Search

Introduction: The GNB1 (guanine nucleotide-binding protein, β1) gene encodes for the ubiquitous β1 subunit of heterotrimeric G proteins, which are associated with G-protein-coupled receptors (GPCRs). GNB1 mutations cause a neurodevelopmental disorder characterized by a broad clinical spectrum. A novel variant has recently been confirmed in a case of rod-cone dystrophy. Case Presentation: We describe the second confirmed case of a classical rod-cone dystrophy associated with a mutation located in exon 6 of GNB1 [NM_002074.5:c.217G>C, p.(Ala73Pro)] in a 56-year-old patient also presenting mild intellectual disability, attention deficit/hyperactivity disorder, and truncal obesity. Conclusion: This paper confirms the role of GNB1 in the pathogenesis of a classic rod-cone dystrophy and highlights the importance of including this gene in the genetic analysis panel for inherited retinal diseases. [ABSTRACT FROM AUTHOR]

Introduction: Mutational screening of inherited retinal disorders is prerequisite for gene targeted therapy. Our aim was to report and analyze the proportions of mutations in inherited retinal disease (IRD)-causing genes from a single center in Switzerland in order to describe the distribution of IRDs in Western Switzerland. Methods: We conducted a retrospective study of patient records. Criteria for inclusion were residence in Western Switzerland for patients and relatives presenting a clinical diagnosis of IRDs and an established molecular diagnosis managed by the genetics service of the Jules-Gonin Eye Hospital (JGEH) of Lausanne between January 2002 and December 2022. We initially investigated the IRD phenotypes in all patients (full cohort) with a clinical diagnosis, then calculated the distribution of IRD gene mutations in the entire cohort (genetically determined cohort). We analyzed a sub-group that comprised pediatric patients (≤18 years of age). In addition, we calculated the distribution of gene mutations within the most represented IRDs. Comprehensive gene screening was performed using a combined approach of different generation of DNA microarray analysis, direct sequencing, and Sanger sequencing. Results: The full cohort comprised 899 individuals from 690 families with a clinical diagnosis of IRDs. We identified 400 individuals from 285 families with an elucidated molecular diagnosis (variants in 84 genes) in the genetically determined cohort. The pediatric cohort included 89 individuals from 65 families with an elucidated molecular diagnosis. The molecular diagnosis rate for the genetically determined cohort was 58.2% (family ratio) and the 5 most frequently implicated genes per family were ABCA4 (11.6%), USH2A (7.4%), EYS (6.7%), PRPH2 (6.3%), and BEST1 (4.6%). The pediatric cohort had a family molecular diagnosis rate of 64.4% and the 5 most common mutated genes per family were RS1 (9.2%), ABCA4 (7.7%), CNGB3 (7.7%), CACNA1F (6.2%), CEP290 (4.6%). Conclusions: This study describes the genetic mutation landscape of IRDs in Western Switzerland in order to quantify their disease burden and contribute to a better orientation of the development of future gene targeted therapies. [ABSTRACT FROM AUTHOR]

The purpose of this clinical report was to describe a case of Cohen syndrome with its classical ophthalmological manifestations and novel VPS13B genetic variants. A 39-year-old Caucasian male patient with severe rod-cone retinal dystrophy and no history of parental consanguinity was referred to our ophthalmology department. Ophthalmologic history included high bilateral myopia and a 3-year prior bilateral cataract surgery. Systemic history included facial dysmorphism, intellectual disability, transient neutropenia, microcephaly, truncal obesity, and joint hyperextensibility. The patient presented classic fundoscopic features of pigmentary retinopathy in both eyes (OU). Optical coherence tomography (OCT) revealed bilateral central and diffuse retinal pigment epithelium (RPE) and outer retinal atrophy without concomitant macular edema, while fluorescein angiography (FA) demonstrated diffuse RPE atrophy with prominent choroidal vessels. The full-field ERG (ffERG) showed no dark-adapted or light-adapted responses and the P50 wave was not identified in the pattern ERG (pERG). The genetic study revealed two novel heterozygous variants in the VPS13B gene: (1) c.5138T>C p.(Leu1713Pro) and (2) c.10179del p.(Asn3393Lysfs*37), thus confirming the diagnosis of Cohen syndrome. This case report introduces these two novel genetic variants to the literature, in a patient with classic phenotypic characteristics of Cohen syndrome, a rare genetic disease which has been increasingly reported since its first description in 1973. [ABSTRACT FROM AUTHOR]

Purpose: We report an unusual case of rapid and severe anterior capsular contraction associated with secondary intraocular lens (IOL) dislocation following cataract surgery in a patient with unspecified rod-cone dystrophy. Case Report: A 68-year-old woman with a history of uncharacterized bilateral rod-cone dystrophy presented with blurry vision 1 month after cataract surgery. Best corrected visual acuity was 20/40 in the operative eye. Slit-lamp exam showed severe anterior capsular phimosis limiting view of the fundus. Our patient underwent 2 sessions of Nd:YAG anterior capsulotomy with limited success. Limited anterior vitrectomy was then performed without success due to densely adherent capsular tissue to the anterior surface of the IOL and additional secondary IOL dislocation. She ultimately underwent pars plana vitrectomy, removal of the capsular bag, and IOL exchange with a scleral fixated IOL. Conclusion: Rapid and severe anterior capsular contraction following cataract surgery is rare but appears to be associated with rod-cone dystrophy. [ABSTRACT FROM AUTHOR]