Which of the following coagulation disorders is characterized by a deficiency of the protein C pathway?

A Prothrombin deficiency
B Factor X deficiency
C Protein S deficiency ✓
D Homocystinuria

Explanation

Protein S is a vitamin K-dependent protein that plays a critical role in the protein C pathway, which regulates the coagulation cascade. A deficiency in protein S can lead to an increased risk of thrombosis.

Source

Harrison's Principles of Internal Medicine
Hematology Hematology: Coagulation Disorders Hematology: Coagulation Disorders Hard MEDICAL Confidence: medium