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Hitti-Malin RJ, Panneman DM, Corradi Z, Boonen EGM, Astuti G, Dhaenens CM, Stöhr H, Weber BHF, Sharon D, Banin E, Karali M, Banfi S, Ben-Yosef T, Glavač D, Farrar GJ, Ayuso C, Liskova P, Dudakova L, Vajter M, Ołdak M, Szaflik JP, Matynia A, Gorin MB, Kämpjärvi K, Bauwens M, De Baere E, Hoyng CB, Li CHZ, Klaver CCW, Inglehearn CF, Fujinami K, Rivolta C, Allikmets R, Zernant J, Lee W, Podhajcer OL, Fakin A, Sajovic J, AlTalbishi A, Valeina S, Taurina G, Vincent AL, Roberts L, Ramesar R, Sartor G, Luppi E, Downes SM, van den Born LI, McLaren TL, De Roach JN, Lamey TM, Thompson JA, Chen FK, Tracewska AM, Kamakari S, Sallum JMF, Bolz HJ, Kayserili H, Roosing S, Cremers FPM. Towards Uncovering the Role of Incomplete Penetrance in Maculopathies through Sequencing of 105 Disease-Associated Genes. Biomolecules 2024; 14:367. [PMID: 38540785 PMCID: PMC10967834 DOI: 10.3390/biom14030367] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2024] [Revised: 03/14/2024] [Accepted: 03/15/2024] [Indexed: 05/02/2024] Open
Abstract
Inherited macular dystrophies (iMDs) are a group of genetic disorders, which affect the central region of the retina. To investigate the genetic basis of iMDs, we used single-molecule Molecular Inversion Probes to sequence 105 maculopathy-associated genes in 1352 patients diagnosed with iMDs. Within this cohort, 39.8% of patients were considered genetically explained by 460 different variants in 49 distinct genes of which 73 were novel variants, with some affecting splicing. The top five most frequent causative genes were ABCA4 (37.2%), PRPH2 (6.7%), CDHR1 (6.1%), PROM1 (4.3%) and RP1L1 (3.1%). Interestingly, variants with incomplete penetrance were revealed in almost one-third of patients considered solved (28.1%), and therefore, a proportion of patients may not be explained solely by the variants reported. This includes eight previously reported variants with incomplete penetrance in addition to CDHR1:c.783G>A and CNGB3:c.1208G>A. Notably, segregation analysis was not routinely performed for variant phasing-a limitation, which may also impact the overall diagnostic yield. The relatively high proportion of probands without any putative causal variant (60.2%) highlights the need to explore variants with incomplete penetrance, the potential modifiers of disease and the genetic overlap between iMDs and age-related macular degeneration. Our results provide valuable insights into the genetic landscape of iMDs and warrant future exploration to determine the involvement of other maculopathy genes.
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Affiliation(s)
- Rebekkah J. Hitti-Malin
- Department of Human Genetics, Radboud University Medical Center, 6500 HB Nijmegen, The Netherlands
| | - Daan M. Panneman
- Department of Human Genetics, Radboud University Medical Center, 6500 HB Nijmegen, The Netherlands
| | - Zelia Corradi
- Department of Human Genetics, Radboud University Medical Center, 6500 HB Nijmegen, The Netherlands
| | - Erica G. M. Boonen
- Department of Human Genetics, Radboud University Medical Center, 6500 HB Nijmegen, The Netherlands
| | - Galuh Astuti
- Department of Human Genetics, Radboud University Medical Center, 6500 HB Nijmegen, The Netherlands
| | - Claire-Marie Dhaenens
- Univ. Lille, Inserm, CHU Lille, U1172-LilNCog-Lille Neuroscience & Cognition, F-59000 Lille, France
| | - Heidi Stöhr
- Institute of Human Genetics, University of Regensburg, 93053 Regensburg, Germany
| | - Bernhard H. F. Weber
- Institute of Human Genetics, University of Regensburg, 93053 Regensburg, Germany
- Institute of Clinical Human Genetics, University Hospital Regensburg, 93053 Regensburg, Germany
| | - Dror Sharon
- Department of Ophthalmology, Hadassah Medical Center, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 91120, Israel
| | - Eyal Banin
- Department of Ophthalmology, Hadassah Medical Center, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 91120, Israel
| | - Marianthi Karali
- Department of Precision Medicine, University of Campania ‘Luigi Vanvitelli’, 80138 Naples, Italy
- Eye Clinic, Multidisciplinary Department of Medical, Surgical and Dental Sciences, University of Campania ‘Luigi Vanvitelli’, 80131 Naples, Italy
| | - Sandro Banfi
- Department of Precision Medicine, University of Campania ‘Luigi Vanvitelli’, 80138 Naples, Italy
- Eye Clinic, Multidisciplinary Department of Medical, Surgical and Dental Sciences, University of Campania ‘Luigi Vanvitelli’, 80131 Naples, Italy
- Telethon Institute of Genetics and Medicine (TIGEM), 80078 Pozzuoli, Italy
| | - Tamar Ben-Yosef
- Ruth and Bruce Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa 31096, Israel
| | - Damjan Glavač
- Department of Molecular Genetics, Institute of Pathology, Faculty of Medicine, University of Ljubljana, 1000 Ljubljana, Slovenia
- Center for Human Genetics and Pharmacogenomics, Faculty of Medicine, University of Maribor, 2000 Maribor, Slovenia
| | - G. Jane Farrar
- The School of Genetics and Microbiology, The University of Dublin Trinity College, D02 VF25 Dublin, Ireland
| | - Carmen Ayuso
- Department of Genetics, Health Research Institute-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), 28049 Madrid, Spain
- Center for Biomedical Network Research on Rare Diseases (CIBERER), Instituto de Salud Carlos III, 28029 Madrid, Spain
| | - Petra Liskova
- Department of Paediatrics and Inherited Metabolic Disorders, First Faculty of Medicine, Charles University and General University Hospital in Prague, 128 08 Prague, Czech Republic
- Department of Ophthalmology, First Faculty of Medicine, Charles University and General University Hospital in Prague, 128 08 Prague, Czech Republic
| | - Lubica Dudakova
- Department of Paediatrics and Inherited Metabolic Disorders, First Faculty of Medicine, Charles University and General University Hospital in Prague, 128 08 Prague, Czech Republic
| | - Marie Vajter
- Department of Paediatrics and Inherited Metabolic Disorders, First Faculty of Medicine, Charles University and General University Hospital in Prague, 128 08 Prague, Czech Republic
- Department of Ophthalmology, First Faculty of Medicine, Charles University and General University Hospital in Prague, 128 08 Prague, Czech Republic
| | - Monika Ołdak
- Department of Histology and Embryology, Medical University of Warsaw, 02-004 Warsaw, Poland
| | - Jacek P. Szaflik
- Department of Ophthalmology, Medical University of Warsaw, SPKSO Ophthalmic University Hospital, 03-709 Warsaw, Poland
| | - Anna Matynia
- College of Optometry, University of Houston, Houston, TX 77004, USA
- 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
| | | | | | - Miriam Bauwens
- Department of Biomolecular Medicine, Ghent University, 9000 Ghent, Belgium
- Center for Medical Genetics, Ghent University Hospital, 9000 Ghent, Belgium
| | - Elfride De Baere
- Department of Biomolecular Medicine, Ghent University, 9000 Ghent, Belgium
- Center for Medical Genetics, Ghent University Hospital, 9000 Ghent, Belgium
| | - Carel B. Hoyng
- Department of Ophthalmology, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands
| | - Catherina H. Z. Li
- Department of Ophthalmology, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands
| | - Caroline C. W. Klaver
- Department of Ophthalmology, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands
| | - Chris F. Inglehearn
- Division of Molecular Medicine, Leeds Institute of Medical Research, St. James’s University Hospital, University of Leeds, Leeds LS9 7TF, UK
| | - Kaoru Fujinami
- Department of Ophthalmology, The Jikei University School of Medicine, Tokyo 105-8461, Japan
| | - Carlo Rivolta
- Institute of Molecular and Clinical Ophthalmology Basel, 4031 Basel, Switzerland
| | - Rando Allikmets
- Department of Ophthalmology, Columbia University, New York, NY 10027, USA
- Department of Pathology & Cell Biology, Columbia University, New York, NY 10027, USA
| | - Jana Zernant
- Department of Ophthalmology, Columbia University, New York, NY 10027, USA
| | - Winston Lee
- Department of Ophthalmology, Columbia University, New York, NY 10027, USA
| | - Osvaldo L. Podhajcer
- Laboratorio de Terapia Molecular y Celular (Genocan), Fundación Instituto Leloir, CONICET, Buenos Aires 1405, Argentina
| | - Ana Fakin
- Eye Hospital, University Medical Centre Ljubljana, 1000 Ljubljana, Slovenia
- Faculty of Medicine, University of Ljubljana, 1000 Ljubljana, Slovenia
| | - Jana Sajovic
- Eye Hospital, University Medical Centre Ljubljana, 1000 Ljubljana, Slovenia
