Factor X (ten) deficiency is a disorder caused by too little of a protein called factor X in the blood. It leads to problems with normal blood clotting (coagulation).
When you bleed, your body starts a series of reactions that help the blood clot. This is called the coagulation cascade. The process involves special proteins called coagulation factors. You can have a higher chance of excess bleeding when one or more of these clotting factors are missing.
Factor X deficiency is often caused by a defect in the factor X gene that is passed through families. This is called inherited factor X deficiency. Bleeding ranges from mild to severe depending on the extent of deficiency
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:
Lack of vitamin K (some newborns are born with vitamin K deficiency), systemic amyloidosis, severe liver disease
Use of medicines that prevent clotting (anticoagulants such as warfarin or Coumadin)
Women with factor X deficiency may first be diagnosed when they have very heavy menstrual bleeding and bleeding after childbirth. The condition may be first noticed in newborn boys if they have bleeding that lasts longer than normal after circumcision.
Inherited factor X deficiency affects 1 out of every 500,000 people.
Yi-Bin Chen, MD, Leukemia/Bone Marrow Transplant Program, Massachusetts General Hospital. Also reviewed by A.D.A.M. Health Solutions, Ebix, Inc., Editorial Team: David Zieve, MD, MHA, David R. Eltz, Stephanie Slon, and Nissi Wang