Lipid Biochemistry USMLE Step 1 Practice Question
A 3-year-old child presents with failure to thrive, hepatosplenomegaly, and a pathologic femur fracture. Vital signs show HR 110/min, RR 28/min, temperature 37.2°C. Laboratory studies reveal elevated acid phosphatase (45 U/L) and chitotriosidase. Bone marrow biopsy demonstrates foamy macrophages engorged with cholesterol esters and glucocerebroside. Pulmonary examination is clear without respiratory distress. Which enzyme deficiency accounts for these pathologic findings?
Answer choices
- ASphingomyelinase
- BAcid lipase (lysosomal cholesterol ester hydrolase)Correct answer
- CLipoprotein lipase
- DGlucocerebrosidase
- EArylsulfatase A
- FLysosomal acid lipase deficiency (Wolman disease)
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