Publications by authors named "Saddek Mohand Said"

Article Synopsis
  • The study focuses on inherited retinal degenerations (IRDs) that can lead to blindness, particularly investigating genetic variations in a North African cohort, which has been less studied compared to European and Asian populations.
  • Researchers used advanced sequencing techniques and expression analyses on various cell types to identify a new gene defect in the UBAP1L gene in four cases of autosomal recessive IRD from Tunisia.
  • Findings suggest that these biallelic UBAP1L variants play a significant role in IRDs, indicating a potential genetic prevalence in the North African population.
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Purpose: To validate a novel mobility test (MOST, MObility Standardized Test) and performance outcomes in real (RL) and virtual (VR) environments to be used for interventional clinical studies in order to characterize vision impairment in rod-cone dystrophies, also known as retinitis pigmentosa (RP).

Design: Prospective, interventional, noninvasive, reliability and validity analysis.

Methods: We designed MOST to be used in both VR and RL and conducted 3 experimental studies with 89 participants to (1) validate the difficulty of the mobility courses (15 controls), (2) determine the optimal number of light levels and training trials (14 participants with RP), and (3) validate the reproducibility (test-retest), reliability (VR/RL), sensitivity, and construct/content validity of the test (30 participants with RP and 30 controls).

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Variants in the X-linked retinitis pigmentosa GTPase regulator gene ( and, specifically, in its retinal opening reading frame-15 isoform () may cause rod-cone (RCD), cone, and cone-rod dystrophies (CDs and CRDs). While -related RCDs have been frequently evaluated, the characteristics and progression of -related CD/CRDs are largely unknown. Therefore, the goal of our work was to perform genotype-phenotype correlations specifically in -related CD/CRDs.

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Purpose: Biallelic variants in CLRN1 are responsible for Usher syndrome 3A and non-syndromic rod-cone dystrophy (RCD). Retinal findings in Usher syndrome 3A have not been well defined. We report the detailed phenotypic description of RCD associated with CLRN1 variants in a prospective cohort.

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Purpose: To report on the safety of the first 5 cohorts of a gene therapy trial using recombinant equine infectious anemia virus expressing ABCA4 (EIAV-ABCA4) in adults with Stargardt dystrophy due to mutations in ABCA4.

Design: Nonrandomized multicenter phase I/IIa clinical trial.

Methods: Patients received a subretinal injection of EIAVABCA4 in the worse-seeing eye at 3 dose levels and were followed for 3 years after treatment.

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In contrast to , variants in are a minor cause of Usher syndrome type 2, and the associated phenotype is less known. The purpose of the study was to characterize the retinal phenotype of 18 patients (9 male, 9 female; median age 52 years) and compare it with that of 204 patients (111 male, 93 female; median age 43 years) in terms of nyctalopia onset, best corrected visual acuity (BCVA), fundus autofluorescence (FAF), and optical coherence tomography (OCT) features. There was no statistical difference in the median age at onset (30 and 18 years; Mann-Whitney U test, = 0.

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Cohen syndrome (CS) is a rare syndromic form of rod-cone dystrophy. Recent case reports have suggested that cystoid maculopathy (CM) could affect CS patients with an early onset and high prevalence. Our study aims at improving our understanding and management of CM in CS patients through a retrospective case series of ten CS patients with identified pathogenic variants in VPS13B.

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The purpose of this work was to identify the gene defect underlying a relatively mild rod-cone dystrophy (RCD), lacking disease-causing variants in known genes implicated in inherited retinal disorders (IRD), and provide transcriptomic and immunolocalization data to highlight the best candidate. The DNA of the female patient originating from a consanguineous family revealed no large duplication or deletion, but several large homozygous regions. In one of these, a homozygous frameshift variant, c.

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Variants of the gene, which encodes tubulin tyrosine ligase-like family member five, are a rare cause of cone dystrophy (COD) or cone-rod dystrophy (CORD). To date, only a few patients have been clinically and genetically described. In this study, we report five patients harbouring biallelic variants of Four adult patients presented either COD or CORD with onset in the late teenage years.

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Purpose: To describe the value of integrating phenotype/genotype data, disease staging, and evaluation of functional vision in patient-centered management of retinal dystrophies.

Methods: (1) Cross-sectional structure-function and retrospective longitudinal studies to assess the correlations between standard fundus autofluorescence (FAF), optical coherence tomography, visual acuity (VA), and perimetry (visual field [VF]) examinations to evaluate photoreceptor functional loss in a cohort of patients with rod-cone dystrophy (RCD); (2) flood-illumination adaptive optics (FIAO) imaging focusing on photoreceptor misalignment and orientation of outer segments; and (3) evaluation of the impact of visual impairment in daily life activities, based on functional (visual and mobility) vision assessment in a naturalistic environment in visually impaired subjects with RCD and subjects treated with Luxturna for RPE65-related Leber congenital amaurosis before and after therapy.

Results: The results of the cross-sectional transversal study showed that (1) VA and macular sensitivity were weakly correlated with the structural variables; and (2) functional impairment (VF) was correlated with reduction of anatomical markers of photoreceptor structure and increased width of autofluorescent ring.

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Goldmann Favre Syndrome (GFS) is a vitreoretinal degenerative disease with macular retinoschisis. The current treatment of foveoschisis is topical and oral carbonic anhydrase inhibitors. A 22-year-old male diagnosed with GFS presented a progressive decrease in vision of the right eye.

