Metabolism USMLE Step 1 Practice Question
A 14-year-old boy presents with recurrent acute pancreatitis. Vital signs show BP 118/76 mmHg, HR 92 bpm, RR 18, temperature 37.2°C, SpO2 98% on room air. Fasting serum appears milky. Laboratory studies reveal serum triglycerides of 1,850 mg/dL and amylase 285 U/L. Abdominal ultrasound shows no gallstones. Genetic testing demonstrates normal lipoprotein lipase structure but impaired enzyme activation. Which apolipoprotein is most likely deficient?
Answer choices
- AApolipoprotein B100
- BApolipoprotein CIICorrect answer
- CApolipoprotein B48
- DApolipoprotein A1
- EApolipoprotein E
- FApolipoprotein CIII
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