Which laboratory finding is associated with Hemophilia A?

Hemophilia A is a genetic disorder characterized by a deficiency in clotting factor VIII, which is essential for normal blood coagulation. One of the hallmark laboratory findings in Hemophilia A is a prolonged activated partial thromboplastin time (aPTT). This test specifically measures the intrinsic pathway of coagulation in which factor VIII plays a crucial role. In patients with Hemophilia A, because factor VIII is deficient or absent, the aPTT is prolonged, indicating a slower coagulation process.

While other factors might be involved in bleeding disorders, in the context of Hemophilia A, the measurement of aPTT is particularly relevant, as it directly reflects the abnormality in the clotting pathway where factor VIII is essential. Understanding this connection can help healthcare professionals interpret laboratory results and manage patients with bleeding disorders effectively.

The normal prothrombin time (PT) typically indicates that the extrinsic pathway is functioning properly, and a decreased factor IX activity would be associated with Hemophilia B, not A. A normal von Willebrand factor level does not directly relate to Hemophilia A; while vWF can affect bleeding, the primary deficiency in Hemophilia A is specifically tied to factor VIII. Thus, the prolonged a