Tan, JK;
Arno, G;
Josifova, D;
Mohamed, MD;
Mahroo, OA;
(2024)
Unusual OCT findings in a patient with CABP4-associated cone–rod synaptic disorder.
Documenta Ophthalmologica
10.1007/s10633-023-09961-8.
(In press).
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Abstract
Purpose: Bi-allelic variants in CABP4 are associated with congenital cone–rod synaptic disorder, which has also been classified, electrophysiologically, as incomplete congenital stationary night blindness (iCSNB). We describe clinical findings in a patient who demonstrated an unusual macular optical coherence tomography (OCT) phenotype, not previously reported in this condition. Methods: Our patient underwent multimodal retinal imaging, international standard full-field ERG testing and whole genome sequencing. Results: The patient was a 60-year-old woman with non-progressive visual impairment since birth, nystagmus and preference for dim lighting. Clinical fundus examination was unremarkable. OCT imaging revealed a hypo-reflective zone under an elevated fovea in both eyes. ERGs showed an electronegative DA10 response, with severely abnormal light-adapted responses. Whole genome sequencing revealed homozygosity for a known pathogenic variant in CABP4. No variants were found in other genes that could explain the patient’s phenotype. Conclusions: OCT findings of foveal elevation and an underlying hypo-reflective zone are novel in this condition. Whilst the clinical history was similar to achromatopsia and other cone dysfunction syndromes, ERG findings suggested disease associated with CACNA1F or CABP4. As CACNA1F is X-linked, CABP4 was more likely, and confirmed on genetic testing. The patient saw better in dim light, confirming that night blindness is not a feature of CABP4-associated disease. Our case highlights the value of ERGs in discriminating between causes of cone dysfunction, and extends the range of retinal imaging phenotypes reported in this disorder.
| Type: | Article |
|---|---|
| Title: | Unusual OCT findings in a patient with CABP4-associated cone–rod synaptic disorder |
| Location: | Netherlands |
| Open access status: | An open access version is available from UCL Discovery |
| DOI: | 10.1007/s10633-023-09961-8 |
| Publisher version: | https://doi.org/10.1007/s10633-023-09961-8 |
| Language: | English |
| Additional information: | Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/. |
| Keywords: | Cone dysfunction, Congenital stationary night blindness, Photoreceptors, Retina |
| URI: | https://discovery.ucl.ac.uk/id/eprint/10186009 |
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