CD59 marker deficiency leads to which of the following disease?
**Core Concept**
The **CD59 marker** is a surface protein that inhibits the formation of the membrane attack complex (MAC), preventing complement-mediated lysis of cells. A deficiency in this protein can lead to uncontrolled complement activation and cellular damage. This concept is crucial in understanding the pathophysiology of certain diseases.
**Why the Correct Answer is Right**
A deficiency in **CD59** leads to **Paroxysmal Nocturnal Hemoglobinuria (PNH)**, a rare, acquired, life-threatening disease of the blood characterized by the destruction of red blood cells, activation of the coagulation system, and impairment of bone marrow function. The lack of **CD59** allows the MAC to form on the surface of red blood cells, leading to their lysis.
**Why Each Wrong Option is Incorrect**
**Option A:** Incorrect because it is not directly related to **CD59** deficiency.
**Option B:** Incorrect as it is not associated with **CD59**.
**Option C:** Incorrect because it does not result from **CD59** deficiency.
**Clinical Pearl / High-Yield Fact**
Remember, **CD59** plays a crucial role in protecting cells from complement-mediated lysis. Its deficiency can lead to significant clinical manifestations, including hemolytic anemia, which is a hallmark of **PNH**.
**Correct Answer:** D. Paroxysmal Nocturnal Hemoglobinuria (PNH)