1
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Pantrangi M, Rath J, Kaetterhenry N, Branham K, Talsness D, Weber JL. Clinical sequencing of the retinitis pigmentosa gene RPGR in over 1,000 cases of vision loss. Mol Vis 2024; 30:49-57. [PMID: 38586605 PMCID: PMC10994678] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2023] [Accepted: 02/17/2024] [Indexed: 04/09/2024] Open
Abstract
RPGR pathogenic variants are the major cause of X-linked retinitis pigmentosa. Here, we report the results from 1,033 clinical DNA tests that included sequencing of RPGR. A total of 184 RPGR variants were identified: 78 pathogenic or likely pathogenic, 14 uncertain, and 92 likely benign or benign. Among the pathogenic and likely pathogenic variants, 23 were novel, and most were frameshift or nonsense mutations (87%) and enriched (67%) in RPGR exon 15 (ORF15). Identical pathogenic variants found in different families were largely on different haplotype backgrounds, indicating relatively frequent, recurrent RPGR mutations. None of the 16 mother/affected son pairs showed de novo mutations; all 16 mothers were heterozygous for the pathogenic variant. These last two observations support the occurrence of most RPGR mutations in the male germline.
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Affiliation(s)
- Madhulatha Pantrangi
- PreventionGenetics, part of Exact Sciences, Marshfield, WI
- Weill Cornell Medicine, Department of Pathology and Laboratory Medicine, New York, NY
| | - Julie Rath
- PreventionGenetics, part of Exact Sciences, Marshfield, WI
| | | | - Kari Branham
- University of Michigan, Kellogg Eye Center, Department of Ophthalmology and Visual Sciences, Ann Arbor, MI
| | - Dana Talsness
- PreventionGenetics, part of Exact Sciences, Marshfield, WI
| | - James L Weber
- PreventionGenetics, part of Exact Sciences, Marshfield, WI
- University of Wisconsin, School of Medicine and Public Health, Department of Pediatrics, Madison, WI
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2
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German RJ, Vuocolo B, Vossaert L, Owen N, Lewis RA, Saba L, Wangler MF, Nagamani S. Novel hemizygous single-nucleotide duplication in RPGR in a patient with retinal dystrophy and sensorineural hearing loss. Mol Genet Genomic Med 2024; 12:e2404. [PMID: 38404254 PMCID: PMC10895382 DOI: 10.1002/mgg3.2404] [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: 06/30/2023] [Revised: 02/02/2024] [Accepted: 02/06/2024] [Indexed: 02/27/2024] Open
Abstract
BACKGROUND The RPGR gene has been associated with X-linked cone-rod dystrophy. This report describes a variant in RPGR detected with exome sequencing (ES). Genes like RPGR have not always been included in panel-based testing and thus genome-wide tests such as ES may be required for accurate diagnosis. METHODS The Texome Project is studying the impact of ES in medically underserved patients who are in need of genomic testing to guide diagnosis and medical management. The hypothesis is that ES could uncover diagnoses not made by standard medical care. RESULTS A 58-year-old male presented with retinitis pigmentosa, sensorineural hearing loss, and a family history of retinal diseases. A previous targeted gene panel for retinal disorders had not identified a molecular cause. ES through the Texome Project identified a novel, hemizygous variant in RPGR (NM_000328.3: c.1302dup, p.L435Sfs*18) that explained the ocular phenotype. CONCLUSIONS Continued genetics evaluation can help to end diagnostic odysseys of patients. Careful consideration of genes represented when utilizing gene panels is crucial to ensure an accurate diagnosis. Medically underserved populations are less likely to receive comprehensive genetic testing in their diagnostic workup. Our report is an example of the medical impact of genomic medicine implementation.
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Affiliation(s)
- Ryan J. German
- Department of Molecular and Human GeneticsBaylor College of MedicineHoustonTexasUSA
- Jan and Dan Duncan Neurological Research InstituteTexas Children's HospitalHoustonTexasUSA
| | - Blake Vuocolo
- Department of Molecular and Human GeneticsBaylor College of MedicineHoustonTexasUSA
- Jan and Dan Duncan Neurological Research InstituteTexas Children's HospitalHoustonTexasUSA
| | - Liesbeth Vossaert
- Department of Molecular and Human GeneticsBaylor College of MedicineHoustonTexasUSA
- Baylor Genetics LaboratoriesHoustonTexasUSA
| | - Nichole Owen
- Department of Molecular and Human GeneticsBaylor College of MedicineHoustonTexasUSA
- Baylor Genetics LaboratoriesHoustonTexasUSA
| | - Richard A. Lewis
- Department of Molecular and Human GeneticsBaylor College of MedicineHoustonTexasUSA
- Department of MedicineBaylor College of MedicineHoustonTexasUSA
- Department of OphthalmologyBaylor College of MedicineHoustonTexasUSA
| | - Lisa Saba
- Department of PathologyTexas Children's HospitalHoustonTexasUSA
| | | | - Michael F. Wangler
- Department of Molecular and Human GeneticsBaylor College of MedicineHoustonTexasUSA
- Jan and Dan Duncan Neurological Research InstituteTexas Children's HospitalHoustonTexasUSA
- Texas Children's HospitalHoustonTexasUSA
| | - Sandesh Nagamani
- Department of Molecular and Human GeneticsBaylor College of MedicineHoustonTexasUSA
- Department of MedicineBaylor College of MedicineHoustonTexasUSA
- Texas Children's HospitalHoustonTexasUSA
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3
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Wongchaisuwat N, Amato A, Lamborn AE, Yang P, Everett L, Pennesi ME. Retinitis pigmentosa GTPase regulator-related retinopathy and gene therapy. Saudi J Ophthalmol 2023; 37:276-286. [PMID: 38155670 PMCID: PMC10752277 DOI: 10.4103/sjopt.sjopt_168_23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Revised: 08/14/2023] [Accepted: 08/16/2023] [Indexed: 12/30/2023] Open
Abstract
Retinitis pigmentosa GTPase regulator (RPGR)-related retinopathy is a retinal dystrophy inherited in a X-linked recessive manner that typically causes progressive visual loss starting in childhood with severe visual impairment by the fourth decade of life. It manifests as an early onset and severe form of retinitis pigmentosa. There are currently no effective treatments for RPGR-related retinopathy; however, there are multiple clinical trials in progress exploring gene augmentation therapy aimed at slowing down or halting the progression of disease and possibly restoring visual function. This review focuses on the molecular biology, clinical manifestations, and the recent progress of gene therapy clinical trials.
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Affiliation(s)
- Nida Wongchaisuwat
- Department of Ophthalmology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
- Department of Ophthalmology, Casey Eye Institute, Oregon Health and Science University, Portland, Oregon, USA
| | - Alessia Amato
- Department of Ophthalmology, Casey Eye Institute, Oregon Health and Science University, Portland, Oregon, USA
| | - Andrew E. Lamborn
- Department of Ophthalmology, Casey Eye Institute, Oregon Health and Science University, Portland, Oregon, USA
| | - Paul Yang
- Department of Ophthalmology, Casey Eye Institute, Oregon Health and Science University, Portland, Oregon, USA
| | - Lesley Everett
- Department of Ophthalmology, Casey Eye Institute, Oregon Health and Science University, Portland, Oregon, USA
- Department of Molecular and Medical Genetics, Oregon Health and Science University, Portland, Oregon, USA
| | - Mark E. Pennesi
- Department of Ophthalmology, Casey Eye Institute, Oregon Health and Science University, Portland, Oregon, USA
- Department of Molecular and Medical Genetics, Oregon Health and Science University, Portland, Oregon, USA
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Benson MD, Mukherjee S, Agather AR, Blain D, Cunningham D, Mays R, Sun X, Li T, Hufnagel RB, Brooks BP, Huryn LA, Zein WM, Cukras CA. RPGR: Deep Phenotyping and Genetic Characterization With Findings Specific to the 3'-end of ORF15. Invest Ophthalmol Vis Sci 2023; 64:19. [PMID: 37695603 PMCID: PMC10501488 DOI: 10.1167/iovs.64.12.19] [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: 12/30/2022] [Accepted: 07/27/2023] [Indexed: 09/12/2023] Open
Abstract
Purpose To describe a group of patients with retinitis pigmentosa GTPase regulator (RPGR)-related retinopathy with a tapetal-like retinal sheen and corresponding changes in the reflectivity of the ellipsoid zone on optical coherence tomography (OCT) imaging. Methods A retrospective case series of 66 patients with a disease-causing variant in RPGR was performed. An expert examiner, masked to patient demographics, clinical evaluations, and specific RPGR variant, analyzed color fundus photographs for the presence of a tapetal-like retinal sheen and assessed OCT images for the presence of an abnormally broad hyper-reflective band in the outer retina. Longitudinal reflectivity profiles were generated and compared with healthy controls. Results Twelve patients (18.2%) had a retinal sheen on color images that cosegregated with an abnormally broad hyper-reflective ellipsoid zone band on OCT imaging. Three-fourths of these patients were male, had a cone-rod dystrophy, and had pathogenic RPGR variants located toward the 3'-end of ORF15. This group had a different longitudinal reflectivity profile signature compared with controls. After a period of prolonged dark adaptation, the abnormal hyper-reflective band on OCT became less apparent, and the outer retinal layers adopted a more normal appearance. Conclusions RPGR-related retinopathy should be considered for males presenting with retinal sheen, abnormal ellipsoid zone hyper-reflectivity, and cone or cone-rod dysfunction on ERG, and pursued with molecular testing. Our results have implications for understanding the role of the C-terminal domain encoded by RPGR ORF15 in the phototransduction cascade. Further, the findings may be important to incorporate into both inclusion criteria and outcome measure developments in future RPGR-related cone or cone-rod dystrophy clinical trials.
