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Ng BW, Kaukonen MK, McClements ME, Shamsnajafabadi H, MacLaren RE, Cehajic-Kapetanovic J. Genetic therapies and potential therapeutic applications of CRISPR activators in the eye. Prog Retin Eye Res 2024; 102:101289. [PMID: 39127142 DOI: 10.1016/j.preteyeres.2024.101289] [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: 06/06/2024] [Revised: 08/05/2024] [Accepted: 08/06/2024] [Indexed: 08/12/2024]
Abstract
Conventional gene therapy involving supplementation only treats loss-of-function diseases and is limited by viral packaging sizes, precluding therapy of large genes. The discovery of CRISPR/Cas has led to a paradigm shift in the field of genetic therapy, with the promise of precise gene editing, thus broadening the range of diseases that can be treated. The initial uses of CRISPR/Cas have focused mainly on gene editing or silencing of abnormal variants via utilising Cas endonuclease to trigger the target cell endogenous non-homologous end joining. Subsequently, the technology has evolved to modify the Cas enzyme and even its guide RNA, leading to more efficient editing tools in the form of base and prime editing. Further advancements of this CRISPR/Cas technology itself have expanded its functional repertoire from targeted editing to programmable transactivation, shifting the therapeutic focus to precise endogenous gene activation or upregulation with the potential for epigenetic modifications. In vivo experiments using this platform have demonstrated the potential of CRISPR-activators (CRISPRa) to treat various loss-of-function diseases, as well as in regenerative medicine, highlighting their versatility to overcome limitations associated with conventional strategies. This review summarises the molecular mechanisms of CRISPRa platforms, the current applications of this technology in vivo, and discusses potential solutions to translational hurdles for this therapy, with a focus on ophthalmic diseases.
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Affiliation(s)
- Benjamin Wj Ng
- Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford, UK; Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK; NIHR Oxford Biomedical Research Centre, Oxford, UK
| | - Maria K Kaukonen
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK; NIHR Oxford Biomedical Research Centre, Oxford, UK; Department of Medical and Clinical Genetics, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Michelle E McClements
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK; NIHR Oxford Biomedical Research Centre, Oxford, UK
| | - Hoda Shamsnajafabadi
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK; NIHR Oxford Biomedical Research Centre, Oxford, UK
| | - Robert E MacLaren
- Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford, UK; Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK; NIHR Oxford Biomedical Research Centre, Oxford, UK
| | - Jasmina Cehajic-Kapetanovic
- Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford, UK; Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK; NIHR Oxford Biomedical Research Centre, Oxford, UK.
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Savastano MC, Placidi G, Fossataro C, Giannuzzi F, D'Onofrio NC, Hu L, Cestrone V, D'Agostino E, Biagini I, Paris L, Coppa G, Rizzo C, Kilian R, Chiurazzi P, Bertelli M, Maltese PE, Falsini B, Rizzo S. Retinal Pigment Epithelium and Outer Retinal Atrophy (RORA) in Retinitis Pigmentosa: Functional, Structural, and Genetic Evaluation. Transl Vis Sci Technol 2024; 13:44. [PMID: 39212608 PMCID: PMC11364178 DOI: 10.1167/tvst.13.8.44] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2023] [Accepted: 07/14/2024] [Indexed: 09/04/2024] Open
Abstract
Purpose To examine whether the extension of retinal pigment epithelium (RPE) and outer retinal atrophy (RORA) and various other morphofunctional parameters correlate with the genetic assessment and severity of retinitis pigmentosa (RP). Methods Thirty-eight patients (76 eyes) with RP were prospectively enrolled and underwent full ophthalmic examination, including visual field testing, full-field electroretinography (ERG), and optical coherence tomography angiography. The severity of the disease was calculated using the RP stage scoring system, and the area of RORA was assessed using the automatically calculated area of sub-RPE illumination. Blood or saliva samples were collected from subjects, and DNA extraction was performed to evaluate genetic mutations and nucleotide and amino acid variations. Results There was a statistically significant correlation between the extent of RORA and patient age, best-corrected visual acuity, ellipsoid zone extension, and disease severity in both eyes (each, P < 0.05). In contrast, RORA did not correlate with either the visual field or the ERG amplitude. Cumulative score and grade severity were both significantly correlated with superficial and deep capillary plexus density (both, P < 0.001) in both eyes. Evaluating RORA, we found genes with an overall less severe phenotype, such as EYS, PCDH15, and PRPF31, and those with a worse phenotype, such as RPGR. Conclusions The correlation of RORA with structural, functional, and genetic assessment in RP disease leads us to consider RORA as a potential biomarker for prediction of disease stage. Multicenter studies are needed to confirm our findings. Translational Relevance The morphofunctional and genetic correlations suggest a role for RORA in RP diagnosis and follow-up.
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Affiliation(s)
- Maria Cristina Savastano
- Ophthalmology Unit, Fondazione Policlinico Universitario Agostino Gemelli IRCCS, Rome, Italy
- Università Cattolica del Sacro Cuore, Rome, Italy
| | - Giorgio Placidi
- Ophthalmology Unit, Fondazione Policlinico Universitario Agostino Gemelli IRCCS, Rome, Italy
- Università Cattolica del Sacro Cuore, Rome, Italy
| | - Claudia Fossataro
- Ophthalmology Unit, Fondazione Policlinico Universitario Agostino Gemelli IRCCS, Rome, Italy
- Università Cattolica del Sacro Cuore, Rome, Italy
| | - Federico Giannuzzi
- Ophthalmology Unit, Fondazione Policlinico Universitario Agostino Gemelli IRCCS, Rome, Italy
- Università Cattolica del Sacro Cuore, Rome, Italy
| | - Nicola Claudio D'Onofrio
- Ophthalmology Unit, Fondazione Policlinico Universitario Agostino Gemelli IRCCS, Rome, Italy
- Università Cattolica del Sacro Cuore, Rome, Italy
| | - Lorenzo Hu
- Ophthalmology Unit, Fondazione Policlinico Universitario Agostino Gemelli IRCCS, Rome, Italy
- Università Cattolica del Sacro Cuore, Rome, Italy
| | - Valentina Cestrone
- Ophthalmology Unit, Fondazione Policlinico Universitario Agostino Gemelli IRCCS, Rome, Italy
- Università Cattolica del Sacro Cuore, Rome, Italy
| | - Elena D'Agostino
- Ophthalmology Unit, Fondazione Policlinico Universitario Agostino Gemelli IRCCS, Rome, Italy
- Università Cattolica del Sacro Cuore, Rome, Italy
| | - Ilaria Biagini
- Ophthalmology Unit, Fondazione Policlinico Universitario Agostino Gemelli IRCCS, Rome, Italy
- Università Cattolica del Sacro Cuore, Rome, Italy
- Department of Neurosciences, Psychology, Drug Research and Child Health (NEUROFARBA), University of Florence and AOU Careggi, Firenze, Italy
| | - Ludovica Paris
- Ophthalmology Unit, Fondazione Policlinico Universitario Agostino Gemelli IRCCS, Rome, Italy
- Università Cattolica del Sacro Cuore, Rome, Italy
| | - Giorgia Coppa
- Ophthalmology Unit, Fondazione Policlinico Universitario Agostino Gemelli IRCCS, Rome, Italy
- Università Cattolica del Sacro Cuore, Rome, Italy
| | - Clara Rizzo
- Ophthalmology, Department of Surgical, Medical and Molecular Pathology and Critical Care Medicine, University of Pisa, Pisa, Italy
| | | | - Pietro Chiurazzi
- Medical Genetics, Fondazione Policlinico Universitario Agostino Gemelli IRCCS, Rome, Italy
- Genomic Medicine, Università Cattolica del Sacro Cuore, Rome, Italy
| | | | | | - Benedetto Falsini
- Ophthalmology Unit, Fondazione Policlinico Universitario Agostino Gemelli IRCCS, Rome, Italy
- Università Cattolica del Sacro Cuore, Rome, Italy
| | - Stanislao Rizzo
- Ophthalmology Unit, Fondazione Policlinico Universitario Agostino Gemelli IRCCS, Rome, Italy
- Università Cattolica del Sacro Cuore, Rome, Italy
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Qi XY, Mi CH, Cao DR, Chen XQ, Zhang P. Retinitis pigmentosa and stem cell therapy. Int J Ophthalmol 2024; 17:1363-1369. [PMID: 39026924 PMCID: PMC11246939 DOI: 10.18240/ijo.2024.07.22] [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: 03/06/2024] [Accepted: 04/15/2024] [Indexed: 07/20/2024] Open
Abstract
Retinitis pigmentosa (RP) is a group of genetic disorders characterized by progressive degeneration of photoreceptors and retinal pigment epithelium (RPE) cells. Its main clinical manifestations include night blindness and progressive loss of peripheral vision, making it a prevalent debilitating eye disease that significantly impacts patients' quality of life. RP exhibits significant phenotypic and genetic heterogeneity. For instance, numerous abnormal genes are implicated in RP, resulting in varying clinical presentations, disease progression rates, and pathological characteristics among different patients. Consequently, gene therapy for RP poses challenges due to these complexities. However, stem cells have garnered considerable attention in the field of RPE therapy since both RPE cells and photoreceptors can be derived from stem cells. In recent years, a large number of animal experiments and clinical trials based on stem cell transplantation attempts, especially cord blood mesenchymal stem cell (MSC) transplantation and bone marrow-derived MSC transplantation, have confirmed that stem cell therapy can effectively and safely improve the outer retinal function of the RP-affected eye. However, stem cell therapy also has certain limitations, such as the fact that RP patients may involve multiple types of retinal cytopathia, which brings great challenges to stem cell transplantation therapy, and further research is needed to solve various problems faced by this approach in the clinic. Through comprehensive analysis of the etiology and histopathological changes associated with RP, this study substantiates the efficacy and safety of stem cell therapy based on rigorous animal experimentation and clinical trials, while also highlighting the existing limitations that warrant further investigation.
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Affiliation(s)
- Xin-Ya Qi
- School of Medicine, Department of Life Sciences and Medicine, Northwest University, Xi'an 710069, Shaanxi Province, China
| | - Chen-Hui Mi
- School of Medicine, Department of Life Sciences and Medicine, Northwest University, Xi'an 710069, Shaanxi Province, China
| | - De-Rui Cao
- School of Medicine, Department of Life Sciences and Medicine, Northwest University, Xi'an 710069, Shaanxi Province, China
| | - Xie-Qun Chen
- School of Medicine, Department of Life Sciences and Medicine, Northwest University, Xi'an 710069, Shaanxi Province, China
- The Third Hospital of Xi'an, Affiliated Hospital of Northwest University, Xi'an 710021, Shaanxi Province, China
| | - Peng Zhang
- School of Medicine, Department of Life Sciences and Medicine, Northwest University, Xi'an 710069, Shaanxi Province, China
- The Third Hospital of Xi'an, Affiliated Hospital of Northwest University, Xi'an 710021, Shaanxi Province, China
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Bodenbender JP, Bethge L, Stingl K, Mazzola P, Haack T, Biskup S, Wissinger B, Weisschuh N, Kohl S, Kühlewein L. Clinical and Genetic Findings in a Cohort of Patients with PRPF31-Associated Retinal Dystrophy. Am J Ophthalmol 2024; 267:213-229. [PMID: 38909744 DOI: 10.1016/j.ajo.2024.06.020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2023] [Revised: 06/12/2024] [Accepted: 06/13/2024] [Indexed: 06/25/2024]
Abstract
PURPOSE The purpose of our study was to assess the phenotypic and genotypic spectrum in a large cohort of patients with PRPF31-associated retinal dystrophy. DESIGN Retrospective cohort study. METHODS In this retrospective chart review study, we collected cross-sectional data on the phenotype and genotype of patients with PRPF31-associated retinal dystrophy from the clinics for inherited retinal dystrophies at the University of Tuebingen and the local RetDis database and biobank. Patients underwent thorough ophthalmological examinations and genetic testing. RESULTS Eighty-six patients from 61 families were available for clinical assessment, while genomic DNA was available for 111 individuals (index patients and family members). Fifty-three different disease-associated variants were observed in our cohort. Point mutations were the most common class. All but two patients exhibited features of a typical Retinitis pigmentosa (RP). One patient showed a cone-rod dystrophy pattern. One mutation carrier revealed no signs of a retinal dystrophy. There was a statistically significant better visual acuity for patients with large deletions in the 20-39 age group. Cystoid macular edema was common in those with preserved central retina and showed an association with female sex. CONCLUSION Our study confirms high phenotypic variability in disease onset and age at which legal blindness is reached in PRPF31-associated RP. Non-penetrance is commonly documented in family history, although poorly represented in our study, possibly indicating that true asymptomatic mutation carriers are rare if followed-up over lifetime with thorough ophthalmologic workup.
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Affiliation(s)
- Jan-Philipp Bodenbender
- University Eye Hospital, Center for Ophthalmology, Eberhard Karls University (J.P.B., L.B., K.S., L.K.), Tübingen, Germany
| | - Leon Bethge
- University Eye Hospital, Center for Ophthalmology, Eberhard Karls University (J.P.B., L.B., K.S., L.K.), Tübingen, Germany
| | - Katarina Stingl
- University Eye Hospital, Center for Ophthalmology, Eberhard Karls University (J.P.B., L.B., K.S., L.K.), Tübingen, Germany
| | - Pascale Mazzola
- Institute of Medical Genetics and Applied Genomics, Eberhard Karls University (P.M., T.H.), Tübingen, Germany
| | - Tobias Haack
- Institute of Medical Genetics and Applied Genomics, Eberhard Karls University (P.M., T.H.), Tübingen, Germany; Center for Rare Diseases, Eberhard Karls University (T.H.), Tübingen, Germany
| | | | - Bernd Wissinger
- Molecular Genetics Laboratory, Institute for Ophthalmic Research, Center for Ophthalmology, Eberhard Karls University (B.W., N.W., S.K.), Tübingen, Germany
| | - Nicole Weisschuh
- Molecular Genetics Laboratory, Institute for Ophthalmic Research, Center for Ophthalmology, Eberhard Karls University (B.W., N.W., S.K.), Tübingen, Germany
| | - Susanne Kohl
- Molecular Genetics Laboratory, Institute for Ophthalmic Research, Center for Ophthalmology, Eberhard Karls University (B.W., N.W., S.K.), Tübingen, Germany
| | - Laura Kühlewein
- University Eye Hospital, Center for Ophthalmology, Eberhard Karls University (J.P.B., L.B., K.S., L.K.), Tübingen, Germany; Institute for Ophthalmic Research, Center for Ophthalmology, Eberhard Karls University (L.K.), Tübingen, Germany.
