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Genetics Home Reference: your guide to understanding genetic conditions
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Fish-eye disease

Reviewed August 2013

What is fish-eye disease?

Fish-eye disease, also called partial LCAT deficiency, is a disorder that causes the clear front surface of the eyes (the corneas) to gradually become cloudy. The cloudiness, which generally first appears in adolescence or early adulthood, consists of small grayish dots of cholesterol (opacities) distributed across the corneas. Cholesterol is a waxy, fat-like substance that is produced in the body and obtained from foods that come from animals; it aids in many functions of the body but can become harmful in excessive amounts. As fish-eye disease progresses, the corneal cloudiness worsens and can lead to severely impaired vision.

How common is fish-eye disease?

Fish-eye disease is a rare disorder. Approximately 30 cases have been reported in the medical literature.

What genes are related to fish-eye disease?

Fish-eye disease is caused by mutations in the LCAT gene. This gene provides instructions for making an enzyme called lecithin-cholesterol acyltransferase (LCAT).

The LCAT enzyme plays a role in removing cholesterol from the blood and tissues by helping it attach to molecules called lipoproteins, which carry it to the liver. Once in the liver, the cholesterol is redistributed to other tissues or removed from the body. The enzyme has two major functions, called alpha- and beta-LCAT activity. Alpha-LCAT activity helps attach cholesterol to a lipoprotein called high-density lipoprotein (HDL). Beta-LCAT activity helps attach cholesterol to other lipoproteins called very low-density lipoprotein (VLDL) and low-density lipoprotein (LDL).

LCAT gene mutations that cause fish-eye disease impair alpha-LCAT activity, reducing the enzyme's ability to attach cholesterol to HDL. Impairment of this mechanism for reducing cholesterol in the body leads to cholesterol-containing opacities in the corneas. It is not known why the cholesterol deposits affect only the corneas in this disorder. Mutations that affect both alpha-LCAT activity and beta-LCAT activity lead to a related disorder called complete LCAT deficiency, which involves corneal opacities in combination with features affecting other parts of the body.

Related Gene(s)

Changes in this gene are associated with fish-eye disease.

  • LCAT

How do people inherit fish-eye disease?

This condition is inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition.

Where can I find information about diagnosis or management of fish-eye disease?

These resources address the diagnosis or management of fish-eye disease and may include treatment providers.

  • Genetic Testing Registry: Fish-eye disease (http://www.ncbi.nlm.nih.gov/gtr/conditions/C0342895)
  • MedlinePlus Encyclopedia: Corneal Transplant (http://www.nlm.nih.gov/medlineplus/ency/article/003008.htm)
  • Oregon Health and Science University: Corneal Dystrophy (http://www.ohsu.edu/xd/health/services/casey-eye/your-eyes/eye-disorders/cornea-disorders/corneal-dystrophy.cfm)
  • The Foundation of the American Academy of Ophthalmology: Corneal Transplants (http://www.eyecareamerica.org/eyecare/treatment/corneal-transplant/index.cfm)

You might also find information on the diagnosis or management of fish-eye disease in Educational resources (http://www.ghr.nlm.nih.gov/condition/fish-eye-disease/show/Educational+resources) and Patient support (http://www.ghr.nlm.nih.gov/condition/fish-eye-disease/show/Patient+support).

General information about the diagnosis (http://ghr.nlm.nih.gov/handbook/consult/diagnosis) and management (http://ghr.nlm.nih.gov/handbook/consult/treatment) of genetic conditions is available in the Handbook. Read more about genetic testing (http://ghr.nlm.nih.gov/handbook/testing), particularly the difference between clinical tests and research tests (http://ghr.nlm.nih.gov/handbook/testing/researchtesting).

To locate a healthcare provider, see How can I find a genetics professional in my area? (http://ghr.nlm.nih.gov/handbook/consult/findingprofessional) in the Handbook.

Where can I find additional information about fish-eye disease?

You may find the following resources about fish-eye disease helpful. These materials are written for the general public.

You may also be interested in these resources, which are designed for healthcare professionals and researchers.

What other names do people use for fish-eye disease?

