Retinal dystrophies with bull’s-eye maculopathy along with negative ERGs.

Authors

Nasser F1,2, Kurtenbach A3, Kohl S3, Obermaier C4, Stingl K3,5, Zrenner E3,6.
  1. Centre for Ophthalmology, University of Tuebingen, Tübingen, Germany. fadi.nasser@med.uni-tuebingen.de.
  2. University Eye Hospital, Elfriede-Aulhorn-Strasse, 72076, Tübingen, Germany. fadi.nasser@med.uni-tuebingen.de.
  3. Centre for Ophthalmology, University of Tuebingen, Tübingen, Germany.
  4. Praxis fuer Humangenetik Tübingen, Tübingen, Germany.
  5. University Eye Hospital, Elfriede-Aulhorn-Strasse, 72076, Tübingen, Germany.
  6. Werner Reichardt Centre for Integrative Neuroscience (CIN), University of Tübingen, Tübingen, Germany.

Abstract

PURPOSE:

The aim of this study was to examine the ophthalmological characteristics and genotypes of patients with congenital retinal pathologies, who display a bull’s-eye maculopathy in the fundus, along with a negative scotopic electroretinogram.

METHODS:

We analysed the results of five patients showing both a bull’s-eye maculopathy, as well as a negative scotopic ERG evoked by a bright flash. Their median age was 39 years (range 11-63 years): three males and two females. All underwent a comprehensive examination with determination of distant visual acuity (ETDRS) and recording of the full-field ERG (scotopic and photopic). Fundus, OCT, and FAF images were obtained, the kinetic visual field was determined, and colour vision (D-15) was tested in most patients. Targeted gene panel sequencing was performed on peripheral blood.

RESULTS:

One patient carried a homozygous ABCA4 mutation and an additional heterozygous variant in CRX. Two of the five patients were shown to have a heterozygous mutation in the CRX gene, one of whom had an additional heterozygous ABCA4 mutation. Two patients had the common heterozygous mutation c.2413G>A;p.Arg838His in GUCY2D. In all of the patients, there was a reduction in the amplitude of the b-wave with a regular a-wave amplitude in the scotopic bright-flash ERG.

CONCLUSIONS:

The five patients with bull’s-eye maculopathy along with a negative ERG had differing genotypes. Mutations were found in the CRX gene (2 patients), the ABCA4 gene (1 patient), and the GUCY2D gene (2 patients).

KEYWORDS:

Bull’s-eye maculopathy; Genotype; Negative ERG; Phenotype

References