1
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Stehle IF, Imventarza JA, Woerz F, Hoffmann F, Boldt K, Beyer T, Quinn PM, Ueffing M. Human CRB1 and CRB2 form homo- and heteromeric protein complexes in the retina. Life Sci Alliance 2024; 7:e202302440. [PMID: 38570189 PMCID: PMC10992996 DOI: 10.26508/lsa.202302440] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2023] [Revised: 03/26/2024] [Accepted: 03/26/2024] [Indexed: 04/05/2024] Open
Abstract
Crumbs homolog 1 (CRB1) is one of the key genes linked to retinitis pigmentosa and Leber congenital amaurosis, which are characterized by a high clinical heterogeneity. The Crumbs family member CRB2 has a similar protein structure to CRB1, and in zebrafish, Crb2 has been shown to interact through the extracellular domain. Here, we show that CRB1 and CRB2 co-localize in the human retina and human iPSC-derived retinal organoids. In retina-specific pull-downs, CRB1 was enriched in CRB2 samples, supporting a CRB1-CRB2 interaction. Furthermore, novel interactors of the crumbs complex were identified, representing a retina-derived protein interaction network. Using co-immunoprecipitation, we further demonstrate that human canonical CRB1 interacts with CRB1 and CRB2, but not with CRB3, which lacks an extracellular domain. Next, we explored how missense mutations in the extracellular domain affect CRB1-CRB2 interactions. We observed no or a mild loss of CRB1-CRB2 interaction, when interrogating various CRB1 or CRB2 missense mutants in vitro. Taken together, our results show a stable interaction of human canonical CRB2 and CRB1 in the retina.
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Affiliation(s)
- Isabel F Stehle
- https://ror.org/03a1kwz48 Institute for Ophthalmic Research, Eberhard Karls University Tübingen, Tübingen, Germany
| | - Joel A Imventarza
- Department of Ophthalmology, Vagelos College of Physicians & Surgeons, Columbia University; New York, NY, USA
| | - Franziska Woerz
- https://ror.org/03a1kwz48 Institute for Ophthalmic Research, Eberhard Karls University Tübingen, Tübingen, Germany
| | - Felix Hoffmann
- https://ror.org/03a1kwz48 Institute for Ophthalmic Research, Eberhard Karls University Tübingen, Tübingen, Germany
| | - Karsten Boldt
- https://ror.org/03a1kwz48 Institute for Ophthalmic Research, Eberhard Karls University Tübingen, Tübingen, Germany
| | - Tina Beyer
- https://ror.org/03a1kwz48 Institute for Ophthalmic Research, Eberhard Karls University Tübingen, Tübingen, Germany
| | - Peter Mj Quinn
- Department of Ophthalmology, Vagelos College of Physicians & Surgeons, Columbia University; New York, NY, USA
| | - Marius Ueffing
- https://ror.org/03a1kwz48 Institute for Ophthalmic Research, Eberhard Karls University Tübingen, Tübingen, Germany
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2
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Jackson D, Moosajee M. The Genetic Determinants of Axial Length: From Microphthalmia to High Myopia in Childhood. Annu Rev Genomics Hum Genet 2023; 24:177-202. [PMID: 37624667 DOI: 10.1146/annurev-genom-102722-090617] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/27/2023]
Abstract
The axial length of the eye is critical for normal visual function by enabling light to precisely focus on the retina. The mean axial length of the adult human eye is 23.5 mm, but the molecular mechanisms regulating ocular axial length remain poorly understood. Underdevelopment can lead to microphthalmia (defined as a small eye with an axial length of less than 19 mm at 1 year of age or less than 21 mm in adulthood) within the first trimester of pregnancy. However, continued overgrowth can lead to axial high myopia (an enlarged eye with an axial length of 26.5 mm or more) at any age. Both conditions show high genetic and phenotypic heterogeneity associated with significant visual morbidity worldwide. More than 90 genes can contribute to microphthalmia, and several hundred genes are associated with myopia, yet diagnostic yields are low. Crucially, the genetic pathways underpinning the specification of eye size are only now being discovered, with evidence suggesting that shared molecular pathways regulate under- or overgrowth of the eye. Improving our mechanistic understanding of axial length determination will help better inform us of genotype-phenotype correlations in both microphthalmia and myopia, dissect gene-environment interactions in myopia, and develop postnatal therapies that may influence overall eye growth.
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Affiliation(s)
- Daniel Jackson
- Institute of Ophthalmology, University College London, London, United Kingdom;
| | - Mariya Moosajee
- Institute of Ophthalmology, University College London, London, United Kingdom;
- The Francis Crick Institute, London, United Kingdom
- Moorfields Eye Hospital NHS Foundation Trust, London, United Kingdom
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3
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Wen S, Wang M, Qian X, Li Y, Wang K, Choi J, Pennesi ME, Yang P, Marra M, Koenekoop RK, Lopez I, Matynia A, Gorin M, Sui R, Yao F, Goetz K, Porto FBO, Chen R. Systematic assessment of the contribution of structural variants to inherited retinal diseases. Hum Mol Genet 2023; 32:2005-2015. [PMID: 36811936 PMCID: PMC10244226 DOI: 10.1093/hmg/ddad032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2022] [Revised: 01/03/2023] [Accepted: 02/11/2023] [Indexed: 02/24/2023] Open
Abstract
Despite increasing success in determining genetic diagnosis for patients with inherited retinal diseases (IRDs), mutations in about 30% of the IRD cases remain unclear or unsettled after targeted gene panel or whole exome sequencing. In this study, we aimed to investigate the contributions of structural variants (SVs) to settling the molecular diagnosis of IRD with whole-genome sequencing (WGS). A cohort of 755 IRD patients whose pathogenic mutations remain undefined were subjected to WGS. Four SV calling algorithms including include MANTA, DELLY, LUMPY and CNVnator were used to detect SVs throughout the genome. All SVs identified by any one of these four algorithms were included for further analysis. AnnotSV was used to annotate these SVs. SVs that overlap with known IRD-associated genes were examined with sequencing coverage, junction reads and discordant read pairs. Polymerase Chain Reaction (PCR) followed by Sanger sequencing was used to further confirm the SVs and identify the breakpoints. Segregation of the candidate pathogenic alleles with the disease was performed when possible. A total of 16 candidate pathogenic SVs were identified in 16 families, including deletions and inversions, representing 2.1% of patients with previously unsolved IRDs. Autosomal dominant, autosomal recessive and X-linked inheritance of disease-causing SVs were observed in 12 different genes. Among these, SVs in CLN3, EYS and PRPF31 were found in multiple families. Our study suggests that the contribution of SVs detected by short-read WGS is about 0.25% of our IRD patient cohort and is significantly lower than that of single nucleotide changes and small insertions and deletions.
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Affiliation(s)
- Shu Wen
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Meng Wang
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Xinye Qian
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX 77030, USA
| | - Yumei Li
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX 77030, USA
| | - Keqing Wang
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX 77030, USA
| | - Jongsu Choi
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Mark E Pennesi
- Department of Ophthalmology, Casey Eye Institute, Oregon Health & Science University, Portland, OR 97239, USA
| | - Paul Yang
- Department of Ophthalmology, Casey Eye Institute, Oregon Health & Science University, Portland, OR 97239, USA
| | - Molly Marra
- Department of Ophthalmology, Casey Eye Institute, Oregon Health & Science University, Portland, OR 97239, USA
| | - Robert K Koenekoop
- McGill Ocular Genetics Laboratory and Centre, Department of Paediatric Surgery, Human Genetics, and Ophthalmology, McGill University Health Centre, Montreal, Quebec, H4A 3S5, Canada
| | - Irma Lopez
- McGill Ocular Genetics Laboratory and Centre, Department of Paediatric Surgery, Human Genetics, and Ophthalmology, McGill University Health Centre, Montreal, Quebec, H4A 3S5, Canada
| | - Anna Matynia
- Jules Stein Eye Institute, Los Angeles, CA 90095, USA
- Ophthalmology, University of California Los Angeles David Geffen School of Medicine, Los Angeles, CA 90095, USA
| | - Michael Gorin
- Jules Stein Eye Institute, Los Angeles, CA 90095, USA
- Ophthalmology, University of California Los Angeles David Geffen School of Medicine, Los Angeles, CA 90095, USA
| | - Ruifang Sui
- Department of Ophthalmology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, 100005, China
| | - Fengxia Yao
- Medical Research Center, State Key Laboratory of Complex Severe and Rare Diseases, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, 100005, China
| | - Kerry Goetz
- Office of the Director, National Eye Institute/National Institutes of Health, Bethesda, MD 20892, USA
| | - Fernanda Belga Ottoni Porto
- INRET Clínica e Centro de Pesquisa, Belo Horizonte, Minas Gerais, 30150270, Brazil
- Department of Ophthalmology, Santa Casa de Misericórdia de Belo Horizonte, Belo Horizonte, Minas Gerais, 30150221, Brazil
- Centro Oftalmológico de Minas Gerais, Belo Horizonte, Minas Gerais, 30180070, Brazil
| | - Rui Chen
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX 77030, USA
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4
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Albakri A, Pisuchpen P, Capasso JE, Schneider A, Kopinsky S, Glaser T, Chiang JPW, Yomai AA, McNear D, Levin AV. Novel CRB1 pathogenic variant in Chuuk families with Leber congenital amaurosis. Am J Med Genet A 2023; 191:1007-1012. [PMID: 36595661 PMCID: PMC10262898 DOI: 10.1002/ajmg.a.63108] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2022] [Revised: 11/13/2022] [Accepted: 11/15/2022] [Indexed: 01/05/2023]
Abstract
The purpose of this article is to determine the cause of Leber congenital amaurosis (LCA) in Chuuk state, Federated States of Micronesia (FSM). In this prospective observational case series, five patients with early-onset vision loss were examined in Chuuk state, FSM, during an ocular genetics visit to study the elevated incidence of microphthalmia. Because of their low vision these patients were incorrectly assumed to have microphthalmia. A complete ophthalmological exam established a clinical diagnosis of LCA. Candidate gene exons were sequenced with a targeted retinal dystrophy panel. Five subjects in three related families were diagnosed with LCA. All five were from Tonoas Island, within the Chuuk Lagoon, with ages ranging from 6 months to 16 years. DNA sequencing of affected individuals revealed a homozygous CRB1 NM_201253.3:c.3134del pathogenic variant, which was heterozygous in their parents. CRB1 genotypes were confirmed by a PCR restriction assay. We report identification of a founder pathogenic variant in CRB1 responsible for autosomal recessive LCA in this isolated community. This discovery will lead to appropriate recurrence risk counseling.
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Affiliation(s)
- Amani Albakri
- Pediatric and Ocular Genetics, Wills Eye Hospital, Philadelphia, Pennsylvania, USA
- Division of Pediatric Ophthalmology, King Khaled Eye Specialist Hospital, Riyadh, Saudi Arabia
| | - Phattrawan Pisuchpen
- Pediatric and Ocular Genetics, Wills Eye Hospital, Philadelphia, Pennsylvania, USA
- Department of Ophthalmology, Faculty of Medicine, Chulalongkorn University and King Chulalongkorn Memorial Hospital, the Thai Red Cross Society, Bangkok, Thailand
| | - Jenina E. Capasso
- Pediatric and Ocular Genetics, Wills Eye Hospital, Philadelphia, Pennsylvania, USA
| | - Adele Schneider
- Pediatric and Ocular Genetics, Wills Eye Hospital, Philadelphia, Pennsylvania, USA
- Division of Genetics, Einstein Healthcare Network, Philadelphia, Pennsylvania, USA
- Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
| | - Sarina Kopinsky
- Division of Genetics, Einstein Healthcare Network, Philadelphia, Pennsylvania, USA
| | - Tom Glaser
- Department of Cell Biology & Human Anatomy, University of California, Davis, California, USA
| | | | | | - Donna McNear
- Independent Educational Consultant, Cambridge, Minnesota, USA
| | - Alex V. Levin
- Pediatric and Ocular Genetics, Wills Eye Hospital, Philadelphia, Pennsylvania, USA
- Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
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5
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Wen S, Wang M, Qian X, Li Y, Wang K, Choi J, Pennesi ME, Yang P, Marra M, Koenekoop RK, Lopez I, Matynia A, Gorin M, Sui R, Yao F, Goetz K, Porto FBO, Chen R. Systematic assessment of the contribution of structural variants to inherited retinal diseases. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.01.02.522522. [PMID: 36789417 PMCID: PMC9928032 DOI: 10.1101/2023.01.02.522522] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Despite increasing success in determining genetic diagnosis for patients with inherited retinal diseases (IRDs), mutations in about 30% of the IRD cases remain unclear or unsettled after targeted gene panel or whole exome sequencing. In this study, we aimed to investigate the contributions of structural variants (SVs) to settling the molecular diagnosis of IRD with whole-genome sequencing (WGS). A cohort of 755 IRD patients whose pathogenic mutations remain undefined was subjected to WGS. Four SV calling algorithms including include MANTA, DELLY, LUMPY, and CNVnator were used to detect SVs throughout the genome. All SVs identified by any one of these four algorithms were included for further analysis. AnnotSV was used to annotate these SVs. SVs that overlap with known IRD-associated genes were examined with sequencing coverage, junction reads, and discordant read pairs. PCR followed by Sanger sequencing was used to further confirm the SVs and identify the breakpoints. Segregation of the candidate pathogenic alleles with the disease was performed when possible. In total, sixteen candidate pathogenic SVs were identified in sixteen families, including deletions and inversions, representing 2.1% of patients with previously unsolved IRDs. Autosomal dominant, autosomal recessive, and X-linked inheritance of disease-causing SVs were observed in 12 different genes. Among these, SVs in CLN3, EYS, PRPF31 were found in multiple families. Our study suggests that the contribution of SVs detected by short-read WGS is about 0.25% of our IRD patient cohort and is significantly lower than that of single nucleotide changes and small insertions and deletions.
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6
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Duan W, Zhou T, Jiang H, Zhang M, Hu M, Zhang L. A novel nonsense variant (c.1499C>G) in CRB1 caused Leber congenital amaurosis-8 in a Chinese family and a literature review. BMC Med Genomics 2022; 15:197. [PMID: 36115989 PMCID: PMC9482190 DOI: 10.1186/s12920-022-01356-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2022] [Accepted: 09/09/2022] [Indexed: 12/04/2022] Open
Abstract
Background Leber’s congenital amaurosis (LCA) is a severe hereditary retinopathy disease that is characterized by early and severe reduction of vision, nystagmus, and sluggish or absent pupillary responses. To date, the pathogenesis of LCA remains unclear, and the majority of cases are caused by autosomal recessive inheritance. In this study, we explored the variant in the Crumbs homologue 1 (CRB1) gene in a Chinese family with LCA.
Methods We conducted comprehensive ocular examinations and collected 5 ml of blood samples from members of a Chinese family with LCA. A pathogenic variant was identified by capturing (the panel in NGS) and Sanger sequencing validation. Results A nonsense variant (c.1499C>G) in the 6th exon of CRB1 gene in a Chinese family with LCA was identified, which predicted a change in the protein p. S500*, may lead to loss of gene function. We summarized the 76 variants reported thus far in CRB1 that caused LCA8. Conclusions This study reported a novel variant c.1499C>G (p. S500*) of the CRB1 gene occurred in a Chinese family with LCA, thus expanding the spectrum of CRB1 variants causing LCA.
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7
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Krueger LA, Morris AC. Eyes on CHARGE syndrome: Roles of CHD7 in ocular development. Front Cell Dev Biol 2022; 10:994412. [PMID: 36172288 PMCID: PMC9512043 DOI: 10.3389/fcell.2022.994412] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2022] [Accepted: 08/19/2022] [Indexed: 11/13/2022] Open
Abstract
The development of the vertebrate visual system involves complex morphogenetic interactions of cells derived from multiple embryonic lineages. Disruptions in this process are associated with structural birth defects such as microphthalmia, anophthalmia, and coloboma (collectively referred to as MAC), and inherited retinal degenerative diseases such as retinitis pigmentosa and allied dystrophies. MAC and retinal degeneration are also observed in systemic congenital malformation syndromes. One important example is CHARGE syndrome, a genetic disorder characterized by coloboma, heart defects, choanal atresia, growth retardation, genital abnormalities, and ear abnormalities. Mutations in the gene encoding Chromodomain helicase DNA binding protein 7 (CHD7) cause the majority of CHARGE syndrome cases. However, the pathogenetic mechanisms that connect loss of CHD7 to the ocular complications observed in CHARGE syndrome have not been identified. In this review, we provide a general overview of ocular development and congenital disorders affecting the eye. This is followed by a comprehensive description of CHARGE syndrome, including discussion of the spectrum of ocular defects that have been described in this disorder. In addition, we discuss the current knowledge of CHD7 function and focus on its contributions to the development of ocular structures. Finally, we discuss outstanding gaps in our knowledge of the role of CHD7 in eye formation, and propose avenues of investigation to further our understanding of how CHD7 activity regulates ocular and retinal development.
