Lipid Biochemistry USMLE Step 1 Practice Question
A 6-year-old boy with failure to thrive presents with fat-soluble vitamin deficiencies (A, D, E, K), steatorrhea, and hepatomegaly. Vital signs show HR 102/min, BP 95/60 mmHg, and normal temperature. Laboratory testing reveals total cholesterol 450 mg/dL, triglycerides 680 mg/dL, and prolonged PT/INR. Abdominal ultrasound shows hepatomegaly without cirrhosis. He denies recent infections. Electron microscopy of jejunal biopsy demonstrates lipid droplet accumulation in enterocytes. Which gene mutation most likely explains this presentation?
Answer choices
- ALIPE (hormone-sensitive lipase)
- BMTP (microsomal triglyceride transfer protein)Correct answer
- CLDLR (LDL receptor)
- DLIPC (hepatic lipase)
- EAPOB (apolipoprotein B)
- FSREBP2 (sterol regulatory element-binding protein 2)
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