All are vitamin K dependent clotting factors of hepatic origin except:
**Core Concept**
Vitamin K dependent clotting factors are a group of essential proteins produced in the liver that play a critical role in blood coagulation. These factors are vitamin K dependent because they require vitamin K to function properly and are synthesized in the liver.
**Why the Correct Answer is Right**
The correct answer is not a vitamin K dependent clotting factor of hepatic origin. The vitamin K dependent clotting factors of hepatic origin are Factor II (prothrombin), Factor VII, Factor IX, and Factor X. These factors are produced in the liver and require vitamin K for their activation. They are then transported to the circulation where they participate in the coagulation cascade.
**Why Each Wrong Option is Incorrect**
* **Option A:** Incorrect because Factor II (prothrombin) is a vitamin K dependent clotting factor of hepatic origin.
* **Option B:** Incorrect because Factor VII is a vitamin K dependent clotting factor of hepatic origin.
* **Option C:** Incorrect because Factor IX is a vitamin K dependent clotting factor of hepatic origin.
* **Option D:** Incorrect because Factor X is a vitamin K dependent clotting factor of hepatic origin.
**Clinical Pearl / High-Yield Fact**
Vitamin K dependent clotting factors are susceptible to deficiency or dysfunction in the presence of vitamin K deficiency, liver disease, or warfarin therapy. This can lead to a coagulopathy characterized by prolonged prothrombin time (PT) and activated partial thromboplastin time (aPTT).
**Correct Answer: D. Factor VIII**