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Affiliation(s)
| | - Ann C. Morris
- Department of Biology, University of Kentucky, Lexington, KY, United States
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8
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Nahar A, Cho SH. Current perspectives in Leber congenital amaurosis type 8 mouse modeling. Dev Dyn 2022; 251:1094-1106. [PMID: 35150033 DOI: 10.1002/dvdy.462] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2021] [Revised: 02/01/2022] [Accepted: 02/05/2022] [Indexed: 11/11/2022] Open
Abstract
Mutations in the CRB1 (Crumbs homolog 1) cause rare retinal diseases like retinitis pigmentosa type 12 (RP12) and Leber congenital amaurosis type 8 (LCA8). RP12 results in progressively worsening peripheral vision, whereas LCA8 causes severe visual impairment at birth or in early life. While several mouse models have been proposed for RP12, few replicate the full spectrum of human LCA8 pathology, such as disorganized retinal layering, abnormal retinal thickening, pigmentary defects, hyperreflective lesions, and severely attenuated electroretinogram responses at birth. Six models have been proposed utilizing the Cre-loxP system to delete candidate genes in specific retinal cell types and developmental stages. The model ablating Crb1 and its homolog Crb2 (using mRx-Cre) from the beginning of the eye development is the most complete as it shows blindness during the eye-opening stage, pigmentary defects in the RPE, ganglion cell layer heterotopia, disruption of retinal lamination, and acellular patches. LCA8 represents a unique type of retinal dystrophy among LCA subtypes, driven by dysfunctional retinal progenitor cells during eye development. In contrast, other LCA types and RP12 are caused by photoreceptor defects. Therefore, the most accurate LCA8-like mouse model must target both alleles of the Crb1 and Crb2 genes in the optic vesicle or earlier. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Ankur Nahar
- Thomas Jefferson University Sidney Kimmel Medical College, 1020 Locust Street, Philadelphia, PA, USA
| | - Seo-Hee Cho
- Center for Translational Medicine, Department of Medicine, Thomas Jefferson University Sidney Kimmel Medical College, 1020 Locust Street, Philadelphia, PA, USA
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9
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Nguyen XTA, Talib M, van Schooneveld MJ, Wijnholds J, van Genderen MM, Schalij-Delfos NE, Klaver CCW, Talsma HE, Fiocco M, Florijn RJ, Ten Brink JB, Cremers FPM, Meester-Smoor MA, van den Born LI, Hoyng CB, Thiadens AAHJ, Bergen AA, Boon CJF. CRB1-Associated Retinal Dystrophies: A Prospective Natural History Study in Anticipation of Future Clinical Trials. Am J Ophthalmol 2022; 234:37-48. [PMID: 34320374 DOI: 10.1016/j.ajo.2021.07.021] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Revised: 07/15/2021] [Accepted: 07/15/2021] [Indexed: 12/28/2022]
Abstract
PURPOSE To investigate the natural disease course of retinal dystrophies associated with crumbs cell polarity complex component 1 (CRB1) and identify clinical end points for future clinical trials. DESIGN Single-center, prospective case series. METHODS An investigator-initiated nationwide collaborative study that included 22 patients with CRB1-associated retinal dystrophies. Patients underwent ophthalmic assessment at baseline and 2 years after baseline. Clinical examination included best-corrected visual acuity (BCVA) using Early Treatment Diabetic Retinopathy Study charts, Goldmann kinetic perimetry (V4e isopter seeing retinal areas), microperimetry, full-field electroretinography, full-field stimulus threshold (FST), fundus photography, spectral-domain optical coherence tomography, and fundus autofluorescence imaging. RESULTS Based on genetic, clinical, and electrophysiological data, patients were diagnosed with retinitis pigmentosa (19 [86%]), cone-rod dystrophy (2 [9%]), or isolated macular dystrophy (1 [5%]). Analysis of the entire cohort at 2 years showed no significant changes in BCVA (P = .069) or V4e isopter seeing retinal areas (P = .616), although signs of clinical progression were present in individual patients. Macular sensitivity measured on microperimetry revealed a significant reduction at the 2-year follow-up (P < .001). FST responses were measurable in patients with nonrecordable electroretinograms. On average, FST responses remained stable during follow-up. CONCLUSION In CRB1-associated retinal dystrophies, visual acuity and visual field measures remain relatively stable over the course of 2 years. Microperimetry showed a significant decrease in retinal sensitivity during follow-up and may be a more sensitive progression marker. Retinal sensitivity on microperimetry may serve as a functional clinical end point in future human treatment trials for CRB1-associated retinal dystrophies.
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Affiliation(s)
- Xuan-Thanh-An Nguyen
- From the Department of Ophthalmology (X.-T.-A.N., M.T., J.W., N.E.S.-D., H.E.T., C.J.F.B.), Leiden University Medical Center, Leiden, the Netherlands
| | - Mays Talib
- From the Department of Ophthalmology (X.-T.-A.N., M.T., J.W., N.E.S.-D., H.E.T., C.J.F.B.), Leiden University Medical Center, Leiden, the Netherlands
| | - Mary J van Schooneveld
- Department of Ophthalmology (M.J.v.S., C.J.F.B.), Amsterdam University Medical Center (UMC), Academic Medical Center, Amsterdam, the Netherlands
| | - Jan Wijnholds
- From the Department of Ophthalmology (X.-T.-A.N., M.T., J.W., N.E.S.-D., H.E.T., C.J.F.B.), Leiden University Medical Center, Leiden, the Netherlands; The Netherlands Institute for Neuroscience (NIN-KNAW) (J.W., A.A.B.), Amsterdam, the Netherlands
| | - Maria M van Genderen
- Bartiméus Diagnostic Centre for Complex Visual Disorders (M.M.v.G., H.E.T.), Zeist, the Netherlands; Department of Ophthalmology (M.M.v.G.), University Medical Centre Utrecht, Utrecht, the Netherlands
| | - Nicoline E Schalij-Delfos
- From the Department of Ophthalmology (X.-T.-A.N., M.T., J.W., N.E.S.-D., H.E.T., C.J.F.B.), Leiden University Medical Center, Leiden, the Netherlands
| | - Caroline C W Klaver
- Department of Ophthalmology (C.C.W.K., M.A.M.-S., A.A.H.J.T.); Department of Epidemiology (C.C.W.K.), Erasmus University Medical Center, Rotterdam, the Netherlands; Department of Ophthalmology (C.C.W.K., C.B.H.), Radboud University Medical Center, Nijmegen, the Netherlands; Institute for Molecular and Clinical Ophthalmology (C.C.W.K.), Basel, Switzerland
| | - Herman E Talsma
- From the Department of Ophthalmology (X.-T.-A.N., M.T., J.W., N.E.S.-D., H.E.T., C.J.F.B.), Leiden University Medical Center, Leiden, the Netherlands; Bartiméus Diagnostic Centre for Complex Visual Disorders (M.M.v.G., H.E.T.), Zeist, the Netherlands
| | - Marta Fiocco
- Mathematical Institute (M.F.), and Department of Biomedical Data Sciences (M.F.), Leiden University Medical Center, Leiden, the Netherlands
| | - Ralph J Florijn
- Department of Clinical Genetics (R.J.F., J.B.t.B., A.A.B.), Amsterdam University Medical Center (UMC), Academic Medical Center, Amsterdam, the Netherlands
| | - Jacoline B Ten Brink
- Department of Clinical Genetics (R.J.F., J.B.t.B., A.A.B.), Amsterdam University Medical Center (UMC), Academic Medical Center, Amsterdam, the Netherlands
| | - Frans P M Cremers
- Department of Human Genetics and Donders Institute for Brain, Cognition and Behaviour (F.P.M.C.), Radboud University Medical Center, Nijmegen, the Netherlands
| | | | | | - Carel B Hoyng
- Department of Ophthalmology (C.C.W.K., C.B.H.), Radboud University Medical Center, Nijmegen, the Netherlands
| | | | - Arthur A Bergen
- The Netherlands Institute for Neuroscience (NIN-KNAW) (J.W., A.A.B.), Amsterdam, the Netherlands; Department of Clinical Genetics (R.J.F., J.B.t.B., A.A.B.), Amsterdam University Medical Center (UMC), Academic Medical Center, Amsterdam, the Netherlands
| | - Camiel J F Boon
- From the Department of Ophthalmology (X.-T.-A.N., M.T., J.W., N.E.S.-D., H.E.T., C.J.F.B.), Leiden University Medical Center, Leiden, the Netherlands; Department of Ophthalmology (M.J.v.S., C.J.F.B.), Amsterdam University Medical Center (UMC), Academic Medical Center, Amsterdam, the Netherlands.
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10
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In Silico Analysis of Pathogenic CRB1 Single Nucleotide Variants and Their Amenability to Base Editing as a Potential Lead for Therapeutic Intervention. Genes (Basel) 2021; 12:genes12121908. [PMID: 34946856 PMCID: PMC8700976 DOI: 10.3390/genes12121908] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2021] [Revised: 11/24/2021] [Accepted: 11/26/2021] [Indexed: 12/26/2022] Open
Abstract
Mutations in the Crumbs homolog 1 (CRB1) gene cause both autosomal recessive retinitis pigmentosa (RP) and Leber congenital amaurosis (LCA). Since three separate CRB1 isoforms are expressed at meaningful levels in the human retina, base editing shows promise as a therapeutic approach. This retrospective analysis aims to summarise the reported pathogenic CRB1 variants and investigate their amenability to treatment with currently available DNA base editors. Pathogenic single nucleotide variants (SNVs) were extracted from the Leiden open-source variation database (LOVD) and ClinVar database and coded by mutational consequence. They were then analyzed for their amenability to currently available DNA base editors and available PAM sites from a selection of different Cas proteins. Of a total of 1115 unique CRB1 variants, 69% were classified as pathogenic SNVs. Of these, 62% were amenable to currently available DNA BEs. Adenine base editors (ABEs) alone have the potential of targeting 34% of pathogenic SNVs; 19% were amenable to a CBE while GBEs could target an additional 9%. Of the pathogenic SNVs targetable with a DNA BE, 87% had a PAM site for a Cas protein. Of the 33 most frequently reported pathogenic SNVs, 70% were targetable with a base editor. The most common pathogenic variant was c.2843G>A, p.Cys948Arg, which is targetable with an ABE. Since 62% of pathogenic CRB1 SNVs are amenable to correction with a base editor and 87% of these mutations had a suitable PAM site, gene editing represents a promising therapeutic avenue for CRB1-associated retinal degenerations.
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CRB1-Related Retinal Dystrophies in a Cohort of 50 Patients: A Reappraisal in the Light of Specific Müller Cell and Photoreceptor CRB1 Isoforms. Int J Mol Sci 2021; 22:ijms222312642. [PMID: 34884448 PMCID: PMC8657784 DOI: 10.3390/ijms222312642] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Revised: 11/15/2021] [Accepted: 11/18/2021] [Indexed: 01/29/2023] Open
Abstract
Pathogenic variants in CRB1 lead to diverse recessive retinal disorders from severe Leber congenital amaurosis to isolated macular dystrophy. Until recently, no clear phenotype-genotype correlation and no appropriate mouse models existed. Herein, we reappraise the phenotype-genotype correlation of 50 patients with regards to the recently identified CRB1 isoforms: a canonical long isoform A localized in Müller cells (12 exons) and a short isoform B predominant in photoreceptors (7 exons). Twenty-eight patients with early onset retinal dystrophy (EORD) consistently had a severe Müller impairment, with variable impact on the photoreceptors, regardless of isoform B expression. Among them, two patients expressing wild type isoform B carried one variant in exon 12, which specifically damaged intracellular protein interactions in Müller cells. Thirteen retinitis pigmentosa patients had mainly missense variants in laminin G-like domains and expressed at least 50% of isoform A. Eight patients with the c.498_506del variant had macular dystrophy. In one family homozygous for the c.1562C>T variant, the brother had EORD and the sister macular dystrophy. In contrast with the mouse model, these data highlight the key role of Müller cells in the severity of CRB1-related dystrophies in humans, which should be taken into consideration for future clinical trials.
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Cheng Z, Hagan R, Yeo DCM. Identification of a novel CRB1 variant in a compound heterozygous state in a patient with CRB1-associated maculopathy and foveal retinoschisis. Ophthalmic Genet 2021; 43:253-257. [PMID: 34783605 DOI: 10.1080/13816810.2021.1998551] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
PURPOSE To report a novel CRB1 variant responsible for autosomal recessive foveal retinoschisis and its associated clinical and electrophysiological data. METHODS A case report. RESULTS A 15-year-old boy has foveal retinoschisis similar to those seen in X-linked retinoschisis (XLRS). During follow-up, we observed the co-existence of foveoschitic changes and parafoveal macular atrophy. Molecular genetic testing identified compound heterozygous variants in the CRB1 gene, including a novel variant, c.3878 G > A, predicted to disrupt the normal translation of CRB1 and a previously reported likely pathogenic mutation, c.498_506del. Full-field electroretinograms (ERG) were normal but multifocal ERG showed focal reduced waveform amplitude corresponding to the area of atrophy. CONCLUSIONS A novel missense variant existing in a compound heterozygous state was identified. Biallelic CRB1 mutations can cause anatomical fovea disruption similar to XLRS but have very different electroretinogram findings. This case report enhances our understanding of the spectrum of biallelic CRB1 mutations.
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Affiliation(s)
- Zhihang Cheng
- Alder Hey Children's Nhs Foundation Trust, Department of Ophthalmology, Alder Hey Children's Hospital, Liverpool, United Kingdom of Great Britain and Northern Ireland
| | - Richard Hagan
- Alder Hey Children's Nhs Foundation Trust, Department of Ophthalmology, Alder Hey Children's Hospital, Liverpool, United Kingdom of Great Britain and Northern Ireland.,Clinical Engineering Department, Royal Liverpool University Hospital, Liverpool, United Kingdom of Great Britain and Northern Ireland
| | - Damien C M Yeo
- Alder Hey Children's Nhs Foundation Trust, Department of Ophthalmology, Alder Hey Children's Hospital, Liverpool, United Kingdom of Great Britain and Northern Ireland
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Amato A, Arrigo A, Aragona E, Manitto MP, Saladino A, Bandello F, Battaglia Parodi M. Gene Therapy in Inherited Retinal Diseases: An Update on Current State of the Art. Front Med (Lausanne) 2021; 8:750586. [PMID: 34722588 PMCID: PMC8553993 DOI: 10.3389/fmed.2021.750586] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Accepted: 09/20/2021] [Indexed: 12/11/2022] Open
Abstract
Background: Gene therapy cannot be yet considered a far perspective, but a tangible therapeutic option in the field of retinal diseases. Although still confined in experimental settings, the preliminary results are promising and provide an overall scenario suggesting that we are not so far from the application of gene therapy in clinical settings. The main aim of this review is to provide a complete and updated overview of the current state of the art and of the future perspectives of gene therapy applied on retinal diseases. Methods: We carefully revised the entire literature to report all the relevant findings related to the experimental procedures and the future scenarios of gene therapy applied in retinal diseases. A clinical background and a detailed description of the genetic features of each retinal disease included are also reported. Results: The current literature strongly support the hope of gene therapy options developed for retinal diseases. Although being considered in advanced stages of investigation for some retinal diseases, such as choroideremia (CHM), retinitis pigmentosa (RP), and Leber's congenital amaurosis (LCA), gene therapy is still quite far from a tangible application in clinical practice for other retinal diseases. Conclusions: Gene therapy is an extremely promising therapeutic tool for retinal diseases. The experimental data reported in this review offer a strong hope that gene therapy will be effectively available in clinical practice in the next years.
