A 45-year-old man presents with premature coronary artery disease and xanthomas on his Achilles tendons. Laboratory studies show LDL cholesterol of 520 mg/dL despite a low-fat diet. His father died of myocardial infarction at age 52. Genetic testing confirms a mutation in the LDL receptor gene. Which of the following mechanisms best explains his lipid abnormality?
- A)Increased conversion of VLDL to IDL due to hepatic lipase deficiency
- B)Overproduction of cholesterol by the liver independent of feedback inhibition
- C)Increased lipoprotein lipase activity in peripheral tissues
- D)Decreased hepatic uptake of LDL due to nonfunctional LDL receptorsGABARITO
- E)Impaired apolipoprotein B synthesis leading to VLDL accumulation
Explicação
This patient has familial hypercholesterolemia due to LDL receptor mutations. LDL receptors mediate hepatic uptake of LDL particles. Without functional receptors, LDL accumulates in the circulation, leading to very high levels and premature atherosclerosis. Ver explicação completa e trilha adaptativa →