Coagulation Factor Deficiency or Dysfunction
A bleeding disorder may be due to a lack of one or more clotting factors or the result of factors that do not function properly. Deficiency or dysfunction of coagulation factors may have genetic causes (inherited) or may be the result of another disease or condition. The following are a few examples:
Von Willebrand disease (VWD): this condition is associated with decreased production or dysfunction of von Willebrand factor and results in reduced platelet adherence to the injured blood vessel and increased blood loss. VWD is the most common inherited bleeding disorder, affecting as many as 1 in 100 people. Rarely, VWD may be due to an acquired VWF deficiency, where there is no family or personal bleeding history up to the point of presentation.
VWD is separated into different types and sub-types, including:
- Type 1 – with this type of VWD, there is a decrease in the amount of VWF produced, but the VWF functions normally. Levels of factor VIII are also typically low but may be normal. This is the most common type of VWD, accounting for about 75% of cases. It tends to cause bruising and mild to moderate bleeding, such as persistent nosebleeds, heavy menstrual periods, and prolonged bleeding following childbirth, trauma, dental procedures, and surgeries. Symptoms and the severity of bleeding will vary from person to person and from episode to episode.
- Type 2 – this type is typically associated with a normal amount of VWF, but the VWF does not function normally. Bleeding may be more severe with this with this type. There are four different subtypes, each caused by unique defects in VWF. Type 2 VWD accounts for 15-20% of all VWD cases.
- Type 3 – this rare type is associated with little to undetectable VWF production, very low factor VIII levels, and moderate to severe bleeding. It is often detected in infancy because of early bleeding episodes.
Hemophilia A (Factor VIII deficiency): This is an X-chromosome linked recessive bleeding disorder that occurs primarily in males. It is the second most common inherited bleeding disorder, occurring in 1 case per 5,000 males world wide. (For more on inheritance, see The Universe of Genetic Testing: The Basics.)
In those with the disease, the first bleeding episode may be with circumcision or other procedures performed on an infant. The severity of the bleeding caused by a factor VIII deficiency depends on its activity level. If it is very low, it may cause severe life-threatening bleeding; if it is moderate, it may only cause mild to moderate bleeding, becoming an issue primarily when having surgery or dental procedures.
Other inherited factor deficiencies include II, V, VII, X, XI, and IX (Hemophilia B, also called Christmas disease, which is also X-linked and occurs in approximately 1 in 25,000 live male births).
- Liver dysfunction or disease – almost all coagulation factors are produced in the liver; liver disease may result in decreased production of factors.
- Vitamin K deficiency – the synthesis of several coagulation factors (II, VII, IX, X) requires vitamin K.
- Fat malabsorption
- Exposure to snake venom
- Some cancers
- Treatment for cancer, such as chemotherapy or radiation therapy
- Massive blood transfusions (e.g., transfuse only red blood cell units)
- Factor inhibitors are antibodies that target a specific clotting factor, such as factor VIII, decreasing its activity.
- Anticoagulant drugs such as warfarin (COUMADIN®) or heparin; these drugs are used to treat clotting disorders but in excessive amounts may cause bleeding.
- Some bacterial infections
- Disseminated intravascular coagulation (DIC), may cause both bleeding and clotting. It is usually an acute condition, may be from a complicated childbirth, from an endotoxin produced during a severe infection, or due to certain cancers such as a certain type of leukemia. DIC causes tiny clot formation throughout the body, using up clotting factors at an accelerated rate, leading to excessive bleeding.