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Affiliation(s)
- Alessia Amato
- Department of Ophthalmology, Scientific Institute San Raffaele Hospital, Milan, Italy
| | - Alessandro Arrigo
- Department of Ophthalmology, Scientific Institute San Raffaele Hospital, Milan, Italy
| | - Emanuela Aragona
- Department of Ophthalmology, Scientific Institute San Raffaele Hospital, Milan, Italy
| | - Maria Pia Manitto
- Department of Ophthalmology, Scientific Institute San Raffaele Hospital, Milan, Italy
| | - Andrea Saladino
- Department of Ophthalmology, Scientific Institute San Raffaele Hospital, Milan, Italy
| | - Francesco Bandello
- Department of Ophthalmology, Scientific Institute San Raffaele Hospital, Milan, Italy
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Huang CH, Yang CM, Yang CH, Hou YC, Chen TC. Leber's Congenital Amaurosis: Current Concepts of Genotype-Phenotype Correlations. Genes (Basel) 2021; 12:genes12081261. [PMID: 34440435 PMCID: PMC8392113 DOI: 10.3390/genes12081261] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Revised: 08/15/2021] [Accepted: 08/18/2021] [Indexed: 12/26/2022] Open
Abstract
Leber’s congenital amaurosis (LCA), one of the most severe inherited retinal dystrophies, is typically associated with extremely early onset of visual loss, nystagmus, and amaurotic pupils, and is responsible for 20% of childhood blindness. With advances in molecular diagnostic technology, the knowledge about the genetic background of LCA has expanded widely, while disease-causing variants have been identified in 38 genes. Different pathogenetic mechanisms have been found among these varieties of genetic mutations, all of which result in the dysfunction or absence of their encoded proteins participating in the visual cycle. Hence, the clinical phenotypes also exhibit extensive heterogenicity, including the course of visual impairment, involvement of the macular area, alteration in retinal structure, and residual function of the diseased photoreceptor. By reviewing the clinical course, fundoscopic images, optical coherent tomography examination, and electroretinogram, genotype-phenotype correlations could be established for common genetic mutations in LCA, which would benefit the timing of the diagnosis and thus promote early intervention. Gene therapy is promising in the management of LCA, while several clinical trials are ongoing and preliminary success has been announced, focusing on RPE65 and other common disease-causing genes. This review provides an update on the genetics, clinical examination findings, and genotype-phenotype correlations in the most well-established causative genetic mutations of LCA.
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Affiliation(s)
- Chu-Hsuan Huang
- Department of Ophthalmology, Cathay General Hospital, Taipei 106, Taiwan; (C.-H.H.); (Y.-C.H.)
| | - Chung-May Yang
- Department of Ophthalmology, National Taiwan University Hospital, Taipei 100, Taiwan; (C.-M.Y.); (C.-H.Y.)
- Department of Ophthalmology, College of Medicine, National Taiwan University, Taipei 100, Taiwan
| | - Chang-Hao Yang
- Department of Ophthalmology, National Taiwan University Hospital, Taipei 100, Taiwan; (C.-M.Y.); (C.-H.Y.)
- Department of Ophthalmology, College of Medicine, National Taiwan University, Taipei 100, Taiwan
| | - Yu-Chih Hou
- Department of Ophthalmology, Cathay General Hospital, Taipei 106, Taiwan; (C.-H.H.); (Y.-C.H.)
| | - Ta-Ching Chen
- Department of Ophthalmology, National Taiwan University Hospital, Taipei 100, Taiwan; (C.-M.Y.); (C.-H.Y.)
- Correspondence: ; Tel.: +886-2-23123456
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García Bohórquez B, Aller E, Rodríguez Muñoz A, Jaijo T, García García G, Millán JM. Updating the Genetic Landscape of Inherited Retinal Dystrophies. Front Cell Dev Biol 2021; 9:645600. [PMID: 34327195 PMCID: PMC8315279 DOI: 10.3389/fcell.2021.645600] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Accepted: 04/30/2021] [Indexed: 12/24/2022] Open
Abstract
Inherited retinal dystrophies (IRD) are a group of diseases characterized by the loss or dysfunction of photoreceptors and a high genetic and clinical heterogeneity. Currently, over 270 genes have been associated with IRD which makes genetic diagnosis very difficult. The recent advent of next generation sequencing has greatly facilitated the diagnostic process, enabling to provide the patients with accurate genetic counseling in some cases. We studied 92 patients who were clinically diagnosed with IRD with two different custom panels. In total, we resolved 53 patients (57.6%); in 12 patients (13%), we found only one mutation in a gene with a known autosomal recessive pattern of inheritance; and 27 patients (29.3%) remained unsolved. We identified 120 pathogenic or likely pathogenic variants; 30 of them were novel. Among the cone-rod dystrophy patients, ABCA4 was the most common mutated gene, meanwhile, USH2A was the most prevalent among the retinitis pigmentosa patients. Interestingly, 10 families carried pathogenic variants in more than one IRD gene, and we identified two deep-intronic variants previously described as pathogenic in ABCA4 and CEP290. In conclusion, the IRD study through custom panel sequencing demonstrates its efficacy for genetic diagnosis, as well as the importance of including deep-intronic regions in their design. This genetic diagnosis will allow patients to make accurate reproductive decisions, enroll in gene-based clinical trials, and benefit from future gene-based treatments.
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Affiliation(s)
- Belén García Bohórquez
- Molecular, Cellular and Genomics Biomedicine, Health Research Institute La Fe, Valencia, Spain
- CIBER of Rare Diseases, Madrid, Spain
| | - Elena Aller
- Molecular, Cellular and Genomics Biomedicine, Health Research Institute La Fe, Valencia, Spain
- CIBER of Rare Diseases, Madrid, Spain
- Unit of Genetics, University Hospital La Fe, Valencia, Spain
| | - Ana Rodríguez Muñoz
- Molecular, Cellular and Genomics Biomedicine, Health Research Institute La Fe, Valencia, Spain
- CIBER of Rare Diseases, Madrid, Spain
| | - Teresa Jaijo
- Molecular, Cellular and Genomics Biomedicine, Health Research Institute La Fe, Valencia, Spain
- CIBER of Rare Diseases, Madrid, Spain
- Unit of Genetics, University Hospital La Fe, Valencia, Spain
| | - Gema García García
- Molecular, Cellular and Genomics Biomedicine, Health Research Institute La Fe, Valencia, Spain
- CIBER of Rare Diseases, Madrid, Spain
| | - José M. Millán
- Molecular, Cellular and Genomics Biomedicine, Health Research Institute La Fe, Valencia, Spain
- CIBER of Rare Diseases, Madrid, Spain
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Talib M, Schooneveld MJ, Wijnholds J, Genderen MM, Schalij‐Delfos NE, Talsma HE, Florijn RJ, Brink JB, Cremers FP, Thiadens AA, Born LI, Hoyng CB, Meester‐Smoor MA, Bergen AA, Boon CJ. Defining inclusion criteria and endpoints for clinical trials: a prospective cross-sectional study in CRB1-associated retinal dystrophies. Acta Ophthalmol 2021; 99:e402-e414. [PMID: 33528094 PMCID: PMC8248330 DOI: 10.1111/aos.14597] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2019] [Revised: 07/20/2020] [Accepted: 07/21/2020] [Indexed: 11/29/2022]
Abstract
Purpose To investigate the retinal structure and function in patients with CRB1‐associated retinal dystrophies (RD) and to explore potential clinical endpoints. Methods In this prospective cross‐sectional study, 22 patients with genetically confirmed CRB1‐RD (aged 6–74 years), and who had a decimal best‐corrected visual acuity (BCVA) ≥ 0.05 at the last visit, were studied clinically with ETDRS BCVA, corneal topography, spectral‐domain optical coherence tomography (SD‐OCT), fundus autofluorescence, Goldmann visual field (VF), microperimetry, full‐field electroretinography (ERG) and full‐field stimulus testing (FST). Ten patients were from a genetic isolate (GI). Results Patients had retinitis pigmentosa (n = 19; GI and non‐GI), cone‐rod dystrophy (n = 2; GI) or macular dystrophy (n = 1; non‐GI). Median age at first symptom onset was 3 years (range 0.8–49). Median decimal BCVA in the better and worse‐seeing eye was 0.18 (range 0.05–0.83) and 0.08 (range light perception‐0.72), respectively. Spectral‐domain optical coherence tomography (SD‐OCT) showed cystoid maculopathy in 8 subjects; inner retinal thickening (n = 20), a well‐preserved (para)foveal outer retina (n = 7) or severe (para)foveal outer retinal atrophy (n = 14). All retinal layers were discernible in 13/21 patients (62%), with mild to moderate laminar disorganization in the others. Nanophthalmos was observed in 8 patients (36%). Full‐field stimulus testing (FST) provided a subjective outcome measure for retinal sensitivity in eyes with (nearly) extinguished ERG amplitudes. Conclusions Despite the generally severe course of CRB1‐RDs, symptom onset and central visual function are variable, even at advanced ages. Phenotypes may vary within the same family. Imaging and functional studies in a prospective longitudinal setting should clarify which endpoints may be most appropriate in a clinical trial.
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Affiliation(s)
- Mays Talib
- Department of Ophthalmology Leiden University Medical Center Leiden The Netherlands
| | - Mary J. Schooneveld
- Department of Ophthalmology Amsterdam UMC University of Amsterdam Amsterdam The Netherlands
- Bartiméus Diagnostic Centre for complex visual disorders Zeist The Netherlands
| | - Jan Wijnholds
- Department of Ophthalmology Leiden University Medical Center Leiden The Netherlands
| | - Maria M. Genderen
- Bartiméus Diagnostic Centre for complex visual disorders Zeist The Netherlands
| | | | - Herman E. Talsma
- Department of Ophthalmology Leiden University Medical Center Leiden The Netherlands
- Bartiméus Diagnostic Centre for complex visual disorders Zeist The Netherlands
| | - Ralph J. Florijn
- Department of Clinical Genetics Amsterdam UMC University of Amsterdam Amsterdam The Netherlands
| | - Jacoline B. Brink
- Department of Clinical Genetics Amsterdam UMC University of Amsterdam Amsterdam The Netherlands
| | - Frans P.M. Cremers
- Department of Human Genetics and Donders Institute for Brain Cognition and Behaviour Radboud University Medical Center Nijmegen The Netherlands
| | | | | | - Carel B. Hoyng
- Department of Ophthalmology Radboud University Medical Center Nijmegen The Netherlands
| | | | - Arthur A. Bergen
- Department of Clinical Genetics Amsterdam UMC University of Amsterdam Amsterdam The Netherlands
- The Netherlands Institute for Neuroscience (NIN‐KNAW) Amsterdam The Netherlands
| | - Camiel J.F. Boon
- Department of Ophthalmology Leiden University Medical Center Leiden The Netherlands
- Department of Ophthalmology Amsterdam UMC University of Amsterdam Amsterdam The Netherlands
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Burger CA, Jiang D, Mackin RD, Samuel MA. Development and maintenance of vision's first synapse. Dev Biol 2021; 476:218-239. [PMID: 33848537 DOI: 10.1016/j.ydbio.2021.04.001] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2021] [Revised: 04/02/2021] [Accepted: 04/03/2021] [Indexed: 12/21/2022]
Abstract
Synapses in the outer retina are the first information relay points in vision. Here, photoreceptors form synapses onto two types of interneurons, bipolar cells and horizontal cells. Because outer retina synapses are particularly large and highly ordered, they have been a useful system for the discovery of mechanisms underlying synapse specificity and maintenance. Understanding these processes is critical to efforts aimed at restoring visual function through repairing or replacing neurons and promoting their connectivity. We review outer retina neuron synapse architecture, neural migration modes, and the cellular and molecular pathways that play key roles in the development and maintenance of these connections. We further discuss how these mechanisms may impact connectivity in the retina.
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Affiliation(s)
- Courtney A Burger
- Huffington Center on Aging, Department of Neuroscience, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Danye Jiang
- Huffington Center on Aging, Department of Neuroscience, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Robert D Mackin
- Huffington Center on Aging, Department of Neuroscience, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Melanie A Samuel
- Huffington Center on Aging, Department of Neuroscience, Baylor College of Medicine, Houston, TX, 77030, USA.
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Wang Y, Sun W, Xiao X, Li S, Jia X, Wang P, Zhang Q. Clinical and Genetic Analysis of 63 Families Demonstrating Early and Advanced Characteristic Fundus as the Signature of CRB1 Mutations. Am J Ophthalmol 2021; 223:160-168. [PMID: 33342761 DOI: 10.1016/j.ajo.2020.10.006] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2020] [Revised: 09/17/2020] [Accepted: 10/12/2020] [Indexed: 11/28/2022]
Abstract
PURPOSE To reveal the characteristics of ocular changes in patients with biallelic CRB1 mutations. DESIGN Comparative exome sequencing and retrospective case series on clinical data. METHODS Seventy-four patients from 63 families with biallelic potential pathogenic variants in CRB1 were selected from our in-house exome sequencing. The clinical data were reviewed and evaluated in detail, including best-corrected visual acuity, fundus photography, optical coherence tomography (OCT), and electroretinogram (ERG). RESULTS Biallelic CRB1 variants, involving 45 variants including 23 novel, were identified in 40 novel families based on exome sequencing. Analyzing clinical data of the 74 individuals from 63 families revealed the following CRB1-associated phenotypes: (1) early-onset reduced visual acuity with congenital nystagmus; (2) 2 types of characteristic retinal changes including yellowish geographic macular degeneration (YMD) or nummular pigment deposits (NPD) at posterior retina with bone-spicule pigmentation at midperipheral retina; (3) undetectable rod and cone responses on ERG; (4) cystoid macular edema or macular atrophy on OCT. YMD and NPD are unique and CRB1-associated. Long-term follow-up examination as well as age- and variant-dependent phenotypic analysis suggested YMD is the early fundus change that would gradually progress to NPD. CONCLUSIONS YMD and NPD are 2 major characteristic CRB1-associated fundus changes and the former one will advance to the latter with age. Recognizing such characteristic signs associated with biallelic CRB1 variants may be of value in areas without widespread access to genetic testing where a more targeted approach is needed and might be biomarkers for evaluation of effects for future intervention.
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Affiliation(s)
- Yingwei Wang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Wenmin Sun
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Xueshan Xiao
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Shiqiang Li
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Xiaoyun Jia
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Panfeng Wang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Qingjiong Zhang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China.
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Talib M, Van Cauwenbergh C, De Zaeytijd J, Van Wynsberghe D, De Baere E, Boon CJF, Leroy BP. CRB1-associated retinal dystrophies in a Belgian cohort: genetic characteristics and long-term clinical follow-up. Br J Ophthalmol 2021; 106:696-704. [PMID: 33579689 DOI: 10.1136/bjophthalmol-2020-316781] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Revised: 11/19/2020] [Accepted: 12/05/2020] [Indexed: 11/04/2022]
Abstract
AIM To investigate the natural history in a Belgian cohort of CRB1-associated retinal dystrophies. METHODS An in-depth retrospective study focusing on visual function and retinal structure. RESULTS Forty patients from 35 families were included (ages: 2.5-80.1 years). In patients with a follow-up of >1 year (63%), the mean follow-up time was 12.0 years (range: 2.3-29.2 years). Based on the patient history, symptoms and/or electroretinography, 22 patients (55%) were diagnosed with retinitis pigmentosa (RP), 15 (38%) with Leber congenital amaurosis (LCA) and 3 (8%) with macular dystrophy (MD), the latter being associated with the p.(Ile167_Gly169del) mutation (in compound heterozygosity). MD later developed into a rod-cone dystrophy in one patient. Blindness at initial presentation was seen in the first decade of life in LCA, and in the fifth decade of life in RP. Eventually, 28 patients (70%) reached visual acuity-based blindness (<0.05). Visual field-based blindness (<10°) was documented in 17/25 patients (68%). Five patients (13%) developed Coats-like exudative vasculopathy. Intermediate/posterior uveitis was found in three patients (8%). Cystoid maculopathy was common in RP (9/21; 43%) and MD (3/3; 100%). Macular involvement, varying from retinal pigment epithelium alterations to complete outer retinal atrophy, was observed in all patients. CONCLUSION Bi-allelic CRB1 mutations result in a range of progressive retinal disorders, most of which are generalised, with characteristically early macular involvement. Visual function and retinal structure analysis indicates a window for potential intervention with gene therapy before the fourth decade of life in RP and the first decade in LCA.
