Related Experiment Video
Updated: Nov 15, 2025

Vibratome Sectioning Mouse Retina to Prepare Photoreceptor Cultures
Published on: December 22, 2014
A homozygous POC1B variant causes recessive cone-rod dystrophy
Ann-Marie C Peturson1, Nicole C L Noel2, Ian M MacDonald1,2
1Department of Ophthalmology and Visual Sciences, University of Alberta, Edmonton, Alberta, Canada.
Abstract:
Purpose: To report a case of initial cone dystrophy that advanced to a cone-rod dystrophy with homozygous variants in the POC1B gene.Methods: Retinal structure and visual function assessments were performed using fundoscopy, spectral-domain optical coherence tomography, full field electroretinography, semi-kinetic perimetry, and Ishihara plate testing. A DNA sample was collected and sent for diagnostic molecular genetic testing with a cone-rod dystrophy panel.Results: Clinical examination and electroretinography confirmed a clinical diagnosis of cone dystrophy. Molecular genetic testing revealed homozygous variants in POC1B (c.1355 G > A, p.(Arg452Gln)). Follow-up three years later showed progression to a cone-rod dystrophy.Conclusion: Our case describes an ophthalmological phenotype associated with a homozygous POC1B missense variant and provides clinical support for variant classification.
Related Concept Videos
Genetic Lingo
The Retinoblastoma Gene
The first-ever tumor suppressor gene called Rb was identified in retinoblastoma - a rare eye tumor in children. In inherited forms of the disease, a child inherits one defective copy of the Rb gene, which predisposes them to retinoblastoma. However,...
Incomplete Dominance
Epistasis
Photoreceptors and Visual Pathways
Pleiotropy

