You have referred a 27-year-old woman to a lipid research center for investigation of moderate hypertriglyceridemia. Analysis of her serum revealed the presence of abnormal lipid and lipoprotein profiles. Both HDL and LDL were less dense than normal and showed significant elevations in triglyceride content with the mass of triglycerides approximately the same as that of cholesterol. A deficiency in which of the following is the most likely cause of the observed lipid abnormalities?

Question

Quizplus · Accepted Answer

Hepatic triglyceride lipase (HTGL, also called hepatic lipase, HL) is an enzyme that is made primarily by hepatocytes that hydrolyzes phospholipids and triglycerides of plasma lipoproteins. The potential significance of the HTGL pathway is that it provides the hepatocyte with a mechanism for the uptake of a subset of phospholipids enriched in unsaturated fatty acids and may allow the uptake of cholesteryl ester, free cholesterol, and phospholipid without catabolism of HDL apolipoproteins. HTGL can hydrolyze triglyceride and phospholipid in all lipoproteins, but is predominant in the conversion of intermediate-density lipoproteins to LDL and the conversion of postprandial triglyceriderich HDL into the postabsorptive triglyceride-poor HDL. HTGL plays a secondary role in the clearance of chylomicron remnants by the liver. A prominent feature of HTGL deficiency is the increase in HDL cholesterol and an approximately 10-fold increase in HDL triglyceride.

You Have Referred a 27-Year-Old Woman to a Lipid Research