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Affiliation(s)
- Mays Talib
- Department of Ophthalmology, Leiden University Medical Center, Leiden, The Netherlands
| | - Caroline Van Cauwenbergh
- Department of Ophthalmology, Ghent University and Ghent University Hospital, Ghent, Belgium.,Center for Medical Genetics, Ghent University and Ghent University Hospital, Ghent, Belgium
| | - Julie De Zaeytijd
- Department of Ophthalmology, Ghent University and Ghent University Hospital, Ghent, Belgium
| | | | - Elfride De Baere
- Center for Medical Genetics, Ghent University and Ghent University Hospital, Ghent, Belgium
| | - Camiel J F Boon
- Department of Ophthalmology, Leiden University Medical Center, Leiden, The Netherlands.,Department of Ophthalmology, Amsterdam UMC, Academic Medical Center, University of Amsterdam, Amsterdam, Netherlands
| | - Bart Peter Leroy
- Department of Ophthalmology, Ghent University and Ghent University Hospital, Ghent, Belgium.,Center for Medical Genetics, Ghent University and Ghent University Hospital, Ghent, Belgium.,Division of Ophthalmology, The Children's Hospital of Philadelphia, Philadelphia, PA, USA.,Centre for Cellular & Molecular Therapeutics, The Children's Hospital of Philadelphia, Philadelphia, PA, USA
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CRB1 maculopathy presenting as fenestrated sheen macular dystrophy with 15-year follow-up. Doc Ophthalmol 2021; 142:381-388. [PMID: 33387055 DOI: 10.1007/s10633-020-09810-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Accepted: 11/25/2020] [Indexed: 10/22/2022]
Abstract
INTRODUCTION We present two patients, the proband and the affected sibling, with biallelic CRB1 mutations leading to a macular dystrophy. CASE PRESENTATION We present two patients, the proband and the affected sibling, with biallelic CRB1 mutations leading to a macular dystrophy. With 15 years of follow-up for the proband, we illustrate the natural history of CRB1 maculopathy based on clinical examination, multimodal imaging, and electrophysiology. In addition, we demonstrate the wide phenotypic spectrum of the condition with the affected sister harboring the same variants but with much milder phenotypic manifestations. CONCLUSION In addition to a previously described pathogenic variant, Ile167_Gly169del, one pathogenic missense variant in CRB1, Lys801Ter, not previously associated with macular dystrophy, is reported here. While CRB1 mutations have been more commonly described in retinitis pigmentosa (RP) and Leber congenital amaurosis (LCA), we demonstrate that mutations in CRB1 can cause a maculopathy with initial features similar to fenestrated sheen macular dystrophy (FSMD) that later evolves into severe macular atrophy.
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21
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Oh DJ, Sheth V, Fishman GA, Grassi MA. Simplex Crumbs Homologue 1 Maculopathy Masquerading as Juvenile X-Linked Retinoschisis in Male Patients. JOURNAL OF VITREORETINAL DISEASES 2020; 4:437-440. [PMID: 33029571 PMCID: PMC7537420 DOI: 10.1177/2474126420916079] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Purpose: We demonstrate that Crumbs homologue 1 ( CRB1) maculopathy should be considered in the differential of petaloid pigmentary changes in the macula of young children with good vision who may be asymptomatic. Methods: We report on 2 unrelated male patients presenting at a young age with decreased vision from a macular dystrophy due to biallelic CRB1 mutations. Results: In addition to a previously described pathogenic variant, Ile167Gly169del, 2 new pathogenic missense variants in CRB1, Thr745Met and Cys948Tyr, are reported here. Conclusions: Although CRB1 mutations have been more commonly described in retinitis pigmentosa and Leber congenital amaurosis, we demonstrate that mutations in CRB1 can cause a maculopathy in which initial features can resemble juvenile X-linked retinoschisis. We show that the accompanying macular edema is responsive to carbonic anhydrase inhibitors. With long-term follow-up for each case, we illustrate the natural history of CRB1 maculopathy based on clinical examination and diagnostic imaging.
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Affiliation(s)
- Daniel J. Oh
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, Chicago, IL, USA
| | | | - Gerald A. Fishman
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, Chicago, IL, USA
- The Chicago Lighthouse, Chicago, IL, USA
| | - Michael A. Grassi
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, Chicago, IL, USA
- Grassi Retina, Naperville, IL, USA
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22
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Grudzinska Pechhacker MK, Di Scipio M, Vig A, Tumber A, Roslin N, Tavares E, Vincent A, Hèon E. CRB1-related retinopathy overlapping the ocular phenotype of S-adenosylhomocysteine hydrolase deficiency. Ophthalmic Genet 2020; 41:457-464. [PMID: 32689861 DOI: 10.1080/13816810.2020.1790013] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
BACKGROUND S-adenosylhomocysteine hydrolase deficiency due to pathologic variants in AHCY gene is a rare neurometabolic disease for which no eye phenotype has been documented. Pathologic variants in CRB1 gene are known to cause a wide spectrum of autosomal recessive retinal diseases with Leber's congenital amaurosis as a most common. The aim of this study is to report co-inheritance of neurometabolic disease and eye disease in a pedigree. MATERIALS AND METHODS Comprehensive eye examination was performed in available family members together with color vision test, visual fields, fundus images, OCT, electroretinogram and visual evoked potentials. Genetic testing included whole-exome sequencing (WES), retinal dystrophy gene panel and segregation analysis. RESULTS Two children from a family not known to be consanguineous were affected with neurometabolic disease and one of them presented with reduced vision due to maculopathy. The mother had symptoms of retinal degeneration of unspecified cause. Clinical WES revealed homozygous missense pathologic variants in AHCY gene c.148G>A, p.(Ala50Thr) as a cause of S-adenosylhomocysteine hydrolase deficiency. Retinal dystrophy gene panel sequencing revealed two heterozygous missense pathologic variants in CRB1 gene c.1831T>C, p.(Ser611Pro) and c.3955T>C, p.(Phe1319Leu) in the proband and her mother. These variants segregated with disease phenotype in family members. CONCLUSIONS Establishing an ocular genetic diagnosis may be challenging with the co-existence of a rare systemic genetic disease with previously unknown eye involvement. Extensive phenotyping and genotyping of available family members showed that the proband and her mother shared a CRB1-related retinopathy at different stages while the brother did not.
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Affiliation(s)
- Monika K Grudzinska Pechhacker
- Department of Ophthalmology and Vision Sciences, The Hospital for Sick Children , Toronto, Canada.,Department of Ophthalmology and Vision Sciences, University of Toronto , Toronto, Canada
| | - Matteo Di Scipio
- Genetics and Genome Biology, The Hospital for Sick Children , Toronto, Canada
| | - Anjali Vig
- Genetics and Genome Biology, The Hospital for Sick Children , Toronto, Canada
| | - Anupreet Tumber
- Department of Ophthalmology and Vision Sciences, The Hospital for Sick Children , Toronto, Canada
| | - Nicole Roslin
- Genetics and Genome Biology, The Hospital for Sick Children , Toronto, Canada
| | - Erika Tavares
- Genetics and Genome Biology, The Hospital for Sick Children , Toronto, Canada
| | - Ajoy Vincent
- Department of Ophthalmology and Vision Sciences, The Hospital for Sick Children , Toronto, Canada.,Department of Ophthalmology and Vision Sciences, University of Toronto , Toronto, Canada.,Genetics and Genome Biology, The Hospital for Sick Children , Toronto, Canada
| | - Elise Hèon
- Department of Ophthalmology and Vision Sciences, The Hospital for Sick Children , Toronto, Canada.,Department of Ophthalmology and Vision Sciences, University of Toronto , Toronto, Canada.,Genetics and Genome Biology, The Hospital for Sick Children , Toronto, Canada
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23
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Talib M, Boon CJF. Retinal Dystrophies and the Road to Treatment: Clinical Requirements and Considerations. Asia Pac J Ophthalmol (Phila) 2020; 9:159-179. [PMID: 32511120 PMCID: PMC7299224 DOI: 10.1097/apo.0000000000000290] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Accepted: 04/01/2020] [Indexed: 12/15/2022] Open
Abstract
: Retinal dystrophies (RDs) comprise relatively rare but devastating causes of progressive vision loss. They represent a spectrum of diseases with marked genetic and clinical heterogeneity. Mutations in the same gene may lead to different diagnoses, for example, retinitis pigmentosa or cone dystrophy. Conversely, mutations in different genes may lead to the same phenotype. The age at symptom onset, and the rate and characteristics of peripheral and central vision decline, may vary widely per disease group and even within families. For most RD cases, no effective treatment is currently available. However, preclinical studies and phase I/II/III gene therapy trials are ongoing for several RD subtypes, and recently the first retinal gene therapy has been approved by the US Food and Drug Administration for RPE65-associated RDs: voretigene neparvovec-rzyl (Luxturna). With the rapid advances in gene therapy studies, insight into the phenotypic spectrum and long-term disease course is crucial information for several RD types. The vast clinical heterogeneity presents another important challenge in the evaluation of potential efficacy in future treatment trials, and in establishing treatment candidacy criteria. This perspective describes these challenges, providing detailed clinical descriptions of several forms of RD that are caused by genes of interest for ongoing and future gene or cell-based therapy trials. Several ongoing and future treatment options will be described.
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Affiliation(s)
- Mays Talib
- Department of Ophthalmology, Leiden, The Netherlands
| | - Camiel J F Boon
- Department of Ophthalmology, Leiden, The Netherlands
- Department of Ophthalmology, Amsterdam UMC, Academic Medical Center, University of Amsterdam. Amsterdam, The Netherlands
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24
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Paolacci S, Iarossi G, Gusson E, Maltese PE, Dallavilla T, Fanelli F, Zulian A, Cerra D, Unfer V, Marchini G, Bertelli M. CRB1-Related Cystic Maculopathy in Twins Conceived Through Heterologous Fertilization With Variant-Carrying Oocytes. J Pediatr Ophthalmol Strabismus 2020; 57:e19-e24. [PMID: 32176805 DOI: 10.3928/01913913-20200204-02] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/16/2019] [Accepted: 12/16/2019] [Indexed: 11/20/2022]
Abstract
Cystic maculopathy has been associated with genetic disorders such as retinitis pigmentosa, X-linked retinoschisis, cone dystrophy, and foveal retinoschisis. Familial foveal retinoschisis was recently described as a rare disease caused by CRB1 variants. The authors report the phenotype-genotype pattern of a pair of dizygotic twins with early-onset cystic maculopathy due to CRB1 pathogenic variants. The twins were conceived by heterologous fertilization with variant-carrying oocytes. The probands were monitored for a period of 4 years. Next generation sequencing of a panel of genes responsible for retinal dystrophies was performed. Both children carried three pathogenic variants in CRB1: a novel heterozygous truncating variant p.(Val855*) inherited from the father and two known heterozygous missense variants, p.[(Phe144Val; Thr745Met)], inherited from the oocyte donor. The findings confirm that CRB1 variants can be responsible for foveal retinoschisis with variable clinical expressivity ranging from schitic macular alteration to early-onset forms of cystic maculopathy. The authors highlight the importance of exome analysis of gamete donors to assess the likelihood of recessively inherited disorders by means of a prediction algorithm able to combine parent and donor exome data. [J Pediatr Ophthalmol Strabismus. 2020;57:e19-e24.].
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25
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Rodríguez-Muñoz A, Aller E, Jaijo T, González-García E, Cabrera-Peset A, Gallego-Pinazo R, Udaondo P, Salom D, García-García G, Millán JM. Expanding the Clinical and Molecular Heterogeneity of Nonsyndromic Inherited Retinal Dystrophies. J Mol Diagn 2020; 22:532-543. [PMID: 32036094 DOI: 10.1016/j.jmoldx.2020.01.003] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2019] [Revised: 11/01/2019] [Accepted: 01/12/2020] [Indexed: 12/21/2022] Open
Abstract
A cohort of 172 patients diagnosed clinically with nonsyndromic retinal dystrophies, from 110 families underwent full ophthalmologic examination, including retinal imaging, electrophysiology, and optical coherence tomography, when feasible. Molecular analysis was performed using targeted next-generation sequencing (NGS). Variants were filtered and prioritized according to the minimum allele frequency, and finally classified according to the American College of Medical Genetics and Genomics guidelines. Multiplex ligation-dependent probe amplification and array comparative genomic hybridization were performed to validate copy number variations identified by NGS. The diagnostic yield of this study was 62% of studied families. Thirty novel mutations were identified. The study found phenotypic intra- and interfamilial variability in families with mutations in C1QTNF5, CERKL, and PROM1; biallelic mutations in PDE6B in a unilateral retinitis pigmentosa patient; interocular asymmetry RP in 50% of the symptomatic RPGR-mutated females; the first case with possible digenism between CNGA1 and CNGB1; and a ROM1 duplication in two unrelated retinitis pigmentosa families. Ten unrelated cases were reclassified. This study highlights the clinical utility of targeted NGS for nonsyndromic inherited retinal dystrophy cases and the importance of full ophthalmologic examination, which allows new genotype-phenotype associations and expands the knowledge of this group of disorders. Identifying the cause of disease is essential to improve patient management, provide accurate genetic counseling, and take advantage of gene therapy-based treatments.
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Affiliation(s)
- Ana Rodríguez-Muñoz
- Molecular, Cellular and Genomics Biomedicine Research Group, Instituto de Investigación Sanitaria La Fe, Valencia, Spain; Unidad Mixta de Enfermedades raras IIS La Fe-Centro de Investigación Príncipe Felipe, Valencia, Spain; Biomedical Research Network for Rare Diseases, Hospital Universitario y Politécnico La Fe, Valencia, Spain
| | - Elena Aller
- Molecular, Cellular and Genomics Biomedicine Research Group, Instituto de Investigación Sanitaria La Fe, Valencia, Spain; Unidad Mixta de Enfermedades raras IIS La Fe-Centro de Investigación Príncipe Felipe, Valencia, Spain; Biomedical Research Network for Rare Diseases, Hospital Universitario y Politécnico La Fe, Valencia, Spain; Genetics Unit, Hospital Universitario y Politécnico La Fe, Valencia, Spain
| | - Teresa Jaijo
- Molecular, Cellular and Genomics Biomedicine Research Group, Instituto de Investigación Sanitaria La Fe, Valencia, Spain; Unidad Mixta de Enfermedades raras IIS La Fe-Centro de Investigación Príncipe Felipe, Valencia, Spain; Biomedical Research Network for Rare Diseases, Hospital Universitario y Politécnico La Fe, Valencia, Spain; Genetics Unit, Hospital Universitario y Politécnico La Fe, Valencia, Spain
| | - Emilio González-García
- Molecular, Cellular and Genomics Biomedicine Research Group, Instituto de Investigación Sanitaria La Fe, Valencia, Spain; Departments of Neurophysiology, Hospital de Manises, Valencia, Spain
| | | | - Roberto Gallego-Pinazo
- Molecular, Cellular and Genomics Biomedicine Research Group, Instituto de Investigación Sanitaria La Fe, Valencia, Spain; Macula Unit, Oftalvist Clinic, Valencia, Spain
| | - Patricia Udaondo
- Ophthalmology, Hospital Universitario y Politécnico La Fe, Valencia, Spain
| | - David Salom
- Molecular, Cellular and Genomics Biomedicine Research Group, Instituto de Investigación Sanitaria La Fe, Valencia, Spain; Biomedical Research Network for Rare Diseases, Hospital Universitario y Politécnico La Fe, Valencia, Spain; Departments of Ophthalmology, Hospital de Manises, Valencia, Spain
| | - Gema García-García
- Molecular, Cellular and Genomics Biomedicine Research Group, Instituto de Investigación Sanitaria La Fe, Valencia, Spain; Unidad Mixta de Enfermedades raras IIS La Fe-Centro de Investigación Príncipe Felipe, Valencia, Spain; Biomedical Research Network for Rare Diseases, Hospital Universitario y Politécnico La Fe, Valencia, Spain.
| | - José M Millán
- Molecular, Cellular and Genomics Biomedicine Research Group, Instituto de Investigación Sanitaria La Fe, Valencia, Spain; Unidad Mixta de Enfermedades raras IIS La Fe-Centro de Investigación Príncipe Felipe, Valencia, Spain; Biomedical Research Network for Rare Diseases, Hospital Universitario y Politécnico La Fe, Valencia, Spain.
