A patient with a diagnosis of hemophilia A is likely to have which of the following laboratory findings?

A Prolonged prothrombin time and normal partial thromboplastin time
B Normal prothrombin time and prolonged partial thromboplastin time ✓
C Prolonged bleeding time and normal clotting times
D Normal bleeding time and prolonged clotting times

Explanation

Hemophilia A is a deficiency of factor VIII, which is part of the intrinsic pathway of coagulation. The partial thromboplastin time (PTT) measures the intrinsic and common pathways, while the prothrombin time (PT) measures the extrinsic and common pathways.

Source

Williams Hematology
Hematology Hematology: Coagulation Disorders Hematology: Coagulation Disorders Easy MEDICAL Confidence: high