- Faculty of Medicine, University of Ljubljana, 1000 Ljubljana, Slovenia
| | - Alaa AlTalbishi
- St John of Jerusalem Eye Hospital Group, East Jerusalem 91198, Palestine
| | - Sandra Valeina
- Department of Ophthalmology, Riga Stradins University, LV-1007 Riga, Latvia
- Children’s Clinical University Hospital, LV-1004 Riga, Latvia
| | - Gita Taurina
- Children’s Clinical University Hospital, LV-1004 Riga, Latvia
| | - Andrea L. Vincent
- Department of Ophthalmology, New Zealand National Eye Centre, Faculty of Medical and Health Sciences, The University of Auckland, Grafton, Auckland 1023, New Zealand
- Eye Department, Greenlane Clinical Centre, Auckland District Health Board, Auckland 1142, New Zealand
| | - Lisa Roberts
- University of Cape Town/MRC Precision and Genomic Medicine Research Unit, Division of Human Genetics, Department of Pathology, Institute of Infectious Disease and Molecular Medicine (IDM), Faculty of Health Sciences, University of Cape Town, Cape Town 7925, South Africa
| | - Raj Ramesar
- University of Cape Town/MRC Precision and Genomic Medicine Research Unit, Division of Human Genetics, Department of Pathology, Institute of Infectious Disease and Molecular Medicine (IDM), Faculty of Health Sciences, University of Cape Town, Cape Town 7925, South Africa
| | - Giovanna Sartor
- Department of Pharmacy and Biotechnology, University of Bologna, 40127 Bologna, Italy
| | - Elena Luppi
- Department of Medical and Surgical Sciences, University of Bologna, 40127 Bologna, Italy
- Unit of Medical Genetics, IRCCS Azienda Ospedaliero-Universitaria di Bologna, 40138 Bologna, Italy
| | - Susan M. Downes
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, Oxford University, Oxford OX3 9DU, UK
- Oxford Eye Hospital, Oxford University NHS Foundation Trust, Oxford OX3 9DU, UK
| | | | - Terri L. McLaren
- Australian Inherited Retinal Disease Registry and DNA Bank, Department of Medical Technology and Physics, Sir Charles Gairdner Hospital, Nedlands, WA 6009, Australia
- Centre for Ophthalmology and Visual Science, The University of Western Australia, Nedlands, WA 6009, Australia
| | - John N. De Roach
- Australian Inherited Retinal Disease Registry and DNA Bank, Department of Medical Technology and Physics, Sir Charles Gairdner Hospital, Nedlands, WA 6009, Australia
- Centre for Ophthalmology and Visual Science, The University of Western Australia, Nedlands, WA 6009, Australia
| | - Tina M. Lamey
- Australian Inherited Retinal Disease Registry and DNA Bank, Department of Medical Technology and Physics, Sir Charles Gairdner Hospital, Nedlands, WA 6009, Australia
- Centre for Ophthalmology and Visual Science, The University of Western Australia, Nedlands, WA 6009, Australia
| | - Jennifer A. Thompson
- Australian Inherited Retinal Disease Registry and DNA Bank, Department of Medical Technology and Physics, Sir Charles Gairdner Hospital, Nedlands, WA 6009, Australia
| | - Fred K. Chen
- Centre for Ophthalmology and Visual Science, The University of Western Australia, Nedlands, WA 6009, Australia
| | | | - Smaragda Kamakari
- Ophthalmic Genetics Unit, OMMA Ophthalmological Institute of Athens, 115 25 Athens, Greece
| | - Juliana Maria Ferraz Sallum
- Department of Ophthalmology and Visual Sciences, Universidade Federal de São Paulo, São Paulo 04023-062, SP, Brazil
- Instituto de Genética Ocular, São Paulo 04552-050, SP, Brazil
| | - Hanno J. Bolz
- Institute of Human Genetics, University Hospital of Cologne, 50937 Cologne, Germany
| | - Hülya Kayserili
- Department of Medical Genetics, Koc University School of Medicine (KUSOM), 34450 Istanbul, Turkey
| | - Susanne Roosing
- Department of Human Genetics, Radboud University Medical Center, 6500 HB Nijmegen, The Netherlands
| | - Frans P. M. Cremers
- Department of Human Genetics, Radboud University Medical Center, 6500 HB Nijmegen, The Netherlands
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Georgiou M, Robson AG, Fujinami K, de Guimarães TAC, Fujinami-Yokokawa Y, Daich Varela M, Pontikos N, Kalitzeos A, Mahroo OA, Webster AR, Michaelides M. Phenotyping and genotyping inherited retinal diseases: Molecular genetics, clinical and imaging features, and therapeutics of macular dystrophies, cone and cone-rod dystrophies, rod-cone dystrophies, Leber congenital amaurosis, and cone dysfunction syndromes. Prog Retin Eye Res 2024; 100:101244. [PMID: 38278208 DOI: 10.1016/j.preteyeres.2024.101244] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2023] [Revised: 01/12/2024] [Accepted: 01/15/2024] [Indexed: 01/28/2024]
Abstract
Inherited retinal diseases (IRD) are a leading cause of blindness in the working age population and in children. The scope of this review is to familiarise clinicians and scientists with the current landscape of molecular genetics, clinical phenotype, retinal imaging and therapeutic prospects/completed trials in IRD. Herein we present in a comprehensive and concise manner: (i) macular dystrophies (Stargardt disease (ABCA4), X-linked retinoschisis (RS1), Best disease (BEST1), PRPH2-associated pattern dystrophy, Sorsby fundus dystrophy (TIMP3), and autosomal dominant drusen (EFEMP1)), (ii) cone and cone-rod dystrophies (GUCA1A, PRPH2, ABCA4, KCNV2 and RPGR), (iii) predominant rod or rod-cone dystrophies (retinitis pigmentosa, enhanced S-Cone syndrome (NR2E3), Bietti crystalline corneoretinal dystrophy (CYP4V2)), (iv) Leber congenital amaurosis/early-onset severe retinal dystrophy (GUCY2D, CEP290, CRB1, RDH12, RPE65, TULP1, AIPL1 and NMNAT1), (v) cone dysfunction syndromes (achromatopsia (CNGA3, CNGB3, PDE6C, PDE6H, GNAT2, ATF6), X-linked cone dysfunction with myopia and dichromacy (Bornholm Eye disease; OPN1LW/OPN1MW array), oligocone trichromacy, and blue-cone monochromatism (OPN1LW/OPN1MW array)). Whilst we use the aforementioned classical phenotypic groupings, a key feature of IRD is that it is characterised by tremendous heterogeneity and variable expressivity, with several of the above genes associated with a range of phenotypes.
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Affiliation(s)
- Michalis Georgiou
- Moorfields Eye Hospital, London, United Kingdom; UCL Institute of Ophthalmology, University College London, London, United Kingdom; Jones Eye Institute, University of Arkansas for Medical Sciences, Little Rock, AR, USA.
| | - Anthony G Robson
- Moorfields Eye Hospital, London, United Kingdom; UCL Institute of Ophthalmology, University College London, London, United Kingdom.
| | - Kaoru Fujinami
- Moorfields Eye Hospital, London, United Kingdom; UCL Institute of Ophthalmology, University College London, London, United Kingdom; Laboratory of Visual Physiology, Division of Vision Research, National Institute of Sensory Organs, National Hospital Organization Tokyo Medical Center, Tokyo, Japan.
| | - Thales A C de Guimarães
- Moorfields Eye Hospital, London, United Kingdom; UCL Institute of Ophthalmology, University College London, London, United Kingdom.
| | - Yu Fujinami-Yokokawa
- UCL Institute of Ophthalmology, University College London, London, United Kingdom; Laboratory of Visual Physiology, Division of Vision Research, National Institute of Sensory Organs, National Hospital Organization Tokyo Medical Center, Tokyo, Japan; Department of Health Policy and Management, Keio University School of Medicine, Tokyo, Japan.
| | - Malena Daich Varela
- Moorfields Eye Hospital, London, United Kingdom; UCL Institute of Ophthalmology, University College London, London, United Kingdom.
| | - Nikolas Pontikos
- Moorfields Eye Hospital, London, United Kingdom; UCL Institute of Ophthalmology, University College London, London, United Kingdom.
| | - Angelos Kalitzeos
- Moorfields Eye Hospital, London, United Kingdom; UCL Institute of Ophthalmology, University College London, London, United Kingdom.
| | - Omar A Mahroo
- Moorfields Eye Hospital, London, United Kingdom; UCL Institute of Ophthalmology, University College London, London, United Kingdom; Section of Ophthalmology, King s College London, St Thomas Hospital Campus, London, United Kingdom; Physiology, Development and Neuroscience, University of Cambridge, Downing Street, Cambridge, United Kingdom; Department of Translational Ophthalmology, Wills Eye Hospital, Philadelphia, PA, USA.
| | - Andrew R Webster
- Moorfields Eye Hospital, London, United Kingdom; UCL Institute of Ophthalmology, University College London, London, United Kingdom.
| | - Michel Michaelides
- Moorfields Eye Hospital, London, United Kingdom; UCL Institute of Ophthalmology, University College London, London, United Kingdom.