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Affiliation(s)
- Matthew D. Benson
- National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States
| | - Souvick Mukherjee
- National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States
| | - Aime R. Agather
- National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States
| | - Delphine Blain
- National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States
| | - Denise Cunningham
- National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States
| | - Robert Mays
- National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States
| | - Xun Sun
- National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States
| | - Tiansen Li
- National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States
| | - Robert B. Hufnagel
- National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States
| | - Brian P. Brooks
- National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States
| | - Laryssa A. Huryn
- National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States
| | - Wadih M. Zein
- National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States
| | - Catherine A. Cukras
- National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States
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5
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Hadalin V, Buscarino M, Sajovic J, Meglič A, Jarc-Vidmar M, Hawlina M, Volk M, Fakin A. Genetic Characteristics and Long-Term Follow-Up of Slovenian Patients with RPGR Retinal Dystrophy. Int J Mol Sci 2023; 24:ijms24043840. [PMID: 36835250 PMCID: PMC9958649 DOI: 10.3390/ijms24043840] [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: 11/15/2022] [Revised: 02/01/2023] [Accepted: 02/06/2023] [Indexed: 02/17/2023] Open
Abstract
Genetic characteristics and a long-term clinical follow-up of 18 Slovenian retinitis pigmentosa GTPase regulator (RPGR) patients from 10 families with retinitis pigmentosa (RP) or cone/cone-rod dystrophy (COD/CORD) are reported. RP (eight families) was associated with two already known (p.(Ser407Ilefs*46) and p.(Glu746Argfs*23)) and five novel variants (c.1245+704_1415-2286del, p.(Glu660*), p.(Ala153Thr), c.1506+1G>T, and p.(Arg780Serfs*54)). COD (two families) was associated with p.(Ter1153Lysext*38). The median age of onset in males with RP (N = 9) was 6 years. At the first examination (median age of 32 years), the median best corrected visual acuity (BCVA) was 0.30 logMAR, and all patients had a hyperautofluorescent ring on fundus autofluorescence (FAF) encircling preserved photoreceptors. At the last follow-up (median age of 39 years), the median BCVA was 0.48 logMAR, and FAF showed ring constriction transitioning to patch in 2/9. Among females (N = 6; median age of 40 years), two had normal/near-normal FAF, one had unilateral RP (male pattern), and three had a radial and/or focal pattern of retinal degeneration. After a median of 4 years (4-21) of follow-up, 2/6 exhibited disease progression. The median age of onset in males with COD was 25 years. At first examination (median age of 35 years), the median BCVA was 1.00 logMAR, and all patients had a hyperautofluorescent FAF ring encircling foveal photoreceptor loss. At the last follow-up (median age of 42 years), the median BCVA was 1.30 logMAR, and FAF showed ring enlargement. The majority of the identified variants (75%; 6/8) had not been previously reported in other RPGR cohorts, which suggested the presence of distinct RPGR alleles in the Slovenian population.
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Affiliation(s)
- Vlasta Hadalin
- Eye Hospital, University Medical Centre Ljubljana, Grablovičeva 46, 1000 Ljubljana, Slovenia
| | - Maša Buscarino
- Eye Hospital, University Medical Centre Ljubljana, Grablovičeva 46, 1000 Ljubljana, Slovenia
| | - Jana Sajovic
- Eye Hospital, University Medical Centre Ljubljana, Grablovičeva 46, 1000 Ljubljana, Slovenia
| | - Andrej Meglič
- Eye Hospital, University Medical Centre Ljubljana, Grablovičeva 46, 1000 Ljubljana, Slovenia
| | - Martina Jarc-Vidmar
- Eye Hospital, University Medical Centre Ljubljana, Grablovičeva 46, 1000 Ljubljana, Slovenia
| | - Marko Hawlina
- Eye Hospital, University Medical Centre Ljubljana, Grablovičeva 46, 1000 Ljubljana, Slovenia
| | - Marija Volk
- Clinical Institute of Genomic Medicine, University Medical Centre Ljubljana, Šlajmerjeva 4, 1000 Ljubljana, Slovenia
| | - Ana Fakin
- Eye Hospital, University Medical Centre Ljubljana, Grablovičeva 46, 1000 Ljubljana, Slovenia
- Correspondence:
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Cehajic-Kapetanovic J, Martinez-Fernandez de la Camara C, Birtel J, Rehman S, McClements ME, Charbel Issa P, Lotery AJ, MacLaren RE. Impaired glutamylation of RPGR ORF15 underlies the cone-dominated phenotype associated with truncating distal ORF15 variants. Proc Natl Acad Sci U S A 2022; 119:e2208707119. [PMID: 36445968 PMCID: PMC9897430 DOI: 10.1073/pnas.2208707119] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Pathogenic variants in the Retinitis pigmentosa GTPase regulator (RPGR) gene lead to a clinically severe form of X-linked retinal dystrophy. However, it remains unclear why some variants cause a predominant rod, while others result in a cone-dominated phenotype. Post-translational glutamylation of the photoreceptor-specific RPGRORF15 isoform by the TTLL5 enzyme is essential for its optimal function in photoreceptors, and loss of TTLL5 leads to retinal dystrophy with a cone phenotype. Here we show that RPGR retinal disease, studied in a single cohort of 116 male patients, leads to a clear progressive shift from rod- to cone-dominating phenotype as the RPGRORF15 variant location approaches the distal part of the Open Reading Frame 15 (ORF15) region. The rod photoreceptor involvement on the contrary diminishes along the RGPR sequence, and the variants associated with the cone only phenotype are located predominantly in the very distal part, including the C-terminal basic domain. Moreover, these distal truncating RPGRORF15 variants disrupt the interaction with TTLL5 and lead to a significant impairment of RPGR glutamylation. Thus, consistent with the phenotype of TTLL5 pathogenic variants, our study shows that RPGRORF15 variants, which disrupt its basic domain and the interaction with TTLL5, also impair RPGR glutamylation and lead to the cone phenotype. This has implications for ongoing gene therapy clinical trials where the application of RPGR with impaired glutamylation may be less effective in treating RGPR dystrophies and may even convert a rod-cone dystrophy into a cone dystrophy phenotype.
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Affiliation(s)
- Jasmina Cehajic-Kapetanovic
- aNuffield Laboratory of Ophthalmology, Department of Clinical Neurosciences, John Radcliffe Hospital, Level 5 & 6, West WingOX3 9DU, United Kingdom
- bOxford Eye Hospital, Oxford University Hospitals The National Health Service Trust, John Radcliffe Hospital, West WingOX3 9DU, United Kingdom
- 2To whom correspondence may be addressed.
| | - Cristina Martinez-Fernandez de la Camara
- aNuffield Laboratory of Ophthalmology, Department of Clinical Neurosciences, John Radcliffe Hospital, Level 5 & 6, West WingOX3 9DU, United Kingdom
- bOxford Eye Hospital, Oxford University Hospitals The National Health Service Trust, John Radcliffe Hospital, West WingOX3 9DU, United Kingdom
- 2To whom correspondence may be addressed.
