A patient presents with fatigue, pallor, and exertional dyspnea. Laboratory tests reveal severe anemia, low serum iron, low transferrin saturation, and elevated total iron-binding capacity (TIBC). Which of the following conditions is most likely to cause these findings?
Correct Answer: A
Rationale: The clinical presentation of fatigue, pallor, exertional dyspnea along with the laboratory findings of severe anemia, low serum iron, low transferrin saturation, and elevated TIBC are consistent with iron deficiency anemia. In iron deficiency anemia, there is inadequate iron available for erythropoiesis leading to microcytic hypochromic anemia. The low serum iron and transferrin saturation, along with the elevated TIBC, indicate decreased iron stores and increased iron-binding capacity as the body tries to compensate for the deficiency by increasing absorption and recycling of iron. Anemia of chronic disease typically presents with mild to moderate anemia, normal to low TIBC, and low transferrin saturation due to iron sequestration in macrophages. Sideroblastic anemia usually has elevated serum iron, high saturation, and normal to low TIBC. Thalassemia presents with microcytic hyp