Congenital fibrinogen deficiency (CFD) is a rare inherited bleeding disorder that occurs when your body is unable to produce ample fibrinogen (also called Factor I) to help the body form blood clots to stop bleeding. CFD is an umbrella term for several related disorders: Afibrinogenemia (a complete lack of fibrinogen), hypofibrinogenemia (low levels of fibrinogen), dysfibrinogenemia (fibrinogen does not work properly), and hypodysfibrinogenemia (a combined defect that involves both low levels of fibrinogen and impaired function). CSL Behring offers fibrinogen replacement therapies to help the body clot properly.