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Wang K, Xu H, Zou R, Zeng G, Yuan Y, Zhu X, Zhao X, Li J, Zhang L. PCYT1A deficiency disturbs fatty acid metabolism and induces ferroptosis in the mouse retina. BMC Biol 2024; 22:134. [PMID: 38858683 PMCID: PMC11165903 DOI: 10.1186/s12915-024-01932-y] [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: 12/09/2023] [Accepted: 06/04/2024] [Indexed: 06/12/2024] Open
Abstract
BACKGROUND Inherited retinal dystrophies (IRDs) are a group of debilitating visual disorders characterized by the progressive degeneration of photoreceptors, which ultimately lead to blindness. Among the causes of this condition, mutations in the PCYT1A gene, which encodes the rate-limiting enzyme responsible for phosphatidylcholine (PC) de novo synthesis via the Kennedy pathway, have been identified. However, the precise mechanisms underlying the association between PCYT1A mutations and IRDs remain unclear. To address this knowledge gap, we focused on elucidating the functions of PCYT1A in the retina. RESULTS We found that PCYT1A is highly expressed in Müller glial (MG) cells in the inner nuclear layer (INL) of the retina. Subsequently, we generated a retina-specific knockout mouse model in which the Pcyt1a gene was targeted (Pcyt1a-RKO or RKO mice) to investigate the molecular mechanisms underlying IRDs caused by PCYT1A mutations. Our findings revealed that the deletion of Pcyt1a resulted in retinal degenerative phenotypes, including reduced scotopic electroretinogram (ERG) responses and progressive degeneration of photoreceptor cells, accompanied by loss of cells in the INL. Furthermore, through proteomic and bioinformatic analyses, we identified dysregulated retinal fatty acid metabolism and activation of the ferroptosis signalling pathway in RKO mice. Importantly, we found that PCYT1A deficiency did not lead to an overall reduction in PC synthesis within the retina. Instead, this deficiency appeared to disrupt free fatty acid metabolism and ultimately trigger ferroptosis. CONCLUSIONS This study reveals a novel mechanism by which mutations in PCYT1A contribute to the development of IRDs, shedding light on the interplay between fatty acid metabolism and retinal degenerative diseases, and provides new insights into the treatment of IRDs.
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Affiliation(s)
- Kaifang Wang
- The Sichuan Provincial Key Laboratory for Human Disease Gene Study, Center for Medical Genetics, Sichuan Provincial People's Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, 610072, Sichuan, China
| | - Huijuan Xu
- The Sichuan Provincial Key Laboratory for Human Disease Gene Study, Center for Medical Genetics, Sichuan Provincial People's Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, 610072, Sichuan, China
- Qinghai Provincial Key Laboratory of Tibetan Medicine Research, Northwest Institute of Plateau Biology, Chinese Academy of Sciences, Xining, 810008, Qinghai, China
| | - Rong Zou
- The Sichuan Provincial Key Laboratory for Human Disease Gene Study, Center for Medical Genetics, Sichuan Provincial People's Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, 610072, Sichuan, China
| | - Guangqun Zeng
- The People's Hospital of Pengzhou, Chengdu, 611930, Sichuan, China
| | - Ye Yuan
- Medical Center Hospital of Qionglai City, Chengdu, 611530, Sichuan, China
| | - Xianjun Zhu
- The Sichuan Provincial Key Laboratory for Human Disease Gene Study, Center for Medical Genetics, Sichuan Provincial People's Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, 610072, Sichuan, China
- Qinghai Provincial Key Laboratory of Tibetan Medicine Research, Northwest Institute of Plateau Biology, Chinese Academy of Sciences, Xining, 810008, Qinghai, China
- Research Unit for Blindness Prevention of Chinese Academy of Medical Sciences (2019RU026), Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, Chengdu, 610072, Sichuan, China
| | - Xiaohui Zhao
- The People's Hospital of Pengzhou, Chengdu, 611930, Sichuan, China.
| | - Jie Li
- The Sichuan Provincial Key Laboratory for Human Disease Gene Study, Center for Medical Genetics, Sichuan Provincial People's Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, 610072, Sichuan, China.
- Department of Ophthalmology, Sichuan Provincial People's Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, 610072, Sichuan, China.
| | - Lin Zhang
- The Sichuan Provincial Key Laboratory for Human Disease Gene Study, Center for Medical Genetics, Sichuan Provincial People's Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, 610072, Sichuan, China.
- Qinghai Provincial Key Laboratory of Tibetan Medicine Research, Northwest Institute of Plateau Biology, Chinese Academy of Sciences, Xining, 810008, Qinghai, China.
- Research Unit for Blindness Prevention of Chinese Academy of Medical Sciences (2019RU026), Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, Chengdu, 610072, Sichuan, China.
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Ciampi L, Serrano L, Irimia M. Unique transcriptomes of sensory and non-sensory neurons: insights from Splicing Regulatory States. Mol Syst Biol 2024; 20:296-310. [PMID: 38438733 PMCID: PMC10987577 DOI: 10.1038/s44320-024-00020-1] [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: 10/31/2023] [Revised: 01/04/2024] [Accepted: 01/12/2024] [Indexed: 03/06/2024] Open
Abstract
Alternative Splicing (AS) programs serve as instructive signals of cell type specificity, particularly within the brain, which comprises dozens of molecularly and functionally distinct cell types. Among them, retinal photoreceptors stand out due to their unique transcriptome, making them a particularly well-suited system for studying how AS shapes cell type-specific molecular functions. Here, we use the Splicing Regulatory State (SRS) as a novel framework to discuss the splicing factors governing the unique AS pattern of photoreceptors, and how this pattern may aid in the specification of their highly specialized sensory cilia. In addition, we discuss how other sensory cells with ciliated structures, for which data is much scarcer, also rely on specific SRSs to implement a proteome specialized in the detection of sensory stimuli. By reviewing the general rules of cell type- and tissue-specific AS programs, firstly in the brain and subsequently in specialized sensory neurons, we propose a novel paradigm on how SRSs are established and how they can diversify. Finally, we illustrate how SRSs shape the outcome of mutations in splicing factors to produce cell type-specific phenotypes that can lead to various human diseases.
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Affiliation(s)
- Ludovica Ciampi
- Center for Genomic Regulation, Barcelona Institute of Science and Technology, Barcelona, Spain.
| | - Luis Serrano
- Center for Genomic Regulation, Barcelona Institute of Science and Technology, Barcelona, Spain.
- Universitat Pompeu Fabra, Barcelona, Spain.
- ICREA, Barcelona, Spain.
| | - Manuel Irimia
- Center for Genomic Regulation, Barcelona Institute of Science and Technology, Barcelona, Spain.
- Universitat Pompeu Fabra, Barcelona, Spain.
- ICREA, Barcelona, Spain.
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Liu X, Dai H, Li G, Jia R, Meng X, Yu S, Yang L, Hong J. Screening copy number variations in 35 unsolved inherited retinal disease families. Hum Genet 2024; 143:197-210. [PMID: 38282009 PMCID: PMC10881639 DOI: 10.1007/s00439-023-02631-4] [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: 09/11/2023] [Accepted: 12/15/2023] [Indexed: 01/30/2024]
Abstract
The purpose of this study was to screen Copy Number Variations (CNVs) in 35 unsolved Inherited Retinal Dystrophy (IRD) families. Initially, next generation sequencing, including a specific Hereditary Eye Disease Enrichment Panel or Whole exome sequencing, was employed to screen (likely) pathogenic Single-nucleotide Variants (SNVs) and small Insertions and Deletions (indels) for these cases. All available SNVs and indels were further validated and co-segregation analyses were performed in available family members by Sanger sequencing. If not, after excluding deep intronic variants, Multiplex ligation-dependent probe amplification (MLPA), quantitative fluorescence PCR (QF-PCR) and Sanger sequencing were employed to screen CNVs. We determined that 18 probands who had heterozygous SNVs/indels or whose parents were not consanguineous but had homozygous SNVs/indels in autosomal recessive IRDs genes had CNVs in another allele of these genes, 11 families had disease-causing hemizygous CNVs in X-linked IRD genes, 6 families had (likely) pathogenic heterozygous CNVs in PRPF31 gene. Of 35 families, 33 different CNVs in 16 IRD-associated genes were detected, with PRPF31, EYS and USH2A the most common disease-causing gene in CNVs. Twenty-six and 7 of them were deletion and duplication CNVs, respectively. Among them, 14 CNVs were first reported in this study. Our research indicates that CNVs contribute a lot to IRDs, and screening of CNVs substantially increases the diagnostic rate of IRD. Our results emphasize that MLPA and QF-PCR are ideal methods to validate CNVs, and the novel CNVs reported herein expand the mutational spectrums of IRDs.
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Affiliation(s)
- Xiaozhen Liu
- Department of Ophthalmology, Peking University Third Hospital, Beijing, 100191, China
- Beijing Key Laboratory of Restoration of Damaged Ocular Nerve, Peking University Third Hospital, Beijing, 100191, China
| | - Hehua Dai
- Department of Ophthalmology, The First Affiliated Hospital of Shandong First Medical University & Shandong Provincial Qianfoshan Hospital, Jinan, 250014, China
| | - Genlin Li
- Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Ophthalmology & Visual Sciences Key Lab, Beijing, 100730, China
| | - Ruixuan Jia
- Department of Ophthalmology, Peking University Third Hospital, Beijing, 100191, China
- Beijing Key Laboratory of Restoration of Damaged Ocular Nerve, Peking University Third Hospital, Beijing, 100191, China
| | - Xiang Meng
- Department of Ophthalmology, Peking University Third Hospital, Beijing, 100191, China
- Beijing Key Laboratory of Restoration of Damaged Ocular Nerve, Peking University Third Hospital, Beijing, 100191, China
| | - Shicheng Yu
- Department of Ophthalmology, Peking University Third Hospital, Beijing, 100191, China
- Beijing Key Laboratory of Restoration of Damaged Ocular Nerve, Peking University Third Hospital, Beijing, 100191, China
| | - Liping Yang
- Department of Ophthalmology, Peking University Third Hospital, Beijing, 100191, China.
- Beijing Key Laboratory of Restoration of Damaged Ocular Nerve, Peking University Third Hospital, Beijing, 100191, China.
| | - Jing Hong
- Department of Ophthalmology, Peking University Third Hospital, Beijing, 100191, China.
- Beijing Key Laboratory of Restoration of Damaged Ocular Nerve, Peking University Third Hospital, Beijing, 100191, China.
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Li RTH, Roman AJ, Sumaroka A, Stanton CM, Swider M, Garafalo AV, Heon E, Vincent A, Wright AF, Megaw R, Aleman TS, Browning AC, Dhillon B, Cideciyan AV. Treatment Strategy With Gene Editing for Late-Onset Retinal Degeneration Caused by a Founder Variant in C1QTNF5. Invest Ophthalmol Vis Sci 2023; 64:33. [PMID: 38133503 PMCID: PMC10746929 DOI: 10.1167/iovs.64.15.33] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2023] [Accepted: 11/28/2023] [Indexed: 12/23/2023] Open
Abstract
Purpose Genome editing is an emerging group of technologies with the potential to ameliorate dominant, monogenic human diseases such as late-onset retinal degeneration (L-ORD). The goal of this study was to identify disease stages and retinal locations optimal for evaluating the efficacy of a future genome editing trial. Methods Twenty five L-ORD patients (age range, 33-77 years; median age, 59 years) harboring the founder variant S163R in C1QTNF5 were enrolled from three centers in the United Kingdom and United States. Patients were examined with widefield optical coherence tomography (OCT) and chromatic perimetry under dark-adapted and light-adapted conditions to derive phenomaps of retinal disease. Results were analyzed with a model of a shared natural history of a single delayed exponential across all subjects and all retinal locations. Results Critical age for the initiation of photoreceptor loss ranged from 48 years at the temporal paramacular retina to 74 years at the inferior midperipheral retina. Subretinal deposits (sRET-Ds) became more prevalent as critical age was approached. Subretinal pigment epithelial deposits (sRPE-Ds) were detectable in the youngest patients showing no other structural or functional abnormalities at the retina. The sRPE-D thickness continuously increased, reaching 25 µm in the extrafoveal retina and 19 µm in the fovea at critical age. Loss of light sensitivity preceded shortening of outer segments and loss of photoreceptors by more than a decade. Conclusions Retinal regions providing an ideal treatment window exist across all severity stages of L-ORD.