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26
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Mayer AK, Balousha G, Sharkia R, Mahajnah M, Ayesh S, Schulze M, Buchert R, Zobor D, Azem A, Schöls L, Bauer P, Wissinger B. Unraveling the genetic cause of hereditary ophthalmic disorders in Arab societies from Israel and the Palestinian Authority. Eur J Hum Genet 2020; 28:742-753. [PMID: 31896775 DOI: 10.1038/s41431-019-0566-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Revised: 11/12/2019] [Accepted: 12/10/2019] [Indexed: 11/09/2022] Open
Abstract
Visual impairment due to inherited ophthalmic disorders is amongst the most common disabilities observed in populations practicing consanguineous marriages. Here we investigated the molecular genetic basis of an unselected broad range of ophthalmic disorders in 20 consanguineous families from Arab villages of Israel and the Palestinian Authority. Most patients had little or very poor prior clinical workup and were recruited in a field study. Homozygosity mapping followed by candidate gene sequencing applying conventional Sanger sequencing or targeted next generation sequencing was performed in six families. In the remaining 14 families, one affected subject per family was chosen for whole exome sequencing. We discovered likely disease-causing variants, all homozygous, in 19 of 20 independent families (95%) including a previously reported novel disease gene for congenital nystagmus associated with foveal hypoplasia. Moreover, we found a family in which disease-causing variants for two collagenopathies - Stickler and Knobloch syndrome - segregate within a large sibship. Nine of the 19 distinct variants observed in this study were novel. Our study demonstrated a very high molecular diagnostic yield for a highly diverse spectrum of rare ophthalmic disorders in Arab patients from Israel and the Palestinian Authority, even with very limited prior clinical investigation. We conclude that 'genetic testing first' may be an economic way to direct clinical care and to support proper genetic counseling and risk assessment in these families.
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Affiliation(s)
- Anja K Mayer
- Institute for Ophthalmic Research, Molecular Genetics Laboratory, Tuebingen, Germany.,Praxis fuer Humangenetik Tuebingen, Tuebingen, Germany
| | - Ghassan Balousha
- Department of Pathology and Histology, Al-Quds University, Eastern Jerusalem, Palestinian Authority, Jerusalem, Israel
| | - Rajech Sharkia
- The Triangle Regional Research and Development Center, Kfar Qari', Israel.,Beit-Berl Academic College, Beit-Berl, Israel
| | - Muhammad Mahajnah
- Child Neurology and Development Center, Hillel-Yaffe Medical Center, Hadera, Israel.,The Ruth and Bruce Rappaport Faculty of Medicine, Technion, Haifa, Israel
| | - Suhail Ayesh
- Molecular Genetic Laboratory, Al-Makassed Islamic Charitable Society Hospital, Jerusalem, Israel
| | - Martin Schulze
- Institute of Medical Genetics and Applied Genomics, University of Tuebingen, Tuebingen, Germany.,Praxis fuer Humangenetik Tuebingen, Tuebingen, Germany
| | - Rebecca Buchert
- Institute of Medical Genetics and Applied Genomics, University of Tuebingen, Tuebingen, Germany
| | - Ditta Zobor
- University Eye Hospital, University of Tuebingen, Tuebingen, Germany
| | - Abdussalam Azem
- The School of Neurobiology, Biochemistry and Biophysics, George S. Wise faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel
| | - Ludger Schöls
- Hertie Institute for Brain Research, University of Tuebingen, Tuebingen, Germany.,German Center of Neurodegenerative Diseases (DZNE), Tuebingen, Germany
| | - Peter Bauer
- Institute of Medical Genetics and Applied Genomics, University of Tuebingen, Tuebingen, Germany
| | - Bernd Wissinger
- Institute for Ophthalmic Research, Molecular Genetics Laboratory, Tuebingen, Germany.
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27
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Langer BE, Roscito JG, Hiller M. REforge Associates Transcription Factor Binding Site Divergence in Regulatory Elements with Phenotypic Differences between Species. Mol Biol Evol 2019; 35:3027-3040. [PMID: 30256993 PMCID: PMC6278867 DOI: 10.1093/molbev/msy187] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Elucidating the genomic determinants of morphological differences between species is key to understanding how morphological diversity evolved. While differences in cis-regulatory elements are an important genetic source for morphological evolution, it remains challenging to identify regulatory elements involved in phenotypic differences. Here, we present Regulatory Element forward genomics (REforge), a computational approach that detects associations between transcription factor binding site divergence in putative regulatory elements and phenotypic differences between species. By simulating regulatory element evolution in silico, we show that this approach has substantial power to detect such associations. To validate REforge on real data, we used known binding motifs for eye-related transcription factors and identified significant binding site divergence in vision-impaired subterranean mammals in 1% of all conserved noncoding elements. We show that these genomic regions are significantly enriched in regulatory elements that are specifically active in mouse eye tissues, and that several of them are located near genes, which are required for eye development and photoreceptor function and are implicated in human eye disorders. Thus, our genome-wide screen detects widespread divergence of eye-regulatory elements and highlights regulatory regions that likely contributed to eye degeneration in subterranean mammals. REforge has broad applicability to detect regulatory elements that could be involved in many other phenotypes, which will help to reveal the genomic basis of morphological diversity.
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Affiliation(s)
- Björn E Langer
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany.,Max Planck Institute for the Physics of Complex Systems, Dresden, Germany.,Center for Systems Biology, Dresden, Germany
| | - Juliana G Roscito
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany.,Max Planck Institute for the Physics of Complex Systems, Dresden, Germany.,Center for Systems Biology, Dresden, Germany
| | - Michael Hiller
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany.,Max Planck Institute for the Physics of Complex Systems, Dresden, Germany.,Center for Systems Biology, Dresden, Germany
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28
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Targeted deletion of Crb1/Crb2 in the optic vesicle models key features of leber congenital amaurosis 8. Dev Biol 2019; 453:141-154. [PMID: 31145883 DOI: 10.1016/j.ydbio.2019.05.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2019] [Revised: 05/20/2019] [Accepted: 05/21/2019] [Indexed: 01/01/2023]
Abstract
The Crb1 and 2 (Crumbs homolog 1 & 2) genes encode large, single-pass transmembrane proteins essential for the apicobasal polarity and adhesion of epithelial cells. Crb1 mutations cause degenerative retinal diseases in humans, including Leber congenital amaurosis type 8 (LCA8) and retinitis pigmentosa type 12 (RP12). In LCA8, impaired photoreceptor development and/or survival is thought to cause blindness during early infancy, whereas, in RP12, progressive photoreceptor degeneration damages peripheral vision later in life. There are multiple animal models of RP12 pathology, but no experimental model of LCA8 recapitulates the full spectrum of its pathological features. To generate a mouse model of LCA8 and identify the functions of Crb1/2 in developing ocular tissues, we used an mRx-Cre driver to generate allelic combinations that enabled conditional gene ablation from the optic vesicle stage. In this series only Crb1/2 double knockout (dKO) mice exhibited characteristics of human LCA8 disease: locally thickened retina with spots devoid of cells, aberrant positioning of retinal cells, severely disrupted lamination, and depigmented retinal-pigmented epithelium. Retinal defects antedated E12.5, which is far earlier than the stage at which photoreceptor cells mainly differentiate. Most remarkably, Crb1/Crb2 dKO showed a severely attenuated electroretinogram at the eye opening stage. These results suggest that human LCA8 can be modeled in the mouse by simultaneously ablating Crb1/2 from the beginning of eye development. Importantly, they also indicate that LCA8 is caused by malfunction of retinal progenitor cells during early ocular development rather than by defective photoreceptor-Muller glial interaction, a mechanism proposed for RP12.
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29
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Moore BA, Roux MJ, Sebbag L, Cooper A, Edwards SG, Leonard BC, Imai DM, Griffey S, Bower L, Clary D, Lloyd KCK, Hérault Y, Thomasy SM, Murphy CJ, Moshiri A. A Population Study of Common Ocular Abnormalities in C57BL/6N rd8 Mice. Invest Ophthalmol Vis Sci 2019; 59:2252-2261. [PMID: 29847629 PMCID: PMC5935295 DOI: 10.1167/iovs.17-23513] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Purpose The purpose of this study was to quantify the frequency and severity of ocular abnormalities affecting wild-type C57BL/6N mice, the most common strain used worldwide for the creation of single-gene knockouts. Methods A total of 2773 animals (5546 eyes) were examined at one colony at UC Davis and in three more colonies at the Institut Clinique de la Souris in Strasbourg, France. Mice were examined at 15 to 16 weeks postnatal age by performing anterior segment biomicroscopy, posterior segment examination by indirect ophthalmoscopy, intraocular pressure measurement, and optical coherence tomography of anterior and posterior segment structures. Results Common ocular findings in the C57BL/6N strain included corneal deposits (3%), increased optical density of the anterior lens capsule (67%), punctate nuclear cataracts (98%), vitreous crystalline deposits (61%), hyaloid vascular remnant (6%), and retinal dysplasia attributed to the rd8 mutation (58%). Interestingly, retinal dysplasia was more common in male mice in all four breeding colonies evaluated in this study. The thickness of ocular tissues and compartments were measured by spectral-domain optical coherence tomography, including the central cornea, anterior chamber, vitreous, and retinal layers. Intraocular pressure was measured by rebound tonometry. Conclusions Ocular abnormalities are common in anterior and posterior segments of the C57BL/6N mouse, the most common background on which single-gene knockout mice have been made. It is important that vision scientists understand the extent and variability of ocular findings associated with this particular genetic background of mice.
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Affiliation(s)
- Bret A Moore
- William R. Pritchard Veterinary Medical Teaching Hospital, School of Veterinary Medicine, University of California-Davis, Davis, California, United States
| | - Michel J Roux
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, Université de Strasbourg, Illkirch, France.,Centre National de la Recherche Scientifique, UMR7104, Illkirch, France.,Institut National de la Santé et de la Recherche Médicale, U964, Illkirch, France.,Université de Strasbourg, Illkirch, France
| | - Lionel Sebbag
- William R. Pritchard Veterinary Medical Teaching Hospital, School of Veterinary Medicine, University of California-Davis, Davis, California, United States
| | - Ann Cooper
- William R. Pritchard Veterinary Medical Teaching Hospital, School of Veterinary Medicine, University of California-Davis, Davis, California, United States
| | - Sydney G Edwards
- William R. Pritchard Veterinary Medical Teaching Hospital, School of Veterinary Medicine, University of California-Davis, Davis, California, United States
| | - Brian C Leonard
- William R. Pritchard Veterinary Medical Teaching Hospital, School of Veterinary Medicine, University of California-Davis, Davis, California, United States
| | - Denise M Imai
- Comparative Pathology Laboratory, School of Veterinary Medicine, UC Davis, Davis, California, United States
| | - Stephen Griffey
- Comparative Pathology Laboratory, School of Veterinary Medicine, UC Davis, Davis, California, United States
| | - Lynette Bower
- Mouse Biology Program, University of California-Davis, Davis, California, United States
| | - Dave Clary
- Mouse Biology Program, University of California-Davis, Davis, California, United States
| | - K C Kent Lloyd
- Mouse Biology Program, University of California-Davis, Davis, California, United States.,Department of Surgery, School of Medicine, University of California-Davis, Sacramento, California, United States
| | - Yann Hérault
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, Université de Strasbourg, Illkirch, France.,Centre National de la Recherche Scientifique, UMR7104, Illkirch, France.,Institut National de la Santé et de la Recherche Médicale, U964, Illkirch, France.,Université de Strasbourg, Illkirch, France.,CELPHEDIA, PHENOMIN, Institut Clinique de la Souris (ICS), CNRS, INSERM, Université de Strasbourg, Illkirch, France
| | - Sara M Thomasy
- Department of Veterinary Surgical and Radiological Sciences, School of Veterinary Medicine, UC Davis, Davis, California, United States.,Department of Ophthalmology & Vision Science, School of Medicine, University of California-Davis, Sacramento, California, United States
| | - Christopher J Murphy
- Department of Veterinary Surgical and Radiological Sciences, School of Veterinary Medicine, UC Davis, Davis, California, United States.,Department of Ophthalmology & Vision Science, School of Medicine, University of California-Davis, Sacramento, California, United States
| | - Ala Moshiri
- Department of Ophthalmology & Vision Science, School of Medicine, University of California-Davis, Sacramento, California, United States
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30
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Chen X, Jiang C, Yang D, Sun R, Wang M, Sun H, Xu M, Zhou L, Chen M, Xie P, Yan B, Liu Q, Zhao C. CRB2 mutation causes autosomal recessive retinitis pigmentosa. Exp Eye Res 2018; 180:164-173. [PMID: 30593785 DOI: 10.1016/j.exer.2018.12.018] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Revised: 12/21/2018] [Accepted: 12/21/2018] [Indexed: 01/29/2023]
Abstract
Retinitis pigmentosa (RP), the most common form of inherited retinal dystrophies, exhibits significant genetic heterogeneity. The crumbs homolog 2 (CRB2) protein, together with CRB1 and CRB3, belongs to the Crumbs family. Given that CRB1 mutations account for 4% of RP cases, the role of CRB2 mutations in RP etiology has long been hypothesized but never confirmed. Herein, we report the identification of CRB2 as a novel RP causative gene in a Chinese consanguineous family and have analyzed its pathogenic effects. Comprehensive ophthalmic and systemic evaluations confirmed the clinical diagnosis of the two patients in this family as RP. WES revealed a homozygous missense mutation, CRB2 p.R1249G, to segregate the RP phenotype, which was highly conserved among multiple species. In vitro cellular study revealed that this mutation not only interrupted the stability of the transcribed CRB2 mRNA and the encoded CRB2 protein, but also interfered with the wild type CRB2 mRNA/protein and decreased their expression. This mutation was also shown to trigger epithelial-mesenchymal transition (EMT) in retinal pigment epithelium (RPE) cells, thus impairing regular RPE phagocytosis and induce RPE degeneration and apoptosis. Thus, we conclude that CRB2 p.R1249G mutation causes RP via accelerating EMT, dysfunction and loss of RPE cells, and establish CRB2 as a novel Crumbs family member associated with non-syndromic RP. We provide important hints for understanding of CRB2 defects and retinopathy, and for the involvement of EMT of RPE cells in RP pathogenesis.
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Affiliation(s)
- Xue Chen
- Department of Ophthalmology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, 210029, China; Department of Ophthalmology and Vision Science, Eye & ENT Hospital, Shanghai Medical College, Fudan University, Shanghai, 200023, China; Key Laboratory of Myopia of State Health Ministry (Fudan University) and Shanghai Key Laboratory of Visual Impairment and Restoration, Shanghai, 200023, China
| | - Chao Jiang
- Department of Ophthalmology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, 210029, China
| | - Daidi Yang
- Department of Ophthalmology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, 210029, China
| | - Ruxu Sun
- Department of Ophthalmology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, 210029, China
| | - Min Wang
- Department of Ophthalmology and Vision Science, Eye & ENT Hospital, Shanghai Medical College, Fudan University, Shanghai, 200023, China; Key Laboratory of Myopia of State Health Ministry (Fudan University) and Shanghai Key Laboratory of Visual Impairment and Restoration, Shanghai, 200023, China
| | - Hong Sun
- Department of Ophthalmology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, 210029, China
| | - Min Xu
- Department of Ophthalmology, Northern Jiangsu People's Hospital, Yangzhou, 211406, China
| | - Luyin Zhou
- Department of Ophthalmology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, 210029, China
| | - Mingkang Chen
- Department of Ophthalmology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, 210029, China
| | - Ping Xie
- Department of Ophthalmology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, 210029, China
| | - Biao Yan
- Department of Ophthalmology and Vision Science, Eye & ENT Hospital, Shanghai Medical College, Fudan University, Shanghai, 200023, China; Key Laboratory of Myopia of State Health Ministry (Fudan University) and Shanghai Key Laboratory of Visual Impairment and Restoration, Shanghai, 200023, China
| | - Qinghuai Liu
- Department of Ophthalmology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, 210029, China.
| | - Chen Zhao
- Department of Ophthalmology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, 210029, China; Department of Ophthalmology and Vision Science, Eye & ENT Hospital, Shanghai Medical College, Fudan University, Shanghai, 200023, China; Key Laboratory of Myopia of State Health Ministry (Fudan University) and Shanghai Key Laboratory of Visual Impairment and Restoration, Shanghai, 200023, China.
