Bilateral Helicoid Peri-papillary Sub-retinal Fibrosis Due to a Biallelic NR2E3 Mutation: Describing Variable Expressivity of a Single Genetic Mutation

Abstract

Background: To describe different clinical presentations of NR2E3 (nuclear receptor subfamily 2, group E, member 3; OMIM 604485) recessive mutation in two families and within one family. Design: Interventional family study. Results: Our first case was a one-year-old male child with high hyperopia and refractive accommodative esotropia. In retinal examination, peri-papillary sub-retinal fibrosis with a helicoid configuration was observed in both eyes. Parents and the only sibling had no pathologic finding in the eyes. The child showed to have severely reduced responses in both photopic and scotopic electroretinogram components. In genetic investigation, a homozygous autosomal recessive mutation in NR2E3 gene was discovered in the affected child, while the other family members were heterozygous for this mutation. We followed up the patient for 3 years and no new lesion developed during this time period. The second case was a 13-year-old male child who was referred to retina clinic for decreased vision in the right eye. In retina examination, there were nummular pigmentary changes at the level of retinal pigment epithelium and along the vascular arcades with foveo-schitic changes in both eyes. A choroidal neovascularization (CNV) was noticed in macula of his right eye. Genetic evaluation proved the same mutation in NR2E3 gene. Family history was remarkable for an uncle, an aunt and two cousins with night blindness. In retina examination, asymptomatic father of proband showed to have slight pallor of optic nerve head and arterial narrowing in both eyes. Conclusion: NR2E3 gene mutation can cause heterogeneous clinical manifestations such as slight retinal changes in the absence of any visual symptoms to high hyperopia associated with helicoid peri-papillary sub-retinal fibrosis.