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Hu Z, Yang J. Structural basis of properties, mechanisms, and channelopathy of cyclic nucleotide-gated channels. Channels (Austin) 2023; 17:2273165. [PMID: 37905307 PMCID: PMC10761061 DOI: 10.1080/19336950.2023.2273165] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2023] [Accepted: 10/07/2023] [Indexed: 11/02/2023] Open
Abstract
Recent years have seen an outpouring of atomic or near atomic resolution structures of cyclic nucleotide-gated (CNG) channels, captured in closed, transition, pre-open, partially open, and fully open states. These structures provide unprecedented molecular insights into the activation, assembly, architecture, regulation, and channelopathy of CNG channels, as well as mechanistic explanations for CNG channel biophysical and pharmacological properties. This article summarizes recent advances in CNG channel structural biology, describes key structural features and elements, and illuminates a detailed conformational landscape of activation by cyclic nucleotides. The review also correlates structures with findings and properties delineated in functional studies, including nonselective monovalent cation selectivity, Ca2+ permeation and block, block by L-cis-diltiazem, location of the activation gate, lack of voltage-dependent gating, and modulation by lipids and calmodulin. A perspective on future research is also offered.
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Affiliation(s)
- Zhengshan Hu
- Department of Biological Sciences, Columbia University, New York, NY, USA
| | - Jian Yang
- Department of Biological Sciences, Columbia University, New York, NY, USA
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Solaki M, Wissinger B, Kohl S, Reuter P. Functional evaluation allows ACMG/AMP-based re-classification of CNGA3 variants associated with achromatopsia. Genet Med 2023; 25:100979. [PMID: 37689994 DOI: 10.1016/j.gim.2023.100979] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Revised: 08/30/2023] [Accepted: 08/30/2023] [Indexed: 09/11/2023] Open
Abstract
PURPOSE CNGA3 encoding the main subunit of the cyclic nucleotide-gated ion channel in cone photoreceptors is one of the major disease-associated genes for achromatopsia. Most CNGA3 variants are missense variants with the majority being functionally uncharacterized and therefore hampering genetic diagnosis. In light of potential gene therapy, objective variant pathogenicity assessment is essential. METHODS We established a medium-throughput aequorin-based luminescence bioassay allowing mutant CNGA3 channel function assessment via quantification of CNGA3 channel-mediated calcium influx in a cell culture system, thereby enabling American College of Medical Genetics and Genomics/Association for Molecular Pathology-based variant re-classification. RESULTS We provide functional read-out obtained for 150 yet uncharacterized CNGA3 missense substitutions of which 55 were previously categorized as variants of uncertain significance (VUS) identifying 25 as functionally normal and 125 as functionally abnormal. These data enabled the American College of Medical Genetics and Genomics/ Association for Molecular Pathology-based variant re-classification of 52/55 VUS as either benign, likely benign, or likely pathogenic reaching a VUS re-classification rate of 94.5%. CONCLUSION Our aequorin-based bioassay allows functionally ensured clinical variant interpretation for 150 CNGA3 missense variants enabling and supporting VUS re-classification and assuring molecular diagnosis to patients affected by CNGA3-associated achromatopsia, hereby identifying patients eligible for future gene therapy trials on this disease.
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Affiliation(s)
- Maria Solaki
- Institute for Ophthalmic Research, Centre for Ophthalmology, University of Tübingen, Tübingen, Germany
| | - Bernd Wissinger
- Institute for Ophthalmic Research, Centre for Ophthalmology, University of Tübingen, Tübingen, Germany
| | - Susanne Kohl
- Institute for Ophthalmic Research, Centre for Ophthalmology, University of Tübingen, Tübingen, Germany.
| | - Peggy Reuter
- Institute for Ophthalmic Research, Centre for Ophthalmology, University of Tübingen, Tübingen, Germany.
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Kugler SA, Valmaggia C, Sturm V, Schorderet DF, Todorova MG. Analysis of Suspected Achromatopsia by Multimodal Diagnostic Testing. Klin Monbl Augenheilkd 2023; 240:1158-1173. [PMID: 37714190 DOI: 10.1055/a-2176-4233] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/17/2023]
Abstract
BACKGROUND Achromatopsia (ACHM) as a hereditary cone disease might manifest in a stationary and progressive manner. The proper clinical and genetic diagnosis may allow an individual prognosis, accurate genetic counselling, and the optimal choice of low vision aids. The primary aim of the study was to determine the spectrum of clinical and genetic diagnostics required to characterize the ACHM. METHODS A retrospective analysis was performed in 8 patients from non-related families (5 ♀,3 ♂); age at diagnosis: 3 - 56 y, mean 18.13 (SD ± 18.22). Clinical phenotyping, supported by colour vision test, fundus photography-, autofluorescence- (FAF), infra-red- (IR), OCT imaging and electroretinography provided information on the current status and the course of the disease over the years. In addition, genetic examinations were performed with ACHM relevant testing (CNGA3, CNGB3, GNAT2, PDE6C, PDE6H and the transcription factor ATF6). RESULTS All patients suffered photophobia and reduced visual acuity (mean: 0.16 [SD ± 0.08]). Nystagmus was identified in 7 from 8 subjects and in one patient a head-turn right helped to reduce the nystagmus amplitude. Colour vision testing confirmed complete achromatopsia in 7 out of 8 patients. Electrophysiology found severely reduced photopic- but also scotopic responses. Thinning and interruption of the inner segment ellipsoid (ISe) line within the macula but also FAF- and IR abnormalities in the fovea and/or parafovea were characteristic in all ACHM patients. Identification of pathogenic mutations in 7 patients helped to confirm the diagnosis of ACHM (3 adults, 4 children; 3 ♀ and 4 ♂). Achromatopsia was linked to CNGA3 (2 ♀, 1 ♂) and CNGB3 variants (2 ♀, 3 ♂). The youngest patient (♀, 10 y) had 3 different CNGB3 variants on different alleles. In a patient (♂, 29 y) carrying 2 pathogenic digenic-triallelic CNGA3- and CNGB3-mutations, a severe progression of ISe discontinuity to coloboma-like macular atrophy was observed during the 12-year follow-up. The oldest female (67 y) showed a compound homozygous CNGA3- and heterozygous CNGB3-, as well as a heterozygous GUCY2D variants. The destruction of her ISe line was significantly enlarged and represented a progressive cone-rod phenotype in comparison to other ACHM patients. In a patient (♂, 45 y) carrying a pathogenic CNGB3 and USH2 mutation, a severe macular oedema and a rod-cone phenotype was observed. In addition, two variants in C2ORF71 considered as VOS were found. One patient showed the rare ATF6 mutation, where a severe coloboma-like macular atrophy was observed on the left eye as early as at the age of three years. CONCLUSION Combining multimodal ophthalmological diagnostics and molecular genetics when evaluating patients with ACHM helps in characterizing the disease and associated modifiers, and is therefore strongly recommended for such patients.
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Affiliation(s)
- Sylvia A Kugler
- Department of Ophthalmology, Cantonal Hospital St. Gallen, Switzerland
| | - Christophe Valmaggia
- Department of Ophthalmology, Cantonal Hospital St. Gallen, Switzerland
- Department of Ophthalmology, University of Zürich, Switzerland
| | - Veit Sturm
- Department of Ophthalmology, University of Zürich, Switzerland
- Ophthalmology, Eye Center Rosengarten, Arbon, Switzerland
| | - Daniel F Schorderet
- Faculty of Biology and Medicine, University of Lausanne and Faculty of Life Sciences, École polytechnique fédérale de Lausanne, Switzerland
| | - Margarita G Todorova
- Department of Ophthalmology, Cantonal Hospital St. Gallen, Switzerland
- Department of Ophthalmology, University of Zürich, Switzerland
- Department of Ophthalmology, University Hospital Basel, Switzerland
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Andersen MKG, Bertelsen M, Grønskov K, Kohl S, Kessel L. Genetic and Clinical Characterization of Danish Achromatopsia Patients. Genes (Basel) 2023; 14:690. [PMID: 36980963 PMCID: PMC10048638 DOI: 10.3390/genes14030690] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2023] [Revised: 03/07/2023] [Accepted: 03/08/2023] [Indexed: 03/16/2023] Open
Abstract
Achromatopsia is a rare congenital condition with cone photoreceptor dysfunction causing color blindness, reduced vision, nystagmus and photophobia. New treatments are being developed, but the current evidence is still conflicting regarding possible progression over time, and there is no clear genotype-phenotype correlation. This natural history study aimed to further explore the course of disease and potential clinical differences between various genotypes. The retrospective design allowed for the study of a large cohort with a long follow-up. Patients were identified from the Danish national registries. If not already available, genetic analysis was offered to the patient. Clinical data from 1945–2022 were retrieved from medical records and included best-corrected visual acuity (BCVA), color vision, refractive error, nystagmus, visual fields and fundoscopic findings. We identified variants believed to be disease causing in five of the known achromatopsia genes: CNGA3; CNGB3; GNAT2; PDE6C and PDE6H; and novel variants were identified in CNGB3 and PDE6C. Progressive deterioration of BCVA only attributable to achromatopsia was found in three of 58 patients. Progressive phenotype was seen with variants in CNGB3 and PDE6C. The results indicate that myopia could be more frequently occurring with variants in GNAT2, PDE6C and PDE6H and support the evidence that achromatopsia is a predominantly stationary condition with respect to BCVA. Although a clear genotype-phenotype correlation can still not be concluded, there may be differences in phenotypical characteristics with variants in different genes.
