Abstract
Purpose: :
X-linked retinoschisis (XLRS) is a leading cause of macular degeneration in juvenile male patients. XLRS is characterized by areas of schisis in the macula at the level of the nerve fiber and ganglion cell layers - splitting that results in the formation of cystic cavities in the central retina - and by a reduced b-wave amplitude in the electroretinogram (ERG). Mutations in the XLRS1 gene are responsible for the disease. The purpose of this study is to report a 18 year old patient with a 5 year history of visual loss in both eyes that was studied for a clinical diagnosis of juvenile retinoschisis.
Methods: :
Clinical examination, electroretinogram (ERG), oculogram, visual field (VF) testing and optical coherence tomography was performed to confirm the diagnosis. Molecular analysis of XLRS1gene was done through PCR amplification and automated sequencing using capillary electrophoresis.
Results: :
he classical fundus appearance suggested XLRS, the ERG showed decreased responses in all phases, oculogram was normal, VF disclosed a peripheral scotoma in both eyes and OCT showed the characteristic retinoschisis appearance with cyst like images in the macula. Molecular analysis revealed a CGC to TGC missense mutation in the sixth exon of RS1 gene that predicted a substitution from arginine to cysteine change in the protein.
Conclusions: :
A case of XLRS is studied clinical and genetically with a R209C mutation in the RS1 gene responsible of the disease.
Keywords: genetics • mutations • retinal degenerations: hereditary