Most common cause of hereditary spherocytosis:
**Core Concept**
Hereditary spherocytosis is a genetic disorder characterized by the production of red blood cells that are sphere-shaped rather than the normal biconcave disk shape. This condition is primarily related to **membrane protein defects**, affecting the structural integrity of red blood cells.
**Why the Correct Answer is Right**
The most common cause of hereditary spherocytosis involves defects in the genes encoding for **spectrin**, a key protein that contributes to the elasticity and shape of red blood cells. Mutations in these genes lead to a loss of membrane surface area, resulting in the characteristic spherical shape of the red blood cells.
**Why Each Wrong Option is Incorrect**
**Option A:** This choice is incorrect because, although it may be related to red blood cell disorders, it is not the most common cause of hereditary spherocytosis.
**Option B:** Similarly, this option does not accurately represent the primary genetic defect leading to hereditary spherocytosis.
**Option D:** This is also an incorrect choice, as it does not directly relate to the primary cause of the condition.
**Clinical Pearl / High-Yield Fact**
Hereditary spherocytosis is often diagnosed in childhood and can lead to **hemolytic anemia**, requiring splenectomy as a treatment option to reduce red blood cell destruction.
**Correct Answer:** D. Ankyrin deficiency