A 35-year-old man of Mediterranean descent presents with orange discoloration of palms and soles and corneal infiltrates. Vital signs are stable (BP 128/82, HR 72, RR 14). Laboratory findings reveal HDL cholesterol of 5 mg/dL and markedly elevated serum lathosterol despite strict low-fat diet adherence. Lipid electrophoresis shows absent apolipoprotein A-I. He denies alcohol use. Which gene defect is most likely responsible?

  1. A)APOB (apolipoprotein B)
  2. B)ApoA-I (apolipoprotein A-I)
  3. C)SR-B1 (scavenger receptor B1)
  4. D)LCAT (lecithin-cholesterol acyltransferase)GABARITO
  5. E)ABCA1 (ATP-binding cassette A1)

Explicação

LCAT deficiency (fish-eye disease) causes severely decreased HDL-C, corneal lipid infiltration, and tissue lipid deposition. Elevated lathosterol indicates abnormal lipid esterification and accumulation of cholesterol precursors in tissues. Ver explicação completa e trilha adaptativa →

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