DefinitionFactor 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).Alternative NamesStuart-Prower deficiencyCauses, incidence, and risk factorsWhen 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. (Factor X is a coagulation factor.) Each factor's reaction triggers the next reaction. The final product of the coagulation cascade is the blood clot. When certain coagulation factors are missing, the chain reaction does not take place normally.Factor X deficiency is often caused by a defect of the factor X gene that is passed through families. This is called inherited f