Titel | Identification of CNGA3 variants in a child with a maculopathy, normal photopic ERG and near normal color vision |
Abstract Nr. | 3025 |
Doel | To unravel the genetic diagnosis in a 9-year old child with a maculopathy. |
Methodes | The patient had a standard ophthalmic examination, Octopus perimetry, optical coherence tomography (OCT) scan, fundus autofluorescence (FAF) and ISCEV full-field ERG. Genetic testing consisted of analysis of a panel of retinal dystrophy genes (RetNet panel) using exome sequencing. |
Resultaten | The visual acuity was decreased: OD(S-2)=0.4,OS(S-2)=0.5. FAF showed a clear foveal lesion and perimetry showed several relative scotomas. Color vision was near normal. OCT showed a disruption of the ellipsoid zone and interruption of the outer segments. Photopic and scotopic ERG was normal, mfERG showed abnormalities, more specifically central rings. Photophobia was only seen with flash ERG. RetNet panel analysis revealed a heterozygous likely pathogenic missense variant in CNGA3: c.830 G>A p.(Arg277His). In addition, a second heterozygous missense CNGA3 variant was found of which the significance is unclear: c.811 C>G p.(Pro271Ala). Both parents were heterozygous carrier of a CNGA3 variant, demonstrating both variants occur in trans. |
Conclusie | The CNGA3 genotype is a likely explanation of the phenotype observed. We expand the phenotypic spectrum of CNGA3-associated retinal dystrophies. |
Belangenverstrengeling | Nee |
Naam | DE VRIES |
Initialen | MJ |
Instituut | Universitair Kinderziekenhuis Koningin Fabiola |
Stad | Brussel |
Naam | Van Genderen |
Initialen | MM |
Instituut | Bartiméus en Universitair Medisch Centrum Utrecht |
Stad | Zeist en Utrecht |
Naam | Postolache |
Initialen | L |
Instituut | Universitair Kinderziekenhuis Koningin Fabiola |
Stad | Brussel |
Naam | De Baere |
Initialen | E |
Instituut | Center for Medical Genetics, Ghent University and Ghent University Hospital |
Stad | Gent |