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Pathology of the Spleen
Published in Harold R. Schumacher, William A. Rock, Sanford A. Stass, Handbook of Hematologic Pathology, 2019
Hereditary deficiency of L-CAT is rare and appears in about equal frequency in both sexes. Symptoms show toward the second decade of life and progress slowly. Deficiency of this enzyme can result in a rare syndrome that includes diffuse corneal opacities, normocytic normochromic anemia with target cells, sea-blue histiocytosis in the spleen (2), proteinuria, and renal failure. There is heterogeneity in gene mutations as well as the clinical and laboratory presentation. Two distinct phenotypes are observed: the classic L-CAT and “fish eye” disease. Patients with fish eye disease have a selective defect in alpha-L-CAT and a normal cholesterol esterification. In contrast, classic L-CAT patients have abnormal cholesterol esters and increased renal and hematologic abnormalities. The structural gene at chromosome l6q22 usually demonstrates point mutations leading to the production of an abnormal enzyme (3). Diagnosis requires a high index of suspicion and evidence of impairment of enzyme mass or activity (or both) and abnormalities of the lipid profile.
Plasma lipids and lipoproteins
Published in Martin Andrew Crook, Clinical Biochemistry & Metabolic Medicine, 2013
In LCAT deficiency, the accumulation of free unesterified cholesterol in the tissues results in corneal opacities, renal damage, premature atherosclerosis and haemolytic anaemia. The enzyme LCAT catalyses the esterification of free cholesterol. Another condition that is probably due to a defect of LCAT is fish-eye disease, in which there may be low HDL cholesterol concentrations and eye abnormalities.
Lipoprotein Metabolism and Implications for Atherosclerosis Risk Determination and Treatment Decisions
Published in P. K. Shah, Risk Factors in Coronary Artery Disease, 2006
H. Robert Superko, Szilard Voros, Spencer King III
LCAT deficiency, or fish eye disease (FED), is caused by respective mutations of the LCAT gene and associated with low HDL-C (80). FED was initially described in a Swedish family with corneal opacifications that resembled boiled fish; excess amounts of VLDL, IDL, and LDL; and low levels of HDL-C. The functional abnormalities of LCAT are known to cause two diseases characterized by severe corneal opacity: familial LCAT deficiency, which is accompanied with anemia and often renal failure, and FED with few other symptoms (81).
A novel pathogenic variant in LCAT causing FLD. A case report
Published in Acta Clinica Belgica, 2022
Nuria Goñi Ros, Ricardo González-Tarancón, Paula Sienes Bailo, Elvira Salvador-Ruperez, Martín Puzo Bayod, José Puzo Foncillas
Genetic LCAT deficiency (this is the general term that includes both disorders – FLD and FED) is due to loss-of-function mutations in the LCAT gene. The genetic defect leads to two known syndromes: familial LCAT deficiency (FLD; OMIM# 245900), also called Norum disease, and fish-eye disease (FED; OMIM#136120). With a prevalence below 1 in 1 million individuals and very few cases described to date, they are both rare genetic disorders [1]. The first is caused by mutations leading to absence or complete inactivity of the enzyme. Nevertheless, the latter is caused by mutations abolishing LCAT’s ability to esterify cholesterol in high-density lipoproteins (HDL), the major substrate, but not its ability to esterify cholesterol in apoB-containing lipoproteins [2]. Typically, clinical signs of FED and FLD include decreased circulating HDL cholesterol (80–90% cases) and dense corneal opacity, due to progressive accumulation of small grayish dots of cholesterol. Kidney injuries have so far only been reported for patients suffering from FLD. Beginning, usually, in adolescence or early adulthood with episodes of proteinuria, they worsen over time ending in kidney failure. In some cases (5–29%), according to Human Phenotype Ontology, other signs such as angina pectoris, atherosclerosis, and hepatomegaly can also appear in this patient [3].
Straylight in fish-eye disease: visual quality and angular dependence of straylight
Published in Expert Review of Ophthalmology, 2022
Didrika Sahira van de Wouw, Bram de Jong, IJE van der Meulen, TJTP van den Berg
This study describes 10 patients with fish-eye disease (FED) and highly elevated straylight, despite maintaining relatively normal visual acuity. These results illustrate the importance of straylight measurements in patients with optic media opacities. While previous studies have documented the prevalence of straylight disturbance in patients with other corneal turbidities [5,6,13,18], these results could not be applied directly to cases of FED due to the singular characteristics of the cholesterol deposits. In addition to quantifying the visual problem caused by light scattering, we also evaluated the angle dependency of straylight in FED. As shown in Figure 4, straylight in advanced FED follows a weakly rising course, whereas the normal PSF and other ocular disturbances follow a weakly declining course. Speculatively, this could be an indication that the cholesterol particles deposited in the corneal stroma are relatively small.