Lipid Biochemistry USMLE Step 1 Practice Question
A 28-year-old woman with Tangier disease presents with hepatosplenomegaly, lymphadenopathy, and progressive peripheral neuropathy. Vital signs show BP 118/76, HR 88, RR 16, Temp 37°C, SpO2 98%. Laboratory studies reveal HDL cholesterol <5 mg/dL, triglycerides 280 mg/dL, and normal LDL cholesterol. Genetic testing confirms ABCA1 mutation. She denies recent infections. Which cellular process is primarily impaired in this condition?
Answer choices
- AHepatic synthesis of apolipoprotein B-100
- BEfflux of cholesterol and phospholipid from macrophages to apolipoprotein A-1Correct answer
- CLecithin-cholesterol acetyltransferase activity in plasma
- DUptake of LDL cholesterol via hepatic receptors
- ELipoprotein lipase-mediated hydrolysis of triglycerides
- FEsterification of cholesterol by acyl-CoA:cholesterol acetyltransferase in macrophages
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