| | - Johannes Birtel
- aNuffield Laboratory of Ophthalmology, Department of Clinical Neurosciences, John Radcliffe Hospital, Level 5 & 6, West WingOX3 9DU, United Kingdom
- bOxford Eye Hospital, Oxford University Hospitals The National Health Service Trust, John Radcliffe Hospital, West WingOX3 9DU, United Kingdom
- cDepartment of Ophthalmology, University of Bonn, 53127Bonn, Germany
| | - Salwah Rehman
- aNuffield Laboratory of Ophthalmology, Department of Clinical Neurosciences, John Radcliffe Hospital, Level 5 & 6, West WingOX3 9DU, United Kingdom
- bOxford Eye Hospital, Oxford University Hospitals The National Health Service Trust, John Radcliffe Hospital, West WingOX3 9DU, United Kingdom
| | - Michelle E. McClements
- aNuffield Laboratory of Ophthalmology, Department of Clinical Neurosciences, John Radcliffe Hospital, Level 5 & 6, West WingOX3 9DU, United Kingdom
- bOxford Eye Hospital, Oxford University Hospitals The National Health Service Trust, John Radcliffe Hospital, West WingOX3 9DU, United Kingdom
| | - Peter Charbel Issa
- aNuffield Laboratory of Ophthalmology, Department of Clinical Neurosciences, John Radcliffe Hospital, Level 5 & 6, West WingOX3 9DU, United Kingdom
- bOxford Eye Hospital, Oxford University Hospitals The National Health Service Trust, John Radcliffe Hospital, West WingOX3 9DU, United Kingdom
| | - Andrew J Lotery
- dClinical Neurosciences Research Group, Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, SO16 6YDSouthampton, United Kingdom
- eUniversity Hospital Southampton NHS Foundation Trust, SO16 6YDSouthampton, United Kingdom
| | - Robert E. MacLaren
- aNuffield Laboratory of Ophthalmology, Department of Clinical Neurosciences, John Radcliffe Hospital, Level 5 & 6, West WingOX3 9DU, United Kingdom
- bOxford Eye Hospital, Oxford University Hospitals The National Health Service Trust, John Radcliffe Hospital, West WingOX3 9DU, United Kingdom
- 2To whom correspondence may be addressed.
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Georgiadis A, Smith AJ, Michaelides M, Naylor S, Forbes A. Letter to the editor: 'Emerging gene therapy products for RPGR-associated X-linked retinitis pigmentosa'. Expert Opin Emerg Drugs 2022; 27:445-447. [PMID: 36562396 DOI: 10.1080/14728214.2022.2152202] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Affiliation(s)
| | - Alexander J Smith
- UCL Institute of Ophthalmology, University College London, London, UK.,Centre for Gene Therapy and Regenerative Medicine, School of Basic and Medical Biosciences, Kings College London, London, UK
| | - Michel Michaelides
- UCL Institute of Ophthalmology, University College London, London, UK.,Moorfields Eye Hospital, London, UK
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Martinez-Fernandez de la Camara C, Cehajic-Kapetanovic J, MacLaren RE. Emerging gene therapy products for RPGR-associated X-linked retinitis pigmentosa. Expert Opin Emerg Drugs 2022; 27:431-443. [PMID: 36562395 DOI: 10.1080/14728214.2022.2152003] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Accepted: 11/22/2022] [Indexed: 12/24/2022]
Abstract
INTRODUCTION Mutations in the RPGR gene are responsible for one of the most prevalent and severe types of retinitis pigmentosa. Gene therapy has shown great promise to treat inherited retinal diseases, and currently, four RPGR gene therapy vectors are being evaluated in clinical trials. AREAS COVERED This manuscript reviews the gene therapy products that are in development for X-linked retinitis pigmentosa caused by mutations in RPGR, and the challenges that scientists and clinicians have faced. EXPERT OPINION The development of a gene therapy product for RPGR-associated retinal degeneration has been a great challenge due to the incomplete understanding of the underlying genetics and mechanism of action of RPGR, and on the other hand, due to the instability of the RPGR gene. Three of the four gene therapy vectors currently in clinical trials include a codon-optimized version of the human RPGR sequence, and the other vector contains a shortened version of the human RPGR. To date, the only Phase I/II results published in a peer-reviewed journal demonstrate a good safety profile and an improvement in the visual field using a codon optimized version of RPGRORF15.
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Affiliation(s)
- Cristina Martinez-Fernandez de la Camara
- Nuffield Laboratory of Ophthalmology, Department of Clinical Neurosciences, John Radcliffe Hospital, Level 5 & 6, West Wing, Headley Way, OX3 9DU, Oxford, UK
- Oxford Eye Hospital, Oxford University Hospitals NHS Trust, John Radcliffe Hospital, West Wing, Headley Way, OX3 9DU, Oxford, UK
| | - Jasmina Cehajic-Kapetanovic
- Nuffield Laboratory of Ophthalmology, Department of Clinical Neurosciences, John Radcliffe Hospital, Level 5 & 6, West Wing, Headley Way, OX3 9DU, Oxford, UK
- Oxford Eye Hospital, Oxford University Hospitals NHS Trust, John Radcliffe Hospital, West Wing, Headley Way, OX3 9DU, Oxford, UK
| | - Robert E MacLaren
- Nuffield Laboratory of Ophthalmology, Department of Clinical Neurosciences, John Radcliffe Hospital, Level 5 & 6, West Wing, Headley Way, OX3 9DU, Oxford, UK
- Oxford Eye Hospital, Oxford University Hospitals NHS Trust, John Radcliffe Hospital, West Wing, Headley Way, OX3 9DU, Oxford, UK
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9
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Du M, Li Y, Zheng P, Zhong L, Zhao W, Zhang Y, Gu H, Li X, Liu Z. Identification of a novel CACNA1F mutation in a Chinese family with CORDX3. Mol Genet Genomic Med 2022; 10:e2060. [PMID: 36165086 PMCID: PMC9651601 DOI: 10.1002/mgg3.2060] [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: 03/28/2022] [Revised: 08/16/2022] [Accepted: 09/08/2022] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND X-linked cone-rod dystrophy (CORDX) is one form of inherited retinal disorders (IRDs) characterized by progressive dysfunction of photoreceptor. Three types of CORDX were reported and CACNA1F gene defect can cause CORDX3. The aim of this study was to investigate the pathogenic variant in a Chinese family with IRD. METHODS The two affected subjects including the proband and his elder sister underwent ophthalmic examinations. Whole exome sequencing (WES) was performed in the proband at first, then co-segregation analysis was performed in the family by Sanger sequencing. Minigene approach was used to verify the effect of the mutation on the splicing of CACNA1F. X-chromosomal inactivation assay was performed to evaluate the inactivation patterns of the female carriers. RESULTS The ophthalmic examination results of the proband fit the clinical description of CORDX3, and the female patient presented with only mild symptoms due to mildly skewed X-chromosomal inactivation (ratio 67: 33). Molecular genetic testing identified a novel splice-site mutation c.3847-2A > G in CACNA1F (NM_005183.4) gene in the patients, which inherited from their asymptomatic mother. Minigene approach confirmed that c.3847-2A > G could affect the splicing of CACNA1F. CONCLUSION Our study identified a novel splice-site mutation in the CACNA1F gene, which expanded the mutational spectrum of CACNA1F-releated diseases and demonstrated the importance of combining clinical and genetic testing in the diagnosis of IRDs.
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Affiliation(s)
- Meng Du
- Hebei Provincial Key Laboratory of Basic Medicine for DiabetesThe Shijiazhuang Second HospitalShijiazhuangChina,Shijiazhuang Technology Innovation Center of Precision Medicine for DiabetesThe Shijiazhuang Second HospitalShijiazhuangChina
| | - Yang Li
- Hebei Provincial Key Laboratory of Basic Medicine for DiabetesThe Shijiazhuang Second HospitalShijiazhuangChina,Shijiazhuang Technology Innovation Center of Precision Medicine for DiabetesThe Shijiazhuang Second HospitalShijiazhuangChina
| | - Panpan Zheng
- Hebei Provincial Key Laboratory of Basic Medicine for DiabetesThe Shijiazhuang Second HospitalShijiazhuangChina,Shijiazhuang Technology Innovation Center of Precision Medicine for DiabetesThe Shijiazhuang Second HospitalShijiazhuangChina
| | - Liang Zhong
- Hebei Provincial Key Laboratory of Basic Medicine for DiabetesThe Shijiazhuang Second HospitalShijiazhuangChina,Shijiazhuang Technology Innovation Center of Precision Medicine for DiabetesThe Shijiazhuang Second HospitalShijiazhuangChina
| | - Weili Zhao
- Hebei Provincial Key Laboratory of Basic Medicine for DiabetesThe Shijiazhuang Second HospitalShijiazhuangChina,Shijiazhuang Technology Innovation Center of Precision Medicine for DiabetesThe Shijiazhuang Second HospitalShijiazhuangChina
| | - Yuxin Zhang
- Hebei Provincial Key Laboratory of Basic Medicine for DiabetesThe Shijiazhuang Second HospitalShijiazhuangChina,Shijiazhuang Technology Innovation Center of Precision Medicine for DiabetesThe Shijiazhuang Second HospitalShijiazhuangChina
| | - Haiyan Gu
- Hebei Provincial Key Laboratory of Basic Medicine for DiabetesThe Shijiazhuang Second HospitalShijiazhuangChina,Shijiazhuang Technology Innovation Center of Precision Medicine for DiabetesThe Shijiazhuang Second HospitalShijiazhuangChina
| | - Xue Li
- Medical Service Department, MyGenostics lnc.BeijingChina
| | - Zanchao Liu
- Hebei Provincial Key Laboratory of Basic Medicine for DiabetesThe Shijiazhuang Second HospitalShijiazhuangChina,Shijiazhuang Technology Innovation Center of Precision Medicine for DiabetesThe Shijiazhuang Second HospitalShijiazhuangChina
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10
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Hassan A, Mir YR, Kuchay RAH. Ocular findings and genomics of X-linked recessive disorders: A review. Indian J Ophthalmol 2022; 70:2386-2396. [PMID: 35791118 PMCID: PMC9426149 DOI: 10.4103/ijo.ijo_252_22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
Advent of new sequencing technologies and modern diagnostic procedures has opened the door for a deeper understanding of disorders about which little was known previously. Discovery of novel genes, new genetic variants in previously known genes and better techniques of functional validation has immensely contributed to unraveling the molecular basis of genetic disorders. Availability of knockout animal models like the zebrafish and gene editing tools like CRISPR-Cas9 has elucidated the function of many new genes and helped us to better understand the functional consequences of various gene defects. This has also led to better diagnosis and therapeutic interventions. In this context, a good body of research work has been done on X-linked recessive disorders with ocular findings. This review will focus on ocular and genetic findings of these rare disorders. To our knowledge, this is the first comprehensive review encompassing ocular and genomic spectrum of X-linked recessive disorders.