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Affiliation(s)
- Randa T. H. Li
- Centre for Clinical Brain Sciences, School of Clinical Sciences, University of Edinburgh, Edinburgh, Scotland, United Kingdom
- Princess Alexandra Eye Pavilion, NHS Lothian, Edinburgh, Scotland, United Kingdom
| | - Alejandro J. Roman
- Center for Hereditary Retinal Degenerations, Scheie Eye Institute, Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States
| | - Alexander Sumaroka
- Center for Hereditary Retinal Degenerations, Scheie Eye Institute, Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States
| | - Chloe M. Stanton
- Medical Research Council Human Genetics Unit, Institute of Genetics and Cancer, University of Edinburgh, Edinburgh, United Kingdom
| | - Malgorzata Swider
- Center for Hereditary Retinal Degenerations, Scheie Eye Institute, Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States
| | - Alexandra V. Garafalo
- Center for Hereditary Retinal Degenerations, Scheie Eye Institute, Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States
| | - Elise Heon
- Department of Ophthalmology and Vision Sciences, The Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada
| | - Ajoy Vincent
- Department of Ophthalmology and Vision Sciences, The Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada
| | - Alan F. Wright
- Medical Research Council Human Genetics Unit, Institute of Genetics and Cancer, University of Edinburgh, Edinburgh, United Kingdom
| | - Roly Megaw
- Princess Alexandra Eye Pavilion, NHS Lothian, Edinburgh, Scotland, United Kingdom
- Medical Research Council Human Genetics Unit, Institute of Genetics and Cancer, University of Edinburgh, Edinburgh, United Kingdom
| | - Tomas S. Aleman
- Center for Hereditary Retinal Degenerations, Scheie Eye Institute, Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States
| | - Andrew C. Browning
- Newcastle Eye Centre, Royal Victoria Infirmary, Newcastle Upon Tyne, United Kingdom
| | - Baljean Dhillon
- Centre for Clinical Brain Sciences, School of Clinical Sciences, University of Edinburgh, Edinburgh, Scotland, United Kingdom
- Princess Alexandra Eye Pavilion, NHS Lothian, Edinburgh, Scotland, United Kingdom
| | - Artur V. Cideciyan
- Center for Hereditary Retinal Degenerations, Scheie Eye Institute, Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States
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9
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Aweidah H, Xi Z, Sahel JA, Byrne LC. PRPF31-retinitis pigmentosa: Challenges and opportunities for clinical translation. Vision Res 2023; 213:108315. [PMID: 37714045 PMCID: PMC10872823 DOI: 10.1016/j.visres.2023.108315] [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: 04/30/2023] [Revised: 08/23/2023] [Accepted: 08/24/2023] [Indexed: 09/17/2023]
Abstract
Mutations in pre-mRNA processing factor 31 cause autosomal dominant retinitis pigmentosa (PRPF31-RP), for which there is currently no efficient treatment, making this disease a prime target for the development of novel therapeutic strategies. PRPF31-RP exhibits incomplete penetrance due to haploinsufficiency, in which reduced levels of gene expression from the mutated allele result in disease. A variety of model systems have been used in the investigation of disease etiology and therapy development. In this review, we discuss recent advances in both in vivo and in vitro model systems, evaluating their advantages and limitations in the context of therapy development for PRPF31-RP. Additionally, we describe the latest approaches for treatment, including AAV-mediated gene augmentation, genome editing, and late-stage therapies such as optogenetics, cell transplantation, and retinal prostheses.
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Affiliation(s)
- Hamzah Aweidah
- Department of Ophthalmology, University of Pittsburgh, Pittsburgh, PA, USA
| | - Zhouhuan Xi
- Department of Ophthalmology, University of Pittsburgh, Pittsburgh, PA, USA; Department of Ophthalmology, Eye Center, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui, China
| | - José-Alain Sahel
- Department of Ophthalmology, University of Pittsburgh, Pittsburgh, PA, USA; Department of Neurobiology, University of Pittsburgh, Pittsburgh, PA, USA; Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, USA
| | - Leah C Byrne
- Department of Ophthalmology, University of Pittsburgh, Pittsburgh, PA, USA; Department of Neurobiology, University of Pittsburgh, Pittsburgh, PA, USA; Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, USA.
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10
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Keuthan CJ, Karma S, Zack DJ. Alternative RNA Splicing in the Retina: Insights and Perspectives. Cold Spring Harb Perspect Med 2023; 13:a041313. [PMID: 36690463 PMCID: PMC10547393 DOI: 10.1101/cshperspect.a041313] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Alternative splicing is a fundamental and highly regulated post-transcriptional process that enhances transcriptome and proteome diversity. This process is particularly important in neuronal tissues, such as the retina, which exhibit some of the highest levels of differentially spliced genes in the body. Alternative splicing is regulated both temporally and spatially during neuronal development, can be cell-type-specific, and when altered can cause a number of pathologies, including retinal degeneration. Advancements in high-throughput sequencing technologies have facilitated investigations of the alternative splicing landscape of the retina in both healthy and disease states. Additionally, innovations in human stem cell engineering, specifically in the generation of 3D retinal organoids, which recapitulate many aspects of the in vivo retinal microenvironment, have aided studies of the role of alternative splicing in human retinal development and degeneration. Here we review these advances and discuss the ongoing development of strategies for the treatment of alternative splicing-related retinal disease.
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Affiliation(s)
- Casey J Keuthan
- Department of Ophthalmology, Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, Maryland 21231, USA
| | - Sadik Karma
- Department of Ophthalmology, Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, Maryland 21231, USA
| | - Donald J Zack
- Departments of Ophthalmology, Wilmer Eye Institute, Neuroscience, Molecular Biology and Genetics, and Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland 21231, USA
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11
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Cheng YM, Ma C, Jin K, Jin ZB. Retinal organoid and gene editing for basic and translational research. Vision Res 2023; 210:108273. [PMID: 37307693 DOI: 10.1016/j.visres.2023.108273] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2023] [Revised: 05/23/2023] [Accepted: 05/24/2023] [Indexed: 06/14/2023]
Abstract
The rapid evolution of two technologies has greatly transformed the basic, translational, and clinical research in the mammalian retina. One is the retinal organoid (RO) technology. Various induction methods have been created or adapted to generate species-specific, disease-specific, and experimental-targeted retinal organoids (ROs). The process of generating ROs can highly mimic the in vivo retinal development, and consequently, the ROs resemble the retina in many aspects including the molecular and cellular profiles. The other technology is the gene editing, represented by the classical CRISPR-Cas9 editing and its derivatives such as prime editing, homology independent targeted integration (HITI), base editing and others. The combination of ROs and gene editing has opened up countless possibilities in the study of retinal development, pathogenesis, and therapeutics. We review recent advances in the ROs, gene editing methodologies, delivery vectors, and related topics that are particularly relevant to retinal studies.
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Affiliation(s)
- You-Min Cheng
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing 100730 China
| | - Chao Ma
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing 100730 China
| | - Kangxin Jin
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing 100730 China.
| | - Zi-Bing Jin
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing 100730 China.
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12
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Daich Varela M, Georgiadis A, Michaelides M. Genetic treatment for autosomal dominant inherited retinal dystrophies: approaches, challenges and targeted genotypes. Br J Ophthalmol 2023; 107:1223-1230. [PMID: 36038193 DOI: 10.1136/bjo-2022-321903] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Accepted: 08/01/2022] [Indexed: 11/04/2022]
Abstract
Inherited retinal diseases (IRDs) have been in the front line of gene therapy development for the last decade, providing a useful platform to test novel therapeutic approaches. More than 40 clinical trials have been completed or are ongoing, tackling autosomal recessive and X-linked conditions, mostly through adeno-associated viral vector delivery of a normal copy of the disease-causing gene. However, only recently has autosomal dominant (ad) disease been targeted, with the commencement of a trial for rhodopsin (RHO)-associated retinitis pigmentosa (RP), implementing antisense oligonucleotide (AON) therapy, with promising preliminary results (NCT04123626).Autosomal dominant RP represents 15%-25% of all RP, with RHO accounting for 20%-30% of these cases. Autosomal dominant macular and cone-rod dystrophies (MD/CORD) correspond to approximately 7.5% of all IRDs, and approximately 35% of all MD/CORD cases, with the main causative gene being BEST1 Autosomal dominant IRDs are not only less frequent than recessive, but also tend to be less severe and have later onset; for example, an individual with RHO-adRP would typically become severely visually impaired at an age 2-3 times older than in X-linked RPGR-RP.Gain-of-function and dominant negative aetiologies are frequently seen in the prevalent adRP genes RHO, RP1 and PRPF31 among others, which would not be effectively addressed by gene supplementation alone and need creative, novel approaches. Zinc fingers, RNA interference, AON, translational read-through therapy, and gene editing by clustered regularly interspaced short palindromic repeats/Cas are some of the strategies that are currently under investigation and will be discussed here.
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Affiliation(s)
- Malena Daich Varela
- Moorfields Eye Hospital, London, UK
- UCL Institute of Ophthalmology, University College London, London, UK
| | | | - Michel Michaelides
- Moorfields Eye Hospital, London, UK
- UCL Institute of Ophthalmology, University College London, London, UK
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13
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Sen P, Srikrupa N, Maitra P, Srilekha S, Porkodi P, Gnanasekaran H, Bhende M, Khetan V, Mathavan S, Bhende P, Ratra D, Raman R, Rao C, Sripriya S. Next-generation sequencing--based genetic testing and phenotype correlation in retinitis pigmentosa patients from India. Indian J Ophthalmol 2023; 71:2512-2520. [PMID: 37322672 PMCID: PMC10417947 DOI: 10.4103/ijo.ijo_2579_22] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2022] [Revised: 03/14/2023] [Accepted: 03/19/2023] [Indexed: 06/17/2023] Open
Abstract
Purpose Inherited retinal dystrophies (IRD) are a heterogeneous group of retinal diseases leading to progressive loss of photoreceptors through apoptosis. Retinitis pigmentosa (RP) is considered the most common form of IRD. Panel-based testing in RP has proven effective in identifying the causative genetic mutations in 70% and 80% of the patients. This is a retrospective, observational, single-center study of 107 RP patients who had undergone next-generation sequencing-based targeted gene panel testing for IRD genes. These patients were inspected for common phenotypic features to arrive at meaningful genotype-phenotype correlation. Methods Patients underwent complete ophthalmic examination, and blood was collected from the proband for DNA extraction after documenting the pedigree. Targeted Next Generation Sequencing (NGS) was done by panel-based testing for IRD genes followed by co-segregation analysis wherever applicable. Results Of the 107 patients, 72 patients had pathogenic mutations. The mean age of onset of symptoms was 14 ± 12 years (range: 5-55). Mean (Best Corrected Visual Acuity) BCVA was 6/48 (0.9 logMAR) (range 0.0-3.0). At presentation, over one-third of eyes had BCVA worse than 6/60 (<1 logMAR). Phenotype analysis with the gene defects showed overlapping features, such as peripheral well-defined chorioretinal atrophic patches in patients with CERKL, PROM1, and RPE65 gene mutations and large macular lesions in patients with RDH12 and CRX gene mutations, respectively. Nummular or clump-like pigmentation was noted in CRB1, TTC8, PDE6A, and PDE6B. Conclusion NGS-based genetic testing can help clinicians to diagnose RP more accurately, and phenotypic correlations can also help in better patient counselling with respect to prognosis and guidance regarding ongoing newer gene-based therapies.
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Affiliation(s)
- Parveen Sen
- Shri Bhagwan Mahavir Vitreoretinal Services, Medical Research Foundation, Sankara Nethralaya, Chennai, Tamil Nadu, India
| | - Natarajan Srikrupa
- SNONGC Department of Genetics and Molecular Biology, Vision Research Foundation, Sankara Nethralaya, Chennai, Tamil Nadu, India
| | - Puja Maitra
- Shri Bhagwan Mahavir Vitreoretinal Services, Medical Research Foundation, Sankara Nethralaya, Chennai, Tamil Nadu, India
| | - Sundaramurthy Srilekha
- SNONGC Department of Genetics and Molecular Biology, Vision Research Foundation, Sankara Nethralaya, Chennai, Tamil Nadu, India
| | - Periyasamy Porkodi
- SNONGC Department of Genetics and Molecular Biology, Vision Research Foundation, Sankara Nethralaya, Chennai, Tamil Nadu, India
| | - Harshavardhini Gnanasekaran
- SNONGC Department of Genetics and Molecular Biology, Vision Research Foundation, Sankara Nethralaya, Chennai, Tamil Nadu, India
| | - Muna Bhende
- Shri Bhagwan Mahavir Vitreoretinal Services, Medical Research Foundation, Sankara Nethralaya, Chennai, Tamil Nadu, India
| | - Vikas Khetan
- Shri Bhagwan Mahavir Vitreoretinal Services, Medical Research Foundation, Sankara Nethralaya, Chennai, Tamil Nadu, India
| | - Sinnakaruppan Mathavan
- SNONGC Department of Genetics and Molecular Biology, Vision Research Foundation, Sankara Nethralaya, Chennai, Tamil Nadu, India
| | - Pramod Bhende
- Shri Bhagwan Mahavir Vitreoretinal Services, Medical Research Foundation, Sankara Nethralaya, Chennai, Tamil Nadu, India
| | - Dhanashree Ratra
- Shri Bhagwan Mahavir Vitreoretinal Services, Medical Research Foundation, Sankara Nethralaya, Chennai, Tamil Nadu, India
| | - Rajiv Raman
- Shri Bhagwan Mahavir Vitreoretinal Services, Medical Research Foundation, Sankara Nethralaya, Chennai, Tamil Nadu, India
| | - Chetan Rao
- Shri Bhagwan Mahavir Vitreoretinal Services, Medical Research Foundation, Sankara Nethralaya, Chennai, Tamil Nadu, India
| | - Sarangapani Sripriya
- SNONGC Department of Genetics and Molecular Biology, Vision Research Foundation, Sankara Nethralaya, Chennai, Tamil Nadu, India
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14
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Han G, Wei P, Han Q. Application of IPSC and Müller glia derivatives in retinal degenerative diseases. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2023; 199:351-362. [PMID: 37678979 DOI: 10.1016/bs.pmbts.2023.03.026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/09/2023]
Abstract
Retinal degenerative diseases cause blindness characterized by a progressive decline in the number and function of retinal pigment epithelium (RPE), photoreceptor cells, and ganglion cells. Such diseases include retinitis pigmentosa (RP), glaucomatous optic neuropathy, age-related macular degeneration and diabetic optic neuropathy. Recent studies have demonstrated that Müller glial cells (MGCs), an endogenous alternative source of retinal neurons, are important glial cells involved in retinal development, damage, and regeneration, making it an excellent target for retinal nerve regeneration. Although hardly differentiate into neuron cells, transplanted MGCs have been shown to induce partial recovery of visual function in experimental retinal degenerative models. This improvement is possibly attributed to the release of neuroprotective factors that derived from the MGCs. With the development of the therapeutic usage of pluripotent stem cell, application of induced pluripotent stem cells (iPSCs) or embryonic stem cells (ESCs) originated derivation of MGCs have been widely used in retinal degenerative disease model such as glaucoma and retinitis pigmentosa model. This chapter summarized the relevant research and mechanisms and provided a broader application and research prospects for effective treatments in retinal degenerative diseases.
