Lipid Biochemistry USMLE Step 1 Practice Question
A 34-year-old man with a history of recurrent acute pancreatitis presents with triglycerides of 450 mg/dL and total cholesterol of 280 mg/dL. His LDL is 140 mg/dL and HDL is 25 mg/dL. He has corneal opacities and eruptive xanthomas. Genetic testing reveals a mutation in the apolipoprotein C-II gene. Which lipoprotein metabolism step is impaired?
Answer choices
- AHepatic synthesis of apolipoprotein B-100
- BHepatic uptake of remnant particles via LDL receptor
- CActivation of lipoprotein lipase by its cofactor apolipoprotein C-IICorrect answer
- DHydrolysis of hepatic lipase on IDL particles
- EEsterification of free cholesterol by LCAT
- FBinding of apolipoprotein E to chylomicron remnants for hepatic uptake
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