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Affiliation(s)
- Asima Hassan
- Department of Health and Medical Education, Srinagar, Jammu and Kashmir, India
| | - Yaser R Mir
- Department of Biotechnology, Baba Ghulam Shah Badshah University, Rajouri, Jammu and Kashmir, India
| | - Raja A H Kuchay
- Department of Biotechnology, Baba Ghulam Shah Badshah University, Rajouri, Jammu and Kashmir, India
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11
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Yang J, Zhou L, Ouyang J, Xiao X, Sun W, Li S, Zhang Q. Genotype-Phenotype Analysis of RPGR Variations: Reporting of 62 Chinese Families and a Literature Review. Front Genet 2021; 12:600210. [PMID: 34745198 PMCID: PMC8565807 DOI: 10.3389/fgene.2021.600210] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2020] [Accepted: 04/27/2021] [Indexed: 02/05/2023] Open
Abstract
Purpose RPGR is the most common cause of X-linked retinitis pigmentosa (RP), of which female carriers are also frequently affected. The aim of the current study was to explore the RPGR variation spectrum and associated phenotype based on the data from our lab and previous studies. Methods Variants in RPGR were selected from exome sequencing data of 7,092 probands with different eye conditions. The probands and their available family members underwent comprehensive ocular examinations. Similar data were collected from previous reports through searches in PubMed, Web of Science, and Google Scholar. Systematic analyses of genotypes, phenotypes and their correlations were performed. Results A total of 46 likely pathogenic variants, including nine missense and one in-frame variants in RCC1-like domain and 36 truncation variants, in RPGR were detected in 62 unrelated families in our in-house cohort. In addition, a total of 585 variants, including 491 (83.9%) truncation variants, were identified from the literature. Systematic analysis of variants from our in-house dataset, literature, and gnomAD suggested that most of the pathogenic variants of RPGR were truncation variants while pathogenic missense and in-frame variants were enriched in the RCC1-like domain. Phenotypic variations were present between males and female carriers, including more severe refractive error but better best corrected visual acuity (BCVA) in female carriers than those in males. The male patients showed a significant reduction of BCVA with increase of age and males with exon1-14 variants presented a better BCVA than those with ORF15 variants. For female carriers, the BCVA also showed significant reduction with increase of age, but BCVA in females with exon1-14 variants was not significant difference compared with those with ORF15 variants. Conclusion Most pathogenic variants of RPGR are truncations. Missense and in-frame variants located outside of the RCC1-like domain might be benign and the pathogenicity criteria for these variants should be considered with greater caution. The BCVA and refractive error are different between males and female carriers. Increase of age and location of variants in ORF15 contribute to the reduction of BCVA in males. These results are valuable for understanding genotypes and phenotypes of RPGR.
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Affiliation(s)
- Junxing Yang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Lin Zhou
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China.,Department of Ophthalmology, West China Hospital, Sichuan University, Chengdu, China
| | - Jiamin Ouyang
- 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
| | - Wenmin Sun
- 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
| | - Qingjiong Zhang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
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12
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Georgiou M, Awadh Hashem S, Daich Varela M, Michaelides M. Gene Therapy in X-linked Retinitis Pigmentosa Due to Defects in RPGR. Int Ophthalmol Clin 2021; 61:97-108. [PMID: 34584047 DOI: 10.1097/iio.0000000000000384] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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13
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A novel mutation of the RPGR gene in a Chinese X-linked retinitis pigmentosa family and possible involvement of X-chromosome inactivation. Eye (Lond) 2021; 35:1688-1696. [PMID: 32839555 PMCID: PMC8169654 DOI: 10.1038/s41433-020-01150-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2020] [Revised: 07/14/2020] [Accepted: 08/13/2020] [Indexed: 01/30/2023] Open
Abstract
OBJECTIVES The objective of this study is to investigate the molecular mechanisms and genotype-phenotype correlations of a Chinese family with X-linked retinitis pigmentosa (XLRP). METHODS A four-generation family with a total of 41 individuals including 7 affected males was recruited. All subjects in this pedigree underwent a complete ophthalmic examination. Targeted capture and next-generation sequencing were performed on the proband using a multigene panel containing 57 known causative genes of retinitis pigmentosa (RP), including RP1, RP2, RPGR, RHO, PRPH2, CRB1 among others. All variants were verified in the remaining family members by polymerase chain reaction amplification and Sanger sequencing. Blood DNA was used for X-chromosome inactivation analysis in female carriers. RESULTS All the affected individuals were diagnosed with RP. The affected males showed symptoms from the first decade, while the female carriers had onset in the second decade or later. A frameshift mutation c.345_348delTGAA in the RPGR gene was identified in all affected males and female carriers. By XCI analysis, we found that there was little correlation between their phenotype and the methylation status of their X chromosomes. CONCLUSIONS A novel mutation c.345_348delTGAA of the RPGR gene was identified, expanding the spectrum of RPGR mutations causing XLRP. In this pedigree, the phenotype extended to female carriers, in whom RP was milder and its onset delayed compared to hemizygous males. Although lack of strong correlation between X-inactivation and the severity of the disease, the milder, variable effects in female carriers still could reflect X-inactivation patterns in the retina of each individual.
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14
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Di Iorio V, Karali M, Melillo P, Testa F, Brunetti-Pierri R, Musacchia F, Condroyer C, Neidhardt J, Audo I, Zeitz C, Banfi S, Simonelli F. Spectrum of Disease Severity in Patients With X-Linked Retinitis Pigmentosa Due to RPGR Mutations. Invest Ophthalmol Vis Sci 2021; 61:36. [PMID: 33372982 PMCID: PMC7774109 DOI: 10.1167/iovs.61.14.36] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Purpose The purpose of this study was to perform a detailed longitudinal phenotyping of X-linked retinitis pigmentosa (RP) caused by mutations in the RPGR gene during a long follow-up period. Methods An Italian cohort of 48 male patients (from 31 unrelated families) with RPGR-associated RP was clinically assessed at a single center (mean follow-up = 6.5 years), including measurements of best-corrected visual acuity (BCVA), Goldmann visual field (GVF), optical coherence tomography (OCT), fundus autofluorescence (FAF), microperimetry, and full-field electroretinography (ERG). Results Patients (29.6 ± 15.2 years) showed a mean BCVA of 0.6 ± 0.7 logMAR, mostly with myopic refraction (79.2%). Thirty patients (62.5%) presented a typical RP fundus, while the remaining sine pigmento RP. Over the follow-up, BCVA significantly declined at a mean rate of 0.025 logMAR/year. Typical RP and high myopia were associated with a significantly faster decline of BCVA. Blindness was driven primarily by GVF loss. ERG responses with a rod-cone pattern of dysfunction were detectable in patients (50%) that were significantly younger and more frequently presented sine pigmento RP. Thirteen patients (27.1%) had macular abnormalities without cystoid macular edema. Patients (50%) with a perimacular hyper-FAF ring were significantly younger, had a higher BCVA and a better-preserved ellipsoid zone band than those with markedly decreased FAF. Patients harboring pathogenic variants in exons 1 to 14 showed a milder phenotype compared to those with ORF15 mutations. Conclusions Our monocentric, longitudinal retrospective study revealed a spectrum disease progression in male patients with RPGR-associated RP. Slow disease progression correlated with sine pigmento RP, absence of high myopia, and mutations in RPGR exons 1 to 14.
