hemophilia A
Pronunciation: hee-moh-FIL-ee-ah
An X-linked bleeding disorder caused by deficiency or dysfunction of coagulation factor VIII, resulting in prolonged bleeding episodes.
Full Definition
Hemophilia A is the most common severe inherited bleeding disorder, affecting approximately 1 in 5,000 males and caused by mutations in the F8 gene encoding factor VIII. The severity is classified based on factor VIII levels: severe (<1%), moderate (1-5%), or mild (5-40% of normal). Patients with severe disease experience spontaneous bleeding into joints and muscles, while those with mild disease may only bleed with trauma or surgery. Treatment involves factor VIII replacement therapy, either prophylactically or on-demand. Complications include development of inhibitory antibodies against factor VIII and chronic arthropathy from recurrent joint bleeding.
Usage
Usage note: Specify 'hemophilia A' to distinguish from hemophilia B (factor IX deficiency).
In Context
- "The patient with severe hemophilia A required prophylactic factor VIII infusions to prevent spontaneous bleeding." — hematology treatment plan
- "Genetic testing confirmed hemophilia A with a novel mutation in the F8 gene." — molecular genetics report