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Cyclic nucleotide-gated channel β1 (CNGB1) encodes the 240-kDa β subunit of the rod photoreceptor cyclic nucleotide-gated ion channel. Disease-causing sequence variants in CNGB1 lead to autosomal recessive rod-cone dystrophy/retinitis pigmentosa (RP). We herein present a comprehensive review and analysis of all previously reported CNGB1 sequence variants, and add 22 novel variants, thereby enlarging the spectrum to 84 variants in total, including 24 missense variants (two of which may also affect splicing), 21 nonsense, 19 splicing defects (7 at noncanonical positions), 10 small deletions, 1 small insertion, 1 small insertion-deletion, 7 small duplications, and 1 gross deletion.

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Background: Leber hereditary optic neuropathy (LHON) is a maternally inherited mitochondrial disease whose primary clinical manifestation is bilateral visual loss. Only a single therapy, idebenone, is approved in Europe for use in exceptional circumstances and no therapy is currently approved in the USA. LHON remains a disease with a high unmet medical need.

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Thirty-eight patients from 37 families with retinitis pigmentosa (RP) underwent macular 6 × 6-mm swept-source optical coherence tomography angiography (SS-OCTA) and 30° near-infrared fundus autofluorescence (NIR-FAF) acquisitions in one eye. Superficial vascular complex (SVC), deep capillary complex (DCC) and choriocapillaris (CC) angiograms were registered with NIR-FAF acquisitions to comparatively assess subjects with and without central area of preserved NIR-FAF (APA). On the subset of patients showing an APA, the vessel densities for SVC and DCC and flow deficits for CC were assessed in three directions (superior, inferior and temporal) from the fovea and compared to healthy 1:1 age-matched controls.

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Choroideremia is an X-linked inherited retinal disorder (IRD) characterized by the degeneration of retinal pigment epithelium, photoreceptors, choriocapillaris and choroid affecting males with variable phenotypes in female carriers. Unlike other IRD, characterized by a large clinical and genetic heterogeneity, choroideremia shows a specific phenotype with causative mutations in only one gene, CHM. Ongoing gene replacement trials raise further interests in this disorder.

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Importance: Biallelic variants in CLN3 lead to a spectrum of diseases, ranging from severe neurodegeneration with retinal involvement (juvenile neuronal ceroid lipofuscinosis) to retina-restricted conditions.

Objective: To provide a detailed description of the retinal phenotype of patients with isolated retinal degeneration harboring biallelic CLN3 pathogenic variants and to attempt a phenotype-genotype correlation associated with this gene defect.

Design, Setting, And Participants: This retrospective cohort study included patients carrying biallelic CLN3 variants extracted from a cohort of patients with inherited retinal disorders (IRDs) investigated at the National Reference Center for Rare Ocular Diseases of the Centre Hospitalier National d'Ophtalmologie des Quinze-Vingts from December 2007 to August 2020.

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Age-related macular degeneration (AMD) is a blinding disease for which most of the patients remain untreatable. Since the disease affects the macula at the center of the retina, a structure specific to the primate lineage, rodent models to study the pathophysiology of AMD and to develop therapies are very limited. Consequently, our understanding relies mostly on genetic studies highlighting risk alleles at many loci.

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Purpose: To evaluate the post-approval long-term outcomes of the Argus II Retinal Prosthesis, with a specific focus on its functional visual benefit in patients' daily activities.

Methods: Eighteen patients with bare light perception due to end-stage retinitis pigmentosa were included in a French prospective, multicentre, single-arm study and followed for 2 years. Visual benefit in patients' daily activities was monitored through the use of the Functional Low-vision Observer Rated Assessment (FLORA), and the final score at 2 years was the primary effectiveness outcome.

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Rod-cone dystrophy (RCD), also called retinitis pigmentosa, is characterized by rod followed by cone photoreceptor degeneration, leading to gradual visual loss. Mutations in over 65 genes have been associated with non-syndromic RCD explaining 60% to 70% of cases, with novel gene defects possibly accounting for the unsolved cases. Homozygosity mapping and whole-exome sequencing applied to a case of autosomal recessive non-syndromic RCD from a consanguineous union identified a homozygous variant in WDR34.

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Purpose: To reappraise the presentation and the course of ITM2B-related retinal dystrophy and give further insights into ITM2B expression in the retina.

Methods: The clinical data of nine subjects with ITM2B-related retinal dystrophy were retrospectively reviewed. The genetic mutation was assessed for its influence on splicing in cultured fibroblasts.

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Purpose: Loss of photoreceptors in atrophic age-related macular degeneration results in severe visual impairment, although some peripheral vision is retained. To restore central vision without compromising the residual peripheral field, we developed a wireless photovoltaic retinal implant (PRIMA; Pixium Vision, Paris, France) in which pixels convert images projected from video glasses using near-infrared light into electric current to stimulate the nearby inner retinal neurons.

Design: We carried out a first-in-human clinical trial to test the safety and efficacy of the prosthesis in patients with geographic atrophy (ClinicalTrials.

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Purpose: To evaluate the correlation between the quantification of peripapillary sparing and electroretinogram (ERG) outcomes in autosomal recessive Stargardt disease (STGD1).

Methods: Near infrared fundus autofluorescence (NIR-FAF) images of 101 eyes of 101 patients were retrospectively reviewed. Peripapillary sparing was assessed both qualitatively and quantitatively.

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We investigated the prevalence of reported deep-intronic variants in a French cohort of 70 patients with Stargardt disease harboring a monoallelic pathogenic variant on the exonic regions of . Direct Sanger sequencing of selected intronic regions of ABCA4 was conducted. Complete phenotypic analysis and correlation with the genotype was performed in case a known intronic pathogenic variant was identified.

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