A 25-year-old woman of Mediterranean descent has mild haemolytic anaemia triggered by fava bean ingestion. Blood film shows Heinz bodies and bite cells. The enzyme deficient in this condition protects red cells from oxidative damage by maintaining:

• A Reduced glutathione (GSH) levels ✓
• B NADH levels for methaemoglobin reduction
• C 2,3-bisphosphoglycerate synthesis
• D ATP production via glycolysis

Explanation

G6PD deficiency impairs the hexose monophosphate shunt, reducing NADPH production; NADPH is the cofactor for glutathione reductase, which regenerates reduced glutathione (GSH) from oxidised glutathione (GSSG). Without adequate GSH, oxidant stress (from fava beans, primaquine, infection) causes globin chain oxidation forming Heinz bodies, which are removed by splenic macrophages producing bite cells. NADH is used by methaemoglobin reductase, a separate pathway; 2,3-BPG and ATP are products of glycolysis, not the HMP shunt.

Reference: Robbins & Cotran Pathologic Basis of Disease, 10th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.