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Reuter P, Walter M, Kohl S, Weisschuh N. Systematic analysis of CNGA3 splice variants identifies different mechanisms of aberrant splicing. Sci Rep 2023; 13:2896. [PMID: 36801918 DOI: 10.1038/s41598-023-29452-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Accepted: 02/06/2023] [Indexed: 02/20/2023] Open
Abstract
Achromatopsia is an autosomal recessive cone photoreceptor disease that is frequently caused by pathogenic variants in the CNGA3 gene. Here, we present a systematic functional analysis of 20 CNGA3 splice site variants detected in our large cohort of achromatopsia patients and/or listed in common variant databases. All variants were analyzed by functional splice assays based on the pSPL3 exon trapping vector. We demonstrated that ten variants, both at canonical and non-canonical splice sites, induced aberrant splicing, including intronic nucleotide retention, exonic nucleotide deletion and exon skipping, resulting in 21 different aberrant transcripts. Of these, eleven were predicted to introduce a premature termination codon. The pathogenicity of all variants was assessed based on established guidelines for variant classification. Incorporation of the results of our functional analyses enabled re-classification of 75% of variants previously classified as variants of uncertain significance into either likely benign or likely pathogenic. Our study is the first in which a systematic characterization of putative CNGA3 splice variants has been performed. We demonstrated the utility of pSPL3 based minigene assays in the effective assessment of putative splice variants. Our findings improve the diagnosis of achromatopsia patients, who may thus benefit from future gene-based therapeutic strategies.
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Gerhardt MJ, Priglinger SG, Biel M, Michalakis S. Biology, Pathobiology and Gene Therapy of CNG Channel-Related Retinopathies. Biomedicines 2023; 11. [PMID: 36830806 DOI: 10.3390/biomedicines11020269] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2023] [Revised: 01/16/2023] [Accepted: 01/17/2023] [Indexed: 01/21/2023] Open
Abstract
The visual process begins with the absorption of photons by photopigments of cone and rod photoreceptors in the retina. In this process, the signal is first amplified by a cyclic guanosine monophosphate (cGMP)-based signaling cascade and then converted into an electrical signal by cyclic nucleotide-gated (CNG) channels. CNG channels are purely ligand-gated channels whose activity can be controlled by cGMP, which induces a depolarizing Na+/Ca2+ current upon binding to the channel. Structurally, CNG channels belong to the superfamily of pore-loop cation channels and share structural similarities with hyperpolarization-activated cyclic nucleotide (HCN) and voltage-gated potassium (KCN) channels. Cone and rod photoreceptors express distinct CNG channels encoded by homologous genes. Mutations in the genes encoding the rod CNG channel (CNGA1 and CNGB1) result in retinitis-pigmentosa-type blindness. Mutations in the genes encoding the cone CNG channel (CNGA3 and CNGB3) lead to achromatopsia. Here, we review the molecular properties of CNG channels and describe their physiological and pathophysiological roles in the retina. Moreover, we summarize recent activities in the field of gene therapy aimed at developing the first gene therapies for CNG channelopathies.
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9
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Hitti-Malin RJ, Dhaenens CM, Panneman DM, Corradi Z, Khan M, den Hollander AI, Farrar GJ, Gilissen C, Hoischen A, van de Vorst M, Bults F, Boonen EGM, Saunders P, Roosing S, Cremers FPM. Using single molecule Molecular Inversion Probes as a cost-effective, high-throughput sequencing approach to target all genes and loci associated with macular diseases. Hum Mutat 2022; 43:2234-2250. [PMID: 36259723 PMCID: PMC10092144 DOI: 10.1002/humu.24489] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Revised: 09/06/2022] [Accepted: 10/17/2022] [Indexed: 01/25/2023]
Abstract
Macular degenerations (MDs) are a subgroup of retinal disorders characterized by central vision loss. Knowledge is still lacking on the extent of genetic and nongenetic factors influencing inherited MD (iMD) and age-related MD (AMD) expression. Single molecule Molecular Inversion Probes (smMIPs) have proven effective in sequencing the ABCA4 gene in patients with Stargardt disease to identify associated coding and noncoding variation, however many MD patients still remain genetically unexplained. We hypothesized that the missing heritability of MDs may be revealed by smMIPs-based sequencing of all MD-associated genes and risk factors. Using 17,394 smMIPs, we sequenced the coding regions of 105 iMD and AMD-associated genes and noncoding or regulatory loci, known pseudo-exons, and the mitochondrial genome in two test cohorts that were previously screened for variants in ABCA4. Following detailed sequencing analysis of 110 probands, a diagnostic yield of 38% was observed. This established an ''MD-smMIPs panel," enabling a genotype-first approach in a high-throughput and cost-effective manner, whilst achieving uniform and high coverage across targets. Further analysis will identify known and novel variants in MD-associated genes to offer an accurate clinical diagnosis to patients. Furthermore, this will reveal new genetic associations for MD and potential genetic overlaps between iMD and AMD.
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Affiliation(s)
- Rebekkah J Hitti-Malin
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands.,Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Claire-Marie Dhaenens
- Inserm, CHU Lille, U1172-LilNCog-Lille Neuroscience & Cognition, Univ. Lille, Lille, France
| | - Daan M Panneman
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands.,Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Zelia Corradi
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands.,Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Mubeen Khan
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Anneke I den Hollander
- Department of Ophthalmology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - G Jane Farrar
- The School of Genetics & Microbiology, The University of Dublin Trinity College, Dublin, Ireland
| | - Christian Gilissen
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands.,Radboud Institute of Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Alexander Hoischen
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands.,Radboud Institute of Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands.,Department of Internal Medicine, Radboud University Medical Center for Infectious Diseases (RCI), Radboud University Medical Center, Nijmegen, The Netherlands
| | - Maartje van de Vorst
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Femke Bults
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Erica G M Boonen
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands
| | | | | | - Susanne Roosing
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands.,Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Frans P M Cremers
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands.,Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands
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10
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Solaki M, Baumann B, Reuter P, Andreasson S, Audo I, Ayuso C, Balousha G, Benedicenti F, Birch D, Bitoun P, Blain D, Bocquet B, Branham K, Català-Mora J, De Baere E, Dollfus H, Falana M, Giorda R, Golovleva I, Gottlob I, Heckenlively JR, Jacobson SG, Jones K, Jägle H, Janecke AR, Kellner U, Liskova P, Lorenz B, Martorell-Sampol L, Messias A, Meunier I, Belga Ottoni Porto F, Papageorgiou E, Plomp AS, de Ravel TJL, Reiff CM, Renner AB, Rosenberg T, Rudolph G, Salati R, Sener EC, Sieving PA, Stanzial F, Traboulsi EI, Tsang SH, Varsanyi B, Weleber RG, Zobor D, Stingl K, Wissinger B, Kohl S. Comprehensive variant spectrum of the CNGA3 gene in patients affected by achromatopsia. Hum Mutat 2022; 43:832-858. [PMID: 35332618 DOI: 10.1002/humu.24371] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2021] [Revised: 02/23/2022] [Accepted: 03/22/2022] [Indexed: 11/06/2022]
Abstract
Achromatopsia (ACHM) is a congenital cone photoreceptor disorder characterized by impaired color discrimination, low visual acuity, photosensitivity, and nystagmus. To date, six genes have been associated with ACHM (CNGA3, CNGB3, GNAT2, PDE6C, PDE6H, and ATF6), the majority of these being implicated in the cone phototransduction cascade. CNGA3 encodes the CNGA3 subunit of the cyclic nucleotide-gated ion channel in cone photoreceptors and is one of the major disease-associated genes for ACHM. Herein, we provide a comprehensive overview of the CNGA3 variant spectrum in a cohort of 1060 genetically confirmed ACHM patients, 385 (36.3%) of these carrying "likely disease-causing" variants in CNGA3. Compiling our own genetic data with those reported in the literature and in public databases, we further extend the CNGA3 variant spectrum to a total of 316 variants, 244 of which we interpreted as "likely disease-causing" according to ACMG/AMP criteria. We report 48 novel "likely disease-causing" variants, 24 of which are missense substitutions underlining the predominant role of this mutation class in the CNGA3 variant spectrum. In addition, we provide extensive in silico analyses and summarize reported functional data of previously analyzed missense, nonsense and splicing variants to further advance the pathogenicity assessment of the identified variants.
