A patient presents with a prolonged prothrombin time and a normal partial thromboplastin time. Which of the following coagulation factors is most likely to be deficient?

A Factor VIII
B Factor IX
C Factor VII ✓
D Factor XII

Explanation

A prolonged prothrombin time with a normal partial thromboplastin time suggests a deficiency in the extrinsic pathway, which involves factor VII.

Source

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