Metabolism USMLE Step 1 Practice Question
A 16-year-old boy presents with progressive tremor, dysarthria, and declining school performance over 6 months. Vital signs show BP 118/76, HR 88, RR 16, Temp 37.2°C, SpO2 98% on room air. Examination reveals jaundice, splenomegaly, and characteristic brown-green Kayser-Fleischer rings at the corneal margins. Laboratory studies demonstrate elevated transaminases (AST 156 U/L, ALT 142 U/L), low serum ceruloplasmin (14 mg/dL), and elevated 24-hour urinary copper. No asterixis is noted. Mutation of which protein is most likely responsible?
Answer choices
- AMicrosomal triglyceride transfer protein
- BATP dependent copper transport protein in hepatocytesCorrect answer
- CIron regulatory protein in enterocytes
- DCopper dependent extracellular collagen cross linking enzyme
- EBile salt export pump
- FHFE protein (hereditary hemochromatosis)
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