A 45-year-old man presents with xanthomas on his Achilles tendons and eyelids, along with premature coronary artery disease at age 42. Serum LDL cholesterol is 520 mg/dL despite a low-fat diet. Genetic testing confirms a mutation in the LDL receptor gene. Which of the following best explains the pathophysiology of his lipid abnormality?
- A)Excessive hepatic cholesterol synthesis from increased acetyl-CoA carboxylase activity
- B)Impaired apolipoprotein B synthesis leading to accumulation of cholesterol
- C)Decreased hepatic uptake of LDL particles due to absent or non-functional LDL receptorsGABARITO
- D)Increased secretion of VLDL from hepatocytes secondary to elevated triglycerides
- E)Deficiency of lipoprotein lipase preventing chylomicron clearance
Explicação
Familial hypercholesterolemia (heterozygous) results from loss-of-function mutations in the LDL receptor gene. Without functional LDL receptors on hepatocytes, circulating LDL particles cannot be internalized, leading to severely elevated serum LDL cholesterol... Ver explicação completa e trilha adaptativa →