Which is the most common red cell defect without Hb abnormality
**Core Concept**
Red cell defects refer to conditions affecting the production, structure, or function of red blood cells (RBCs). Hemoglobin (Hb) abnormalities are a common type of red cell defect, but not the only one. This question tests the student's knowledge of other types of red cell defects.
**Why the Correct Answer is Right**
The most common red cell defect without Hb abnormality is Hereditary Spherocytosis (HS). It is a genetic disorder characterized by the production of RBCs that are sphere-shaped rather than the normal biconcave disk shape. This abnormal shape makes the RBCs more prone to premature destruction, particularly in the spleen. The defect is usually caused by mutations in genes encoding for proteins involved in the RBC membrane skeleton, such as spectrin, ankyrin, or band 3.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is not provided.
**Option B:** This option is also not provided.
**Option C:** This option is not provided.
**Option D:** This option is not provided.
**Clinical Pearl / High-Yield Fact**
Hereditary Spherocytosis can be diagnosed with a combination of clinical features, family history, and laboratory tests, including a peripheral blood smear showing spherocytic RBCs, a positive osmotic fragility test, and genetic testing for mutations in relevant genes.
**Correct Answer:** C. Hereditary Spherocytosis