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Updated: Sep 9, 2025
Imaging Ca2+ Dynamics in Cone Photoreceptor Axon Terminals of the Mouse Retina
Published on: May 6, 2015
Intrafamilial variability of phenotype in CACNA2D4-associated retinal dysfunction: more or less
Vasily Smirnov1,2, Claire-Marie Dhaenens3, Vincent Canel4
1CHU Lille, Service d'Exploration de la Vision et de Neuro-Ophtalmologie, Hôpital Salengro, 59037, Lille, France. vasily.smirnov@chu-lille.fr.
Introduction:
Retinal dysfunction associated with CACNA2D4 gene defects is a rare disorder of photoreceptor to bipolar cell signaling. We report two affected siblings presenting a surprising disparity of retinal involvement.
Materials And Methods:
Patients underwent complete ocular examination, multimodal fundus imaging, and full-field electroretinography (ffERG). Genetic testing was performed by a targeted Next Generation Sequencing panel.
Results:
Two siblings presented a reduced visual acuity and light sensitivity. ffERG was specific for CACNA2D4-related retinal dysfunction, but amplitudes of responses were different in the two patients. Additionally, an x-wave to a dim red flash was well preserved, and there was a reduced b/a ratio to a high intensity (30cd/m2) dark-adapted stimulus. Both patients were homozygous for the variant c.2406C > A, p.(Tyr802*) in CACNA2D4. During 17 years of follow-up, vision remained stable in patient 1, with no evidence of retinal degeneration.
Conclusion:
Intrafamily clinical and electrophysiological expression of CACNA2D4-associated retinal dysfunction can be variable.
