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?
- A)Decreased hepatic VLDL synthesis due to reduced substrate availability
- B)Impaired conversion of cholesterol to bile acids, causing cholestasis and lipid accumulationGABARITO
- C)Increased LDL receptor expression due to intracellular cholesterol depletion
- D)Inhibition of intestinal lipid absorption via reduced bile acid secretion
- 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 →