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Affiliation(s)
- Guoge Han
- Clinical College of Ophthalmology, Tianjin Medical University, Tianjin, P.R. China; Tianjin Eye Hospital, Tianjin Key Lab of Ophthalmology and Visual Science, Tianjin, P.R. China; Nankai University Eye Institute, Nankai University Affiliated Eye Hospital, Nankai University, Tianjin, P.R. China.
| | - Pinghui Wei
- Clinical College of Ophthalmology, Tianjin Medical University, Tianjin, P.R. China; Tianjin Eye Hospital, Tianjin Key Lab of Ophthalmology and Visual Science, Tianjin, P.R. China; Nankai University Eye Institute, Nankai University Affiliated Eye Hospital, Nankai University, Tianjin, P.R. China
| | - Quanhong Han
- Clinical College of Ophthalmology, Tianjin Medical University, Tianjin, P.R. China; Tianjin Eye Hospital, Tianjin Key Lab of Ophthalmology and Visual Science, Tianjin, P.R. China; Nankai University Eye Institute, Nankai University Affiliated Eye Hospital, Nankai University, Tianjin, P.R. China
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15
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Lisbjerg K, Grønskov K, Bertelsen M, Møller LB, Kessel L. Genetic Modifiers of Non-Penetrance and RNA Expression Levels in PRPF31-Associated Retinitis Pigmentosa in a Danish Cohort. Genes (Basel) 2023; 14:435. [PMID: 36833363 PMCID: PMC9956082 DOI: 10.3390/genes14020435] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2022] [Revised: 02/03/2023] [Accepted: 02/07/2023] [Indexed: 02/11/2023] Open
Abstract
(1) Background/aims: To examine potential genetic modifiers of disease penetrance in PRPF31-associated retinitis pigmentosa 11 (RP11). (2) Methods: Blood samples from individuals (n = 37) with PRPF31 variants believed to be disease-causing were used for molecular genetic testing and, in some cases (n = 23), also for mRNA expression analyses. Medical charts were used to establish if individuals were symptomatic (RP) or asymptomatic non-penetrant carriers (NPC). RNA expression levels of PRPF31 and CNOT3 were measured on peripheral whole blood using quantitative real-time PCR normalized to GAPDH. Copy number variation of minisatellite repeat element 1 (MSR1) was performed with DNA fragment analysis. (3) Results: mRNA expression analyses on 22 individuals (17 with RP and 5 non-penetrant carriers) revealed no statistically significant differences in PRPF31 or CNOT3 mRNA expression levels between individuals with RP and non-penetrant carriers. Among 37 individuals, we found that all three carriers of a 4-copy MSR1 sequence on their wild-type (WT) allele were non-penetrant carriers. However, copy number variation of MSR1 is not the sole determinant factor of non-penetrance, as not all non-penetrant carriers carried a 4-copy WT allele. A 4-copy MSR1 mutant allele was not associated with non-penetrance. (4) Conclusions: In this Danish cohort, a 4-copy MSR1 WT allele was associated with non-penetrance of retinitis pigmentosa caused by PRPF31 variants. The level of PRPF31 mRNA expression in peripheral whole blood was not a useful indicator of disease status.
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Affiliation(s)
- Kristian Lisbjerg
- Department of Ophthalmology, Copenhagen University Hospital-Rigshospitalet, 2600 Glostrup, Denmark
| | - Karen Grønskov
- Department of Clinical Genetics, Copenhagen University Hospital-Rigshospitalet, 2100 Copenhagen, Denmark
| | - Mette Bertelsen
- Department of Clinical Genetics, Copenhagen University Hospital-Rigshospitalet, 2100 Copenhagen, Denmark
| | - Lisbeth Birk Møller
- Department of Clinical Genetics, Copenhagen University Hospital-Rigshospitalet, 2100 Copenhagen, Denmark
| | - Line Kessel
- Department of Ophthalmology, Copenhagen University Hospital-Rigshospitalet, 2600 Glostrup, Denmark
- Department of Clinical Medicine, University of Copenhagen, 2200 Copenhagen, Denmark
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16
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Gene augmentation prevents retinal degeneration in a CRISPR/Cas9-based mouse model of PRPF31 retinitis pigmentosa. Nat Commun 2022; 13:7695. [PMID: 36509783 PMCID: PMC9744804 DOI: 10.1038/s41467-022-35361-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2022] [Accepted: 11/29/2022] [Indexed: 12/14/2022] Open
Abstract
Mutations in PRPF31 cause autosomal dominant retinitis pigmentosa, an untreatable form of blindness. Gene therapy is a promising treatment for PRPF31-retinitis pigmentosa, however, there are currently no suitable animal models in which to develop AAV-mediated gene augmentation. Here we establish Prpf31 mutant mouse models using AAV-mediated CRISPR/Cas9 knockout, and characterize the resulting retinal degeneration phenotype. Mouse models with early-onset morphological and functional impairments like those in patients were established, providing new platforms in which to investigate pathogenetic mechanisms and develop therapeutic methods. AAV-mediated PRPF31 gene augmentation restored the retinal structure and function in a rapidly degenerating mouse model, demonstrating the first in vivo proof-of-concept for AAV-mediated gene therapy to treat PRPF31-retinitis pigmentosa. AAV-CRISPR/Cas9-PRPF31 knockout constructs also mediated efficient PRPF31 knockout in human and non-human primate retinal explants, laying a foundation for establishing non-human primate models using the method developed here.
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17
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Chen Z, Chen J, Gao M, Liu Y, Wu Y, Wang Y, Gong Y, Yu S, Liu W, Wan X, Sun X. Comprehensive analysis of the PRPF31 gene in retinitis pigmentosa patients: Four novel Alu-mediated copy number variations at the PRPF31 locus. Hum Mutat 2022; 43:2279-2294. [PMID: 36317469 DOI: 10.1002/humu.24494] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Revised: 10/10/2022] [Accepted: 10/24/2022] [Indexed: 11/11/2022]
Abstract
Retinitis pigmentosa (RP) is a monogenic disease characterized by irreversible degeneration of the retina. PRPF31, the second most common causative gene of autosomal dominant RP, frequently harbors copy number variations (CNVs), but the underlying mechanism is unclear. In this study, we summarized the phenotypic and genotypic characteristics of 18 RP families (F01-F18) with variants in PRPF31. The prevalence of PRPF31 variants in our cohort of Chinese RP families was 1.7% (18/1024). Seventeen different variants in PRPF31 were detected, including eight novel variants. Notably, four novel CNVs encompassing PRPF31, with a proportion of 22.2% (4/18), were validated to harbor gross deletions involving Alu/Alu-mediated rearrangements (AAMRs) in the same orientation. Among a total of 12 CNVs of PRPF31 with breakpoints mapped on nucleotide-resolution, 10 variants (83.3%) were presumably mediated by Alu elements. Furthermore, we described the correlation between the genotypes and phenotypes in PRPF31-related RP. Our findings expand the mutational spectrum of the PRPF31 gene and provide strong evidence that Alu elements of PRPF31 probably contribute to the susceptibility to genomic rearrangement in this locus.
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Affiliation(s)
- Zhixuan Chen
- Department of Ophthalmology, School of Medicine, Shanghai General Hospital (Shanghai First People's Hospital), Shanghai Jiao Tong University, Shanghai, China.,Department of Ophthalmology, National Clinical Research Center for Eye Diseases, Shanghai, China.,Department of Ophthalmology, Shanghai Key Laboratory of Fundus Diseases, Shanghai, China.,Department of Ophthalmology, Shanghai Engineering Center for Visual Science and Photomedicine, Shanghai, China
| | - Jieqiong Chen
- Department of Ophthalmology, School of Medicine, Shanghai General Hospital (Shanghai First People's Hospital), Shanghai Jiao Tong University, Shanghai, China.,Department of Ophthalmology, National Clinical Research Center for Eye Diseases, Shanghai, China.,Department of Ophthalmology, Shanghai Key Laboratory of Fundus Diseases, Shanghai, China.,Department of Ophthalmology, Shanghai Engineering Center for Visual Science and Photomedicine, Shanghai, China
| | - Min Gao
- Department of Ophthalmology, School of Medicine, Shanghai General Hospital (Shanghai First People's Hospital), Shanghai Jiao Tong University, Shanghai, China.,Department of Ophthalmology, National Clinical Research Center for Eye Diseases, Shanghai, China.,Department of Ophthalmology, Shanghai Key Laboratory of Fundus Diseases, Shanghai, China.,Department of Ophthalmology, Shanghai Engineering Center for Visual Science and Photomedicine, Shanghai, China
| | - Yang Liu
- Department of Ophthalmology, School of Medicine, Shanghai General Hospital (Shanghai First People's Hospital), Shanghai Jiao Tong University, Shanghai, China.,Department of Ophthalmology, National Clinical Research Center for Eye Diseases, Shanghai, China.,Department of Ophthalmology, Shanghai Key Laboratory of Fundus Diseases, Shanghai, China.,Department of Ophthalmology, Shanghai Engineering Center for Visual Science and Photomedicine, Shanghai, China
| | - Yidong Wu
- Department of Ophthalmology, School of Medicine, Shanghai General Hospital (Shanghai First People's Hospital), Shanghai Jiao Tong University, Shanghai, China.,Department of Ophthalmology, National Clinical Research Center for Eye Diseases, Shanghai, China.,Department of Ophthalmology, Shanghai Key Laboratory of Fundus Diseases, Shanghai, China.,Department of Ophthalmology, Shanghai Engineering Center for Visual Science and Photomedicine, Shanghai, China
| | - Yafang Wang
- Department of Ophthalmology, School of Medicine, Shanghai General Hospital (Shanghai First People's Hospital), Shanghai Jiao Tong University, Shanghai, China.,Department of Ophthalmology, National Clinical Research Center for Eye Diseases, Shanghai, China.,Department of Ophthalmology, Shanghai Key Laboratory of Fundus Diseases, Shanghai, China.,Department of Ophthalmology, Shanghai Engineering Center for Visual Science and Photomedicine, Shanghai, China
| | - Yuanyuan Gong
- Department of Ophthalmology, School of Medicine, Shanghai General Hospital (Shanghai First People's Hospital), Shanghai Jiao Tong University, Shanghai, China.,Department of Ophthalmology, National Clinical Research Center for Eye Diseases, Shanghai, China.,Department of Ophthalmology, Shanghai Key Laboratory of Fundus Diseases, Shanghai, China.,Department of Ophthalmology, Shanghai Engineering Center for Visual Science and Photomedicine, Shanghai, China
| | - Suqin Yu
- Department of Ophthalmology, School of Medicine, Shanghai General Hospital (Shanghai First People's Hospital), Shanghai Jiao Tong University, Shanghai, China.,Department of Ophthalmology, National Clinical Research Center for Eye Diseases, Shanghai, China.,Department of Ophthalmology, Shanghai Key Laboratory of Fundus Diseases, Shanghai, China.,Department of Ophthalmology, Shanghai Engineering Center for Visual Science and Photomedicine, Shanghai, China
| | - Wenjia Liu
- Department of Ophthalmology, School of Medicine, Shanghai General Hospital (Shanghai First People's Hospital), Shanghai Jiao Tong University, Shanghai, China.,Department of Ophthalmology, National Clinical Research Center for Eye Diseases, Shanghai, China.,Department of Ophthalmology, Shanghai Key Laboratory of Fundus Diseases, Shanghai, China.,Department of Ophthalmology, Shanghai Engineering Center for Visual Science and Photomedicine, Shanghai, China
| | - Xiaoling Wan
- Department of Ophthalmology, School of Medicine, Shanghai General Hospital (Shanghai First People's Hospital), Shanghai Jiao Tong University, Shanghai, China.,Department of Ophthalmology, National Clinical Research Center for Eye Diseases, Shanghai, China.,Department of Ophthalmology, Shanghai Key Laboratory of Fundus Diseases, Shanghai, China.,Department of Ophthalmology, Shanghai Engineering Center for Visual Science and Photomedicine, Shanghai, China
| | - Xiaodong Sun
- Department of Ophthalmology, School of Medicine, Shanghai General Hospital (Shanghai First People's Hospital), Shanghai Jiao Tong University, Shanghai, China.,Department of Ophthalmology, National Clinical Research Center for Eye Diseases, Shanghai, China.,Department of Ophthalmology, Shanghai Key Laboratory of Fundus Diseases, Shanghai, China.,Department of Ophthalmology, Shanghai Engineering Center for Visual Science and Photomedicine, Shanghai, China
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18
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A 69 kb Deletion in chr19q13.42 including PRPF31 Gene in a Chinese Family Affected with Autosomal Dominant Retinitis Pigmentosa. J Clin Med 2022; 11:jcm11226682. [PMID: 36431159 PMCID: PMC9695658 DOI: 10.3390/jcm11226682] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2022] [Revised: 10/20/2022] [Accepted: 11/08/2022] [Indexed: 11/16/2022] Open
Abstract
We aimed to identify the genetic cause of autosomal dominant retinitis pigmentosa (adRP) and characterize the underlying molecular mechanisms of incomplete penetrance in a Chinese family affected with adRP. All enrolled family members underwent ophthalmic examinations. Whole-genome sequencing (WGS), multiplex ligation-dependent probe amplification (MLPA), linkage analysis and haplotype construction were performed in all participants. RNA-seq was performed to analyze the regulating mechanism of incomplete penetrance among affected patients, mutation carriers and healthy controls. In the studied family, 14 individuals carried a novel heterozygous large deletion of 69 kilobase (kb) in 19q13.42 encompassing exon 1 of the PRPF31 gene and five upstream genes: TFPT, OSCAR, NDUFA3, TARM1, and VSTM1. Three family members were sequenced and diagnosed as non-penetrant carriers (NPCs). RNA-seq showed significant differential expression of genes in deletion between mutation carriers and healthy control. The RP11 pedigree in this study was the largest pedigree compared to other reported RP11 pedigrees with large deletions. Early onset in all affected members in this pedigree was considered to be a special phenotype and was firstly reported in a RP11 family for the first time. Differential expression of PRPF31 between affected and unaffected subjects indicates a haploinsufficiency to cause the disease in the family. The other genes with significant differential expression might play a cooperative effect on the penetrance of RP11.