  • alpha-LCAT deficiency
  • alpha-lecithin:cholesterol acyltransferase deficiency
  • dyslipoproteinemic corneal dystrophy
  • FED
  • LCATA deficiency
  • partial LCAT deficiency

For more information about naming genetic conditions, see the Genetics Home Reference Condition Naming Guidelines (http://ghr.nlm.nih.gov/ConditionNameGuide) and How are genetic conditions and genes named? (http://ghr.nlm.nih.gov/handbook/mutationsanddisorders/naming) in the Handbook.

What if I still have specific questions about fish-eye disease?

Ask the Genetic and Rare Diseases Information Center (http://rarediseases.info.nih.gov/GARD/).

What glossary definitions help with understanding fish-eye disease?

autosomal ; autosomal recessive ; cell ; cholesterol ; deficiency ; enzyme ; gene ; HDL ; LDL ; lipoprotein ; recessive ; VLDL

You may find definitions for these and many other terms in the Genetics Home Reference Glossary (http://www.ghr.nlm.nih.gov/glossary).

References

  • Calabresi L, Pisciotta L, Costantin A, Frigerio I, Eberini I, Alessandrini P, Arca M, Bon GB, Boscutti G, Busnach G, Frascà G, Gesualdo L, Gigante M, Lupattelli G, Montali A, Pizzolitto S, Rabbone I, Rolleri M, Ruotolo G, Sampietro T, Sessa A, Vaudo G, Cantafora A, Veglia F, Calandra S, Bertolini S, Franceschini G. The molecular basis of lecithin:cholesterol acyltransferase deficiency syndromes: a comprehensive study of molecular and biochemical findings in 13 unrelated Italian families. Arterioscler Thromb Vasc Biol. 2005 Sep;25(9):1972-8. Epub 2005 Jun 30. (http://www.ncbi.nlm.nih.gov/pubmed/15994445?dopt=Abstract)
  • Contacos C, Sullivan DR, Rye KA, Funke H, Assmann G. A new molecular defect in the lecithin: cholesterol acyltransferase (LCAT) gene associated with fish eye disease. J Lipid Res. 1996 Jan;37(1):35-44. (http://www.ncbi.nlm.nih.gov/pubmed/8820100?dopt=Abstract)
  • Kuivenhoven JA, Stalenhoef AF, Hill JS, Demacker PN, Errami A, Kastelein JJ, Pritchard PH. Two novel molecular defects in the LCAT gene are associated with fish eye disease. Arterioscler Thromb Vasc Biol. 1996 Feb;16(2):294-303. Review. (http://www.ncbi.nlm.nih.gov/pubmed/8620346?dopt=Abstract)
  • Reshetnyak Y, Tchedre KT, Nair MP, Pritchard PH, Lacko AG. Structural differences between wild-type and fish eye disease mutant of lecithin:cholesterol acyltransferase. J Biomol Struct Dyn. 2006 Aug;24(1):75-82. (http://www.ncbi.nlm.nih.gov/pubmed/16780378?dopt=Abstract)
  • Savel J, Lafitte M, Pucheu Y, Pradeau V, Tabarin A, Couffinhal T. Very low levels of HDL cholesterol and atherosclerosis, a variable relationship--a review of LCAT deficiency. Vasc Health Risk Manag. 2012;8:357-61. doi: 10.2147/VHRM.S29985. Epub 2012 Jun 5. Review. (http://www.ncbi.nlm.nih.gov/pubmed/22701329?dopt=Abstract)
  • Winder AF, Owen JS, Pritchard PH, Lloyd-Jones D, Vallance DT, White P, Wray R. A first British case of fish-eye disease presenting at age 75 years: a double heterozygote for defined and new mutations affecting LCAT structure and expression. J Clin Pathol. 1999 Mar;52(3):228-30. (http://www.ncbi.nlm.nih.gov/pubmed/10450185?dopt=Abstract)

 

The resources on this site should not be used as a substitute for professional medical care or advice. Users seeking information about a personal genetic disease, syndrome, or condition should consult with a qualified healthcare professional. See How can I find a genetics professional in my area? (http://ghr.nlm.nih.gov/handbook/consult/findingprofessional) in the Handbook.

 
Reviewed: August 2013
Published: July 7, 2014