A 42-year-old man presents with orange discoloration of his palms and soles, eruptive xanthomas, and laboratory findings of total cholesterol 320 mg/dL, triglycerides 180 mg/dL, and elevated direct bilirubin. He is found to have a mutation in the gene encoding cholestanol 7α-hydroxylase. Which of the following represents the primary biochemical consequence?

  1. A)Decreased hepatic VLDL synthesis due to reduced substrate availability
  2. B)Impaired conversion of cholesterol to bile acids, causing cholestasis and lipid accumulationGABARITO
  3. C)Increased LDL receptor expression due to intracellular cholesterol depletion
  4. D)Inhibition of intestinal lipid absorption via reduced bile acid secretion
  5. E)Primary defect in hepatic triglyceride synthesis

Explicação

Cholestanol 7α-hydroxylase (sterol 27-hydroxylase) catalyzes the first committed step in bile acid synthesis from cholesterol. Deficiency impairs cholesterol catabolism to bile acids, causing hepatic cholesterol accumulation, resulting in cholestasis, hyperlip... Ver explicação completa e trilha adaptativa →

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