Factor X deficiency
Factor X deficiency is a disorder caused by too little of a protein called factor X in the blood. It leads to problems with blood clotting (coagulation).
Causes, incidence, and risk factors
When you bleed, the body launches a series of reactions that help the blood clot. This is called the coagulation cascade. The process involves special proteins called coagulation factors. When one or more of these clotting factors are missing, there is usually a higher chance of bleeding.
Factor X deficiency is often caused by a defect of the factor X gene that is passed through families. This is called inherited factor X deficiency. Bleeding ranges from mild to severe.
Factor X deficiency may also develop due to another condition or use of medications. This is called acquired factor X deficiency. Acquired factor X deficiency is common. It may be caused by a lack of vitamin K, amyloidosis, severe liver disease, and use of drugs that prevent clotting (anticoagulants such as warfarin or Coumadin). Some newborns are born with vitamin K deficiency. See: Vitamin k deficiency bleeding in newborns
Women with factor X deficiency may have very heavy menstrual bleeding and bleeding after delivery. Newborn boys with the condition may have longer-than-normal bleeding after circumcision.
Inherited factor X deficiency affects 1 out of every 500,000 people.
Signs and tests
- Low factor X activity
- Normal thrombin time
- Prolonged partial thromboplastin time
- Prolonged prothrombin time
You can control blood loss by getting infusions of fresh or frozen plasma or concentrates of clotting factors into the blood. If a lack of vitamin K is causing the disorder, you can take vitamin K by mouth, through injections under the skin, or through a vein (intravenously).
Diagnosing a bleeding disorder is important so that the doctor can take extra care if you need surgery, and can test or warn other family members who might be affected.
You can ease the stress of illness by joining a support group where members share common experiences and problems.
The outcome is usually good with mild disease or treatment.
Inherited factor X deficiency is a life-long condition.
The outlook for acquired factor X deficiency depends on the cause. If it is caused by liver disease, the outcome depends on how well your liver disease can be treated. Taking vitamin K supplements will treat vitamin K deficiency. If the disorder is caused by amyloidosis, there are several treatment options, including surgery to remove your spleen.
Severe bleeding or sudden loss of blood (hemorrhage) can occur. The joints may get deformed in severe disease from many bleeds.
Calling your health care provider
Call your health care provider, go to the emergency room, or call the local emergency number (such as 911) if you have an unexplained or severe loss of blood.
Inherited factor X deficiency is rare. There is no known prevention.
Gailani D, Neff AT. Rare coagulation factor deficiencies. In: Hoffman R, Benz EJ Jr., Shattil SJ, et al, eds. Hoffman Hematology: Basic Principles and Practice. 5th ed. Philadelphia, Pa: Churchill Livingstone Elsevier;2008:chap 127.
Kessler C. Hemorrhagic disorders: Coagulation factor deficiencies. In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier; 2007:chap 180.
Last reviewed 2/28/2011 by David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine; and Yi-Bin Chen, MD, Leukemia/Bone Marrow Transplant Program, Massachusetts General Hospital. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.
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