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31
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Gaspar P, Almudi I, Nunes MDS, McGregor AP. Human eye conditions: insights from the fly eye. Hum Genet 2018; 138:973-991. [PMID: 30386938 DOI: 10.1007/s00439-018-1948-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2018] [Accepted: 10/20/2018] [Indexed: 12/22/2022]
Abstract
The fruit fly Drosophila melanogaster has served as an excellent model to study and understand the genetics of many human diseases from cancer to neurodegeneration. Studying the regulation of growth, determination and differentiation of the compound eyes of this fly, in particular, have provided key insights into a wide range of diseases. Here we review the regulation of the development of fly eyes in light of shared aspects with human eye development. We also show how understanding conserved regulatory pathways in eye development together with the application of tools for genetic screening and functional analyses makes Drosophila a powerful model to diagnose and characterize the genetics underlying many human eye conditions, such as aniridia and retinitis pigmentosa. This further emphasizes the importance and vast potential of basic research to underpin applied research including identifying and treating the genetic basis of human diseases.
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Affiliation(s)
- Pedro Gaspar
- Department of Biological and Medical Sciences, Oxford Brookes University, Gipsy Lane, Oxford, OX3 0BP, UK
| | - Isabel Almudi
- Centro Andaluz de Biología del Desarrollo, CSIC/ Universidad Pablo de Olavide, Carretera de Utrera Km1, 41013, Sevilla, Spain
| | - Maria D S Nunes
- Department of Biological and Medical Sciences, Oxford Brookes University, Gipsy Lane, Oxford, OX3 0BP, UK
| | - Alistair P McGregor
- Department of Biological and Medical Sciences, Oxford Brookes University, Gipsy Lane, Oxford, OX3 0BP, UK.
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32
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Dolón JF, Paniagua AE, Valle V, Segurado A, Arévalo R, Velasco A, Lillo C. Expression and localization of the polarity protein CRB2 in adult mouse brain: a comparison with the CRB1 rd8 mutant mouse model. Sci Rep 2018; 8:11652. [PMID: 30076417 PMCID: PMC6076319 DOI: 10.1038/s41598-018-30210-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2018] [Accepted: 07/24/2018] [Indexed: 11/09/2022] Open
Abstract
Acquisition of cell polarization is essential for the performance of crucial functions, like a successful secretion and appropriate cell signaling in many tissues, and it depends on the correct functioning of polarity proteins, including the Crumbs complex. The CRB proteins, CRB1, CRB2 and CRB3, identified in mammals, are expressed in epithelial-derived tissues like brain, kidney and retina. CRB2 has a ubiquitous expression and has been detected in embryonic brain tissue; but currently there is no data regarding its localization in the adult brain. In our study, we characterized the presence of CRB2 in adult mice brain, where it is particularly enriched in cortex, hippocampus, hypothalamus and cerebellum. Double immunofluorescence analysis confirmed that CRB2 is a neuron-specific protein, present in both soma and projections where colocalizes with certain populations of exocytic and endocytic vesicles and with other members of the Crumbs complex. Finally, in the cortex of CRB1rd8 mutant mice that contain a mutation in the Crb1 gene generating a truncated CRB1 protein, there is an abnormal increase in the expression levels of the CRB2 protein which suggests a possible compensatory mechanism for the malfunction of CRB1 in this mutant background.
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Affiliation(s)
- Jorge F Dolón
- Institute of Neurosciences of Castilla y León, IBSAL, Cell Biology and Pathology, University of Salamanca, 37007, Salamanca, Spain
| | - Antonio E Paniagua
- Institute of Neurosciences of Castilla y León, IBSAL, Cell Biology and Pathology, University of Salamanca, 37007, Salamanca, Spain.,Department of Ophthalmology and Stein Eye Institute, University of California, Los Angeles, CA, 90095, USA
| | - Vicente Valle
- Institute of Neurosciences of Castilla y León, IBSAL, Cell Biology and Pathology, University of Salamanca, 37007, Salamanca, Spain
| | - Alicia Segurado
- Institute of Neurosciences of Castilla y León, IBSAL, Cell Biology and Pathology, University of Salamanca, 37007, Salamanca, Spain
| | - Rosario Arévalo
- Institute of Neurosciences of Castilla y León, IBSAL, Cell Biology and Pathology, University of Salamanca, 37007, Salamanca, Spain
| | - Almudena Velasco
- Institute of Neurosciences of Castilla y León, IBSAL, Cell Biology and Pathology, University of Salamanca, 37007, Salamanca, Spain
| | - Concepción Lillo
- Institute of Neurosciences of Castilla y León, IBSAL, Cell Biology and Pathology, University of Salamanca, 37007, Salamanca, Spain.
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33
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Nanophthalmos: A Review of the Clinical Spectrum and Genetics. J Ophthalmol 2018; 2018:2735465. [PMID: 29862063 PMCID: PMC5971257 DOI: 10.1155/2018/2735465] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2017] [Revised: 02/20/2018] [Accepted: 04/08/2018] [Indexed: 11/28/2022] Open
Abstract
Nanophthalmos is a clinical spectrum of disorders with a phenotypically small but structurally normal eye. These disorders present significant clinical challenges to ophthalmologists due to a high rate of secondary angle-closure glaucoma, spontaneous choroidal effusions, and perioperative complications with cataract and retinal surgeries. Nanophthalmos may present as a sporadic or familial disorder, with autosomal-dominant or recessive inheritance. To date, five genes (i.e., MFRP, TMEM98, PRSS56, BEST1, and CRB1) and two loci have been implicated in familial forms of nanophthalmos. Here, we review the definition of nanophthalmos, the clinical and pathogenic features of the condition, and the genetics of this disorder.
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34
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Clinical and genetic characteristics of 251 consecutive patients with macular and cone/cone-rod dystrophy. Sci Rep 2018; 8:4824. [PMID: 29555955 PMCID: PMC5859282 DOI: 10.1038/s41598-018-22096-0] [Citation(s) in RCA: 134] [Impact Index Per Article: 22.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2017] [Accepted: 02/16/2018] [Indexed: 12/14/2022] Open
Abstract
Macular and cone/cone-rod dystrophies (MD/CCRD) demonstrate a broad genetic and phenotypic heterogeneity, with retinal alterations solely or predominantly involving the central retina. Targeted next-generation sequencing (NGS) is an efficient diagnostic tool for identifying mutations in patient with retinitis pigmentosa, which shows similar genetic heterogeneity. To detect the genetic causes of disease in patients with MD/CCRD, we implemented a two-tier procedure consisting of Sanger sequencing and targeted NGS including genes associated with clinically overlapping conditions. Disease-causing mutations were identified in 74% of 251 consecutive MD/CCRD patients (33% of the variants were novel). Mutations in ABCA4, PRPH2 and BEST1 accounted for 57% of disease cases. Further mutations were identified in CDHR1, GUCY2D, PROM1, CRX, GUCA1A, CERKL, MT-TL1, KIF11, RP1L1, MERTK, RDH5, CDH3, C1QTNF5, CRB1, JAG1, DRAM2, POC1B, NPHP1 and RPGR. We provide detailed illustrations of rare phenotypes, including autofluorescence and optical coherence tomography imaging. Targeted NGS also identified six potential novel genotype-phenotype correlations for FAM161A, INPP5E, MERTK, FBLN5, SEMA4A and IMPDH1. Clinical reassessment of genetically unsolved patients revealed subgroups with similar retinal phenotype, indicating a common molecular disease cause in each subgroup.
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35
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Khan KN, Robson A, Mahroo OAR, Arno G, Inglehearn CF, Armengol M, Waseem N, Holder GE, Carss KJ, Raymond LF, Webster AR, Moore AT, McKibbin M, van Genderen MM, Poulter JA, Michaelides M. A clinical and molecular characterisation of CRB1-associated maculopathy. Eur J Hum Genet 2018; 26:687-694. [PMID: 29391521 PMCID: PMC5945653 DOI: 10.1038/s41431-017-0082-2] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2017] [Revised: 11/14/2017] [Accepted: 12/05/2017] [Indexed: 12/22/2022] Open
Abstract
To date, over 150 disease-associated variants in CRB1 have been described, resulting in a range of retinal disease phenotypes including Leber congenital amaurosis and retinitis pigmentosa. Despite this, no genotype–phenotype correlations are currently recognised. We performed a retrospective review of electronic patient records to identify patients with macular dystrophy due to bi-allelic variants in CRB1. In total, seven unrelated individuals were identified. The median age at presentation was 21 years, with a median acuity of 0.55 decimalised Snellen units (IQR = 0.43). The follow-up period ranged from 0 to 19 years (median = 2.0 years), with a median final decimalised Snellen acuity of 0.65 (IQR = 0.70). Fundoscopy revealed only a subtly altered foveal reflex, which evolved into a bull’s-eye pattern of outer retinal atrophy. Optical coherence tomography identified structural changes—intraretinal cysts in the early stages of disease, and later outer retinal atrophy. Genetic testing revealed that one rare allele (c.498_506del, p.(Ile167_Gly169del)) was present in all patients, with one patient being homozygous for the variant and six being heterozygous. In trans with this, one variant recurred twice (p.(Cys896Ter)), while the four remaining alleles were each observed once (p.(Pro1381Thr), p.(Ser478ProfsTer24), p.(Cys195Phe) and p.(Arg764Cys)). These findings show that the rare CRB1 variant, c.498_506del, is strongly associated with localised retinal dysfunction. The clinical findings are much milder than those observed with bi-allelic, loss-of-function variants in CRB1, suggesting this in-frame deletion acts as a hypomorphic allele. This is the most prevalent disease-causing CRB1 variant identified in the non-Asian population to date.
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Affiliation(s)
- Kamron N Khan
- University College London Institute of Ophthalmology, University College London, London, UK. .,Inherited Eye Disease Service, Moorfields Eye Hospital, London, UK. .,Section of Ophthalmology and Neuroscience, Leeds Institute of Biomedical and Clinical Sciences, University of Leeds, Leeds, UK. .,Department of Ophthalmology, St. James's University Teaching Hospital, Leeds, UK.
| | - Anthony Robson
- Department of Electrophysiology, Moorfields Eye Hospital, London, UK
| | - Omar A R Mahroo
- University College London Institute of Ophthalmology, University College London, London, UK.,Inherited Eye Disease Service, Moorfields Eye Hospital, London, UK
| | - Gavin Arno
- University College London Institute of Ophthalmology, University College London, London, UK
| | - Chris F Inglehearn
- Section of Ophthalmology and Neuroscience, Leeds Institute of Biomedical and Clinical Sciences, University of Leeds, Leeds, UK
| | - Monica Armengol
- Inherited Eye Disease Service, Moorfields Eye Hospital, London, UK
| | - Naushin Waseem
- Section of Ophthalmology and Neuroscience, Leeds Institute of Biomedical and Clinical Sciences, University of Leeds, Leeds, UK
| | - Graham E Holder
- Department of Electrophysiology, Moorfields Eye Hospital, London, UK
| | - Keren J Carss
- NIHR BioResource - Rare Diseases, Cambridge University Hospitals NHS Foundation Trust, Cambridge Biomedical Campus, Cambridge, UK.,Department of Haematology, NHS Blood and Transplant Centre, University of Cambridge, Cambridge, CB2 0PT, UK.,Department of Medical Genetics, Cambridge Institute for Medical Research, University of Cambridge, Cambridge, CB2 0XY, UK
| | - Lucy F Raymond
- NIHR BioResource - Rare Diseases, Cambridge University Hospitals NHS Foundation Trust, Cambridge Biomedical Campus, Cambridge, UK.,Department of Haematology, NHS Blood and Transplant Centre, University of Cambridge, Cambridge, CB2 0PT, UK.,Department of Medical Genetics, Cambridge Institute for Medical Research, University of Cambridge, Cambridge, CB2 0XY, UK
| | - Andrew R Webster
- University College London Institute of Ophthalmology, University College London, London, UK.,Inherited Eye Disease Service, Moorfields Eye Hospital, London, UK
| | - Anthony T Moore
- University College London Institute of Ophthalmology, University College London, London, UK.,Inherited Eye Disease Service, Moorfields Eye Hospital, London, UK.,Ophthalmology Department, University of California San Francisco Medical School, San Francisco, CA, USA
| | - Martin McKibbin
- Section of Ophthalmology and Neuroscience, Leeds Institute of Biomedical and Clinical Sciences, University of Leeds, Leeds, UK.,Department of Ophthalmology, St. James's University Teaching Hospital, Leeds, UK
| | - Maria M van Genderen
- Bartiméus Diagnostic Centre for Complex Visual Disorders, Zeist, The Netherlands.,Department of Ophthalmology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - James A Poulter
- Section of Ophthalmology and Neuroscience, Leeds Institute of Biomedical and Clinical Sciences, University of Leeds, Leeds, UK
| | - Michel Michaelides
- University College London Institute of Ophthalmology, University College London, London, UK.,Inherited Eye Disease Service, Moorfields Eye Hospital, London, UK
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36
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Srikrupa N, Srilekha S, Sen P, Arokiasamy T, Meenakshi S, Bhende M, Kapur S, Soumittra N. Genetic profile and mutation spectrum of Leber congenital amaurosis in a larger Indian cohort using high throughput targeted re-sequencing. Clin Genet 2018; 93:329-339. [DOI: 10.1111/cge.13159] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2017] [Revised: 09/22/2017] [Accepted: 10/16/2017] [Indexed: 01/02/2023]
Affiliation(s)
- N.N. Srikrupa
- SNONGC Department of Genetics and Molecular Biology; Vision Research Foundation; Chennai India
- PhD Scholar; Birla Institute of Technology & Science (BITS); Hyderabad India
| | - S. Srilekha
- SNONGC Department of Genetics and Molecular Biology; Vision Research Foundation; Chennai India
| | - P. Sen
- Department of Vitreo-Retinal Services; Medical Research Foundation; Chennai India
| | - T. Arokiasamy
- SNONGC Department of Genetics and Molecular Biology; Vision Research Foundation; Chennai India
| | - S. Meenakshi
- Department of Pediatric Ophthalmology; Medical Research Foundation; Chennai India
| | - M. Bhende
- Department of Vitreo-Retinal Services; Medical Research Foundation; Chennai India
| | - S. Kapur
- Department of Biological Sciences; Birla Institute of Technology & Science (BITS); Hyderabad India
| | - N. Soumittra
- SNONGC Department of Genetics and Molecular Biology; Vision Research Foundation; Chennai India
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37
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Castro-Sánchez S, Álvarez-Satta M, Tohamy MA, Beltran S, Derdak S, Valverde D. Whole exome sequencing as a diagnostic tool for patients with ciliopathy-like phenotypes. PLoS One 2017; 12:e0183081. [PMID: 28800606 PMCID: PMC5553726 DOI: 10.1371/journal.pone.0183081] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Accepted: 07/29/2017] [Indexed: 12/13/2022] Open
Abstract
Ciliopathies are a group of rare disorders characterized by a high genetic and phenotypic variability, which complicates their molecular diagnosis. Hence the need to use the latest powerful approaches to faster identify the genetic defect in these patients. We applied whole exome sequencing to six consanguineous families clinically diagnosed with ciliopathy-like disease, and for which mutations in predominant Bardet-Biedl syndrome (BBS) genes had previously been excluded. Our strategy, based on first applying several filters to ciliary variants and using many of the bioinformatics tools available, allowed us to identify causal mutations in BBS2, ALMS1 and CRB1 genes in four families, thus confirming the molecular diagnosis of ciliopathy. In the remaining two families, after first rejecting the presence of pathogenic variants in common cilia-related genes, we adopted a new filtering strategy combined with prioritisation tools to rank the final candidate genes for each case. Thus, we propose CORO2B, LMO7 and ZNF17 as novel candidate ciliary genes, but further functional studies will be needed to confirm their role. Our data show the usefulness of this strategy to diagnose patients with unclear phenotypes, and therefore the success of applying such technologies to achieve a rapid and reliable molecular diagnosis, improving genetic counselling for these patients. In addition, the described pipeline also highlights the common pitfalls associated to the large volume of data we have to face and the difficulty of assigning a functional role to these changes, hence the importance of designing the most appropriate strategy according to each case.
