Two Novel Disease-Causing Variants in the PDE6C Gene Underlying Achromatopsia

• Main Authors: Carolina Madeira, Gonçalo Godinho, Ana Grangeia, Manuel Falcão, Renato Silva, Ângela Carneiro, Elisete Brandão, Augusto Magalhães, Fernando Falcão-Reis, Sérgio Estrela-Silva
• Format: Article
• Language: English
• Published: Karger Publishers 2021-09-01
• Series: Case Reports in Ophthalmology
• Subjects: pde6c gene; achromatopsia; multimodal imaging
• Online Access: https://www.karger.com/Article/FullText/512284

We report the clinical phenotype and genetic findings of two variants in PDE6C underlying achromatopsia (ACHM). Four patients with the variant c.1670G>A in exon 13 of the PDE6C gene were identified. Additionally, one had compound heterozygous genotype, with two variants in the PDE6C gene, a variant of c.2192G>A in exon 18 and c.1670G>A in exon 13. All patients presented the symptomatic triad of decreased visual acuity, severe photophobia, and colour vision disturbances. SD-OCT showed an absence of the ellipsoid zone, creating an optically empty cavity at the fovea in three patients. The patient with the compound heterozygous genotype presented a more severe subfoveal outer retina atrophy. ERG recordings showed extinguished responses under photopic and 30-Hz flicker stimulation, with a normal rod response. We identified two new variants in the PDE6C gene that leads to ACHM.