Anemias USMLE Step 1 Practice Question
A 4-year-old boy presents with chronic hemolytic anemia, scleral icterus, and splenomegaly. Vital signs: HR 110/min, RR 22/min, BP 95/60 mmHg, temperature 37.2°C. Laboratory studies reveal hemoglobin 7.2 g/dL with echinocytes on peripheral smear. Red blood cell ATP concentration is markedly decreased. Reticulocyte count is elevated at 8%. He denies recent infections or medications. Which metabolic consequence is most likely present in these erythrocytes?
Answer choices
- ADecreased NADPH production causing Heinz bodies
- BIncreased 2,3 bisphosphoglycerate causing a right shift of the oxygen dissociation curveCorrect answer
- CDecreased 2,3 bisphosphoglycerate causing increased oxygen affinity
- DAccumulation of porphobilinogen causing neuropathy
- EIncreased reduced glutathione causing resistance to oxidant injury
- FDecreased pyruvate kinase activity causing accumulation of upstream glycolytic intermediates
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