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Affiliation(s)
- Sheila Castro-Sánchez
- Departamento de Bioquímica, Genética e Inmunología, Facultad de Biología, Universidad de Vigo, Vigo, Spain
- Research Group of Rare Diseases & Pediatric Medicine, Instituto de Investigación Sanitaria Galicia Sur (IISGS), SERGAS-UVIGO, Hospital Álvaro Cunqueiro, Vigo, Spain
- Centro de Investigaciones Biomédicas (CINBIO) (Centro Singular de Investigación de Galicia), Universidad de Vigo, Vigo, Spain
| | - María Álvarez-Satta
- Departamento de Bioquímica, Genética e Inmunología, Facultad de Biología, Universidad de Vigo, Vigo, Spain
- Research Group of Rare Diseases & Pediatric Medicine, Instituto de Investigación Sanitaria Galicia Sur (IISGS), SERGAS-UVIGO, Hospital Álvaro Cunqueiro, Vigo, Spain
- Centro de Investigaciones Biomédicas (CINBIO) (Centro Singular de Investigación de Galicia), Universidad de Vigo, Vigo, Spain
| | - Mohamed A. Tohamy
- Departamento de Bioquímica, Genética e Inmunología, Facultad de Biología, Universidad de Vigo, Vigo, Spain
| | - Sergi Beltran
- CNAG-CRG, Centre for Genomic Regulation (CRG), Barcelona Institute of Science and Technology (BIST), Barcelona, Spain
- Universitat Pompeu Fabra (UPF), Barcelona, Spain
| | - Sophia Derdak
- CNAG-CRG, Centre for Genomic Regulation (CRG), Barcelona Institute of Science and Technology (BIST), Barcelona, Spain
- Universitat Pompeu Fabra (UPF), Barcelona, Spain
| | - Diana Valverde
- Departamento de Bioquímica, Genética e Inmunología, Facultad de Biología, Universidad de Vigo, Vigo, Spain
- Research Group of Rare Diseases & Pediatric Medicine, Instituto de Investigación Sanitaria Galicia Sur (IISGS), SERGAS-UVIGO, Hospital Álvaro Cunqueiro, Vigo, Spain
- Centro de Investigaciones Biomédicas (CINBIO) (Centro Singular de Investigación de Galicia), Universidad de Vigo, Vigo, Spain
- * E-mail:
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38
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Lajko M, Cardona HJ, Taylor JM, Farrow KN, Fawzi AA. Photoreceptor oxidative stress in hyperoxia-induced proliferative retinopathy accelerates rd8 degeneration. PLoS One 2017; 12:e0180384. [PMID: 28671996 PMCID: PMC5495396 DOI: 10.1371/journal.pone.0180384] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2017] [Accepted: 06/14/2017] [Indexed: 12/13/2022] Open
Abstract
To investigate the impact of photoreceptor oxidative stress on photoreceptor degeneration in mice carrying the rd8 mutation (C57BL/6N). We compared the hyperoxia-induced proliferative retinopathy (HIPR) model in two mouse strains (C57BL/6J and C57BL/6N). Pups were exposed to 75% oxygen, starting at birth and continuing for 14 days (P14). Mice were euthanized at P14, or allowed to recover in room air for one day (P15), seven days (P21), or 14 days (P28). We quantified retinal thickness and the length of residual photoreceptors not affected by rosette formation. In addition we explored differences in retinal immunostaining for NADPH oxidase 4 (NOX4), Rac1, vascular endothelium, and activated Mϋller cells. We analyzed photoreceptor oxidative stress using DCF staining in cross sections and quantified NOX4 protein levels using western blotting. C57BL/6N mice in HIPR showed increased oxidative stress, NOX4, and Rac1 in the photoreceptors at P14 and P15 compared to C57BL/6J. In addition, we observed significant progression of photoreceptor degeneration, with significantly accelerated rosette formation in C57BL/6N under HIPR, compared to their room air counterparts. Furthermore, C57BL/6N under HIPR had significantly thinner central retinas than C57BL/6J in HIPR. We did not find a difference in vascular disruption or Mϋller cell activation comparing the two strains in hyperoxia. In HIPR, the C57BL/6N strain carrying the rd8 mutation showed significantly accelerated photoreceptor degeneration, mediated via exacerbated photoreceptor oxidative stress, which we believe relates to Rac1-NOX dysregulation in the setting of Crb1 loss-of-function.
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Affiliation(s)
- Michelle Lajko
- Department of Ophthalmology, Feinberg School of Medicine at Northwestern University, Chicago, Illinois, United States of America
| | - Herminio J. Cardona
- Department of Pediatrics, Feinberg School of Medicine at Northwestern University, Chicago, Illinois, United States of America
| | - Joann M. Taylor
- Department of Pediatrics, Feinberg School of Medicine at Northwestern University, Chicago, Illinois, United States of America
| | - Kathryn N. Farrow
- Department of Pediatrics, Feinberg School of Medicine at Northwestern University, Chicago, Illinois, United States of America
| | - Amani A. Fawzi
- Department of Ophthalmology, Feinberg School of Medicine at Northwestern University, Chicago, Illinois, United States of America
- * E-mail:
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39
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Whole exome sequencing using Ion Proton system enables reliable genetic diagnosis of inherited retinal dystrophies. Sci Rep 2017; 7:42078. [PMID: 28181551 PMCID: PMC5299602 DOI: 10.1038/srep42078] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2016] [Accepted: 01/05/2017] [Indexed: 01/17/2023] Open
Abstract
Inherited retinal dystrophies (IRD) comprise a wide group of clinically and genetically complex diseases that progressively affect the retina. Over recent years, the development of next-generation sequencing (NGS) methods has transformed our ability to diagnose heterogeneous diseases. In this work, we have evaluated the implementation of whole exome sequencing (WES) for the molecular diagnosis of IRD. Using Ion ProtonTM system, we simultaneously analyzed 212 genes that are responsible for more than 25 syndromic and non-syndromic IRD. This approach was used to evaluate 59 unrelated families, with the pathogenic variant(s) successfully identified in 71.18% of cases. Interestingly, the mutation detection rate varied substantially depending on the IRD subtype. Overall, we found 63 different mutations (21 novel) in 29 distinct genes, and performed in vivo functional studies to determine the deleterious impact of variants identified in MERTK, CDH23, and RPGRIP1. In addition, we provide evidences that support CDHR1 as a gene responsible for autosomal recessive retinitis pigmentosa with early macular affectation, and present data regarding the disease mechanism of this gene. Altogether, these results demonstrate that targeted WES of all IRD genes is a reliable, hypothesis-free approach, and a cost- and time-effective strategy for the routine genetic diagnosis of retinal dystrophies.
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40
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Unravelling the genetic basis of simplex Retinitis Pigmentosa cases. Sci Rep 2017; 7:41937. [PMID: 28157192 PMCID: PMC5291209 DOI: 10.1038/srep41937] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2016] [Accepted: 01/04/2017] [Indexed: 12/20/2022] Open
Abstract
Retinitis Pigmentosa (RP) is the most common form of inherited retinal dystrophy (IRD) characterized ultimately by photoreceptors degeneration. Exhibiting great clinical and genetic heterogeneity, RP can be inherited as an autosomal dominant (ad), autosomal recessive (ar) and X-linked (xl) disorder. Although the relative prevalence of each form varies somewhat between populations, a major proportion (41% in Spain) of patients represent simplex cases (sRP) in which the mode of inheritance is unknown. Molecular genetic diagnostic is crucial, but also challenging, for sRP patients because any of the 81 RP genes identified to date may be causative. Herein, we report the use of a customized targeted gene panel consisting of 68 IRD genes for the molecular characterization of 106 sRP cases. The diagnostic rate was 62.26% (66 of 106) with a proportion of clinical refinements of 30.3%, demonstrating the high efficiency of this genomic approach even for clinically ambiguous cases. The high number of patients diagnosed here has allowed us to study in detail the genetic basis of the sRP. The solved sRP cohort is composed of 62.1% of arRP cases, 24.2% of adRP and 13.6% of xlRP, which implies consequences for counselling of patients and families.
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41
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Arno G, Carss KJ, Hull S, Zihni C, Robson AG, Fiorentino A, Hardcastle AJ, Holder GE, Cheetham ME, Plagnol V, Moore AT, Raymond FL, Matter K, Balda MS, Webster AR. Biallelic Mutation of ARHGEF18, Involved in the Determination of Epithelial Apicobasal Polarity, Causes Adult-Onset Retinal Degeneration. Am J Hum Genet 2017; 100:334-342. [PMID: 28132693 PMCID: PMC5294887 DOI: 10.1016/j.ajhg.2016.12.014] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2016] [Accepted: 12/15/2016] [Indexed: 01/19/2023] Open
Abstract
Mutations in more than 250 genes are implicated in inherited retinal dystrophy; the encoded proteins are involved in a broad spectrum of pathways. The presence of unsolved families after highly parallel sequencing strategies suggests that further genes remain to be identified. Whole-exome and -genome sequencing studies employed here in large cohorts of affected individuals revealed biallelic mutations in ARHGEF18 in three such individuals. ARHGEF18 encodes ARHGEF18, a guanine nucleotide exchange factor that activates RHOA, a small GTPase protein that is a key component of tight junctions and adherens junctions. This biological pathway is known to be important for retinal development and function, as mutation of CRB1, encoding another component, causes retinal dystrophy. The retinal structure in individuals with ARHGEF18 mutations resembled that seen in subjects with CRB1 mutations. Five mutations were found on six alleles in the three individuals: c.808A>G (p.Thr270Ala), c.1617+5G>A (p.Asp540Glyfs∗63), c.1996C>T (p.Arg666∗), c.2632G>T (p.Glu878∗), and c.2738_2761del (p.Arg913_Glu920del). Functional tests suggest that each disease genotype might retain some ARHGEF18 activity, such that the phenotype described here is not the consequence of nullizygosity. In particular, the p.Thr270Ala missense variant affects a highly conserved residue in the DBL homology domain, which is required for the interaction and activation of RHOA. Previously, knock-out of Arhgef18 in the medaka fish has been shown to cause larval lethality which is preceded by retinal defects that resemble those seen in zebrafish Crumbs complex knock-outs. The findings described here emphasize the peculiar sensitivity of the retina to perturbations of this pathway, which is highlighted as a target for potential therapeutic strategies.
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Affiliation(s)
- Gavin Arno
- UCL Institute of Ophthalmology, University College London, London EC1V 9EL, UK; Moorfields Eye Hospital, London EC1V 2PD, UK
| | - Keren J Carss
- Department of Haematology, University of Cambridge NHS Blood and Transplant Centre, Cambridge CB2 0PT, UK; NIHR BioResource - Rare Diseases, Cambridge University Hospitals NHS Foundation, Cambridge Biomedical Campus, Cambridge CB2 0QQ, UK
| | - Sarah Hull
- UCL Institute of Ophthalmology, University College London, London EC1V 9EL, UK; Moorfields Eye Hospital, London EC1V 2PD, UK
| | - Ceniz Zihni
- UCL Institute of Ophthalmology, University College London, London EC1V 9EL, UK
| | - Anthony G Robson
- UCL Institute of Ophthalmology, University College London, London EC1V 9EL, UK; Moorfields Eye Hospital, London EC1V 2PD, UK
| | - Alessia Fiorentino
- UCL Institute of Ophthalmology, University College London, London EC1V 9EL, UK
| | - Alison J Hardcastle
- UCL Institute of Ophthalmology, University College London, London EC1V 9EL, UK
| | - Graham E Holder
- UCL Institute of Ophthalmology, University College London, London EC1V 9EL, UK; Moorfields Eye Hospital, London EC1V 2PD, UK
| | - Michael E Cheetham
- UCL Institute of Ophthalmology, University College London, London EC1V 9EL, UK
| | - Vincent Plagnol
- University College London Genetics Institute, London WC1E 6BT, UK
| | - Anthony T Moore
- UCL Institute of Ophthalmology, University College London, London EC1V 9EL, UK; Moorfields Eye Hospital, London EC1V 2PD, UK; Ophthalmology Department, UCSF School of Medicine, Koret Vision Centre, San Francisco, CA 94133-0644, USA
| | - F Lucy Raymond
- NIHR BioResource - Rare Diseases, Cambridge University Hospitals NHS Foundation, Cambridge Biomedical Campus, Cambridge CB2 0QQ, UK; Department of Medical Genetics, Cambridge Institute for Medical Research, University of Cambridge, Cambridge CB2 0XY, UK
| | - Karl Matter
- UCL Institute of Ophthalmology, University College London, London EC1V 9EL, UK
| | - Maria S Balda
- UCL Institute of Ophthalmology, University College London, London EC1V 9EL, UK
| | - Andrew R Webster
- UCL Institute of Ophthalmology, University College London, London EC1V 9EL, UK; Moorfields Eye Hospital, London EC1V 2PD, UK.
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LONG-TERM FOLLOW-UP OF PATIENTS WITH RETINITIS PIGMENTOSA TYPE 12 CAUSED BY CRB1 MUTATIONS. Retina 2017; 37:161-172. [PMID: 27380427 DOI: 10.1097/iae.0000000000001127] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Lu L, Wang X, Lo D, Weng J, Liu X, Yang J, He F, Wang Y, Liu X. Novel mutations in CRB1 gene identified in a chinese pedigree with retinitis pigmentosa by targeted capture and next generation sequencing. Oncotarget 2016; 7:79797-79804. [PMID: 27806333 PMCID: PMC5346751 DOI: 10.18632/oncotarget.12971] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2016] [Accepted: 10/17/2016] [Indexed: 11/25/2022] Open
Abstract
PURPOSE To detect the disease-causing gene in a Chinese pedigree with autosomal-recessive retinitis pigmentosa (ARRP). METHODS All subjects in this family underwent a complete ophthalmic examination. Targeted-capture next generation sequencing (NGS) was performed on the proband to detect variants. All variants were verified in the remaining family members by PCR amplification and Sanger sequencing. RESULTS All the affected subjects in this pedigree were diagnosed with retinitis pigmentosa (RP). The compound heterozygous c.138delA (p.Asp47IlefsX24) and c.1841G>T (p.Gly614Val) mutations in the Crumbs homolog 1 (CRB1) gene were identified in all the affected patients but not in the unaffected individuals in this family. These mutations were inherited from their parents, respectively. CONCLUSION The novel compound heterozygous mutations in CRB1 were identified in a Chinese pedigree with ARRP using targeted-capture next generation sequencing. After evaluating the significant heredity and impaired protein function, the compound heterozygous c.138delA (p.Asp47IlefsX24) and c.1841G>T (p.Gly614Val) mutations are the causal genes of early onset ARRP in this pedigree. To the best of our knowledge, there is no previous report regarding the compound mutations.