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19
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Wang J, Xiao X, Li S, Jiang H, Sun W, Wang P, Zhang Q. Landscape of pathogenic variants in six pre-mRNA processing factor genes for retinitis pigmentosa based on large in-house data sets and database comparisons. Acta Ophthalmol 2022; 100:e1412-e1425. [PMID: 35138024 DOI: 10.1111/aos.15104] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2021] [Revised: 12/31/2021] [Accepted: 01/20/2022] [Indexed: 12/29/2022]
Abstract
PURPOSE Variants in six genes encoding pre-mRNA processing factors (PRPFs) are a common cause of autosomal dominant retinitis pigmentosa (ADRP). This study aims to determine the characteristics of potential pathogenic variants (PPVs) in the six genes. METHODS Variants in six PRPF genes were identified from in-house exome sequencing data. PPVs were identified based on comparative bioinformatics analysis, clinical phenotypes and the ACMG/AMP guidelines. The features of PPVs were revealed by comparative analysis of in-house data set, gnomAD and previously published literature. RESULTS Totally, 36 heterozygous PPVs, including 19 novels, were detected from 45 families, which contributed to 4.4% (45/1019) of RP cases. These PPVs were distributed in PRPF31 (17/45, 37.8%), SNRNP200 (12/45, 26.7%), PRPF8 (10/45, 22.2%) and PRPF3 (6/45, 13.3%) but not in PRPF6 or PRPF4. Different types of PPVs were predominant in different PRPF genes, such as loss-of-function variants in PRPF31 and missense variants in the five remaining genes. The clustering of PPVs in specific regions was observed in SNRNP200, PRPF8 and PRPF3. The pathogenicity for certain classes of variants in these genes, such as loss-of-function variants in PRPF6 and missense variants in PRPF31 and PRPF4, requires careful consideration and further validation. The predominant fundus changes were early macular involvement, widespread RPE atrophy and pigmentation in the mid- and far-peripheral retina. CONCLUSION Systemic comparative analysis may shed light on the characterization of PPVs in these genes. Our findings provide a brief landscape of PPVs in PRPF genes and the associated phenotypes and emphasize the careful classification of pathogenicity for certain types of variants that warrant further characterization.
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Affiliation(s)
- Junwen Wang
- 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
| | - Hongmei Jiang
- 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
| | - 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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20
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Ali-Nasser T, Zayit-Soudry S, Banin E, Sharon D, Ben-Yosef T. Autosomal dominant retinitis pigmentosa with incomplete penetrance due to an intronic mutation of the PRPF31 gene. Mol Vis 2022; 28:359-368. [PMID: 36338669 PMCID: PMC9603903] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Accepted: 10/04/2022] [Indexed: 11/10/2022] Open
Abstract
Purpose To identify the molecular mechanisms of the development of autosomal dominant retinitis pigmentosa (adRP) with incomplete penetrance in an Israeli Muslim Arab family. Methods Two patients with adRP underwent a detailed ophthalmic evaluation, including funduscopic examination, visual field testing, optical coherence tomography, and electroretinography. Genetic analysis was performed using a combination of whole exome sequencing (WES) and Sanger sequencing. The pathogenicity of the identified intronic variant was evaluated in silico using several web-based tools, in vitro using a minigene-based assay, and in vivo using reverse transcription PCR analysis of lymphocyte-derived RNA. The relative abundance of alternatively spliced transcripts was evaluated using amplicon-based next-generation sequencing. The relative expression levels of PRPF31 and CNOT3 were measured using quantitative PCR (qPCR) analysis. Results The two patients recruited in this study had childhood-onset RP, with night blindness as the initial symptom, followed by concentric restriction of the visual field. The funduscopic findings included narrowed retinal blood vessels and peripheral bone spicule pigmentation. By the third decade of life, the full-field electroretinography findings had been remarkably attenuated. In these patients, we identified a novel heterozygous intronic variant at position +5 of PRPF31 intron 11 (c.1146+5G>T). The same variant was also detected in one asymptomatic family member. Through in silico analysis, the variant was predicted to alter the splicing of intron 11. An in vitro splicing assay and a reverse transcription PCR analysis of lymphocyte-derived RNA revealed that the mutant allele yielded mainly a shorter transcript in which exon 11 was skipped. The skipping of exon 11 was expected to cause a frameshift and an aberrant truncated protein (p.Tyr359Serfs*29). The qPCR analysis revealed reduced PRPF31 expression levels in the mutation carriers, without a significant difference between the affected patient and his asymptomatic brother. We evaluated several factors that have been suggested to correlate with non-penetrance of PRPF31 mutations, including the number of cis-acting MSR1 elements adjacent to the PRPF31 core promoter, CNOT3 expression level, and CNOT3 rs4806718 single-nucleotide polymorphism. None of these factors correlated with non-penetrance in the family in this study. Conclusions We report a novel intronic mutation in PRPF31 underlying adRP. This report expands the spectrum of pathogenic mutations in PRPF31 and further demonstrates the importance of intronic mutations. Moreover, it demonstrates the phenomenon of incomplete penetrance previously associated with PRPF31 mutations. The fact that the non-penetrance in the family in this study could not be explained by any of the known mechanisms suggests the possible contribution of a novel modifier of PRPF31 penetrance.
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Affiliation(s)
- Tahleel Ali-Nasser
- Ruth & Bruce Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel
| | - Shiri Zayit-Soudry
- Ruth & Bruce Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel,Department of Ophthalmology, Rambam Health Care Campus, Haifa, Israel,Clinical Research Institute at Rambam, Rambam Health Care Campus, Haifa, Israel
| | - Eyal Banin
- Department of Ophthalmology, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - Dror Sharon
- Department of Ophthalmology, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - Tamar Ben-Yosef
- Ruth & Bruce Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel
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21
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Nazlamova L, Villa Vasquez SS, Lord J, Karthik V, Cheung MK, Lakowski J, Wheway G. Microtubule modification defects underlie cilium degeneration in cell models of retinitis pigmentosa associated with pre-mRNA splicing factor mutations. Front Genet 2022; 13:1009430. [PMID: 36176300 PMCID: PMC9513239 DOI: 10.3389/fgene.2022.1009430] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Accepted: 08/19/2022] [Indexed: 11/17/2022] Open
Abstract
Retinitis pigmentosa (RP) is the most common cause of hereditary blindness, and may occur in isolation as a non-syndromic condition or alongside other features in a syndromic presentation. Biallelic or monoallelic mutations in one of eight genes encoding pre-mRNA splicing factors are associated with non-syndromic RP. The molecular mechanism of disease remains incompletely understood, limiting opportunities for targeted treatment. Here we use CRISPR and base edited PRPF6 and PRPF31 mutant cell lines, and publicly-available data from human PRPF31+/− patient derived retinal organoids and PRPF31 siRNA-treated organotypic retinal cultures to confirm an enrichment of differential splicing of microtubule, centrosomal, cilium and DNA damage response pathway genes in these cells. We show that genes with microtubule/centrosome/centriole/cilium gene ontology terms are enriched for weak 3′ and 5′ splice sites, and that subtle defects in spliceosome activity predominantly affect efficiency of splicing of these exons. We suggest that the primary defect in PRPF6 or PRPF31 mutant cells is microtubule and centrosomal defects, leading to defects in cilium and mitotic spindle stability, with the latter leading to DNA damage, triggering differential splicing of DNA damage response genes to activate this pathway. Finally, we expand understanding of “splicing factor RP” by investigating the function of TTLL3, one of the most statistically differentially expressed genes in PRPF6 and PRPF31 mutant cells. We identify that TTLL3 is the only tubulin glycylase expressed in the human retina, essential for monoglycylation of microtubules of the cilium, including the retinal photoreceptor cilium, to prevent cilium degeneration and retinal degeneration. Our preliminary data suggest that rescue of tubulin glycylation through overexpression of TTLL3 is sufficient to rescue cilium number in PRPF6 and PRPF31 mutant cells, suggesting that this defect underlies the cellular defect and may represent a potential target for therapeutic intervention in this group of disorders.
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Affiliation(s)
- Liliya Nazlamova
- Human Development and Health, Faculty of Medicine, University of Southampton, Southampton, United Kingdom
| | - Suly Saray Villa Vasquez
- Human Development and Health, Faculty of Medicine, University of Southampton, Southampton, United Kingdom
| | - Jenny Lord
- Human Development and Health, Faculty of Medicine, University of Southampton, Southampton, United Kingdom
| | - Varshini Karthik
- Human Development and Health, Faculty of Medicine, University of Southampton, Southampton, United Kingdom
| | - Man-Kim Cheung
- Centre for Research in Biosciences, University of the West of England, Bristol, United Kingdom
| | - Jörn Lakowski
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, United Kingdom
| | - Gabrielle Wheway
- Human Development and Health, Faculty of Medicine, University of Southampton, Southampton, United Kingdom
- *Correspondence: Gabrielle Wheway,
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22
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Modeling PRPF31 retinitis pigmentosa using retinal pigment epithelium and organoids combined with gene augmentation rescue. NPJ Regen Med 2022; 7:39. [PMID: 35974011 PMCID: PMC9381579 DOI: 10.1038/s41536-022-00235-6] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2021] [Accepted: 07/20/2022] [Indexed: 11/17/2022] Open
Abstract
Mutations in the ubiquitously expressed pre-mRNA processing factor (PRPF) 31 gene, one of the most common causes of dominant form of Retinitis Pigmentosa (RP), lead to a retina-specific phenotype. It is uncertain which retinal cell types are affected and animal models do not clearly present the RP phenotype observed in PRPF31 patients. Retinal organoids and retinal pigment epithelial (RPE) cells derived from human-induced pluripotent stem cells (iPSCs) provide potential opportunities for studying human PRPF31-related RP. We demonstrate here that RPE cells carrying PRPF31 mutations present important morphological and functional changes and that PRPF31-mutated retinal organoids recapitulate the human RP phenotype, with a rod photoreceptor cell death followed by a loss of cones. The low level of PRPF31 expression may explain the defective phenotypes of PRPF31-mutated RPE and photoreceptor cells, which were not observed in cells derived from asymptomatic patients or after correction of the pathogenic mutation by CRISPR/Cas9. Transcriptome profiles revealed differentially expressed and mis-spliced genes belonging to pathways in line with the observed defective phenotypes. The rescue of RPE and photoreceptor defective phenotypes by PRPF31 gene augmentation provide the proof of concept for future therapeutic strategies.
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23
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Ellingford JM, Ahn JW, Bagnall RD, Baralle D, Barton S, Campbell C, Downes K, Ellard S, Duff-Farrier C, FitzPatrick DR, Greally JM, Ingles J, Krishnan N, Lord J, Martin HC, Newman WG, O'Donnell-Luria A, Ramsden SC, Rehm HL, Richardson E, Singer-Berk M, Taylor JC, Williams M, Wood JC, Wright CF, Harrison SM, Whiffin N. Recommendations for clinical interpretation of variants found in non-coding regions of the genome. Genome Med 2022; 14:73. [PMID: 35850704 PMCID: PMC9295495 DOI: 10.1186/s13073-022-01073-3] [Citation(s) in RCA: 66] [Impact Index Per Article: 33.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2022] [Accepted: 06/16/2022] [Indexed: 01/28/2023] Open
Abstract
BACKGROUND The majority of clinical genetic testing focuses almost exclusively on regions of the genome that directly encode proteins. The important role of variants in non-coding regions in penetrant disease is, however, increasingly being demonstrated, and the use of whole genome sequencing in clinical diagnostic settings is rising across a large range of genetic disorders. Despite this, there is no existing guidance on how current guidelines designed primarily for variants in protein-coding regions should be adapted for variants identified in other genomic contexts. METHODS We convened a panel of nine clinical and research scientists with wide-ranging expertise in clinical variant interpretation, with specific experience in variants within non-coding regions. This panel discussed and refined an initial draft of the guidelines which were then extensively tested and reviewed by external groups. RESULTS We discuss considerations specifically for variants in non-coding regions of the genome. We outline how to define candidate regulatory elements, highlight examples of mechanisms through which non-coding region variants can lead to penetrant monogenic disease, and outline how existing guidelines can be adapted for the interpretation of these variants. CONCLUSIONS These recommendations aim to increase the number and range of non-coding region variants that can be clinically interpreted, which, together with a compatible phenotype, can lead to new diagnoses and catalyse the discovery of novel disease mechanisms.
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Affiliation(s)
- Jamie M Ellingford
- Division of Evolution, Infection and Genomic Sciences, School of Biological Sciences, Faculty of Biology, Medicines and Health, University of Manchester, Manchester, M13 9PT, UK.
- Manchester Centre for Genomic Medicine, St Mary's Hospital, Manchester University NHS Foundation Trust, Manchester, M13 9WL, UK.