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Affiliation(s)
- Maria Solaki
- Centre for Ophthalmology, Institute for Ophthalmic Research, University of Tübingen, Tübingen, Germany
| | - Britta Baumann
- Centre for Ophthalmology, Institute for Ophthalmic Research, University of Tübingen, Tübingen, Germany
| | - Peggy Reuter
- Centre for Ophthalmology, Institute for Ophthalmic Research, University of Tübingen, Tübingen, Germany
| | - Sten Andreasson
- Department of Ophthalmology, University Hospital Lund, Lund, Sweden
| | - Isabelle Audo
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, Paris, France
- CHNO des Quinze-Vingts, Centre de Référence Maladies Rares REFERET, and INSERM-DGOS CIC1423, Paris, France
| | - Carmen Ayuso
- Department of Genetics & Genomics, Instituto de Investigación Sanitaria - Fundación Jiménez Díaz University Hospital - Universidad Autónoma de Madrid (IIS-FJD, UAM), Madrid, Spain
- Center for Biomedical Network Research on Rare Diseases (CIBERER), ISCIII, Madrid, Spain
| | - Ghassan Balousha
- Department of Pathology and Histology, Faculty of Medicine, Al-Quds University, Eastern Jerusalem, Palestine
| | - Francesco Benedicenti
- Clinical Genetics Service and South Tyrol Coordination Center for Rare Diseases, Department of Pediatrics, Regional Hospital of Bolzano, Bolzano, Italy
| | - David Birch
- Retina Foundation of the Southwest, Dallas, Texas, USA
| | - Pierre Bitoun
- Genetique Medicale, CHU Paris Nord, Hopital Jean Verdier, Bondy Cedex, France
| | | | - Beatrice Bocquet
- National Reference Centre for Inherited Sensory Diseases, Institute for Neurosciences of Montpellier (INM), University of Montpellier, INSERM, Montpellier, France
| | - Kari Branham
- Department of Ophthalmology and Visual Sciences, Kellogg Eye Center, University of Michigan, Ann Arbor, Michigan, USA
| | - Jaume Català-Mora
- Unitat de Distròfies Hereditàries de Retina Hospital Sant Joan de Déu, Barcelona, Esplugues de Llobregat, Spain
| | - Elfride De Baere
- Department of Biomolecular Medicine, Center for Medical Genetics, Ghent University and Ghent University Hospital, Ghent, Belgium
| | - Helene Dollfus
- CARGO, Hôpitaux Universitaires de Strasbourg, Strasbourg, France
- U-1112, Inserm, Faculté de Médecine, Université de Strasbourg, Strasbourg, France
| | - Mohammed Falana
- Department of Pathology and Histology, Faculty of Medicine, Al-Quds University, Eastern Jerusalem, Palestine
| | - Roberto Giorda
- Molecular Biology Laboratory, Scientific Institute IRCCS E. Medea, Bosisio Parini, Lecco, Italy
| | - Irina Golovleva
- Department of Medical Biosciences/Medical and Clinical Genetics, University of Umea, Umea, Sweden
| | - Irene Gottlob
- The University of Leicester Ulverscroft Eye Unit, Leicester Royal Infirmary, Leicester, UK
| | - John R Heckenlively
- Department of Ophthalmology and Visual Sciences, Kellogg Eye Center, University of Michigan, Ann Arbor, Michigan, USA
| | - Samuel G Jacobson
- Department of Ophthalmology, Perelman School of Medicine, Scheie Eye Institute, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Kaylie Jones
- Retina Foundation of the Southwest, Dallas, Texas, USA
| | - Herbert Jägle
- Department of Ophthalmology, University of Regensburg, Regensburg, Germany
| | - Andreas R Janecke
- Institute of Human Genetics, Medical University of Innsbruck, Innsbruck, Austria
| | - Ulrich Kellner
- Zentrum für Seltene Netzhauterkrankungen, AugenZentrum Siegburg, MVZ Augenärztliches Diagnostik- und Therapiecentrum Siegburg GmbH, Siegburg, Germany
- RetinaScience, Bonn, 53192, Germany
| | - Petra Liskova
- Department of Paediatrics and Inherited Metabolic Disorders, First Faculty of Medicine, Charles University and General University Hospital in Prague, Prague, Czech Republic
- Department of Ophthalmology, First Faculty of Medicine, Charles University and General University Hospital in Prague, Prague, Czech Republic
| | - Birgit Lorenz
- Department of Ophthalmology, Justus-Liebig University Giessen, Giessen, Germany
- Department of Ophthalmology, Universitaetsklinikum Bonn, Bonn, Germany
| | | | - André Messias
- Department of Ophthalmology, Otorhinolaryngology, and Head and Neck Surgery, School of Medicine of Ribeirão Preto, University of São Paulo, Ribeirão Preto, Brazil
| | - Isabelle Meunier
- National Reference Centre for Inherited Sensory Diseases, Montpellier University Hospital, University of Montpellier, Montpellier, France
- Sensgene Care Network, France
| | | | - Eleni Papageorgiou
- Department of Ophthalmology, University Hospital of Larissa, Mezourlo, Larissa, Greece
| | - Astrid S Plomp
- Department of Human Genetics, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
| | - Thomy J L de Ravel
- Centre for Medical Genetics, University Hospital Brussels, Brussels, Belgium
| | | | | | - Thomas Rosenberg
- Department of Ophthalmology, National Eye Clinic, Glostrup Hospital, Glostrup, Denmark
| | - Günther Rudolph
- University Eye Hospital, Ludwig Maximilians University, Munich, Germany
| | - Roberto Salati
- Scientific Institute, IRCCS Eugenio Medea, Pediatric Ophthalmology Unit, Bosisio Parini, Lecco, Italy
| | - E Cumhur Sener
- Strabismus and Pediatric Ophthalmology, Private Practice, Ankara, Turkey
| | - Paul A Sieving
- Center for Ocular Regenerative Therapy, School of Medicine, University of California Davis, Sacramento, USA
| | - Franco Stanzial
- Clinical Genetics Service and South Tyrol Coordination Center for Rare Diseases, Department of Pediatrics, Regional Hospital of Bolzano, Bolzano, Italy
| | - Elias I Traboulsi
- Center for Genetic Eye Diseases, Cole Eye Institute, Cleveland Clinic Foundation, Cleveland, Ohio, USA
| | - Stephen H Tsang
- Department of Ophthalmology, Pathology and Cell Biology, College of Physicians and Surgeons, Columbia Stem Cell Initiative, Columbia University, New York City, New York, USA
| | - Balázs Varsanyi
- Department of Ophthalmology, Medical School, University of Pécs and Ganglion Medical Center, Pécs, Pécs, Hungary
| | - Richard G Weleber
- Oregon Health & Science University, Ophthalmic Genetics Service of the Casey Eye Institute, 515 SW Campus Drive, 97239, Portland, Oregon, USA
| | - Ditta Zobor
- Centre for Ophthalmology, Institute for Ophthalmic Research, University Hospital Tübingen, Tübingen, Germany
- Department of Ophthalmology, Semmelweis University Budapest, Budapest, Hungary
| | - Katarina Stingl
- Center for Ophthalmology, University Eye Hospital, University of Tübingen, Tübingen, Germany
- Center for Rare Eye Diseases, University of Tübingen, Tübingen, Germany
| | - Bernd Wissinger
- Centre for Ophthalmology, Institute for Ophthalmic Research, University of Tübingen, Tübingen, Germany
| | - Susanne Kohl
- Centre for Ophthalmology, Institute for Ophthalmic Research, University of Tübingen, Tübingen, Germany
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11
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Hollingsworth TJ, Wang X, White WA, Simpson RN, Jablonski MM. Chronic Proinflammatory Signaling Accelerates the Rate of Degeneration in a Spontaneous Polygenic Model of Inherited Retinal Dystrophy. Front Pharmacol 2022; 13:839424. [PMID: 35387333 PMCID: PMC8978607 DOI: 10.3389/fphar.2022.839424] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Accepted: 02/21/2022] [Indexed: 11/18/2022] Open
Abstract
Collectively, retinal neurodegenerative diseases are comprised of numerous subtypes of disorders which result in loss of a varying cell types in the retina. These diseases can range from glaucoma, which results in retinal ganglion cell death, to age-related macular degeneration and retinitis pigmentosa, which result in cell death of the retinal pigment epithelium, photoreceptors, or both. Regardless of the disease, it’s been recently found that increased release of proinflammatory cytokines and proliferation of active microglia result in a remarkably proinflammatory microenvironment that assists in the pathogenesis of the disease; however, many of the details of these inflammatory events have yet to be elucidated. In an ongoing study, we have used systems genetics to identify possible models of spontaneous polygenic age-related macular degeneration by mining the BXD family of mice using single nucleotide polymorphism analyses of known genes associated with the human retinal disease. One BXD strain (BXD32) was removed from the study as the rate of degeneration observed in these animals was markedly increased with a resultant loss of most all photoreceptors by 6 months of age. Using functional and anatomical exams including optokinetic nystamography, funduscopy, fluorescein angiography, and optical coherence tomography, along with immunohistochemical analyses, we show that the BXD32 mouse strain exhibits a severe neurodegenerative phenotype accompanied by adverse effects on the retinal vasculature. We also expose the concurrent establishment of a chronic proinflammatory microenvironment including the TNFα secretion and activation of the NF-κB and JAK/STAT pathways with an associated increase in activated macrophages and phagoptosis. We conclude that the induced neuronal death and proinflammatory pathways work synergistically in the disease pathogenesis to enhance the rate of degeneration in this spontaneous polygenic model of inherited retinal dystrophy.
