Review
Copyright ©The Author(s) 2015. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Clin Cases. Feb 16, 2015; 3(2): 112-124
Published online Feb 16, 2015. doi: 10.12998/wjcc.v3.i2.112
Review and update on the molecular basis of Leber congenital amaurosis
Oscar Francisco Chacon-Camacho, Juan Carlos Zenteno
Oscar Francisco Chacon-Camacho, Juan Carlos Zenteno, Genetics Department-Research Unit, Institute of Ophthalmology, “Conde de Valenciana”, Mexico City 06800, Mexico
Juan Carlos Zenteno, Biochemistry Department, Faculty of Medicine, National Autonomous University of Mexico, Mexico City 04510, Mexico
Author contributions: Chacon-Camacho OF and Zenteno JC contributed to this paper.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Correspondence to: Dr. Juan Carlos Zenteno, Genetics Department-Research Unit, Institute of Ophthalmology, "Conde de Valenciana", Chimalpopoca #14, Col. Obrera, Cuauhtemoc, Mexico City 06800, Mexico. jczenteno@institutodeoftalmologia.org
Telephone: +52-55-54421700 Fax: +52-55-789748
Received: July 29, 2014
Peer-review started: July 29, 2014
First decision: September 16, 2014
Revised: November 4, 2014
Accepted: November 17, 2014
Article in press: November 19, 2014
Published online: February 16, 2015
Processing time: 191 Days and 7.3 Hours
Abstract

Inherited retinal diseases are uncommon pathologies and one of the most harmful causes of childhood and adult blindness. Leber congenital amaurosis (LCA) is the most severe kind of these diseases accounting for approximately 5% of the whole retinal dystrophies and 20% of the children that study on blind schools. Clinical ophthalmologic findings including severe vision loss, nystagmus and ERG abnormalities should be suspected through the first year of life in this group of patients. Phenotypic variability is found when LCA patients have a full ophthalmologic examination. However, a correct diagnosis may be carried out; the determination of ophthalmologic clues as light sensibility, night blindness, fundus pigmentation, among other, join with electroretinographics findings, optical coherence tomography, and new technologies as molecular gene testing may help to reach to a precise diagnosis. Several retinal clinical features in LCA may suggest a genetic or gene particular defect; thus genetic-molecular tools could directly corroborate the clinical diagnosis. Currently, approximately 20 genes have been associated to LCA. In this review, historical perspective, clinical ophthalmological findings, new molecular-genetics technologies, possible phenotype-genotypes correlations, and gene therapy for some LCA genes are described.

Keywords: Gene therapy; Leber congenital amaurosis; Retinal dystrophies; Childhood blindness

Core tip: Leber congenital amaurosis (LCA) is the most severe retinal dystrophy causing blindness before the age of 1 year. Clinical ophthalmological findings together with electroretinogram study, OCT imaging and retinal molecular-genetic technologies provide a precise diagnosis in these individuals. Gene-specific phenotypic features exist in LCA, and in this way is possible to predict the underlying genetic defect in some patients on the basis of ophthalmological clues. Clinical, molecular-genetics, phenotype-genotype and gene therapy aspects of LCA are described.