- Genomics England, London, UK.
| | - Joo Wook Ahn
- Cambridge Genomics Laboratory, Cambridge University Hospitals NHS Foundation Trust, Cambridge Biomedical Campus, Cambridge, UK
| | - Richard D Bagnall
- Agnes Ginges Centre for Molecular Cardiology at Centenary Institute, University of Sydney, Sydney, Australia
| | - Diana Baralle
- School of Human Development and Health, Faculty of Medicine, University of Southampton, Southampton, UK
- Wessex Clinical Genetics Service, University Hospital Southampton NHS Foundation Trust, Southampton, UK
| | - Stephanie Barton
- Manchester Centre for Genomic Medicine, St Mary's Hospital, Manchester University NHS Foundation Trust, Manchester, M13 9WL, UK
| | - Chris Campbell
- Manchester Centre for Genomic Medicine, St Mary's Hospital, Manchester University NHS Foundation Trust, Manchester, M13 9WL, UK
| | - Kate Downes
- Cambridge Genomics Laboratory, Cambridge University Hospitals NHS Foundation Trust, Cambridge Biomedical Campus, Cambridge, UK
| | - Sian Ellard
- Institute of Biomedical and Clinical Science, University of Exeter Medical School, Exeter, UK
- South West Genomic Laboratory Hub, Exeter Genomic Laboratory, Royal Devon and Exeter NHS Foundation Trust, Exeter, UK
| | - Celia Duff-Farrier
- South West NHS Genomic Laboratory Hub, Bristol Genetics Laboratory, North Bristol NHS Trust, Bristol, UK
| | - David R FitzPatrick
- MRC Human Genetics Unit, Institute of Genetics and Cancer, University of Edinburgh, Western General Hospital, Edinburgh, UK
| | - John M Greally
- Department of Pediatrics, Division of Pediatric Genetic, Medicine, Children's Hospital at Montefiore/Montefiore Medical Center/Albert, Einstein College of Medicine, Bronx, NY, USA
| | - Jodie Ingles
- Centre for Population Genomics, Garvan Institute of Medical Research, and UNSW Sydney, Sydney, Australia
- Centre for Population Genomics, Murdoch Children's Research Institute, Melbourne, Australia
| | - Neesha Krishnan
- Centre for Population Genomics, Garvan Institute of Medical Research, and UNSW Sydney, Sydney, Australia
- Centre for Population Genomics, Murdoch Children's Research Institute, Melbourne, Australia
| | - Jenny Lord
- School of Human Development and Health, Faculty of Medicine, University of Southampton, Southampton, UK
| | - Hilary C Martin
- Human Genetics Programme, Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, UK
| | - William G Newman
- Division of Evolution, Infection and Genomic Sciences, School of Biological Sciences, Faculty of Biology, Medicines and Health, University of Manchester, Manchester, M13 9PT, UK
- Manchester Centre for Genomic Medicine, St Mary's Hospital, Manchester University NHS Foundation Trust, Manchester, M13 9WL, UK
| | - Anne O'Donnell-Luria
- Program in Medical and Population Genetics, Broad Institute of MIT and Harvard, Cambridge, MA, USA
- Division of Genetics and Genomics, Boston Children's Hospital, Boston, MA, USA
- Analytic and Translational Genetics Unit, Massachusetts General Hospital, Boston, MA, USA
| | - Simon C Ramsden
- Manchester Centre for Genomic Medicine, St Mary's Hospital, Manchester University NHS Foundation Trust, Manchester, M13 9WL, UK
| | - Heidi L Rehm
- Program in Medical and Population Genetics, Broad Institute of MIT and Harvard, Cambridge, MA, USA
- Analytic and Translational Genetics Unit, Massachusetts General Hospital, Boston, MA, USA
| | - Ebony Richardson
- Centre for Population Genomics, Garvan Institute of Medical Research, and UNSW Sydney, Sydney, Australia
- Centre for Population Genomics, Murdoch Children's Research Institute, Melbourne, Australia
| | - Moriel Singer-Berk
- Program in Medical and Population Genetics, Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Jenny C Taylor
- National Institute for Health Research Oxford Biomedical Research Centre, Wellcome Centre for Human Genetics, University of Oxford, Oxford, OX3 7BN, UK
- Wellcome Centre for Human Genetics, University of Oxford, Oxford, OX3 7BN, UK
| | - Maggie Williams
- South West NHS Genomic Laboratory Hub, Bristol Genetics Laboratory, North Bristol NHS Trust, Bristol, UK
| | - Jordan C Wood
- Program in Medical and Population Genetics, Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Caroline F Wright
- Institute of Biomedical and Clinical Science, University of Exeter Medical School, Exeter, UK
| | - Steven M Harrison
- Program in Medical and Population Genetics, Broad Institute of MIT and Harvard, Cambridge, MA, USA
- Ambry Genetics, Aliso Viejo, CA, USA
| | - Nicola Whiffin
- Program in Medical and Population Genetics, Broad Institute of MIT and Harvard, Cambridge, MA, USA.
- Wellcome Centre for Human Genetics, University of Oxford, Oxford, OX3 7BN, UK.
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24
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Bhardwaj A, Yadav A, Yadav M, Tanwar M. Genetic dissection of non-syndromic retinitis pigmentosa. Indian J Ophthalmol 2022; 70:2355-2385. [PMID: 35791117 PMCID: PMC9426071 DOI: 10.4103/ijo.ijo_46_22] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Retinitis pigmentosa (RP) belongs to a group of pigmentary retinopathies. It is the most common form of inherited retinal dystrophy, characterized by progressive degradation of photoreceptors that leads to nyctalopia, and ultimately, complete vision loss. RP is distinguished by the continuous retinal degeneration that progresses from the mid-periphery to the central and peripheral retina. RP was first described and named by Franciscus Cornelius Donders in the year 1857. It is one of the leading causes of bilateral blindness in adults, with an incidence of 1 in 3000 people worldwide. In this review, we are going to focus on the genetic heterogeneity of this disease, which is provided by various inheritance patterns, numerosity of variations and inter-/intra-familial variations based upon penetrance and expressivity. Although over 90 genes have been identified in RP patients, the genetic cause of approximately 50% of RP cases remains unknown. Heterogeneity of RP makes it an extremely complicated ocular impairment. It is so complicated that it is known as “fever of unknown origin”. For prognosis and proper management of the disease, it is necessary to understand its genetic heterogeneity so that each phenotype related to the various genetic variations could be treated.
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Affiliation(s)
- Aarti Bhardwaj
- Department of Genetics, M. D. University, Rohtak, Haryana, India
| | - Anshu Yadav
- Department of Genetics, M. D. University, Rohtak, Haryana, India
| | - Manoj Yadav
- Department of Genetics, M. D. University, Rohtak, Haryana, India
| | - Mukesh Tanwar
- Department of Genetics, M. D. University, Rohtak, Haryana, India
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25
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Determinants of Disease Penetrance in PRPF31-Associated Retinopathy. Genes (Basel) 2021; 12:genes12101542. [PMID: 34680937 PMCID: PMC8535263 DOI: 10.3390/genes12101542] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2021] [Revised: 09/25/2021] [Accepted: 09/27/2021] [Indexed: 11/17/2022] Open
Abstract
Retinitis pigmentosa 11 (RP11) is caused by dominant mutations in PRPF31, however a significant proportion of mutation carriers do not develop retinopathy. Here, we investigated the relationship between CNOT3 polymorphism, MSR1 repeat copy number and disease penetrance in RP11 patients and non-penetrant carriers (NPCs). We further characterized PRPF31 and CNOT3 expression in fibroblasts from eight RP11 patients and one NPC from a family carrying the c.1205C>T variant. Retinal organoids (ROs) and retinal pigment epithelium (RPE) were differentiated from induced pluripotent stem cells derived from RP11 patients, an NPC and a control subject. All RP11 patients were homozygous for the 3-copy MSR1 repeat in the PRPF31 promoter, while 3/5 NPCs carried a 4-copy MSR1 repeat. The CNOT3 rs4806718 genotype did not correlate with disease penetrance. PRFP31 expression declined with age in adult cadaveric retina. PRPF31 and CNOT3 expression was reduced in RP11 fibroblasts, RO and RPE compared with controls. Both RP11 and NPC RPE displayed shortened primary cilia compared with controls, however a subpopulation of cells with normal cilia lengths was present in NPC RPE monolayers. Our results indicate that RP11 non-penetrance is associated with the inheritance of a 4-copy MSR1 repeat, but not with CNOT3 polymorphisms.
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26
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Roshandel D, Thompson JA, Heath Jeffery RC, Zhang D, Lamey TM, McLaren TL, De Roach JN, McLenachan S, Mackey DA, Chen FK. Clinical Evidence for the Importance of the Wild-Type PRPF31 Allele in the Phenotypic Expression of RP11. Genes (Basel) 2021; 12:genes12060915. [PMID: 34198599 PMCID: PMC8232116 DOI: 10.3390/genes12060915] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2021] [Revised: 06/09/2021] [Accepted: 06/12/2021] [Indexed: 11/16/2022] Open
Abstract
PRPF31-associated retinopathy (RP11) is a common form of autosomal dominant retinitis pigmentosa (adRP) that exhibits wide variation in phenotype ranging from non-penetrance to early-onset RP. Herein, we report inter-familial and intra-familial variation in the natural history of RP11 using multimodal imaging and microperimetry. Patients were recruited prospectively. The age of symptom onset, best-corrected visual acuity, microperimetry mean sensitivity (MS), residual ellipsoid zone span and hyperautofluorescent ring area were recorded. Genotyping was performed using targeted next-generation and Sanger sequencing and copy number variant analysis. PRPF31 mutations were found in 14 individuals from seven unrelated families. Four disease patterns were observed: (A) childhood onset with rapid progression (N = 4), (B) adult-onset with rapid progression (N = 4), (C) adult-onset with slow progression (N = 4) and (D) non-penetrance (N = 2). Four different patterns were observed in a family harbouring c.267del; patterns B, C and D were observed in a family with c.772_773delins16 and patterns A, B and C were observed in 3 unrelated individuals with large deletions. Our findings suggest that the RP11 phenotype may be related to the wild-type PRPF31 allele rather than the type of mutation. Further studies that correlate in vitro wild-type PRPF31 allele expression level with the disease patterns are required to investigate this association.
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Affiliation(s)
- Danial Roshandel
- Centre for Ophthalmology and Visual Science, The University of Western Australia, Perth, WA 6009, Australia; (D.R.); (R.C.H.J.); (T.M.L.); (T.L.M.); (J.N.D.R.); (S.M.); (D.A.M.)
- Ocular Tissue Engineering Laboratory, Lions Eye Institute, 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;
| | - Rachael C. Heath Jeffery
- Centre for Ophthalmology and Visual Science, The University of Western Australia, Perth, WA 6009, Australia; (D.R.); (R.C.H.J.); (T.M.L.); (T.L.M.); (J.N.D.R.); (S.M.); (D.A.M.)
- Ocular Tissue Engineering Laboratory, Lions Eye Institute, Nedlands, WA 6009, Australia;
- Department of Ophthalmology, Royal Perth Hospital, Perth, WA 6000, Australia
| | - Dan Zhang
- Ocular Tissue Engineering Laboratory, Lions Eye Institute, Nedlands, WA 6009, Australia;
| | - Tina M. Lamey
- Centre for Ophthalmology and Visual Science, The University of Western Australia, Perth, WA 6009, Australia; (D.R.); (R.C.H.J.); (T.M.L.); (T.L.M.); (J.N.D.R.); (S.M.); (D.A.M.)
- Australian Inherited Retinal Disease Registry and DNA Bank, Department of Medical Technology and Physics, Sir Charles Gairdner Hospital, Nedlands, WA 6009, Australia;
| | - Terri L. McLaren
- Centre for Ophthalmology and Visual Science, The University of Western Australia, Perth, WA 6009, Australia; (D.R.); (R.C.H.J.); (T.M.L.); (T.L.M.); (J.N.D.R.); (S.M.); (D.A.M.)
- Australian Inherited Retinal Disease Registry and DNA Bank, Department of Medical Technology and Physics, Sir Charles Gairdner Hospital, Nedlands, WA 6009, Australia;
| | - John N. De Roach
- Centre for Ophthalmology and Visual Science, The University of Western Australia, Perth, WA 6009, Australia; (D.R.); (R.C.H.J.); (T.M.L.); (T.L.M.); (J.N.D.R.); (S.M.); (D.A.M.)
- Australian Inherited Retinal Disease Registry and DNA Bank, Department of Medical Technology and Physics, Sir Charles Gairdner Hospital, Nedlands, WA 6009, Australia;
| | - Samuel McLenachan
- Centre for Ophthalmology and Visual Science, The University of Western Australia, Perth, WA 6009, Australia; (D.R.); (R.C.H.J.); (T.M.L.); (T.L.M.); (J.N.D.R.); (S.M.); (D.A.M.)
- Ocular Tissue Engineering Laboratory, Lions Eye Institute, Nedlands, WA 6009, Australia;
| | - David A. Mackey
- Centre for Ophthalmology and Visual Science, The University of Western Australia, Perth, WA 6009, Australia; (D.R.); (R.C.H.J.); (T.M.L.); (T.L.M.); (J.N.D.R.); (S.M.); (D.A.M.)
- Ocular Tissue Engineering Laboratory, Lions Eye Institute, Nedlands, WA 6009, Australia;
- 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, Perth, WA 6009, Australia; (D.R.); (R.C.H.J.); (T.M.L.); (T.L.M.); (J.N.D.R.); (S.M.); (D.A.M.)
