What characterizes classic hemophilia A?

Classic hemophilia A is primarily characterized by mild to severe bleeding episodes. This condition arises from a deficiency in clotting factor VIII, which is essential for the normal clotting process. Patients with hemophilia A may experience spontaneous bleeding or prolonged bleeding following injuries or surgical procedures. The severity of the disorder often correlates with the level of factor VIII in the blood; those with very low levels tend to have more severe bleeding tendencies.

In contrast, prolonged bleeding time is not a definitive characteristic of classic hemophilia A, as it specifically reflects the ability of blood vessels to constrict and platelets to aggregate, rather than the activity of coagulation factors. The inheritance pattern of hemophilia A is X-linked recessive, rather than autosomal recessive, which clearly separates it from options related to inheritance. Additionally, while patients with hemophilia A may have a prolonged activated partial thromboplastin time (aPTT) due to the clotting factor VIII deficiency, their prothrombin time (PT) is usually normal, making prolonged PT an inaccurate representation of the disorder.