A 62-year-old man with a history of myocardial infarction is found to have extremely low LDL cholesterol (25 mg/dL) and very low plasma levels of apolipoprotein B-containing lipoproteins. He reports a lifelong history of fat malabsorption and steatorrhea. Genetic testing reveals mutations affecting microsomal triglyceride transfer protein (MTP). Which of the following best describes the pathophysiology?
- A)Impaired assembly and secretion of apoB-containing lipoproteins from liver and intestineGABARITO
- B)Impaired synthesis of apolipoprotein B-100 mRNA
- C)Loss-of-function mutation in lipoprotein lipase gene
- D)Accelerated catabolism of LDL particles by enhanced hepatic receptor activity
- E)Increased clearance of VLDL by peripheral lipoprotein lipase
Explicação
Abetalipoproteinemia results from MTP mutations, which prevent assembly of chylomicrons (intestine) and VLDL (liver). MTP is essential for lipidating apoB proteins. This causes severe fat malabsorption, absent apoB-containing particles, and paradoxically low c... Ver explicação completa e trilha adaptativa →