| Autor: |
de Guimaraes, Thales A. C., Lai, Francesco, Colombatti, Raffaella, Sato, Giovanni, Rizzo, Roberta, Kalitzeos, Angelos, Michaelides, Michel |
| Předmět: |
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| Zdroj: |
Ophthalmic Genetics; Aug2024, Vol. 45 Issue 4, p425-434, 10p |
| Abstrakt: |
Background: Disease-causing variants in the KCNV2 gene are associated with "cone dystrophy with supernormal rod responses," a rare autosomal recessive retinal dystrophy. There is no previous report of hypomorphic variants in the disease. Material and Methods: Medical history, genetic testing, ocular examination, high-resolution retinal imaging including adaptive optics scanning light ophthalmoscopy (AOSLO), and functional assessments. Results: A 16-year-old male with mild cone-rod dystrophy presented with reduced central vision and photophobia. Genetic testing showed two variants in KCNV2, c.614_617dupAGCG (p.207AlafsTer166) and c.854T>G (p.Met285Arg), the latter which was previously considered benign. Electrophysiological assessment revealed the pathognomic electroretinogram waveforms associated with KCNV2-retinopathy. Optical coherence tomography showed discrete focal ellipsoid zone disruption, while fundus autofluorescence was normal. Non-waveguiding cones corresponding to areas of loss of photoreceptor integrity were visible on adaptive optics scanning light ophthalmoscopy. Retinal sensitivity and fixation were relatively preserved, with a demonstrable deterioration after 14 months of follow-up. Conclusions: We provide functional and structural evidence that the variant M285R is disease-causing if associated with a loss-of-function variant. To the best of our knowledge, this is the first hypomorphic allele reported in KCNV2. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
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