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Affiliation(s)
- T J Hollingsworth
- Hamilton Eye Institute, Department of Ophthalmology, University of Tennessee Health Science Center, Memphis, TN, United States.,Department of Anatomy and Neurobiology, University of Tennessee Health Science Center, Memphis, TN, United States
| | - Xiangdi Wang
- Hamilton Eye Institute, Department of Ophthalmology, University of Tennessee Health Science Center, Memphis, TN, United States
| | - William A White
- Hamilton Eye Institute, Department of Ophthalmology, University of Tennessee Health Science Center, Memphis, TN, United States
| | - Raven N Simpson
- Hamilton Eye Institute, Department of Ophthalmology, University of Tennessee Health Science Center, Memphis, TN, United States
| | - Monica M Jablonski
- Hamilton Eye Institute, Department of Ophthalmology, University of Tennessee Health Science Center, Memphis, TN, United States.,Department of Anatomy and Neurobiology, University of Tennessee Health Science Center, Memphis, TN, United States.,Department of Pharmaceutical Sciences, University of Tennessee Health Science Center, Memphis, TN, United States.,Department of Genetics, Genomics and Informatics, University of Tennessee Health Science Center, Memphis, TN, United States
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12
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Riedmayr LM, Hinrichsmeyer KS, Karguth N, Böhm S, Splith V, Michalakis S, Becirovic E. dCas9-VPR-mediated transcriptional activation of functionally equivalent genes for gene therapy. Nat Protoc 2022; 17:781-818. [PMID: 35132255 DOI: 10.1038/s41596-021-00666-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Accepted: 11/18/2021] [Indexed: 12/19/2022]
Abstract
Many disease-causing genes possess functionally equivalent counterparts, which are often expressed in distinct cell types. An attractive gene therapy approach for inherited disorders caused by mutations in such genes is to transcriptionally activate the appropriate counterpart(s) to compensate for the missing gene function. This approach offers key advantages over conventional gene therapies because it is mutation- and gene size-independent. Here, we describe a protocol for the design, execution and evaluation of such gene therapies using dCas9-VPR. We offer guidelines on how to identify functionally equivalent genes, design and clone single guide RNAs and evaluate transcriptional activation in vitro. Moreover, focusing on inherited retinal diseases, we provide a detailed protocol on how to apply this strategy in mice using dual recombinant adeno-associated virus vectors and how to evaluate its functionality and off-target effects in the target tissue. This strategy is in principle applicable to all organisms that possess functionally equivalent genes suitable for transcriptional activation and addresses pivotal unmet needs in gene therapy with high translational potential. The protocol can be completed in 15-20 weeks.
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Affiliation(s)
- Lisa M Riedmayr
- Department of Pharmacy-Center for Drug Research, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Klara S Hinrichsmeyer
- Department of Pharmacy-Center for Drug Research, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Nina Karguth
- Department of Pharmacy-Center for Drug Research, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Sybille Böhm
- Department of Pharmacy-Center for Drug Research, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Victoria Splith
- Department of Pharmacy-Center for Drug Research, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Stylianos Michalakis
- Department of Ophthalmology, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Elvir Becirovic
- Department of Pharmacy-Center for Drug Research, Ludwig-Maximilians-Universität München, Munich, Germany.
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13
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Zernant J, Lee W, Wang J, Goetz K, Ullah E, Nagasaki T, Su PY, Fishman GA, Tsang SH, Tumminia SJ, Brooks BP, Hufnagel RB, Chen R, Allikmets R. Rare and common variants in ROM1 and PRPH2 genes trans-modify Stargardt/ABCA4 disease. PLoS Genet 2022; 18:e1010129. [PMID: 35353811 PMCID: PMC9000055 DOI: 10.1371/journal.pgen.1010129] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2021] [Revised: 04/11/2022] [Accepted: 03/02/2022] [Indexed: 11/18/2022] Open
Abstract
Over 1,500 variants in the ABCA4 locus cause phenotypes ranging from severe, early-onset retinal degeneration to very late-onset maculopathies. The resulting ABCA4/Stargardt disease is the most prevalent Mendelian eye disorder, although its underlying clinical heterogeneity, including penetrance of many alleles, are not well-understood. We hypothesized that a share of this complexity is explained by trans-modifiers, i.e., variants in unlinked loci, which are currently unknown. We sought to identify these by performing exome sequencing in a large cohort for a rare disease of 622 cases and compared variation in seven genes known to clinically phenocopy ABCA4 disease to cohorts of ethnically matched controls. We identified a significant enrichment of variants in 2 out of the 7 genes. Moderately rare, likely functional, variants, at the minor allele frequency (MAF) <0.005 and CADD>25, were enriched in ROM1, where 1.3% of 622 patients harbored a ROM1 variant compared to 0.3% of 10,865 controls (p = 2.41E04; OR 3.81 95% CI [1.77; 8.22]). More importantly, analysis of common variants (MAF>0.1) identified a frequent haplotype in PRPH2, tagged by the p.Asp338 variant with MAF = 0.21 in the matched general population that was significantly increased in the patient cohort, MAF 0.25, p = 0.0014. Significant differences were also observed between ABCA4 disease subgroups. In the late-onset subgroup, defined by the hypomorphic p.Asn1868Ile variant and including c.4253+43G>A, the allele frequency for the PRPH2 p.Asp338 variant was 0.15 vs 0.27 in the remaining cohort, p = 0.00057. Known functional data allowed suggesting a mechanism by which the PRPH2 haplotype influences the ABCA4 disease penetrance. These associations were replicated in an independent cohort of 408 patients. The association was highly statistically significant in the combined cohorts of 1,030 cases, p = 4.00E-05 for all patients and p = 0.00014 for the hypomorph subgroup, suggesting a substantial trans-modifying role in ABCA4 disease for both rare and common variants in two unlinked loci.
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Affiliation(s)
- Jana Zernant
- Department of Ophthalmology, Columbia University, New York, New York, United States of America
| | - Winston Lee
- Department of Ophthalmology, Columbia University, New York, New York, United States of America
- Department of Genetics & Development, Columbia University, New York, New York, United States of America
| | - Jun Wang
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, United States of America
| | - Kerry Goetz
- National Eye Institute, NIH, Bethesda, Maryland, United States of America
| | - Ehsan Ullah
- National Eye Institute, NIH, Bethesda, Maryland, United States of America
| | - Takayuki Nagasaki
- Department of Ophthalmology, Columbia University, New York, New York, United States of America
| | - Pei-Yin Su
- Department of Ophthalmology, Columbia University, New York, New York, United States of America
| | - Gerald A. Fishman
- The Pangere Center for Inherited Retinal Diseases, The Chicago Lighthouse, Chicago, Illinois, United States of America
| | - Stephen H. Tsang
- Department of Ophthalmology, Columbia University, New York, New York, United States of America
- Department of Pathology & Cell Biology, Columbia University, New York, New York, United States of America
| | - Santa J. Tumminia
- National Eye Institute, NIH, Bethesda, Maryland, United States of America
| | - Brian P. Brooks
- National Eye Institute, NIH, Bethesda, Maryland, United States of America
| | - Robert B. Hufnagel
- National Eye Institute, NIH, Bethesda, Maryland, United States of America
| | - Rui Chen
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, United States of America
| | - Rando Allikmets
- Department of Ophthalmology, Columbia University, New York, New York, United States of America
- Department of Pathology & Cell Biology, Columbia University, New York, New York, United States of America
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14
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Zheng X, Hu Z, Li H, Yang J. Structure of the human cone photoreceptor cyclic nucleotide-gated channel. Nat Struct Mol Biol 2022; 29:40-6. [PMID: 34969976 DOI: 10.1038/s41594-021-00699-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Accepted: 11/09/2021] [Indexed: 11/08/2022]
Abstract
Cyclic nucleotide-gated (CNG) channels transduce light-induced chemical signals into electrical signals in retinal cone and rod photoreceptors. Structures of native CNG channels, which are heterotetramers formed by CNGA and CNGB subunits, have not been obtained. In the present study, we report a high-resolution cryo-electron microscopy structure of the human cone CNG channel in the apo closed state. The channel contains three CNGA3 and one CNGB3 subunits. Arg403 in the pore helix of CNGB3 projects into an asymmetric selectivity filter and forms hydrogen bonds with two pore-lining backbone carbonyl oxygens. Arg442 in S6 of CNGB3 protrudes into and occludes the pore below the hydrophobic cavity gate previously observed in homotetrameric CNGA channels. It is interesting that Arg403Gln is a disease mutation, and Arg442 is replaced by glutamine in some animal species with dichromatic or monochromatic vision. These and other unique structural features and the disease link conferred by CNGB3 indicate a critical role of CNGB3 in shaping cone photoresponses.
