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Updated: Oct 31, 2025

Determining the Likelihood of Variant Pathogenicity Using Amino Acid-level Signal-to-Noise Analysis of Genetic Variation
Published on: January 16, 2019
Spectrum of Disease Severity in Nonsyndromic Patients With Mutations in the CEP290 Gene: A Multicentric Longitudinal
Francesco Testa1, Andrea Sodi2, Sabrina Signorini3
1Eye Clinic, Multidisciplinary Department of Medical, Surgical and Dental Sciences, Università degli Studi della Campania "Luigi Vanvitelli", Naples, Italy.
Purpose:
The purpose of this study was to perform a detailed longitudinal phenotyping and genetic characterization of 32 Italian patients with a nonsyndromic retinal dystrophy and mutations in the CEP290 gene.
Methods:
We reviewed the clinical history and examinations of 32 patients with a nonsyndromic retinal dystrophy due to mutations in the CEP290 gene, followed up (mean follow-up: 5.9 years) at 3 Italian centers. The clinical examinations included: best corrected visual acuity (BCVA), optical coherence tomography (OCT), and full-field electroretinogram (ERG).
Results:
Patients (mean age = 19.0 ± 3.4 years) had a mean BCVA of 1.73 ± 0.20 logMAR. Longitudinal analysis of BCVA showed a nonsignificant decline. Central retinal thickness (CRT) declined significantly with age at an exponential rate of 1.0%/year (P = 0.001). At disease onset, most patients (19/32; 49.4%) had nystagmus. The absence of nystagmus was significantly associated with better BCVA and more preserved CRT (P < 0.05). ERG showed undetectable responses in most patients (64.0%), whereas reduced scotopic and photopic responses were observed in four patients (16.0%) who had no nystagmus. We identified 35 different variants, among which 12 were novel. Our genotype-phenotype correlation analysis shows a significantly worse BCVA in patients harboring a loss-of-function mutation and the deep-intronic variant c.2991+1655A>G.
Conclusions:
Our study highlights a mild phenotype of the disease, characterized by absence of nystagmus, good visual acuity, considerably preserved retinal morphology, and recordable ERG, confirming the wide spectrum of CEP290-related retinal dystrophies. Finally, in our cohort, the deep intronic variant c.2991+1655A>G was associated with a more severe phenotype.
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