Anemias USMLE Step 1 Practice Question
A 15 year old boy is brought for recurrent jaundice and fatigue. He has had multiple episodes of pigmented gallstones, and his mother had a splenectomy at age 20. Examination shows scleral icterus and splenomegaly. Peripheral smear shows numerous spherocytes, and osmotic fragility is increased. Which of the following is the most likely underlying defect?
Answer choices
- ADefect in beta globin chain synthesis
- BDeficiency of spectrin or ankyrin in the red cell membrane skeletonCorrect answer
- CDeficiency of pyruvate kinase in erythrocytes
- DAutoimmune destruction of red cells by IgM
- EAbsence of CD55 and CD59 on blood cells
- FHereditary elliptocytosis
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