autosomal pattern (see how are Bleeding Disorders inherited).
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- Type 1 is the most common. About 75% of women with VWD have Type 1. With this type, the VWF works normally, but there is less of it than normal.
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- Type 2 is the next most common. The vWF protein is abnormal and does not work properly. Type 2 VWD includes several sub-types. Together, they make up 20-25% of VWD cases. In Type 2 VWD, the VWF molecule may be present in normal quantity, but it does not work properly. The VWF does not play its role in binding platelets to the wall of the blood vessel; sometimes it binds to platelets in the bloodstream instead of at the site of the broken vessel wall.
- Type 3 vWD is the rarest and the most severe form. People with Type 3 vWD have almost no vWF. As vWF transports Factor VIII in the bloodstream, people with Type 3 vWD have very low levels of Factor VIII as well. Bleeding disorders are rare and health professionals may not be familiar with them – or know that women and girls have bleeding symptoms too. Educating yourself about your bleeding disorder, getting a diagnosis and a treatment plan from a specialist Haemophilia Treatment Centre (HTC) and preparing for emergencies and procedures with your HTC – this will make a huge difference to your treatment experience.
Platelet Function Disorders
Platelet function disorders may affect as many as 1% of the population. The majority of these disorders are mild and many go undiagnosed. However, some types of platelet function disorders, such as Glanzmann’s Thrombasthenia, are more serious. Depending on the type of platelet function disorder, platelets may not stick to the walls of damaged blood vessels or form a proper surface so that other blood factors can form a clot at the site of an injury. The congenital platelet function disorders have variable inheritance patterns.
Immune Thrombocytopenia (ITP) is a blood disorder that causes the number of platelets in the blood to drop to such a low level that there is a risk of bleeding. The disorder is a spontaneously occurring condition that can affect both children and adults, and is not hereditary. ITP can be short-lived or become ‘chronic’. Here, the term chronic does not necessarily mean that one never gets rid of the disease. This means that it can last for several or many years. Fortunately, most people with ITP can live a relatively normal life, taking into account the disease and following the necessary precautions.
Carriers of Haemophilia A and B
Women who carry the haemophilia gene may also have mild or moderate haemophilia, and while it is extremely rare, it is also possible for women to have severe haemophilia.
The term “carrier” should be used and understood by health professionals to indicate the possibility to pass on a gene for haemophilia by a male or female.
Many carriers have a clotting level between 40-70% which would fit in the normal and do not usually suffer from severe bleeding, although they may still have difficulties from the most common symptom – heavy menstrual bleeding.
Other Clotting Deficiencies
There are other bleeding disorders that are caused by deficiencies of other clotting proteins in the blood and these are often called Rare Bleeding Disorders.
Rare clotting factor deficiencies:
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- factor II (2) deficiency
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- factor V (5) deficiency
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- combined factor V (5) and VIII (8) deficiency
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- factor VII (7) deficiency
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- factor 10 (X)
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- factor XI (11) deficiency
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- factor XIII (13) deficiency
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- Bernard-Soulier syndrome
Read more about bleeding disorders affecting women in our Women and Bleeding Disorders booklet.