Anemias USMLE Step 1 Practice Question
A 16-year-old boy is evaluated for recurrent jaundice and fatigue. His mother had a splenectomy in her twenties. Physical examination shows scleral icterus and splenomegaly. Laboratory studies demonstrate anemia, elevated reticulocyte count, elevated indirect bilirubin, and increased mean corpuscular hemoglobin concentration. Peripheral smear shows numerous spherocytes. Which of the following is the most likely cause of this condition?
Answer choices
- ADeficiency of ferrochelatase causing impaired heme synthesis
- BDeficiency of pyruvate kinase causing low ATP
- CDefective beta-globin synthesis causing target cells
- DAutoimmune antibody binding to Rh antigens
- EDefect in red cell membrane cytoskeletal proteins causing loss of membrane surface areaCorrect answer
- FWarm autoimmune hemolytic anemia
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