RT Book, Section A1 Santamarina-Fojo, Silvia A1 Hoeg†, Jeffrey M. A1 Assmann, Gerd A1 Bryan Brewer, H. A2 Valle, David L. A2 Antonarakis, Stylianos A2 Ballabio, Andrea A2 Beaudet, Arthur L. A2 Mitchell, Grant A. SR Print(0) ID 1181449708 T1 Lecithin Cholesterol Acyltransferase Deficiency and Fish Eye Disease T2 The Online Metabolic and Molecular Bases of Inherited Disease YR 2019 FD 2019 PB McGraw-Hill Education PP New York, NY SN 9780071459969 LK ommbid.mhmedical.com/content.aspx?aid=1181449708 RD 2024/12/02 AB Lecithin cholesterol acyltransferase (LCAT) is a plasma enzyme that esterifies free cholesterol present in circulating plasma lipoproteins.LCAT deficiency leads to the development of two clinically distinct syndromes: familial LCAT deficiency (FLD) and fish eye disease (FED).FLD is characterized by corneal opacities, anemia, and proteinuria that may progress to renal failure. Foam cells and membrane-bound vesicles, which appear to be composed of cholesterol and phospholipid, accumulate in many tissues including the cornea, kidneys, liver, spleen, bone marrow, and arteries. Target cells containing abnormally high amounts of unesterified cholesterol and lecithin are present. Plasma contains high levels of unesterified cholesterol and phospholipids and low concentrations of plasma cholesteryl esters and lysophosphatidylcholine. Plasma triglycerides are normal to increased, low density lipoprotein (LDL) levels are reduced, and high-density lipoprotein (HDL) levels are markedly decreased. The morphology of the lipoproteins is abnormal, with the presence in plasma of multilamellar vesicles, rouleaux, LpX-like particles, discs, and small spherical particles. The diagnosis of FLD is confirmed by a virtual absence of plasma LCAT activity in patients presenting with hypoalphalipoproteinemia, anemia, proteinuria, or renal disease.FED is characterized by corneal opacities. The plasma triglyceride levels are normal to increased, and HDL levels are markedly decreased. The diagnosis of FED is confirmed by finding a partial deficiency of LCAT activity in the plasma of patients presenting with corneal opacities and marked hypoalphalipoproteinemia.The LCAT gene is organized into six exons interrupted by five introns and is located on the long arm of chromosome 16. Approximately 40 different mutations in the LCAT gene leading to either FLD or FED have been described to date.Characterization of FLD and FED patients as well as different LCAT-transgenic and knockout animal models has demonstrated an important role for LCAT in modulating the metabolism of both HDLs and LDLs, as well as the development of atherosclerosis.