Hemophilia A, B, or C
Overview
Plain-Language Overview
Hemophilia A, B, and C are genetic bleeding disorders that affect the body's ability to form blood clots properly. These conditions involve the blood clotting system, specifically deficiencies in certain clotting factors that help stop bleeding. People with these disorders may experience excessive bleeding from injuries, surgeries, or even spontaneously, especially into joints and muscles. The severity of bleeding varies depending on the level of the missing clotting factor. These conditions primarily affect the blood and vascular system and can lead to serious complications if bleeding is not controlled. Understanding these disorders helps explain why some people bruise easily or bleed longer than usual.
Clinical Definition
Hemophilia A, B, and C are inherited bleeding disorders characterized by deficiencies in specific coagulation factors: factor VIII in Hemophilia A, factor IX in Hemophilia B, and factor XI in Hemophilia C. These deficiencies impair the intrinsic pathway of the coagulation cascade, leading to defective fibrin clot formation and prolonged bleeding. Hemophilia A and B are X-linked recessive disorders caused by mutations in the F8 and F9 genes, respectively, predominantly affecting males. Hemophilia C is autosomal recessive and caused by mutations in the F11 gene, often presenting with milder bleeding symptoms. Clinically, these disorders manifest as prolonged bleeding, spontaneous hemarthroses, and deep tissue hemorrhages. The severity correlates with the residual activity of the deficient factor. Early diagnosis and management are critical to prevent morbidity from bleeding complications.