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15
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Abstract
Achromatopsia (ACHM), also known as rod monochromatism or total color blindness, is an autosomal recessively inherited retinal disorder that affects the cones of the retina, the type of photoreceptors responsible for high-acuity daylight vision. ACHM is caused by pathogenic variants in one of six cone photoreceptor-expressed genes. These mutations result in a functional loss and a slow progressive degeneration of cone photoreceptors. The loss of cone photoreceptor function manifests at birth or early in childhood and results in decreased visual acuity, lack of color discrimination, abnormal intolerance to light (photophobia), and rapid involuntary eye movement (nystagmus). Up to 90% of patients with ACHM carry mutations in CNGA3 or CNGB3, which are the genes encoding the alpha and beta subunits of the cone cyclic nucleotide-gated (CNG) channel, respectively. No authorized therapy for ACHM exists, but research activities have intensified over the past decade and have led to several preclinical gene therapy studies that have shown functional and morphological improvements in animal models of ACHM. These encouraging preclinical data helped advance multiple gene therapy programs for CNGA3- and CNGB3-linked ACHM into the clinical phase. Here, we provide an overview of the genetic and molecular basis of ACHM, summarize the gene therapy-related research activities, and provide an outlook for their clinical application.
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Affiliation(s)
- Stylianos Michalakis
- Department of Ophthalmology, University Hospital, LMU Munich, Mathildenstr. 8, 80336, Munich, Germany.
| | - Maximilian Gerhardt
- Department of Ophthalmology, University Hospital, LMU Munich, Mathildenstr. 8, 80336, Munich, Germany
| | - Günther Rudolph
- Department of Ophthalmology, University Hospital, LMU Munich, Mathildenstr. 8, 80336, Munich, Germany
| | - Siegfried Priglinger
- Department of Ophthalmology, University Hospital, LMU Munich, Mathildenstr. 8, 80336, Munich, Germany
| | - Claudia Priglinger
- Department of Ophthalmology, University Hospital, LMU Munich, Mathildenstr. 8, 80336, Munich, Germany
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16
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Li J, Liu T, Flynn OJ, Turriff A, Liu Z, Ullah E, Liu J, Dubra A, Johnson MA, Brooks BP, Hufnagel RB, Hammer DX, Huryn LA, Jeffrey BG, Tam J. Persistent Dark Cones in Oligocone Trichromacy Revealed by Multimodal Adaptive Optics Ophthalmoscopy. Front Aging Neurosci 2021; 13:629214. [PMID: 33767618 PMCID: PMC7985087 DOI: 10.3389/fnagi.2021.629214] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2020] [Accepted: 02/09/2021] [Indexed: 11/13/2022] Open
Abstract
Dark cone photoreceptors, defined as those with diminished or absent reflectivity when observed with adaptive optics (AO) ophthalmoscopy, are increasingly reported in retinal disorders. However, their structural and functional impact remain unclear. Here, we report a 3-year longitudinal study on a patient with oligocone trichromacy (OT) who presented with persistent, widespread dark cones within and near the macula. Diminished electroretinogram (ERG) cone but normal ERG rod responses together with normal color vision confirmed the OT diagnosis. In addition, the patient had normal to near normal visual acuity and retinal sensitivity. Occasional dark gaps in the photoreceptor layer were observed on optical coherence tomography, in agreement with reflectance AO scanning light ophthalmoscopy, which revealed that over 50% of the cones in the fovea were dark, increasing to 74% at 10° eccentricity. In addition, the cone density was 78% lower than normal histologic value at the fovea, and 20-40% lower at eccentricities of 5-15°. Interestingly, color vision testing was near normal at locations where cones were predominantly dark. These findings illustrate how a retina with predominant dark cones that persist over at least 3 years can support near normal central retinal function. Furthermore, this study adds to the growing evidence that cones can continue to survive under non-ideal conditions.
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Affiliation(s)
- Joanne Li
- National Eye Institute, National Institutes of Health, Bethesda, MD, United States
| | - Tao Liu
- National Eye Institute, National Institutes of Health, Bethesda, MD, United States
| | - Oliver J Flynn
- National Eye Institute, National Institutes of Health, Bethesda, MD, United States
| | - Amy Turriff
- National Eye Institute, National Institutes of Health, Bethesda, MD, United States
| | - Zhuolin Liu
- Center for Devices and Radiological Health, U.S. Food and Drug Administration, Silver Spring, MD, United States
| | - Ehsan Ullah
- National Eye Institute, National Institutes of Health, Bethesda, MD, United States
| | - Jianfei Liu
- National Eye Institute, National Institutes of Health, Bethesda, MD, United States
| | - Alfredo Dubra
- Department of Ophthalmology, Stanford University, Palo Alto, CA, Unites States
| | - Mary A Johnson
- Ophthalmology and Visual Sciences, University of Maryland School of Medicine, Baltimore, MD, United States
| | - Brian P Brooks
- National Eye Institute, National Institutes of Health, Bethesda, MD, United States
| | - Robert B Hufnagel
- National Eye Institute, National Institutes of Health, Bethesda, MD, United States
| | - Daniel X Hammer
- Center for Devices and Radiological Health, U.S. Food and Drug Administration, Silver Spring, MD, United States
| | - Laryssa A Huryn
- National Eye Institute, National Institutes of Health, Bethesda, MD, United States
| | - Brett G Jeffrey
- National Eye Institute, National Institutes of Health, Bethesda, MD, United States
| | - Johnny Tam
- National Eye Institute, National Institutes of Health, Bethesda, MD, United States
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17
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Kabra M, Pattnaik BR. Sensing through Non-Sensing Ocular Ion Channels. Int J Mol Sci 2020; 21:E6925. [PMID: 32967234 DOI: 10.3390/ijms21186925] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2020] [Revised: 09/17/2020] [Accepted: 09/18/2020] [Indexed: 12/12/2022] Open
Abstract
Ion channels are membrane-spanning integral proteins expressed in multiple organs, including the eye. In the eye, ion channels are involved in various physiological processes, like signal transmission and visual processing. A wide range of mutations have been reported in the corresponding genes and their interacting subunit coding genes, which contribute significantly to an array of blindness, termed ocular channelopathies. These mutations result in either a loss- or gain-of channel functions affecting the structure, assembly, trafficking, and localization of channel proteins. A dominant-negative effect is caused in a few channels formed by the assembly of several subunits that exist as homo- or heteromeric proteins. Here, we review the role of different mutations in switching a “sensing” ion channel to “non-sensing,” leading to ocular channelopathies like Leber’s congenital amaurosis 16 (LCA16), cone dystrophy, congenital stationary night blindness (CSNB), achromatopsia, bestrophinopathies, retinitis pigmentosa, etc. We also discuss the various in vitro and in vivo disease models available to investigate the impact of mutations on channel properties, to dissect the disease mechanism, and understand the pathophysiology. Innovating the potential pharmacological and therapeutic approaches and their efficient delivery to the eye for reversing a “non-sensing” channel to “sensing” would be life-changing.
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18
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Jinda W, Tuekprakhon A, Thongnoppakhun W, Limwongse C, Trinavarat A, Atchaneeyasakul LO. Molecular and clinical characterization of Thai patients with achromatopsia: identification of three novel disease-associated variants in the CNGA3 and CNGB3 genes. Int Ophthalmol 2020; 41:121-134. [PMID: 32869108 DOI: 10.1007/s10792-020-01559-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2020] [Accepted: 08/17/2020] [Indexed: 11/24/2022]
Abstract
PURPOSE Achromatopsia (ACHM) is an autosomal recessive cone disorder characterized by pendular nystagmus, photophobia, reduced visual acuity, and partial or total absence of color vision. Mutations in six genes (CNGA3, CNGB3, GNAT2, PDE6C, PDE6H, and ATF6) have been reported in ACHM. There is no information on these disease-associated genes in Thai population. This study aimed to investigate the molecular and clinical characteristics in Thai patients with ACHM. METHODS Seven unrelated Thai patients with ACHM were recruited. Detailed ophthalmologic examination was performed. Polymerase chain reaction (PCR)-coupled single-strand conformation polymorphism (SSCP) screening followed by Sanger sequencing was used to identify sequence variants in all exons and splice junctions of three genes (CNGA3, CNGB3, and GNAT2). The pathogenicity of the detected variants was interpreted. Segregation analysis was performed to determine variant sharing in available family members. RESULTS Four patients displayed different SSCP migration patterns. Sequence analysis revealed a reported pathogenic and a novel disease-associated variant in the CNGA3 gene. For the CNGB3 gene, we found two novel disease-associated variants and a reported variant of uncertain significance (VUS). Segregation analysis confirmed that the variants identified in each patient were present in the heterozygous state in their corresponding family members, which was consistent with an autosomal recessive mode of inheritance. CONCLUSIONS This study demonstrated the first molecular and clinical characterization of ACHM in Thai patients. The identification of disease-associated genes in a specific population leads to a personalized gene therapy benefiting those affected patients.
