Factor VII deficiencyDefinition:
Factor VII deficiency is an inherited disorder in which a lack (deficiency) of plasma protein factor VII leads to abnormal bleeding.
Extrinsic factor deficiency
Causes, incidence, and risk factors:
This disorder occurs when the body does not have enough factor VII, an important blood clotting protein.
When you bleed, the body launches a series of reactions that help the blood clot. The process involves special proteins called coagulation factors. Factor VII is one of many coagulation factors. The final product of these reactions is the blood clot .
When certain coagulation factors are missing, your blood may not clot normally and you can bleed abnormally. Bleeding can vary from mild to severe in the same person over time. Bleeding may begin during infancy or childhood.
Most often a deficiency of factor VII is caused by:
- Severe liver disease
- Use of drugs that prevent clotting (anticoagulants such as warfarin or coumadin)
- Lack of vitamin K due to long-term use of antibiotics, bile duct obstruction , or poor absorption of vitamin K from the intestines
Some babies are born with vitamin K deficiency. It is very rare to be born with factor VII deficiency that is due to the body's inability to make working factor VII.
Patients can control bleeding episodes by receiving normal plasma, concentrates of factor VII, or genetically produced (recombinant) factor VII through a vein (intravenous). People need frequent treatment during bleeding episodes because factor VII does not last for long inside the body.
Women can better control menstrual bleeding with oral birth control (contraceptives). A form of factor VII called Novo-7 can also be used.
If a lack of vitamin K is causing the disorder, you can take vitamin K by mouth, through injections under the skin, or intravenously.
You can often help the stress of illness by joining a support group where members share common experiences and problems. See hemophilia - resources .
The outcome can be good with proper treatment.
This is a life-long disorder if you get it from your parents. If it is caused by liver disease, the outcome depends on how well you control the liver problem.
- Excessive bleeding (hemorrhage)
Stroke or other nervous system problems from central nervous system bleeding
- Joint problems in severe cases when bleeding happens often
Calling your health care provider:
Go to the emergency room or call the local emergency number (such as 911) if you have severe, unexplained bleeding.
Genetic counseling may be helpful for disorders that start at birth (congenital). Taking vitamin K can help if you have a vitamin K deficiency.
Kessler C. Hemorrhagic disorders: coagulation factor deficiencies. In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa:Saunders Elsevier;2007:chap 180.