Question

Regarding the pathophysiology of beta-thalassemia major, which of the following correctly describes the disease mechanism?

• A. Ineffective (defective) erythropoiesis
• B. Hepcidin is markedly increased
• C. Hepcidin is suppressed, causing iron overload
• D. Predominantly intravascular hemolysis

Hint:

Unpaired alpha-chains kill precursors in the marrow before they mature.

Answer 1

The Correct Option is A

Step 1: Basic defect. In beta-thalassemia major there is severely reduced or absent synthesis of beta-globin chains. The unpaired alpha-globin chains precipitate within erythroid precursors in the bone marrow.

Step 2: Ineffective erythropoiesis. These alpha-chain inclusions damage and cause apoptosis of red cell precursors before they mature, so erythropoiesis is markedly expanded but largely ineffective (defective). This is the central, defining mechanism and the best single answer.

Step 3: Why the others are wrong. Hepcidin is not increased - the expanded ineffective erythropoiesis releases erythroferrone, which suppresses hepcidin; this drives increased gut iron absorption and (together with transfusions) causes iron overload. So option 2 is false, and although option 3 (suppressed hepcidin / iron overload) is a real downstream consequence, it is secondary to the primary erythroid defect. Hemolysis in thalassemia is predominantly extravascular (splenic clearance of defective cells) plus intramedullary destruction, not chiefly intravascular, so option 4 is incorrect.

Key fact: Ineffective erythropoiesis from precipitated alpha-chains is the core pathology of beta-thalassemia major; erythroferrone-mediated hepcidin suppression and iron overload follow from it.