A. Defect in DNA synthesis.
B. Defect in RNA synthesis.
C. Defect in protein synthesis.
D. All.
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Correct Answer » A
Explanation
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The hematological disorder shown in the picture above represents Megaloblastic anemia.
Megaloblastic anemia
- Megaloblastic anemia is an anemia which results from inhibition of DNA synthesis during red blood cell production.
- It is characterized by many large immature and dysfunctional red blood cells (megaloblasts) in the bone marrow, and also by hypersegmented neutrophils.
Pathogenesis of megaloblastic anemia
- Vit B1, and folic acid are required for DNA synthesis.
- Any factor that results in deficiency of vit B1, or folic acid will lead to defective DNA synthesis.
- Inadequate DNA synthesis results in defective nuclear maturation.
- However, the synthesis of RNA and proteins is not altered, so cytoplasmic maturation proceeds in advance of nuclear maturation → Nuclear/Cytoplasmic asynchrony that results in formation of megaloblasts. o DNA synthesis is impaired in all proliferating cells.
1. Cells of bone marrow → Precursors of RBCs, WBCs, Platelets.
2. Mucosal lining of G1T.