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Affiliation(s)
- Valentina Di Iorio
- Eye Clinic, Multidisciplinary Department of Medical, Surgical and Dental Sciences, Università degli Studi della Campania "Luigi Vanvitelli," Naples, Italy
| | - Marianthi Karali
- Eye Clinic, Multidisciplinary Department of Medical, Surgical and Dental Sciences, Università degli Studi della Campania "Luigi Vanvitelli," Naples, Italy.,Telethon Institute of Genetics and Medicine, Pozzuoli, Italy
| | - Paolo Melillo
- Eye Clinic, Multidisciplinary Department of Medical, Surgical and Dental Sciences, Università degli Studi della Campania "Luigi Vanvitelli," Naples, Italy
| | - Francesco Testa
- Eye Clinic, Multidisciplinary Department of Medical, Surgical and Dental Sciences, Università degli Studi della Campania "Luigi Vanvitelli," Naples, Italy
| | - Raffaella Brunetti-Pierri
- Eye Clinic, Multidisciplinary Department of Medical, Surgical and Dental Sciences, Università degli Studi della Campania "Luigi Vanvitelli," Naples, Italy
| | | | | | - John Neidhardt
- Human Genetics, Faculty of Medicine and Health Sciences, University of Oldenburg, Oldenburg, Germany.,Research Center Neurosensory Science, University Oldenburg, Oldenburg, Germany
| | - Isabelle Audo
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, Paris, France.,CHNO des Quinze-Vingts, DHU Sight Restore, INSERM-DGOS CIC, France.,Institute of Ophthalmology, University College of London, London, United Kingdom
| | - Christina Zeitz
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, Paris, France
| | - Sandro Banfi
- Telethon Institute of Genetics and Medicine, Pozzuoli, Italy.,Medical Genetics, Department of Precision Medicine, Università degli Studi della Campania "Luigi Vanvitelli," Naples, Italy
| | - Francesca Simonelli
- Eye Clinic, Multidisciplinary Department of Medical, Surgical and Dental Sciences, Università degli Studi della Campania "Luigi Vanvitelli," Naples, Italy
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Hadalin V, Šuštar M, Volk M, Maver A, Sajovic J, Jarc-Vidmar M, Peterlin B, Hawlina M, Fakin A. Cone Dystrophy Associated with a Novel Variant in the Terminal Codon of the RPGR- ORF15. Genes (Basel) 2021; 12:genes12040499. [PMID: 33805381 PMCID: PMC8066792 DOI: 10.3390/genes12040499] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2021] [Revised: 03/23/2021] [Accepted: 03/24/2021] [Indexed: 12/30/2022] Open
Abstract
Mutations in RPGRORF15 are associated with rod-cone or cone/cone-rod dystrophy, the latter associated with mutations at the distal end. We describe the phenotype associated with a novel variant in the terminal codon of the RPGRORF15 c.3457T>A (Ter1153Lysext*38), which results in a C-terminal extension. Three male patients from two families were recruited, aged 31, 35, and 38 years. Genetic testing was performed by whole exome sequencing. Filtered variants were analysed according to the population frequency, ClinVar database, the variant’s putative impact, and predicted pathogenicity; and were classified according to the ACMG guidelines. Examination included visual acuity (Snellen), colour vision (Ishihara), visual field, fundus autofluorescence (FAF), optical coherence tomography (OCT), and electrophysiology. All patients were myopic, and had central scotoma and reduced colour vision. Visual acuities on better eyes were counting fingers, 0.3 and 0.05. Electrophysiology showed severely reduced cone-specific responses and macular dysfunction, while the rod-specific response was normal. FAF showed hyperautofluorescent ring centred at the fovea encompassing an area of photoreceptor loss approximately two optic discs in diameter (3462–6342 μm). Follow up after 2–11 years showed enlargement of the diameter (avg. 100 μm/year). The novel c.3457T>A (Ter1153Lysext*38) mutation in the terminal RPGRORF15 codon is associated with cone dystrophy, which corresponds to the previously described phenotypes associated with mutations in the distal end of the RPGRORF15. Minimal progression during follow-up years suggests a relatively stable disease after the initial loss of the central cones.
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Affiliation(s)
- Vlasta Hadalin
- Eye Hospital, University Medical Centre Ljubljana, Grablovičeva 46, 1000 Ljubljana, Slovenia; (V.H.); (M.Š.); (J.S.); (M.J.-V.); (M.H.)
| | - Maja Šuštar
- Eye Hospital, University Medical Centre Ljubljana, Grablovičeva 46, 1000 Ljubljana, Slovenia; (V.H.); (M.Š.); (J.S.); (M.J.-V.); (M.H.)
| | - Marija Volk
- Clinical Institute of Medical Genetics, University Medical Centre Ljubljana, Šlajmerjeva ulica 4, 1000 Ljubljana, Slovenia; (M.V.); (A.M.); (B.P.)
| | - Aleš Maver
- Clinical Institute of Medical Genetics, University Medical Centre Ljubljana, Šlajmerjeva ulica 4, 1000 Ljubljana, Slovenia; (M.V.); (A.M.); (B.P.)
| | - Jana Sajovic
- Eye Hospital, University Medical Centre Ljubljana, Grablovičeva 46, 1000 Ljubljana, Slovenia; (V.H.); (M.Š.); (J.S.); (M.J.-V.); (M.H.)
| | - Martina Jarc-Vidmar
- Eye Hospital, University Medical Centre Ljubljana, Grablovičeva 46, 1000 Ljubljana, Slovenia; (V.H.); (M.Š.); (J.S.); (M.J.-V.); (M.H.)
| | - Borut Peterlin
- Clinical Institute of Medical Genetics, University Medical Centre Ljubljana, Šlajmerjeva ulica 4, 1000 Ljubljana, Slovenia; (M.V.); (A.M.); (B.P.)
| | - Marko Hawlina
- Eye Hospital, University Medical Centre Ljubljana, Grablovičeva 46, 1000 Ljubljana, Slovenia; (V.H.); (M.Š.); (J.S.); (M.J.-V.); (M.H.)
| | - Ana Fakin
- Eye Hospital, University Medical Centre Ljubljana, Grablovičeva 46, 1000 Ljubljana, Slovenia; (V.H.); (M.Š.); (J.S.); (M.J.-V.); (M.H.)
- Correspondence:
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16
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Huchzermeyer C, Fars J, Stöhr H, Kremers J. [New techniques for quantification of color vision in disorders of cone function : Cambridge color test and photoreceptor-specific temporal contrast sensitivity in patients with heterozygous RP1L1 and RPGR mutations]. Ophthalmologe 2021; 118:144-153. [PMID: 32458067 PMCID: PMC7862517 DOI: 10.1007/s00347-020-01119-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Hintergrund Erbliche Netzhauterkrankungen mit Zapfendysfunktion können trotz relativ unauffälligem Fundusbefund ausgeprägte Visusminderung und deutliche Farbsinnstörungen aufweisen. Beispiele hierfür sind die autosomal-dominante okkulte Makuladystrophie (RP1L1-Gen) und die X‑chromosomale Retinitis pigmentosa (RPGR-Gen) – Letztere auch bei heterozygoten, weiblichen Merkmalsträgerinnen (Konduktorinnen). Neue Untersuchungsmethoden erlauben es, das Ausmaß der Farbsinnstörung zu quantifizieren. Methoden Nach einer umfangreichen klinischen Untersuchung führten wir Messungen zur Quantifizierung der Farbdiskriminierung und der Zapfenfunktion durch. Beim Cambridge-Color-Test werden pseudoisochromatische Tafeln mit Landolt-C-Figuren computergesteuert generiert, um die Farbunterscheidungsschwelle entlang mehrerer Achsen im Farbraum zu bestimmen. Bei der Untersuchung der photorezeptorspezifischen zeitlichen Kontrastempfindlichkeit kann durch geschickte zyklische Veränderung der spektralen Zusammensetzung eines Lichtreizes die Kontrastwahrnehmungsschwelle isolierter Photorezeptortypen bestimmt werden. Die molekulargenetische Diagnostik erfolgte mithilfe von Next Generation Sequencing(NGS)-basierter gezielter Genpanelanalyse sowie Sanger-Sequenzierung. Ergebnisse Bei 2 Patienten mit okkulter Makuladystrophie und 2 heterozygoten Trägerinnen von RPGR-Mutationen zeigten sich eine deutlich verminderte Fähigkeit zur Farbdiskriminierung und eine verminderte photorezeptorspezifische zeitliche Kontrastempfindlichkeit. Diskussion Bei erblichen Netzhauterkrankungen sind neben den modernen bildgebenden Verfahren (okuläre Kohärenztomographie [OCT] und Fundusautofluoreszenz) auch die sinnesphysiologischen Untersuchungen diagnostisch wegweisend – der Nachweis von Farbsinnstörungen spielt hierbei eine wichtige Rolle. Neuere Methoden erlauben eine Quantifizierung der Farbsinnstörungen und könnten in klinischen Studien zu gen- und stammzellbasierter Therapie zur Messung des Therapieerfolges dienen.
