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Inherited retinal diseases (IRDs) are the leading cause of vision loss in the working-age population. We performed a retrospective epidemiological study to determine the genetic basis of IRDs in a large Italian cohort (n = 2790) followed at a single referral center. We provided, mainly by next generation sequencing, potentially conclusive molecular diagnosis for 2036 patients (from 1683 unrelated families). We identified a total of 1319 causative sequence variations in 132 genes, including 353 novel variants, and 866 possibly actionable genotypes for therapeutic approaches. ABCA4 was the most frequently mutated gene (n = 535; 26.3% of solved cases), followed by USH2A (n = 228; 11.2%) and RPGR (n = 102; 5.01%). The other 129 genes had a lower contribution to IRD pathogenesis (e.g. CHM 3.5%, RHO 3.5%; MYO7A 3.4%; CRB1 2.7%; RPE65 2%, RP1 1.8%; GUCY2D 1.7%). Seventy-eight genes were mutated in five patients or less. Mitochondrial DNA variants were responsible for 2.1% of cases. Our analysis confirms the complex genetic etiology of IRDs and reveals the high prevalence of ABCA4 and USH2A mutations. This study also uncovers genetic associations with a spectrum of clinical subgroups and highlights a valuable number of cases potentially eligible for clinical trials and, ultimately, for molecular therapies. [ABSTRACT FROM AUTHOR]

To report quantitative retinal changes assessed by spectral-domain optical coherence tomography (SD-OCT) in children treated with voretigene neparvovec (VN) at a single center in Italy. Retrospective review of six consecutive pediatric patients with biallelic RPE65-related dystrophy treated bilaterally with VN. SD-OCT scans were analyzed to extract Early Treatment Diabetic Retinopathy Study (ETDRS) thickness maps of the whole retina and the outer nuclear layer (ONL). Changes in visual function were assessed by best-corrected visual acuity (BCVA) and retinal morphology at Days 30/45 and 180. BCVA significantly improved at Day 30/45 and 6 months (both P < 0.001). Central foveal retinal thickness and central foveal ONL thickness tended to increase (6.4 ± 19.2 µm; P = 0.080 and 3.42 ± 7.68 µm; P = 0.091, respectively). ONL thickness of the internal ETDRS-ring significantly increased at day 30/45 (4.7 ± 8.4 µm; P < 0.001) and day 180 (5.0 ± 5.7 µm; P = 0.009). Intra-operative foveal detachment was not associated with a higher function gain in terms of BCVA, but with a mild thinning of foveal ONL after treatment. The improvement of BCVA and thickening of the ONL layer suggest that improvement of visual acuity could be related to partial recovery of retinal morphology in the perifoveal ring. [ABSTRACT FROM AUTHOR]

Accumulating evidence on the role of non-protein-coding RNA sequences in the regulation of gene expression is greatly expanding our understanding of the flow of genetic information within biological systems. The interplay between protein-coding and non-coding RNAs (ncRNAs) is essential for tissue development, homeostasis, and function. NcRNAs can be divided in short ncRNAs, whose main subtype is represented by microRNAs, and long ncRNAs, which constitute a more heterogeneous class. The retina is a light-sensitive tissue consisting of highly interconnected cell types and is the primary target of many genetic diseases. Among these, the genetically heterogeneous group of inherited retinal diseases (IRDs) represents the most frequent monogenic cause of visual impairment that can ultimately lead to blindness. Here, we provide an overview on the role of ncRNAs in retinal development and function with an emphasis on microRNAs and on different types of long ncRNAs. We also review how sequence variations in ncRNAs can play a pathogenic role in IRDs as well as in multifactorial ocular disorders. These data indicate that a comprehensive study of the contribution of ncRNAs to the mutation repertoire associated with retinal disease can shed light on previously unknown pathophysiological mechanisms and open new therapeutic avenues. We conclude that a more comprehensive dissection of the pathogenic role of non-coding RNAs in retinal function and disease will not only improve our diagnostic ability, but will allow the development of novel targeted therapies for ocular disease. [ABSTRACT FROM AUTHOR]