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Affiliation(s)
- Lan Lu
- Department of Ophthalmology, Fujian Medical University Union Hospital, Fuzhou, Fujian, 350001, China
| | - Xizhen Wang
- Shenzhen Key Laboratory of Ophthalmology, Shenzhen Eye Hospital, Jinan University, Shenzhen, Guangdong, 518000, China
| | - David Lo
- Department of Internal Medicine, Danbury, CT 06810, USA
| | - Jingning Weng
- Department of Ophthalmology, Fujian Medical University Union Hospital, Fuzhou, Fujian, 350001, China
| | - xiaohong Liu
- Department of Ophthalmology, The People's Hospital of Baoan Shenzhen, Guangdong, 518101, China
| | - Juhua Yang
- Biomedical Engineering Center, Fujian Medical University, Fuzhou, Fujian, 350001, China
| | - Fen He
- Shenzhen Key Laboratory of Ophthalmology, Shenzhen Eye Hospital, Jinan University, Shenzhen, Guangdong, 518000, China
| | - Yun Wang
- Shenzhen Key Laboratory of Ophthalmology, Shenzhen Eye Hospital, Jinan University, Shenzhen, Guangdong, 518000, China
| | - Xuyang Liu
- Shenzhen Key Laboratory of Ophthalmology, Shenzhen Eye Hospital, Jinan University, Shenzhen, Guangdong, 518000, China
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Djuric I, Siebrasse JP, Schulze U, Granado D, Schlüter MA, Kubitscheck U, Pavenstädt H, Weide T. The C-terminal domain controls the mobility of Crumbs 3 isoforms. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2016; 1863:1208-17. [DOI: 10.1016/j.bbamcr.2016.03.008] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2015] [Revised: 03/07/2016] [Accepted: 03/08/2016] [Indexed: 01/12/2023]
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Shah N, Damani MR, Zhu XS, Bedoukian EC, Bennett J, Maguire AM, Leroy BP. Isolated maculopathy associated with biallelic CRB1 mutations. Ophthalmic Genet 2016; 38:190-193. [PMID: 27096895 DOI: 10.3109/13816810.2016.1155225] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Affiliation(s)
- Neepa Shah
- a Division of Ophthalmology , Children's Hospital of Philadelphia , Philadelphia , Pennsylvania , USA.,b Scheie Eye Institute, University of Pennsylvania , Philadelphia , Pennsylvania , USA
| | - Mausam R Damani
- a Division of Ophthalmology , Children's Hospital of Philadelphia , Philadelphia , Pennsylvania , USA.,b Scheie Eye Institute, University of Pennsylvania , Philadelphia , Pennsylvania , USA
| | - Xiaosong Sonia Zhu
- a Division of Ophthalmology , Children's Hospital of Philadelphia , Philadelphia , Pennsylvania , USA
| | - Emma C Bedoukian
- c Individualized Medical Genetics Center, Children's Hospital of Philadelphia , Philadelphia , Pennsylvania , USA
| | - Jean Bennett
- b Scheie Eye Institute, University of Pennsylvania , Philadelphia , Pennsylvania , USA
| | - Albert M Maguire
- a Division of Ophthalmology , Children's Hospital of Philadelphia , Philadelphia , Pennsylvania , USA.,b Scheie Eye Institute, University of Pennsylvania , Philadelphia , Pennsylvania , USA
| | - Bart P Leroy
- a Division of Ophthalmology , Children's Hospital of Philadelphia , Philadelphia , Pennsylvania , USA.,d Department of Ophthalmology & Center for Medical Genetics , Ghent University Hospital & Ghent University , Ghent , Belgium
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Bifari IN, Khan AO. Bilateral retinal hemorrhages following finger pressure against the soft palate (الترفيع) in recessive CRB1-related retinopathy. Ophthalmic Genet 2016; 37:441-444. [PMID: 27007588 DOI: 10.3109/13816810.2015.1126613] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
PURPOSE To report two siblings with CRB1-related retinopathy who developed retinal hemorrhages following village traditional treatment of upward finger pressure against the soft palate ([Formula: see text]). METHODS A retrospective case series. RESULTS Two sisters were clinically diagnosed and genetically confirmed to have recessive CRB1-related retinal dystrophy. The family did not accept the condition as non-treatable and took both sisters for a traditional village therapy, consisting of several sessions of intense upward index finger pressure by the healer against the soft palate for each child. When examined following this therapy, both sisters had bilateral pre-retinal hemorrhages which were not present before the intervention and resolved without sequelae over the next several months. CONCLUSIONS The traditional village therapy may have compromised retinal venous outflow and/or provoked a Valsalva phenomenon, leading to the bilateral retinal hemorrhages. The fact that this occurred bilaterally and in both sisters supports the concept of relative vessel wall incompetence as part of CRB1-related retinopathy.
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Affiliation(s)
- Inam N Bifari
- a Division of Pediatric Ophthalmology, King Khaled Eye Specialist Hospital , Riyadh , Saudi Arabia
| | - Arif O Khan
- b Eye Institute, Cleveland Clinic Abu Dhabi , Abu Dhabi , United Arab Emirates
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Jimeno D, Gómez C, Calzada N, de la Villa P, Lillo C, Santos E. RASGRF2 controls nuclear migration in postnatal retinal cone photoreceptors. J Cell Sci 2016; 129:729-42. [PMID: 26743081 DOI: 10.1242/jcs.180919] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2015] [Accepted: 12/29/2015] [Indexed: 02/04/2023] Open
Abstract
Detailed immunocytochemical analyses comparing wild-type (WT), GRF1-knockout (KO), GRF2-KO and GRF1/2 double-knockout (DKO) mouse retinas uncovered the specific accumulation of misplaced, 'ectopic' cone photoreceptor nuclei in the photoreceptor segment (PS) area of retinas from GRF2-KO and GRF1/2-DKO, but not of WT or GRF1-KO mice. Localization of ectopic nuclei in the PS area of GRF2-depleted retinas occurred postnatally and peaked between postnatal day (P)11 and P15. Mechanistically, the generation of this phenotype involved disruption of the outer limiting membrane and intrusion into the PS layer by cone nuclei displaying significant perinuclear accumulation of signaling molecules known to participate in nuclear migration and cytoskeletal reorganization, such as PAR3, PAR6 and activated, phosphorylated forms of PAK, MLC2 and VASP. Electroretinographic recordings showed specific impairment of cone-mediated retinal function in GRF2-KO and GRF1/2-DKO retinas compared with WT controls. These data identify defective cone nuclear migration as a novel phenotype in mouse retinas lacking GRF2 and support a crucial role of GRF2 in control of the nuclear migration processes required for proper postnatal development and function of retinal cone photoreceptors.
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Affiliation(s)
- David Jimeno
- Centro de Investigación del Cáncer-Instituto de Biología Molecular y Celular del Cáncer (CSIC - Universidad de Salamanca), Salamanca 37007, Spain
| | - Carmela Gómez
- Centro de Investigación del Cáncer-Instituto de Biología Molecular y Celular del Cáncer (CSIC - Universidad de Salamanca), Salamanca 37007, Spain
| | - Nuria Calzada
- Centro de Investigación del Cáncer-Instituto de Biología Molecular y Celular del Cáncer (CSIC - Universidad de Salamanca), Salamanca 37007, Spain
| | - Pedro de la Villa
- Departamento de Fisiología, Universidad Alcalá, Alcalá de Henares 28871, Spain, Spain
| | | | - Eugenio Santos
- Centro de Investigación del Cáncer-Instituto de Biología Molecular y Celular del Cáncer (CSIC - Universidad de Salamanca), Salamanca 37007, Spain
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48
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Boulanger-Scemama E, El Shamieh S, Démontant V, Condroyer C, Antonio A, Michiels C, Boyard F, Saraiva JP, Letexier M, Souied E, Mohand-Saïd S, Sahel JA, Zeitz C, Audo I. Next-generation sequencing applied to a large French cone and cone-rod dystrophy cohort: mutation spectrum and new genotype-phenotype correlation. Orphanet J Rare Dis 2015; 10:85. [PMID: 26103963 PMCID: PMC4566196 DOI: 10.1186/s13023-015-0300-3] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2014] [Accepted: 06/15/2015] [Indexed: 12/21/2022] Open
Abstract
Background Cone and cone-rod dystrophies are clinically and genetically heterogeneous inherited retinal disorders with predominant cone impairment. They should be distinguished from the more common group of rod-cone dystrophies (retinitis pigmentosa) due to their more severe visual prognosis with early central vision loss. The purpose of our study was to document mutation spectrum of a large French cohort of cone and cone-rod dystrophies. Methods We applied Next-Generation Sequencing targeting a panel of 123 genes implicated in retinal diseases to 96 patients. A systematic filtering approach was used to identify likely disease causing variants, subsequently confirmed by Sanger sequencing and co-segregation analysis when possible. Results Overall, the likely causative mutations were detected in 62.1 % of cases, revealing 33 known and 35 novel mutations. This rate was higher for autosomal dominant (100 %) than autosomal recessive cases (53.8 %). Mutations in ABCA4 and GUCY2D were responsible for 19.2 % and 29.4 % of resolved cases with recessive and dominant inheritance, respectively. Furthermore, unexpected genotype-phenotype correlations were identified, confirming the complexity of inherited retinal disorders with phenotypic overlap between cone-rod dystrophies and other retinal diseases. Conclusions In summary, this time-efficient approach allowed mutation detection in the most important cohort of cone-rod dystrophies investigated so far covering the largest number of genes. Association of known gene defects with novel phenotypes and mode of inheritance were established. Electronic supplementary material The online version of this article (doi:10.1186/s13023-015-0300-3) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Elise Boulanger-Scemama
- INSERM, U968, Paris, F-75012, France.,Institut de la Vision, Sorbonne Universités, UPMC Univ Paris 06, UMR_S 968, 17, rue Moreau, Paris, F-75012, France.,CNRS, UMR_7210, Paris, F-75012, France
| | - Said El Shamieh
- INSERM, U968, Paris, F-75012, France.,Institut de la Vision, Sorbonne Universités, UPMC Univ Paris 06, UMR_S 968, 17, rue Moreau, Paris, F-75012, France.,CNRS, UMR_7210, Paris, F-75012, France
| | - Vanessa Démontant
- INSERM, U968, Paris, F-75012, France.,Institut de la Vision, Sorbonne Universités, UPMC Univ Paris 06, UMR_S 968, 17, rue Moreau, Paris, F-75012, France.,CNRS, UMR_7210, Paris, F-75012, France
| | - Christel Condroyer
- INSERM, U968, Paris, F-75012, France.,Institut de la Vision, Sorbonne Universités, UPMC Univ Paris 06, UMR_S 968, 17, rue Moreau, Paris, F-75012, France.,CNRS, UMR_7210, Paris, F-75012, France
| | - Aline Antonio
- INSERM, U968, Paris, F-75012, France.,Institut de la Vision, Sorbonne Universités, UPMC Univ Paris 06, UMR_S 968, 17, rue Moreau, Paris, F-75012, France.,CNRS, UMR_7210, Paris, F-75012, France.,Centre Hospitalier National d'Ophtalmologie des Quinze-Vingts, DHU ViewMaintain, INSERM-DHOS CIC 1423, Paris, F-75012, France
| | - Christelle Michiels
- INSERM, U968, Paris, F-75012, France.,Institut de la Vision, Sorbonne Universités, UPMC Univ Paris 06, UMR_S 968, 17, rue Moreau, Paris, F-75012, France.,CNRS, UMR_7210, Paris, F-75012, France
| | - Fiona Boyard
- INSERM, U968, Paris, F-75012, France.,Institut de la Vision, Sorbonne Universités, UPMC Univ Paris 06, UMR_S 968, 17, rue Moreau, Paris, F-75012, France.,CNRS, UMR_7210, Paris, F-75012, France
| | - Jean-Paul Saraiva
- IntegraGen SA, Genopole CAMPUS 1 bat G8 FR-91030 EVRY, Paris, France
| | - Mélanie Letexier
- IntegraGen SA, Genopole CAMPUS 1 bat G8 FR-91030 EVRY, Paris, France
| | - Eric Souied
- Centre Hospitalier Intercommunal de Créteil, Department of Ophthalmology, Université Paris-Est Créteil, 94000, Créteil, France
| | - Saddek Mohand-Saïd
- INSERM, U968, Paris, F-75012, France.,Institut de la Vision, Sorbonne Universités, UPMC Univ Paris 06, UMR_S 968, 17, rue Moreau, Paris, F-75012, France.,CNRS, UMR_7210, Paris, F-75012, France.,Centre Hospitalier National d'Ophtalmologie des Quinze-Vingts, DHU ViewMaintain, INSERM-DHOS CIC 1423, Paris, F-75012, France
| | - José-Alain Sahel
- INSERM, U968, Paris, F-75012, France.,Institut de la Vision, Sorbonne Universités, UPMC Univ Paris 06, UMR_S 968, 17, rue Moreau, Paris, F-75012, France.,CNRS, UMR_7210, Paris, F-75012, France.,Centre Hospitalier National d'Ophtalmologie des Quinze-Vingts, DHU ViewMaintain, INSERM-DHOS CIC 1423, Paris, F-75012, France.,Fondation Ophtalmologique Adolphe de Rothschild, 75019, Paris, France.,Académie des Sciences-Institut de France, 75006, Paris, France.,University College London Institute of Ophthalmology, 11-43 Bath Street, London, EC1V 9EL, UK
| | - Christina Zeitz
- INSERM, U968, Paris, F-75012, France. .,Institut de la Vision, Sorbonne Universités, UPMC Univ Paris 06, UMR_S 968, 17, rue Moreau, Paris, F-75012, France. .,CNRS, UMR_7210, Paris, F-75012, France.
| | - Isabelle Audo
- INSERM, U968, Paris, F-75012, France. .,Institut de la Vision, Sorbonne Universités, UPMC Univ Paris 06, UMR_S 968, 17, rue Moreau, Paris, F-75012, France. .,CNRS, UMR_7210, Paris, F-75012, France. .,Centre Hospitalier National d'Ophtalmologie des Quinze-Vingts, DHU ViewMaintain, INSERM-DHOS CIC 1423, Paris, F-75012, France. .,University College London Institute of Ophthalmology, 11-43 Bath Street, London, EC1V 9EL, UK.
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Krol J, Krol I, Alvarez CPP, Fiscella M, Hierlemann A, Roska B, Filipowicz W. A network comprising short and long noncoding RNAs and RNA helicase controls mouse retina architecture. Nat Commun 2015; 6:7305. [PMID: 26041499 PMCID: PMC4468907 DOI: 10.1038/ncomms8305] [Citation(s) in RCA: 66] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2014] [Accepted: 04/27/2015] [Indexed: 12/25/2022] Open
Abstract
Brain regions, such as the cortex and retina, are composed of layers of uniform thickness. The molecular mechanism that controls this uniformity is not well understood. Here we show that during mouse postnatal development the timed expression of Rncr4, a retina-specific long noncoding RNA, regulates the similarly timed processing of pri-miR-183/96/182, which is repressed at an earlier developmental stage by RNA helicase Ddx3x. Shifting the timing of mature miR-183/96/182 accumulation or interfering with Ddx3x expression leads to the disorganization of retinal architecture, with the photoreceptor layer being most affected. We identify Crb1, a component of the adhesion belt between glial and photoreceptor cells, as a link between Rncr4-regulated miRNA metabolism and uniform retina layering. Our results suggest that the precise timing of glia–neuron interaction controlled by noncoding RNAs and Ddx3x is important for the even distribution of cells across layers. The mammalian retina is a modular brain region, in which cell layers are of uniform thickness but the molecular mechanism controlling this process is not well understood. Here the authors identify a regulatory network consisting of the long noncoding RNA Rncr4, RNA helicase Ddx3x and miR-183/96/182 that controls the even distribution of cells across layers.
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Affiliation(s)
- Jacek Krol
- Neural Circuit Laboratories, Friedrich Miescher Institute for Biomedical Research, 4058 Basel, Switzerland
| | - Ilona Krol
- Neural Circuit Laboratories, Friedrich Miescher Institute for Biomedical Research, 4058 Basel, Switzerland
| | | | | | | | - Botond Roska
- 1] Neural Circuit Laboratories, Friedrich Miescher Institute for Biomedical Research, 4058 Basel, Switzerland [2] Faculty of Medicine, University of Basel, 4056 Basel, Switzerland
| | - Witold Filipowicz
- 1] Neural Circuit Laboratories, Friedrich Miescher Institute for Biomedical Research, 4058 Basel, Switzerland [2] Biozentrum, University of Basel, 4056 Basel, Switzerland
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50
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Leber Congenital Amaurosis: First Genotyped Hungarian Patients and Report of 2 Novel Mutations in the CRB1 and CEP290 Genes. Eur J Ophthalmol 2015; 26:78-84. [DOI: 10.5301/ejo.5000643] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/03/2015] [Indexed: 01/17/2023]
Abstract
Purpose To introduce the first Hungarian patients with genetically defined Leber congenital amaurosis (LCA) and to report 2 novel mutations. Methods Seven otherwise healthy patients (4-29 years, 5 male and 2 female) who had an onset of severe visual impairment before age 2 years were investigated. The diagnosis was established in all individuals by medical history, funduscopy, and full-field electroretinogram (ERG). Ocular examination included visual acuity testing, digital fundus photography, and in 6 patients retinal imaging with optical coherence tomography (OCT). Arrayed primer extension microarray screening was performed in all probands. In 2 patients, further Sanger sequencing and targeted next-generation sequencing revealed the second disease allele. Results A cone-rod type LCA was revealed in 4 patients and a rod-cone type disease in 3 patients. Five patients presented with maculopathy. Optical coherence tomography (OCT) imaging showed diffuse retinal thickening in 3 probands with severe macular atrophy in one. Full-field ERGs were undetectable or residual in all patients. Genetic screening revealed AIPL1, CRB1, and CEP290 gene-related pathology in 6 patients; in 1 proband, no mutation was found. Three homozygous and 3 compound heterozygous mutations were identified. Two novel variants were detected: c.2536G>T (p.G846X) in the CRB1 gene and c.4929delA (p.Lys1643fsX2) in the CEP290 gene. Conclusions Genetic subtypes identified are among the most common ones in LCA; the phenotypes are consistent with those reported previously. Both novel mutations are predicted to result in a premature translation termination. The phenotype related to the novel CRB1 mutation results in severe atrophic maculopathy.
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