Abstract
Purpose: :
To describe the phenotype associated with a novel mutation of the RDH12 gene in Leber congenital amaurosis (LCA).
Methods: :
Visual acuity, retinal findings, retinal structure (by spectral-domain optical coherence tomography), retinal function (by electroretinography) in a child with LCA with a novel mutation in RDH12 gene are described. The natural history of the disease process over a period of 5 years is also discussed.
Results: :
The characteristic features were late onset of symptoms (age 2 years), late onset of nystagmus (rotary), photoaversion, oculo-digital phenomenon, relatively better visual acuity at age 7 years (20/60 each eye), presence of myopia and increasing astigmatism (no keratoconus yet). Retinal findings at the most recent exam included waxy pale discs, attenuated vessels, atrophic changes in both maculae, and diffuse salt-and-pepper-type retinopathy with evolution of bone-spicule pigments in both eyes. SD-OCT showed thinning of macular area consistent with atrophy. ERG showed non-detectable scotopic and photopic responses. Genetic testing showed two heterozygous sequence variations in the coding sequence of the RDH12 gene (Arg295Stop and 1 bp deletion starting in codon 260). Another unique feature in this case was one episode of Charles-Bonnet syndrome.
Conclusions: :
The clinical phenotype in a novel LCA mutation in the RDH12 gene is described.
Keywords: genetics • photoreceptors • retinal degenerations: hereditary