Phenotypic Features of Patients With NR2E3 Mutations

Abstract

To describe the phenotypes of 5 patients with NR2E3 mutations. Two patients with familial and 3 with sporadic early-onset nyctalopia and retinal pigment abnormalities were screened for mutations in the NR2E3 gene (OMIM 604485). The clinical course, fundus features, visual field test results, and fluorescein angiographic and electrophysiologic findings were compared. Three different mutations in NR2E3 were identified: R311Q and 2 novel mutations--missense change Q350R and an in-frame deletion of phenylalanine at position 71 (delF71) in exon 2. Three patients who were homozygous for R311Q had posterior subcapsular cataracts and a concentric ring of round pigment clumps. Electroretinograms were extinguished. A fourth patient, a 24-year-old man who was heterozygotic for R311Q and Q350R, had Goldmann-Favre syndrome. A fifth patient, a 10-year-old boy with heterozygotic mutations R311Q and delF71, had diminished foveal reflexes and subtle pigmentary changes, perhaps a forme fruste of Goldmann-Favre syndrome. Both of these patients had an identical spectral electroretinographic pattern characteristic of enhanced S-cone syndrome. Molecular genetic testing is essential for establishing the correct diagnosis in patients with NR2E3 mutations because of the variable phenotype associated with these degenerations. Two novel NR2E3 mutations are described that are associated with Goldmann-Favre syndrome and enhanced S-cone syndrome.