Lipid Biochemistry USMLE Step 1 Practice Question
A 38-year-old woman presenting for routine screening has a total cholesterol of 680 mg/dL and LDL of 520 mg/dL despite never taking statins. Physical examination reveals tendon xanthomas over the Achilles tendon and corneal arcus. Her father died of myocardial infarction at age 42. Which of the following genetic mutations is most likely responsible?
Answer choices
- AGain-of-function mutation in apolipoprotein B-100
- BMutation in cholesterol 7α-hydroxylase gene
- CLoss-of-function mutation in PCSK9 gene
- DDeficiency of lipoprotein lipase
- ELoss-of-function mutation in LDL receptor geneCorrect answer
- FSitosterolemia (ABCG5/ABCG8 mutation)
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