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Affiliation(s)
- Cord Huchzermeyer
- Augenklinik mit Poliklinik, Universitätsklinik Erlangen, Erlangen, Deutschland.
| | - Julien Fars
- Augenklinik mit Poliklinik, Universitätsklinik Erlangen, Erlangen, Deutschland
| | - Heidi Stöhr
- Institut für Humangenetik, Universität Regensburg, Regensburg, Deutschland
| | - Jan Kremers
- Augenklinik mit Poliklinik, Universitätsklinik Erlangen, Erlangen, Deutschland
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Hu S, Du J, Chen N, Jia R, Zhang J, Liu X, Yang L. In Vivo CRISPR/Cas9-Mediated Genome Editing Mitigates Photoreceptor Degeneration in a Mouse Model of X-Linked Retinitis Pigmentosa. Invest Ophthalmol Vis Sci 2020; 61:31. [PMID: 32330228 PMCID: PMC7401909 DOI: 10.1167/iovs.61.4.31] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Purpose Retinitis pigmentosa GTPase regulator (RPGR)-related X-linked retinitis pigmentosa is associated with one of the most severe phenotypes among inherited retinal disease. The aim of this study was to investigate Clustered Regularly Interspaced Short Palindromic Repeat/Cas9-mediated gene editing therapy in a mouse model of Rpgr. Methods The Rpgr−/yCas9+/WT male mice were used for this study. At 6 months of age, they received a single subretinal injection of adeno-associated virus vectors carrying sgRNA and donor template separately, and therapeutic effect was examined after 1, 6, and 12 months. Results Rpgr knockout mouse showed slow but progressive age-related retinal degeneration, which emulates the disease occurring in humans. Significant photoreceptor preservation was observed in the treated part of the retina, in sharp contrast to the untreated part of the retina in the same eye after 6 and 12 months. It was surprising that precise modification at the target locus as demonstrated by genomic DNA sequencing in the post-mitotic photoreceptor was observed. Moreover, the therapeutic effect lasts for up to 12 months and no off-target effects were shown. Conclusions Our study strongly demonstrates that gene editing therapy is a promising therapeutic strategy to treat inherited retinal degeneration.
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CLINICAL AND GENETIC CHARACTERISTICS OF MALE PATIENTS WITH RPGR-ASSOCIATED RETINAL DYSTROPHIES: A Long-Term Follow-up Study. Retina 2020. [PMID: 29528978 DOI: 10.1097/iae.0000000000002125] [Citation(s) in RCA: 53] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE To describe the phenotype and clinical course of patients with RPGR-associated retinal dystrophies, and to identify genotype-phenotype correlations. METHODS A multicenter medical records review of 74 male patients with RPGR-associated retinal dystrophies. RESULTS Patients had retinitis pigmentosa (RP; n = 52; 70%), cone dystrophy (COD; n = 5; 7%), or cone-rod dystrophy (CORD; n = 17; 23%). The median follow-up time was 11.6 years (range 0-57.1). The median age at symptom onset was 5.0 years (range 0-14 years) for patients with RP and 23.0 years (range 0-60 years) for patients with COD/CORD. The probability of being blind (best-corrected visual acuity <0.05) at the age of 40 was 20% and 55% in patients with RP and COD/CORD, respectively. RPGR-ORF15 mutations were associated with high myopia (P = 0.01), which led to a faster best-corrected visual acuity decline in patients with RP (P < 0.001) and COD/CORD (P = 0.03). Patients with RP with RPGR-ORF15 mutations had a faster visual field decline (P = 0.01) and thinner central retina (P = 0.03) than patients with mutations in exon 1 to 14. CONCLUSION Based on best-corrected visual acuity survival probabilities, the intervention window for gene therapy for RPGR-associated retinal dystrophies is relatively broad in patients with RP. RPGR-ORF15 mutations were associated with COD/CORD and with a more severe phenotype in RP. High myopia is a risk factor for faster best-corrected visual acuity decline.
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19
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Zou X, Fang S, Wu S, Li H, Sun Z, Zhu T, Wei X, Sui R. Detailed comparison of phenotype between male patients carrying variants in exons 1-14 and ORF15 of RPGR. Exp Eye Res 2020; 198:108147. [PMID: 32702353 DOI: 10.1016/j.exer.2020.108147] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2020] [Revised: 07/05/2020] [Accepted: 07/08/2020] [Indexed: 12/19/2022]
Abstract
PURPOSE To compare disease severity in detail between patients carrying variants in exons 1-14 and ORF15 of retinitis pigmentosa GTPase regulator (RPGR). METHODS Systematic next-generation sequencing data analysis, Sanger sequencing validation and segregation analysis were utilised to identify the pathogenic variants. Detailed ophthalmic examinations, including electroretinograms, fundus photography, fundus autofluorescence and optical coherence tomography were performed. Statistical analysis, including age adjustment and comparison, were performed based on cross-sectional level to compare disease severity between variants in the two RPGR variant groups. RESULTS Sixty-two variants were identified in RPGR in 86 patients from 77 unrelated families. Twenty-nine (37.7%) had variants in RPGR-exons 1-14 (group 1) and 48 (62.3%) in RPGR-ORF15 (group 2). Eighty-four patients were diagnosed with X-linked retinitis pigmentosa and only two patients with cone-rod dystrophy. LogMAR visual acuity increased 0.035 and 0.022 each year on average in group 1 and group 2, respectively. Group 2 patients had better visual acuity with a mean logMAR difference of 0.4378, which is significant after age adjustment (P < 0.01). Neither the value of log (ellipsoid zone width) nor central retinal thickness was significantly correlated with variant grouping after considering the effect of the age variable (P = 0.56 and 0.40, respectively). Spherical refractive error did not differ significantly between the two variant groups (P = 0.17). Patterns of autofluorescence included a hyperfluorescent ring at the posterior pole, diffuse hyperfluorescence in the macular area, and dark macular autofluorescence with or without fovea hyperfluorescence. The age and proportion of fundus autofluorescence patterns between the two variant groups were significantly different (P < 0.01). CONCLUSIONS Patients with variants in exons 1-14 retained less visual acuity than patients with ORF15 variants and deteriorated faster. However, the ellipsoid zone widths, central retinal thickness and refractions were comparable between the two groups. Autofluorescence pattern relates to the age and the variant grouping.
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Affiliation(s)
- Xuan Zou
- Department of Ophthalmology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, 100730, China
| | - Sha Fang
- School of Statistics, Capital University of Economics and Business, Beijing, 100070, China
| | - Shijing Wu
- Department of Ophthalmology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, 100730, China
| | - Hui Li
- Department of Ophthalmology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, 100730, China
| | - Zixi Sun
- Department of Ophthalmology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, 100730, China
| | - Tian Zhu
- Department of Ophthalmology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, 100730, China
| | - Xing Wei
- Department of Ophthalmology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, 100730, China
| | - Ruifang Sui
- Department of Ophthalmology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, 100730, China.
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20
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Talib M, Boon CJF. Retinal Dystrophies and the Road to Treatment: Clinical Requirements and Considerations. Asia Pac J Ophthalmol (Phila) 2020; 9:159-179. [PMID: 32511120 PMCID: PMC7299224 DOI: 10.1097/apo.0000000000000290] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Accepted: 04/01/2020] [Indexed: 12/15/2022] Open
Abstract
: Retinal dystrophies (RDs) comprise relatively rare but devastating causes of progressive vision loss. They represent a spectrum of diseases with marked genetic and clinical heterogeneity. Mutations in the same gene may lead to different diagnoses, for example, retinitis pigmentosa or cone dystrophy. Conversely, mutations in different genes may lead to the same phenotype. The age at symptom onset, and the rate and characteristics of peripheral and central vision decline, may vary widely per disease group and even within families. For most RD cases, no effective treatment is currently available. However, preclinical studies and phase I/II/III gene therapy trials are ongoing for several RD subtypes, and recently the first retinal gene therapy has been approved by the US Food and Drug Administration for RPE65-associated RDs: voretigene neparvovec-rzyl (Luxturna). With the rapid advances in gene therapy studies, insight into the phenotypic spectrum and long-term disease course is crucial information for several RD types. The vast clinical heterogeneity presents another important challenge in the evaluation of potential efficacy in future treatment trials, and in establishing treatment candidacy criteria. This perspective describes these challenges, providing detailed clinical descriptions of several forms of RD that are caused by genes of interest for ongoing and future gene or cell-based therapy trials. Several ongoing and future treatment options will be described.
