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Leber congenital amaurosis (LCA) is a retinal dystrophy and/or dysplasia of prenatal onset. About 10 to 20% of blind children are thought to suffer from LCA, which makes it one of the frequent causes of childhood blindness. It is thought to account for 5% of inherited retinal disease. Affected children fail to fix and follow due to little or no retinal sensitivity to visual stimuli. Electroretinography shows either no or very reduced retinal function. Fundus examination in the first months of life is frequently normal, but later chorioretinal atrophy with intraretinal pigment migration becomes apparent. In some patients, a macular punched-out lesion is present. Patients have nystagmus and frequently poke their eyes. LCA is inherited as an autosomal recessive trait in the large majority of patients, with only a limited number of cases with autosomal dominant inheritance described. LCA is genetically heterogeneous, and, to date, mutations have been identified in six different genes known to be associated with LCA: AIPL1, CRB1, CRX, GUCY2D, RPE65 and RPGRIP1. At least another three additional loci have been linked to the condition. Although therapy is not currently available, encouraging results have been obtained with gene therapy in a dog model for this disease. |