- Ocular Tissue Engineering Laboratory, Lions Eye Institute, Nedlands, WA 6009, Australia;
- Australian Inherited Retinal Disease Registry and DNA Bank, Department of Medical Technology and Physics, Sir Charles Gairdner Hospital, Nedlands, WA 6009, Australia;
- Department of Ophthalmology, Royal Perth Hospital, Perth, WA 6000, Australia
- Department of Ophthalmology, Perth Children’s Hospital, Nedlands, WA 6009, Australia
- Correspondence: ; Tel.: +61-08-9381-0777
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27
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Next-Generation Sequencing Applications for Inherited Retinal Diseases. Int J Mol Sci 2021; 22:ijms22115684. [PMID: 34073611 PMCID: PMC8198572 DOI: 10.3390/ijms22115684] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Revised: 05/21/2021] [Accepted: 05/22/2021] [Indexed: 12/12/2022] Open
Abstract
Inherited retinal diseases (IRDs) represent a collection of phenotypically and genetically diverse conditions. IRDs phenotype(s) can be isolated to the eye or can involve multiple tissues. These conditions are associated with diverse forms of inheritance, and variants within the same gene often can be associated with multiple distinct phenotypes. Such aspects of the IRDs highlight the difficulty met when establishing a genetic diagnosis in patients. Here we provide an overview of cutting-edge next-generation sequencing techniques and strategies currently in use to maximise the effectivity of IRD gene screening. These techniques have helped researchers globally to find elusive causes of IRDs, including copy number variants, structural variants, new IRD genes and deep intronic variants, among others. Resolving a genetic diagnosis with thorough testing enables a more accurate diagnosis and more informed prognosis and should also provide information on inheritance patterns which may be of particular interest to patients of a child-bearing age. Given that IRDs are heritable conditions, genetic counselling may be offered to help inform family planning, carrier testing and prenatal screening. Additionally, a verified genetic diagnosis may enable access to appropriate clinical trials or approved medications that may be available for the condition.
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Fadaie Z, Whelan L, Dockery A, Li CHZ, van den Born LI, Hoyng CB, Gilissen C, Corominas J, Rowlands C, Megaw R, Lampe AK, Cremers FPM, Farrar GJ, Ellingford JM, Kenna PF, Roosing S. BBS1 branchpoint variant is associated with non-syndromic retinitis pigmentosa. J Med Genet 2021; 59:438-444. [PMID: 33910932 DOI: 10.1136/jmedgenet-2020-107626] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Revised: 02/11/2021] [Accepted: 02/26/2021] [Indexed: 11/03/2022]
Abstract
BACKGROUND Inherited retinal diseases (IRDs) can be caused by variants in >270 genes. The Bardet-Biedl syndrome 1 (BBS1) gene is one of these genes and may be associated with syndromic and non-syndromic autosomal recessive retinitis pigmentosa (RP). Here, we identified a branchpoint variant in BBS1 and assessed its pathogenicity by in vitro functional analysis. METHODS Whole genome sequencing was performed for three unrelated monoallelic BBS1 cases with non-syndromic RP. A fourth case received MGCM 105 gene panel analysis. Functional analysis using a midigene splice assay was performed for the putative pathogenic branchpoint variant in BBS1. After confirmation of its pathogenicity, patients were clinically re-evaluated, including assessment of non-ocular features of Bardet-Biedl syndrome. RESULTS Clinical assessments of probands showed that all individuals displayed non-syndromic RP with macular involvement. Through detailed variant analysis and prioritisation, two pathogenic variants in BBS1, the most common missense variant, c.1169T>G (p.(Met390Arg)), and a branchpoint variant, c.592-21A>T, were identified. Segregation analysis confirmed that in all families, probands were compound heterozygous for c.1169T>G and c.592-21A>T. Functional analysis of the branchpoint variant revealed a complex splicing defect including exon 8 and exon 7/8 skipping, and partial in-frame deletion of exon 8. CONCLUSION A putative severe branchpoint variant in BBS1, together with a mild missense variant, underlies non-syndromic RP in four unrelated individuals. To our knowledge, this is the first report of a pathogenic branchpoint variant in IRDs that results in a complex splice defect. In addition, this research highlights the importance of the analysis of non-coding regions in order to provide a conclusive molecular diagnosis.
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Affiliation(s)
- Zeinab Fadaie
- Department of Human Genetics, Radboudumc, Nijmegen, The Netherlands
- Donders Institute for Brain Cognition and Behaviour, RadboudUMC, Nijmegen, The Netherlands
| | - Laura Whelan
- School of Genetics & Microbiology, Smurfit Institute of Genetics, Trinity College Dublin, Dublin, Ireland
| | - Adrian Dockery
- School of Genetics & Microbiology, Smurfit Institute of Genetics, Trinity College Dublin, Dublin, Ireland
| | - Catherina H Z Li
- Donders Institute for Brain Cognition and Behaviour, RadboudUMC, Nijmegen, The Netherlands
- Department of Ophthalmology, Radboudumc, Nijmegen, The Netherlands
| | | | - Carel B Hoyng
- Donders Institute for Brain Cognition and Behaviour, RadboudUMC, Nijmegen, The Netherlands
- Department of Ophthalmology, Radboudumc, Nijmegen, The Netherlands
| | - Christian Gilissen
- Department of Human Genetics, Radboudumc, Nijmegen, The Netherlands
- Radboud Institute of Molecular Life Sciences, RadboudUMC, Nijmegen, The Netherlands
| | - Jordi Corominas
- Department of Human Genetics, Radboudumc, Nijmegen, The Netherlands
- Radboud Institute of Molecular Life Sciences, RadboudUMC, Nijmegen, The Netherlands
| | - Charlie Rowlands
- North West Genomic Laboratory Hub, Manchester Centre for Genomic Medicine, Manchester University Hospitals NHS Foundation Trust, St Mary's Hospital, Manchester, UK
- Division of Evolution and Genomic Sciences, Neuroscience and Mental Health Domain, The University of Manchester Faculty of Biology Medicine and Health, Manchester, UK
| | - Roly Megaw
- MRC Human Genetics Unit, University of Edinburgh Western General Hospital, Edinburgh, UK
- Princess Alexandra Eye Pavilion, Department of Ophthalmology, University of Edinburgh Western General Hospital, Edinburgh, UK
| | - Anne K Lampe
- South East of Scotland Clinical Genetics Service, Western General Hospital, Edinburgh, UK
| | - Frans P M Cremers
- Department of Human Genetics, Radboudumc, Nijmegen, The Netherlands
- Donders Institute for Brain Cognition and Behaviour, RadboudUMC, Nijmegen, The Netherlands
| | - Gwyneth Jane Farrar
- School of Genetics & Microbiology, Smurfit Institute of Genetics, Trinity College Dublin, Dublin, Ireland
| | - Jamie M Ellingford
- North West Genomic Laboratory Hub, Manchester Centre for Genomic Medicine, Manchester University Hospitals NHS Foundation Trust, St Mary's Hospital, Manchester, UK
- Division of Evolution and Genomic Sciences, Neuroscience and Mental Health Domain, The University of Manchester Faculty of Biology Medicine and Health, Manchester, UK
| | - Paul F Kenna
- School of Genetics & Microbiology, Smurfit Institute of Genetics, Trinity College Dublin, Dublin, Ireland
- Research Foundation, Royal Victoria Eye and Ear Hospital, Dublin, Ireland
| | - Susanne Roosing
- Department of Human Genetics, Radboudumc, Nijmegen, The Netherlands
- Donders Institute for Brain Cognition and Behaviour, RadboudUMC, Nijmegen, The Netherlands
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Li J, Liu F, Lv Y, Sun K, Zhao Y, Reilly J, Zhang Y, Tu J, Yu S, Liu X, Qin Y, Huang Y, Gao P, Jia D, Chen X, Han Y, Shu X, Luo D, Tang Z, Liu M. Prpf31 is essential for the survival and differentiation of retinal progenitor cells by modulating alternative splicing. Nucleic Acids Res 2021; 49:2027-2043. [PMID: 33476374 PMCID: PMC7913766 DOI: 10.1093/nar/gkab003] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Revised: 01/01/2021] [Accepted: 01/05/2021] [Indexed: 12/23/2022] Open
Abstract
Dysfunction of splicing factors often result in abnormal cell differentiation and apoptosis, especially in neural tissues. Mutations in pre-mRNAs processing factor 31 (PRPF31) cause autosomal dominant retinitis pigmentosa, a progressive retinal degeneration disease. The transcriptome-wide splicing events specifically regulated by PRPF31 and their biological roles in the development and maintenance of retina are still unclear. Here, we showed that the differentiation and viability of retinal progenitor cells (RPCs) are severely perturbed in prpf31 knockout zebrafish when compared with other tissues at an early embryonic stage. At the cellular level, significant mitotic arrest and DNA damage were observed. These defects could be rescued by the wild-type human PRPF31 rather than the disease-associated mutants. Further bioinformatic analysis and experimental verification uncovered that Prpf31 deletion predominantly causes the skipping of exons with a weak 5′ splicing site. Moreover, genes necessary for DNA repair and mitotic progression are most enriched among the differentially spliced events, which may explain the cellular and tissular defects in prpf31 mutant retinas. This is the first time that Prpf31 is demonstrated to be essential for the survival and differentiation of RPCs during retinal neurogenesis by specifically modulating the alternative splicing of genes involved in DNA repair and mitosis.
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Affiliation(s)
- Jingzhen Li
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430074, PR China
| | - Fei Liu
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430074, PR China
| | - Yuexia Lv
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430074, PR China
| | - Kui Sun
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430074, PR China
| | - Yuntong Zhao
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Innovation Academy for Seed Design, Chinese Academy of Science, Wuhan 430072, PR China
| | - Jamas Reilly
- Department of Life Sciences, Glasgow Caledonian University, Glasgow G4 0BA, Scotland, UK
| | - Yangjun Zhang
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430074, PR China
| | - Jiayi Tu
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430074, PR China
| | - Shanshan Yu
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430074, PR China
| | - Xiliang Liu
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430074, PR China
| | - Yayun Qin
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430074, PR China
| | - Yuwen Huang
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430074, PR China
| | - Pan Gao
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430074, PR China
| | - Danna Jia
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430074, PR China
| | - Xiang Chen
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430074, PR China
| | - Yunqiao Han
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430074, PR China
| | - Xinhua Shu
- Department of Life Sciences, Glasgow Caledonian University, Glasgow G4 0BA, Scotland, UK
| | - Daji Luo
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Innovation Academy for Seed Design, Chinese Academy of Science, Wuhan 430072, PR China
| | - Zhaohui Tang
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430074, PR China
| | - Mugen Liu
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430074, PR China
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Quinn J, Musa A, Kantor A, McClements ME, Cehajic-Kapetanovic J, MacLaren RE, Xue K. Genome-Editing Strategies for Treating Human Retinal Degenerations. Hum Gene Ther 2021; 32:247-259. [PMID: 32993386 PMCID: PMC7987357 DOI: 10.1089/hum.2020.231] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Inherited retinal degenerations (IRDs) are a leading cause of blindness. Although gene-supplementation therapies have been developed, they are only available for a small proportion of recessive IRD mutations. In contrast, genome editing using clustered-regularly interspaced short palindromic repeats (CRISPR) CRISPR-associated (Cas) systems could provide alternative therapeutic avenues for treating a wide range of genetic retinal diseases through targeted knockdown or correction of mutant alleles. Progress in this rapidly evolving field has been highlighted by recent Food and Drug Administration clinical trial approval for EDIT-101 (Editas Medicine, Inc., Cambridge, MA), which has demonstrated efficacious genome editing in a mouse model of CEP290-associated Leber congenital amaurosis and safety in nonhuman primates. Nonetheless, there remains a significant number of challenges to developing clinically viable retinal genome-editing therapies. In particular, IRD-causing mutations occur in more than 200 known genes, with considerable heterogeneity in mutation type and position within each gene. Additionally, there are remaining safety concerns over long-term expression of Cas9 in vivo. This review highlights (i) the technological advances in gene-editing technology, (ii) major safety concerns associated with retinal genome editing, and (iii) potential strategies for overcoming these challenges to develop clinical therapies.
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Affiliation(s)
- Joel Quinn
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom
| | - Ayesha Musa
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom
| | - Ariel Kantor
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom
| | - Michelle E. McClements
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom
| | - Jasmina Cehajic-Kapetanovic
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom
- Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford, United Kingdom
| | - Robert E. MacLaren
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom
- Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford, United Kingdom
| | - Kanmin Xue
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom
- Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford, United Kingdom
- Correspondence: Dr. Kanmin Xue, Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom.
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31
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Hebbar S, Lehmann M, Behrens S, Hälsig C, Leng W, Yuan M, Winkler S, Knust E. Mutations in the splicing regulator Prp31 lead to retinal degeneration in Drosophila. Biol Open 2021; 10:10/1/bio052332. [PMID: 33495354 PMCID: PMC7860132 DOI: 10.1242/bio.052332] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Retinitis pigmentosa (RP) is a clinically heterogeneous disease affecting 1.6 million people worldwide. The second-largest group of genes causing autosomal dominant RP in human encodes regulators of the splicing machinery. Yet, how defects in splicing factor genes are linked to the aetiology of the disease remains largely elusive. To explore possible mechanisms underlying retinal degeneration caused by mutations in regulators of the splicing machinery, we induced mutations in Drosophila Prp31, the orthologue of human PRPF31, mutations in which are associated with RP11. Flies heterozygous mutant for Prp31 are viable and develop normal eyes and retina. However, photoreceptors degenerate under light stress, thus resembling the human disease phenotype. Degeneration is associated with increased accumulation of the visual pigment rhodopsin 1 and increased mRNA levels of twinfilin, a gene associated with rhodopsin trafficking. Reducing rhodopsin levels by raising animals in a carotenoid-free medium not only attenuates rhodopsin accumulation, but also retinal degeneration. Given a similar importance of proper rhodopsin trafficking for photoreceptor homeostasis in human, results obtained in flies presented here will also contribute to further unravel molecular mechanisms underlying the human disease. This paper has an associated First Person interview with the co-first authors of the article. Summary: Retinitis pigmentosa (RP) is a human disease resulting in blindness, which affects 1 in 4.000 people worldwide. So far >90 genes have been identified that are causally related to RP. Mutations in the splicing factor PRPF31 are linked to RP11. We induced mutations in the Drosophila orthologue Prp31 and show that flies heterozygous for Prp31 undergo light-dependent retinal degeneration. Degeneration is associated with increased accumulation of the light-sensitive molecule, rhodopsin 1. In fact, reducing rhodopsin levels by dietary intervention modifies the extent of retinal degeneration. This model will further contribute to better understand the aetiology of the human disease.
