Lipid Biochemistry USMLE Step 1 Practice Question
A 10-year-old male with short stature is being evaluated for progressive neuropathy. Deep tendon reflexes are decreased, and vibratory sensation and proprioception are impaired. He has ataxia and a spastic gait. Ophthalmologic examination reveals decreased vision in dim light and pigmentary retinal degeneration. He has a history of frequent diarrhea with fatty stools. A serum lipid profile shows: Cholesterol 33 mg/dL (normal 132-220), Triglyceride 0 mg/dL (normal 32-150), HDL cholesterol 28 mg/dL (normal 34-86). Genetic testing reveals a mutation in a gene encoding a protein necessary for normal lipoprotein metabolism. In which of the following genes is this mutation most likely?
Answer choices
- AApoB100 receptor gene
- BLecithin acyl cholesterol transferase (LCAT) gene
- CApoB geneCorrect answer
- DApoC2 gene
- EApoE gene
- FMicrosomal triglyceride transfer protein (MTP) gene
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