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Affiliation(s)
- Mays Talib
- Department of Ophthalmology, Leiden, The Netherlands
| | - Camiel J F Boon
- Department of Ophthalmology, Leiden, The Netherlands
- Department of Ophthalmology, Amsterdam UMC, Academic Medical Center, University of Amsterdam. Amsterdam, The Netherlands
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RPGR-Associated Dystrophies: Clinical, Genetic, and Histopathological Features. Int J Mol Sci 2020; 21:ijms21030835. [PMID: 32012938 PMCID: PMC7038140 DOI: 10.3390/ijms21030835] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2019] [Revised: 01/21/2020] [Accepted: 01/27/2020] [Indexed: 12/11/2022] Open
Abstract
This study describes the clinical, genetic, and histopathological features in patients with RPGR-associated retinal dystrophies. Nine male patients from eight unrelated families underwent a comprehensive ophthalmic examination. Additionally, the histopathology of the right eye from a patient with an end-stage cone-rod-dystrophy (CRD)/sector retinitis pigmentosa (RP) phenotype was examined. All RPGR mutations causing a CRD phenotype were situated in exon ORF15. The mean best-corrected visual acuity (BCVA, decimals) was 0.58 (standard deviation (SD)): 0.34; range: 0.05-1.13); and the mean spherical refractive error was -4.1 D (SD: 2.11; range: -1.38 to -8.19). Hyperautofluorescent rings were observed in six patients. Full-field electroretinography responses were absent in all patients. The visual field defects ranged from peripheral constriction to central islands. The mean macular sensitivity on microperimetry was 11.6 dB (SD: 7.8; range: 1.6-24.4) and correlated significantly with BCVA (r = 0.907; p = 0.001). A histological examination of the donor eye showed disruption of retinal topology and stratification, with a more severe loss found in the peripheral regions. Reactive gliosis was seen in the inner layers of all regions. Our study demonstrates the highly variable phenotype found in RPGR-associated retinal dystrophies. Therapies should be applied at the earliest signs of photoreceptor degeneration, prior to the remodeling of the inner retina.
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De La Camara CMF, Cehajic-Kapetanovic J, MacLaren RE. RPGR gene therapy presents challenges in cloning the coding sequence. Expert Opin Biol Ther 2020; 20:63-71. [PMID: 31612744 PMCID: PMC7104355 DOI: 10.1080/14712598.2020.1680635] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Introduction: Currently, there are three Phase I/II clinical trials based on gene therapy ongoing to test different AAV.RPGR or deleted RPGR vectors on patients affected by X-linked retinitis pigmentosa. These three vectors differ in the adeno-associated viral (AAV) vector capsid used, and the coding sequences: two contain codon optimized versions of RPGR which give the full-length protein, whilst the third uses a wild-type sequence that contains a large deletion encoding part of the functional domain of the RPGR protein.Areas covered: This review approaches the different studies that have led to the initiation of three different clinical trials for RPGR related X-linked retinitis pigmentosa.Expert opinion: The development of a gene therapy vector to deliver a normal copy of the RPGR gene into the photoreceptors has presented a challenge for the scientific community. The instability of its sequence and the fact that its function is not well understood can lead to the production of a nonfunctional or deleterious protein for the human retina. Since the RPGR protein undergoes post-translational glutamylation in the protein domain that may be particularly affected by gene instability, a functional assay of glutamylation is essential to verify the correct coding sequence.
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Affiliation(s)
- Cristina Martinez-Fernandez De La Camara
- Department of Clinical Neurosciences, Nuffield Laboratory of Ophthalmology, University of Oxford, John Radcliffe Hospital, Headley Way, UK
- Oxford Eye Hospital, Oxford University Hospitals NHS Trust, John Radcliffe Hospital, Headley Way, UK
| | - Jasmina Cehajic-Kapetanovic
- Department of Clinical Neurosciences, Nuffield Laboratory of Ophthalmology, University of Oxford, John Radcliffe Hospital, Headley Way, UK
- Oxford Eye Hospital, Oxford University Hospitals NHS Trust, John Radcliffe Hospital, Headley Way, UK
| | - Robert E. MacLaren
- Department of Clinical Neurosciences, Nuffield Laboratory of Ophthalmology, University of Oxford, John Radcliffe Hospital, Headley Way, UK
- Oxford Eye Hospital, Oxford University Hospitals NHS Trust, John Radcliffe Hospital, Headley Way, UK
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Fahim AT, Sullivan LS, Bowne SJ, Jones KD, Wheaton DKH, Khan NW, Heckenlively JR, Jayasundera KT, Branham KH, Andrews CA, Othman MI, Karoukis AJ, Birch DG, Daiger SP. X-Chromosome Inactivation Is a Biomarker of Clinical Severity in Female Carriers of RPGR-Associated X-Linked Retinitis Pigmentosa. Ophthalmol Retina 2019; 4:510-520. [PMID: 31953110 DOI: 10.1016/j.oret.2019.11.010] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2019] [Revised: 11/08/2019] [Accepted: 11/11/2019] [Indexed: 11/16/2022]
Abstract
PURPOSE X-linked retinitis pigmentosa can manifest in female carriers with widely variable severity, whereas others remain unaffected. The contribution of X-chromosome inactivation (XCI) to phenotypic variation has been postulated but not demonstrated. Furthermore, the impact of genotype and genetic modifiers has been demonstrated in affected males but has not been well established in female carriers. The purpose of this study was to describe the scope of clinical phenotype in female carriers with mutations in RPGR and quantify the contribution of genotype, genetic modifiers, and XCI to phenotypic severity. DESIGN Cohort study. PARTICIPANTS Seventy-seven female carriers with RPGR mutations from 41 pedigrees. METHODS Coding single nucleotide polymorphisms were sequenced in candidate genetic modifier genes encoding known RPGR-interacting proteins. X-chromosome inactivation ratios were determined in genomic DNA isolated from blood (n = 42) and saliva (n = 20) using methylation status of X-linked polymorphic repeats. These genetic data were compared with disease severity based on quantitative clinical parameters. MAIN OUTCOME MEASURES Visual acuity, Humphrey visual field (HVF) results, full-field electroretinography results, and dark adaptation. RESULTS Most individuals at all ages were mildly affected or unaffected, whereas those who progressed to moderate or severe vision loss were older than 30 years. RPGR genotype was not associated with clinical severity. The D1264N variant in RPGRIP1L was associated with more severe disease. Skewed XCI toward inactivation of the normal RPGR allele was associated with more severe disease. The XCI ratio in both blood and saliva was a predictor of visual function as measured by HVF diameter, rod amplitude, flicker amplitude, and flicker implicit time. For carriers with extreme XCI skewing of 80:20 or more, 57% were affected severely compared with 8% for those with XCI of less than 80:20 (P = 0.002). CONCLUSIONS Female carriers with mutations in RPGR demonstrate widely variable clinical severity. X-chromosome inactivation ratios correlate with clinical severity and may serve as a predictor of clinically significant disease. Because RPGR gene therapy trials are underway, a future imperative exists to determine which carriers require intervention and when to intervene. X-chromosome inactivation analysis may be useful for identifying candidates for early intervention.
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Affiliation(s)
- Abigail T Fahim
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, Michigan.
| | - Lori S Sullivan
- Department of Genetics, University of Texas Health Science Center, Houston, Texas
| | - Sara J Bowne
- Department of Genetics, University of Texas Health Science Center, Houston, Texas
| | | | | | - Naheed W Khan
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, Michigan
| | - John R Heckenlively
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, Michigan
| | - K Thiran Jayasundera
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, Michigan
| | - Kari H Branham
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, Michigan
| | - Chris A Andrews
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, Michigan
| | - Mohammad I Othman
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, Michigan
| | - Athanasios J Karoukis
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, Michigan
| | | | - Stephen P Daiger
- Department of Genetics, University of Texas Health Science Center, Houston, Texas
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Boulanger-Scemama E, Mohand-Saïd S, El Shamieh S, Démontant V, Condroyer C, Antonio A, Michiels C, Boyard F, Saraiva JP, Letexier M, Sahel JA, Zeitz C, Audo I. Phenotype Analysis of Retinal Dystrophies in Light of the Underlying Genetic Defects: Application to Cone and Cone-Rod Dystrophies. Int J Mol Sci 2019; 20:ijms20194854. [PMID: 31574917 PMCID: PMC6801687 DOI: 10.3390/ijms20194854] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2019] [Revised: 09/20/2019] [Accepted: 09/25/2019] [Indexed: 12/29/2022] Open
Abstract
Phenotypes observed in a large cohort of patients with cone and cone-rod dystrophies (COD/CORDs) are described based on multimodal retinal imaging features in order to help in analyzing massive next-generation sequencing data. Structural abnormalities of 58 subjects with molecular diagnosis of COD/CORDs were analyzed through specific retinal imaging including spectral-domain optical coherence tomography (SD-OCT) and fundus autofluorescence (BAF/IRAF). Findings were analyzed with the underlying genetic defects. A ring of increased autofluorescence was mainly observed in patients with CRX and GUCY2D mutations (33% and 22% of cases respectively). “Speckled” autofluorescence was observed with mutations in three different genes (ABCA4 64%; C2Orf71 and PRPH2, 18% each). Peripapillary sparing was only found in association with mutations in ABCA4, although only present in 40% of such genotypes. Regarding SD-OCT, specific outer retinal abnormalities were more commonly observed in particular genotypes: focal retrofoveal interruption and GUCY2D mutations (50%), foveal sparing and CRX mutations (50%), and outer retinal atrophy associated with hyperreflective dots and ABCA4 mutations (69%). This study outlines the phenotypic heterogeneity of COD/CORDs hampering statistical correlations. A larger study correlating retinal imaging with genetic results is necessary to identify specific clinical features that may help in selecting pathogenic variants generated by high-throughput sequencing.
