Megaloblastic anaemia is caused by ?
**Core Concept:**
Megaloblastic anaemia is a type of anaemia caused by defects in the maturation of red blood cells in the bone marrow. It is characterized by the presence of large, immature red blood cells called megaloblasts. This condition is associated with impaired folate and vitamin B12 absorption, leading to impaired DNA synthesis and maturation of red blood cells.
**Why the Correct Answer is Right:**
Megaloblastic anaemia is primarily caused by deficiencies in vitamin B12 and folic acid. These vitamins are essential for the synthesis of methionine, which is required for the production of DNA. When there is a deficiency of vitamin B12 or folic acid, the maturation of red blood cells is impaired, leading to the accumulation of megaloblasts in the bone marrow. The correct answer focuses on the primary cause of megaloblastic anaemia, which is the deficiency of these essential vitamins.
**Why Each Wrong Option is Incorrect:**
A. Vitamin C deficiency (scurvy) causes scurvy, which is a separate condition characterized by the accumulation of deformed red blood cells due to impaired collagen synthesis. Scurvy is not related to megaloblastic anaemia.
B. Iron deficiency anemia results from a decrease in red blood cell production, not maturation.
C. Hemolytic anaemia is caused by the premature breakdown of red blood cells, whereas megaloblastic anaemia is caused by impaired red blood cell maturation.
D. Thalassemia is a genetic disorder characterized by the reduced synthesis of hemoglobin, not impaired red blood cell maturation.
**Clinical Pearl:**
Megaloblastic anaemia should be suspected in patients with fatigue, weakness, pallor, and neurological symptoms such as peripheral neuropathy, dementia, and optic neuritis. Early diagnosis and treatment are crucial to prevent the progression of the disease and its severe complications. Megaloblastic anaemia can be managed with vitamin supplementation, ensuring adequate levels of vitamin B12 and folic acid in the diet is essential to prevent the development of this condition.