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Affiliation(s)
- Sarita Hebbar
- Max-Planck-Institute of Molecular Cell Biology and Genetics, Pfotenhauerstrasse 108, 01307 Dresden, Germany
| | - Malte Lehmann
- Max-Planck-Institute of Molecular Cell Biology and Genetics, Pfotenhauerstrasse 108, 01307 Dresden, Germany
| | - Sarah Behrens
- Max-Planck-Institute of Molecular Cell Biology and Genetics, Pfotenhauerstrasse 108, 01307 Dresden, Germany
| | - Catrin Hälsig
- Max-Planck-Institute of Molecular Cell Biology and Genetics, Pfotenhauerstrasse 108, 01307 Dresden, Germany
| | - Weihua Leng
- Max-Planck-Institute of Molecular Cell Biology and Genetics, Pfotenhauerstrasse 108, 01307 Dresden, Germany
| | - Michaela Yuan
- Max-Planck-Institute of Molecular Cell Biology and Genetics, Pfotenhauerstrasse 108, 01307 Dresden, Germany
| | - Sylke Winkler
- Max-Planck-Institute of Molecular Cell Biology and Genetics, Pfotenhauerstrasse 108, 01307 Dresden, Germany
| | - Elisabeth Knust
- Max-Planck-Institute of Molecular Cell Biology and Genetics, Pfotenhauerstrasse 108, 01307 Dresden, Germany
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32
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Strubbe I, Van Cauwenbergh C, De Zaeytijd J, De Jaegere S, De Bruyne M, Rosseel T, Van de Sompele S, De Baere E, Leroy BP. Phenocopy of a heterozygous carrier of X-linked retinitis pigmentosa due to mosaicism for a RHO variant. Sci Rep 2021; 11:117. [PMID: 33420188 PMCID: PMC7794345 DOI: 10.1038/s41598-020-80400-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2020] [Accepted: 12/17/2020] [Indexed: 11/16/2022] Open
Abstract
We describe both phenotype and pathogenesis in two male siblings with typical retinitis pigmentosa (RP) and the potentially X-linked RP (XLRP) carrier phenotype in their mother. Two affected sons, two unaffected daughters, and their mother underwent detailed ophthalmological assessments including Goldmann perimetry, color vision testing, multimodal imaging and ISCEV-standard electroretinography. Genetic testing consisted of targeted next-generation sequencing (NGS) of known XLRP genes and whole exome sequencing (WES) of known inherited retinal disease genes (RetNet-WES). Variant validation and segregation analysis were performed by Sanger sequencing. The mutational load of the RHO variant in the mother was assessed in DNA from leucocytes, buccal cells and hair follicles using targeted NGS. Both affected sons showed signs of classical RP, while the mother displayed patches of hyperautofluorescence on blue light autofluorescence imaging and regional, intraretinal, spicular pigmentation, reminiscent of a carrier phenotype of XLRP. XLRP testing was negative. RetNet-WES testing revealed RHO variant c.404G > C p.(Arg135Pro) in a mosaic state (21% of the reads) in the mother and in a heterozygous state in both sons. Targeted NGQSS of the RHO variant in different maternal tissues showed a mutation load between 25.06% and 41.72%. We report for the first time that somatic mosaicism of RHO variant c.404G > C p.(Arg135Pro) mimics the phenotype of a female carrier of XLRP, in combination with heterozygosity for the variant in the two affected sons.
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Affiliation(s)
- Ine Strubbe
- Department of Ophthalmology, Ghent University Hospital, Ghent, Belgium.,Department of Head & Skin, Ghent University, Ghent, Belgium
| | - Caroline Van Cauwenbergh
- Department of Ophthalmology, Ghent University Hospital, Ghent, Belgium.,Department of Head & Skin, Ghent University, Ghent, Belgium
| | - Julie De Zaeytijd
- Department of Ophthalmology, Ghent University Hospital, Ghent, Belgium
| | - Sarah De Jaegere
- Center for Medical Genetics, Ghent University Hospital, Ghent, Belgium
| | - Marieke De Bruyne
- Center for Medical Genetics, Ghent University Hospital, Ghent, Belgium
| | - Toon Rosseel
- Center for Medical Genetics, Ghent University Hospital, Ghent, Belgium
| | - Stijn Van de Sompele
- Center for Medical Genetics, Ghent University Hospital, Ghent, Belgium.,Department of Biomolecular Medicine, Ghent University, Ghent, Belgium
| | - Elfride De Baere
- Department of Head & Skin, Ghent University, Ghent, Belgium. .,Center for Medical Genetics, Ghent University Hospital, Ghent, Belgium. .,Department of Biomolecular Medicine, Ghent University, Ghent, Belgium.
| | - Bart P Leroy
- Department of Ophthalmology, Ghent University Hospital, Ghent, Belgium. .,Department of Head & Skin, Ghent University, Ghent, Belgium. .,Center for Medical Genetics, Ghent University Hospital, Ghent, Belgium. .,Division of Ophthalmology, Children's Hospital of Philadelphia, Philadelphia, PA, USA. .,Center for Cellular and Molecular Therapeutics, Children's Hospital of Philadelphia, Philadelphia, PA, USA.
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33
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Kantor A, McClements ME, Peddle CF, Fry LE, Salman A, Cehajic-Kapetanovic J, Xue K, MacLaren RE. CRISPR genome engineering for retinal diseases. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2021; 182:29-79. [PMID: 34175046 DOI: 10.1016/bs.pmbts.2021.01.024] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Novel gene therapy treatments for inherited retinal diseases have been at the forefront of translational medicine over the past couple of decades. Since the discovery of CRISPR mechanisms and their potential application for the treatment of inherited human conditions, it seemed inevitable that advances would soon be made using retinal models of disease. The development of CRISPR technology for gene therapy and its increasing potential to selectively target disease-causing nucleotide changes has been rapid. In this chapter, we discuss the currently available CRISPR toolkit and how it has been and can be applied in the future for the treatment of inherited retinal diseases. These blinding conditions have until now had limited opportunity for successful therapeutic intervention, but the discovery of CRISPR has created new hope of achieving such, as we discuss within this chapter.
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Affiliation(s)
- Ariel Kantor
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences & NIHR Oxford Biomedical Research Centre, University of Oxford, Oxford, United Kingdom.
| | - Michelle E McClements
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences & NIHR Oxford Biomedical Research Centre, University of Oxford, Oxford, United Kingdom
| | - Caroline F Peddle
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences & NIHR Oxford Biomedical Research Centre, University of Oxford, Oxford, United Kingdom
| | - Lewis E Fry
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences & NIHR Oxford Biomedical Research Centre, University of Oxford, Oxford, United Kingdom; Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford, United Kingdom
| | - Ahmed Salman
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences & NIHR Oxford Biomedical Research Centre, University of Oxford, Oxford, United Kingdom
| | - Jasmina Cehajic-Kapetanovic
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences & NIHR Oxford Biomedical Research Centre, University of Oxford, Oxford, United Kingdom; Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford, United Kingdom
| | - Kanmin Xue
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences & NIHR Oxford Biomedical Research Centre, University of Oxford, Oxford, United Kingdom; Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford, United Kingdom
| | - Robert E MacLaren
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences & NIHR Oxford Biomedical Research Centre, University of Oxford, Oxford, United Kingdom; Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford, United Kingdom
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34
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Ellingford JM, Hufnagel RB, Arno G. Phenotype and Genotype Correlations in Inherited Retinal Diseases: Population-Guided Variant Interpretation, Variable Expressivity and Incomplete Penetrance. Genes (Basel) 2020; 11:genes11111274. [PMID: 33137882 PMCID: PMC7692259 DOI: 10.3390/genes11111274] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Revised: 10/23/2020] [Accepted: 10/25/2020] [Indexed: 12/15/2022] Open
Affiliation(s)
- Jamie M. Ellingford
- North West Genomic Laboratory Hub, Manchester Centre for Genomic Medicine, Manchester University NHS Foundation Trust, St Mary’s Hospital, Manchester M13 9WL, UK
- Division of Evolution and Genomic Sciences, Neuroscience and Mental Health Domain, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester M13 9PT, UK
- Correspondence: (J.M.E.); (R.B.H.); (G.A.)
| | - Robert B. Hufnagel
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, MD 20016, USA
- Correspondence: (J.M.E.); (R.B.H.); (G.A.)
| | - Gavin Arno
- University College London Institute of Ophthalmology, London EC1V 9EL, UK
- Moorfields Eye Hospital, London EC1V 2PD, UK
- Correspondence: (J.M.E.); (R.B.H.); (G.A.)
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35
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A CRISPR and high-content imaging assay compliant with ACMG/AMP guidelines for clinical variant interpretation in ciliopathies. Hum Genet 2020; 140:593-607. [PMID: 33095315 PMCID: PMC7981318 DOI: 10.1007/s00439-020-02228-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Accepted: 10/14/2020] [Indexed: 11/04/2022]
Abstract
Ciliopathies are a broad range of inherited developmental and degenerative diseases associated with structural or functional defects in motile or primary non-motile cilia. There are around 200 known ciliopathy disease genes and whilst genetic testing can provide an accurate diagnosis, 24–60% of ciliopathy patients who undergo genetic testing do not receive a genetic diagnosis. This is partly because following current guidelines from the American College of Medical Genetics and the Association for Molecular Pathology, it is difficult to provide a confident clinical diagnosis of disease caused by missense or non-coding variants, which account for more than one-third of cases of disease. Mutations in PRPF31 are the second most common cause of the degenerative retinal ciliopathy autosomal dominant retinitis pigmentosa. Here, we present a high-throughput high-content imaging assay providing quantitative measure of effect of missense variants in PRPF31 which meets the recently published criteria for a baseline standard in vitro test for clinical variant interpretation. This assay utilizes a new PRPF31+/– human retinal cell line generated using CRISPR gene editing to provide a stable cell line with significantly fewer cilia in which novel missense variants are expressed and characterised. We show that high-content imaging of cells expressing missense variants in a ciliopathy gene on a null background can allow characterisation of variants according to the cilia phenotype. We hope that this will be a useful tool for clinical characterisation of PRPF31 variants of uncertain significance, and can be extended to variant classification in other ciliopathies.
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Cao L, Peng C, Yu J, Jiang W, Yang J. Identification of two novel PRPF31 mutations in Chinese families with non-syndromic autosomal dominant retinitis pigmentosa. Mol Genet Genomic Med 2020; 8:e1537. [PMID: 33085829 PMCID: PMC7767543 DOI: 10.1002/mgg3.1537] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Revised: 09/30/2020] [Accepted: 10/02/2020] [Indexed: 12/05/2022] Open
Abstract
Background Retinitis pigmentosa is a heterogeneous group of inherited retinal diseases leading to progressive vision loss. It has been estimated that the etiology is still unclear in 22%‐40% of cases, indicating that many novel pathogenic variations related to RP remain unidentified in many patients. In this study, our aim was to investigate the disease‐causing variants and function of the variants in two Chinese families with non‐syndromic autosomal dominant retinitis pigmentosa (adRP). Methods Clinical data and peripheral blood DNA samples were collected. Whole exome sequencing (WES) was conducted to screen for variations. Then, the expression of green fluorescent protein (GFP)‐fused wild‐type PRPF31 protein and its variants was evaluated via western blotting and GFP fluorescence detection in vitro. Results Two novel heterozygous variants of PRPF31 (NM_015629.4): c.855+5G>A and c.849_855del (p.Pro284Ilefs*35) were identified respectively in two families. The variant c.855+5G>A is co‐segregated with the disease in adRP‐01 family. The pedigree analysis result for c.849_855del (p. Pro284Ilefs*35) shows an inheritance pattern with incomplete penetrance for adRP‐02 family. The RT‐PCR analysis shows the PRPF31 gene c.855+5G>A leading to the missing from the 997th to the 1405th positions of the PRPF31 gene (NM_015629.4) cDNA. The expressions of the mutant GFP‐fused PRPF31 protein were not detected in HEK293 cells or Cos7 cells via western blotting and immunofluorescence. Conclusions Our findings identified two novel variants in PRPF31 in two Chinese families with adRP, expanding the mutational spectrum of this gene. Functional analysis reveals that these variants lead to the truncation of the PRPF31 protein.
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Affiliation(s)
- Li Cao
- College of Medical Technology, Chengdu University of Traditional Chinese Medicine, Chengdu, PR China
| | - Chunyan Peng
- The Key Laboratory for Human Disease Gene Study of Sichuan Province, Prenatal Diagnosis Center, Sichuan Provincial People's Hospital, the University of Electronic Science and Technology of China, Chengdu, PR China.,School of Medicine, University of Electronic Science and Technology of China, Chengdu, PR China
| | - Jing Yu
- College of Medical Technology, Chengdu University of Traditional Chinese Medicine, Chengdu, PR China
| | - Wei Jiang
- The Key Laboratory for Human Disease Gene Study of Sichuan Province, Prenatal Diagnosis Center, Sichuan Provincial People's Hospital, the University of Electronic Science and Technology of China, Chengdu, PR China.,School of Medicine, University of Electronic Science and Technology of China, Chengdu, PR China
| | - Jiyun Yang
- The Key Laboratory for Human Disease Gene Study of Sichuan Province, Prenatal Diagnosis Center, Sichuan Provincial People's Hospital, the University of Electronic Science and Technology of China, Chengdu, PR China.,School of Medicine, University of Electronic Science and Technology of China, Chengdu, PR China
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