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Affiliation(s)
- Worapoj Jinda
- Division of Medical Genetics Research and Laboratory, Research Department, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | - Aekkachai Tuekprakhon
- Clinical Molecular Pathology Laboratory, Department of Clinical Pathology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | - Wanna Thongnoppakhun
- Division of Medical Genetics Research and Laboratory, Research Department, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | - Chanin Limwongse
- Division of Medical Genetics Research and Laboratory, Research Department, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand.,Division of Medical Genetics, Department of Medicine, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | - Adisak Trinavarat
- Department of Ophthalmology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, 10700, Thailand
| | - La-Ongsri Atchaneeyasakul
- Department of Ophthalmology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, 10700, Thailand.
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Sun W, Li S, Xiao X, Wang P, Zhang Q. Genotypes and phenotypes of genes associated with achromatopsia: A reference for clinical genetic testing. Mol Vis 2020; 26:588-602. [PMID: 32913385 PMCID: PMC7479066] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2019] [Accepted: 08/20/2020] [Indexed: 11/23/2022] Open
Abstract
PURPOSE Achromatopsia is a congenital autosomal recessive cone disorder, and it has been found to be associated with six genes. However, pathogenic variants in these six genes have been identified in patients with various retinal dystrophies with the exception of achromatopsia. Thus, this study aims to investigate the contribution of these genes in hereditary retinal diseases and the potential genotype-phenotype correlations. METHODS Biallelic variants in six achromatopsia-related genes, namely, CNGA3, CNGB3, GNAT2, ATF6, PDE6C, and PDE6H, were analyzed based on data obtained from 7,195 probands with different eye conditions. A systematic genotype-phenotype analysis of these genes was performed based on these data, along with the data reported in the literature. RESULTS Biallelic potential pathogenic variants (PPVs) in five of the six genes were identified in 119 probands with genetic eye diseases. The variants in CNGA3 were the most common and accounted for 81.5% (97/119). Of the 119 probands, 62.2% (74/119) have cone-rod dystrophy, whereas only 25.2% (30/119) have achromatopsia. No biallelic pathogenic variants in these genes were identified in patients with rod-dominant degeneration. A systematic review of genotypes and phenotypes revealed certain characteristics of each of the six genes, providing clues for the pathogenicity evaluation of the variants of the genes. CONCLUSIONS PPVs in the six genes were identified in various inherited retinal degeneration diseases, most of which are cone-dominant diseases but no rod-dominant diseases based on the data from a cohort of 7,195 probands with different eye conditions. The systematic genotype-phenotype analysis of these genes will be useful in drafting guidelines for the clinical genetic diagnostic application for the investigated genes.
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Böhm S, Splith V, Riedmayr LM, Rötzer RD, Gasparoni G, Nordström KJV, Wagner JE, Hinrichsmeyer KS, Walter J, Wahl-Schott C, Fenske S, Biel M, Michalakis S, Becirovic E. A gene therapy for inherited blindness using dCas9-VPR-mediated transcriptional activation. Sci Adv 2020; 6:eaba5614. [PMID: 32875106 PMCID: PMC7438099 DOI: 10.1126/sciadv.aba5614] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2019] [Accepted: 07/08/2020] [Indexed: 05/08/2023]
Abstract
Catalytically inactive dCas9 fused to transcriptional activators (dCas9-VPR) enables activation of silent genes. Many disease genes have counterparts, which serve similar functions but are expressed in distinct cell types. One attractive option to compensate for the missing function of a defective gene could be to transcriptionally activate its functionally equivalent counterpart via dCas9-VPR. Key challenges of this approach include the delivery of dCas9-VPR, activation efficiency, long-term expression of the target gene, and adverse effects in vivo. Using dual adeno-associated viral vectors expressing split dCas9-VPR, we show efficient transcriptional activation and long-term expression of cone photoreceptor-specific M-opsin (Opn1mw) in a rhodopsin-deficient mouse model for retinitis pigmentosa. One year after treatment, this approach yields improved retinal function and attenuated retinal degeneration with no apparent adverse effects. Our study demonstrates that dCas9-VPR-mediated transcriptional activation of functionally equivalent genes has great potential for the treatment of genetic disorders.
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Affiliation(s)
- Sybille Böhm
- Center for Integrated Protein Science Munich CIPSM, Munich, Germany
- Department of Pharmacy - Center for Drug Research, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Victoria Splith
- Center for Integrated Protein Science Munich CIPSM, Munich, Germany
- Department of Pharmacy - Center for Drug Research, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Lisa Maria Riedmayr
- Center for Integrated Protein Science Munich CIPSM, Munich, Germany
- Department of Pharmacy - Center for Drug Research, Ludwig-Maximilians-Universität München, Munich, Germany
| | - René Dominik Rötzer
- Center for Integrated Protein Science Munich CIPSM, Munich, Germany
- Department of Pharmacy - Center for Drug Research, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Gilles Gasparoni
- Department of Genetics, Saarland University, Saarbrücken, Germany
| | | | - Johanna Elisabeth Wagner
- Center for Integrated Protein Science Munich CIPSM, Munich, Germany
- Department of Pharmacy - Center for Drug Research, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Klara Sonnie Hinrichsmeyer
- Center for Integrated Protein Science Munich CIPSM, Munich, Germany
- Department of Pharmacy - Center for Drug Research, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Jörn Walter
- Department of Genetics, Saarland University, Saarbrücken, Germany
| | | | - Stefanie Fenske
- Center for Integrated Protein Science Munich CIPSM, Munich, Germany
- Department of Pharmacy - Center for Drug Research, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Martin Biel
- Center for Integrated Protein Science Munich CIPSM, Munich, Germany
- Department of Pharmacy - Center for Drug Research, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Stylianos Michalakis
- Center for Integrated Protein Science Munich CIPSM, Munich, Germany
- Department of Pharmacy - Center for Drug Research, Ludwig-Maximilians-Universität München, Munich, Germany
- Department of Ophthalmology, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Elvir Becirovic
- Center for Integrated Protein Science Munich CIPSM, Munich, Germany
- Department of Pharmacy - Center for Drug Research, Ludwig-Maximilians-Universität München, Munich, Germany
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21
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Méjécase C, Malka S, Guan Z, Slater A, Arno G, Moosajee M. Practical guide to genetic screening for inherited eye diseases. Ther Adv Ophthalmol 2020; 12:2515841420954592. [PMID: 33015543 PMCID: PMC7513416 DOI: 10.1177/2515841420954592] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Accepted: 07/29/2020] [Indexed: 12/16/2022] Open
Abstract
Genetic eye diseases affect around one in 1000 people worldwide for which the molecular aetiology remains unknown in the majority. The identification of disease-causing gene variant(s) allows a better understanding of the disorder and its inheritance. There is now an approved retinal gene therapy for autosomal recessive RPE65-retinopathy, and numerous ocular gene/mutation-targeted clinical trials underway, highlighting the importance of establishing a genetic diagnosis so patients can fully access the latest research developments and treatment options. In this review, we will provide a practical guide to managing patients with these conditions including an overview of inheritance patterns, required pre- and post-test genetic counselling, different types of cytogenetic and genetic testing available, with a focus on next generation sequencing using targeted gene panels, whole exome and genome sequencing. We will expand on the pros and cons of each modality, variant interpretation and options for family planning for the patient and their family. With the advent of genomic medicine, genetic screening will soon become mainstream within all ophthalmology subspecialties for prevention of disease and provision of precision therapeutics.
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Affiliation(s)
- Cécile Méjécase
- Institute of Ophthalmology, University College
London, London, UK
| | - Samantha Malka
- Institute of Ophthalmology, University College
London, London, UK
- Moorfields Eye Hospital NHS Foundation Trust,
London, UK
| | - Zeyu Guan
- Moorfields Eye Hospital NHS Foundation Trust,
London, UK
| | - Amy Slater
- Royal Brompton and Harefield NHS Foundation
Trust, London, UK
| | - Gavin Arno
- Institute of Ophthalmology, University College
London, London, UK
- Moorfields Eye Hospital NHS Foundation Trust,
London, UK
- Great Ormond Street Hospital for Children NHS
Trust, London, UK
| | - Mariya Moosajee
- Professor, Institute of Ophthalmology,
University College London, 11-43 Bath Street, London EC1V 9EL, UK
- Moorfields Eye Hospital NHS Foundation Trust,
London, UK
- Great Ormond Street Hospital for Children NHS
Trust, London, UK
- The Francis Crick Institute, London, UK
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