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Affiliation(s)
- Elise Boulanger-Scemama
- Institut de la Vision, Sorbonne Universités, UPMC Univ Paris 06, INSERM, CNRS, 17 rue Moreau, 75012 Paris, France.
- Fondation Ophtalmologique Adolphe de Rothschild, 75012 Paris, France.
| | - Saddek Mohand-Saïd
- Institut de la Vision, Sorbonne Universités, UPMC Univ Paris 06, INSERM, CNRS, 17 rue Moreau, 75012 Paris, France.
- CHNO des Quinze-Vingts, DHU Sight Restore, INSERM-DHOS CIC1423, 28 rue de Charenton, 75012 Paris, France.
| | - Said El Shamieh
- Institut de la Vision, Sorbonne Universités, UPMC Univ Paris 06, INSERM, CNRS, 17 rue Moreau, 75012 Paris, France.
- Department of Medical Laboratory Sciences, Faculty of Health Sciences, Beirut Arab University, Beirut, Lebanon.
| | - Vanessa Démontant
- Institut de la Vision, Sorbonne Universités, UPMC Univ Paris 06, INSERM, CNRS, 17 rue Moreau, 75012 Paris, France.
| | - Christel Condroyer
- Institut de la Vision, Sorbonne Universités, UPMC Univ Paris 06, INSERM, CNRS, 17 rue Moreau, 75012 Paris, France.
| | - Aline Antonio
- Institut de la Vision, Sorbonne Universités, UPMC Univ Paris 06, INSERM, CNRS, 17 rue Moreau, 75012 Paris, France.
- CHNO des Quinze-Vingts, DHU Sight Restore, INSERM-DHOS CIC1423, 28 rue de Charenton, 75012 Paris, France.
| | - Christelle Michiels
- Institut de la Vision, Sorbonne Universités, UPMC Univ Paris 06, INSERM, CNRS, 17 rue Moreau, 75012 Paris, France.
| | - Fiona Boyard
- Institut de la Vision, Sorbonne Universités, UPMC Univ Paris 06, INSERM, CNRS, 17 rue Moreau, 75012 Paris, France.
| | | | | | - José-Alain Sahel
- Institut de la Vision, Sorbonne Universités, UPMC Univ Paris 06, INSERM, CNRS, 17 rue Moreau, 75012 Paris, France.
- Fondation Ophtalmologique Adolphe de Rothschild, 75012 Paris, France.
- CHNO des Quinze-Vingts, DHU Sight Restore, INSERM-DHOS CIC1423, 28 rue de Charenton, 75012 Paris, France.
- Académie des Sciences-Institut de France, 75006 Paris, France.
- Department of Ophthalmology, The University of Pittsburgh School of Medicine, Pittsburg, PA 15213, USA.
| | - Christina Zeitz
- Institut de la Vision, Sorbonne Universités, UPMC Univ Paris 06, INSERM, CNRS, 17 rue Moreau, 75012 Paris, France.
| | - Isabelle Audo
- Institut de la Vision, Sorbonne Universités, UPMC Univ Paris 06, INSERM, CNRS, 17 rue Moreau, 75012 Paris, France.
- CHNO des Quinze-Vingts, DHU Sight Restore, INSERM-DHOS CIC1423, 28 rue de Charenton, 75012 Paris, France.
- University College London Institute of Ophthalmology, 11-43 Bath Street, London EC1V 9EL, UK.
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Mawatari G, Fujinami K, Liu X, Yang L, Yokokawa YF, Komori S, Ueno S, Terasaki H, Katagiri S, Hayashi T, Kuniyoshi K, Miyake Y, Tsunoda K, Yoshitake K, Iwata T, Nao-i N. Clinical and genetic characteristics of 14 patients from 13 Japanese families with RPGR-associated retinal disorder: report of eight novel variants. Hum Genome Var 2019; 6:34. [PMID: 31645972 PMCID: PMC6804603 DOI: 10.1038/s41439-019-0065-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2019] [Revised: 05/21/2019] [Accepted: 06/30/2019] [Indexed: 01/08/2023] Open
Abstract
Variants in the retinitis pigmentosa GTPase regulator (RPGR) gene are a major cause of X-linked inherited retinal disorder (IRD). We herein describe the clinical and genetic features of 14 patients from 13 Japanese families harboring RPGR variants in a nationwide cohort. Comprehensive ophthalmological examinations were performed to classify the patients into one of the phenotype subgroups: retinitis pigmentosa (RP) and cone rod dystrophy (CORD). The mean age of onset/at examination was 13.8/38.1 years (range, 0-50/11-72), respectively. The mean visual acuity in the right/left eye was 0.43/0.43 (range, 0.1-1.7/-0.08-1.52) LogMAR unit. Eight patients had RP, and six had CORD. Whole-exome sequencing with target analyses identified 13 RPGR variants in 730 families with IRD, including 8 novel variants. An association between the phenotype subgroup and the position of variants (cutoff of amino acid 950) was revealed. To conclude, the clinical and genetic spectrum of RPGR-associated retinal disorder was first illustrated in a Japanese population, with a high proportion of novel variants. These results suggest the distinct genetic background of RPGR in the Japanese population, in which the genotype-phenotype association was affirmed. This evidence should be helpful monitoring and counseling patients and in selecting patients for future therapeutic trials.
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Affiliation(s)
- Go Mawatari
- Department of Ophthalmology, Faculty of Medicine, University of Miyazaki, Kiyotake, Miyazaki, Japan
| | - Kaoru Fujinami
- Laboratory of Visual Physiology, Division of Vision Research, National Institute of Sensory Organs, National Hospital Organization Tokyo Medical Center, Meguro-ku, Tokyo, Japan
- Department of Ophthalmology, Keio University School of Medicine, Tokyo, Japan
- UCL Institute of Ophthalmology, London, UK
- Moorfields Eye Hospital, London, UK
| | - Xiao Liu
- Laboratory of Visual Physiology, Division of Vision Research, National Institute of Sensory Organs, National Hospital Organization Tokyo Medical Center, Meguro-ku, Tokyo, Japan
- Department of Ophthalmology, Keio University School of Medicine, Tokyo, Japan
- Southwest Hospital/Southwest Eye Hospital, Third Military Medical University, Chongqing, China
| | - Lizhu Yang
- Laboratory of Visual Physiology, Division of Vision Research, National Institute of Sensory Organs, National Hospital Organization Tokyo Medical Center, Meguro-ku, Tokyo, Japan
- Department of Ophthalmology, Keio University School of Medicine, Tokyo, Japan
| | - Yu-Fujinami Yokokawa
- Laboratory of Visual Physiology, Division of Vision Research, National Institute of Sensory Organs, National Hospital Organization Tokyo Medical Center, Meguro-ku, Tokyo, Japan
- Graduate School of Health Management, Keio University, Tokyo, Japan
- Division of Public Health, Yokokawa Clinic, Suita, Osaka, Japan
| | - Shiori Komori
- Department of Ophthalmology, Nagoya University Graduate School of Medicine, Showa-ku, Nagoya, Aichi Japan
| | - Shinji Ueno
- Department of Ophthalmology, Nagoya University Graduate School of Medicine, Showa-ku, Nagoya, Aichi Japan
| | - Hiroko Terasaki
- Department of Ophthalmology, Nagoya University Graduate School of Medicine, Showa-ku, Nagoya, Aichi Japan
| | - Satoshi Katagiri
- Department of Ophthalmology, The Jikei University School of Medicine, Nishi-Shimbashi, Minato-ku, Tokyo, Japan
| | - Takaaki Hayashi
- Department of Ophthalmology, The Jikei University School of Medicine, Nishi-Shimbashi, Minato-ku, Tokyo, Japan
| | - Kazuki Kuniyoshi
- Department of Ophthalmology, Kinki University Faculty of Medicine, Osaka-Sayama City, Osaka, Japan
| | - Yozo Miyake
- Laboratory of Visual Physiology, Division of Vision Research, National Institute of Sensory Organs, National Hospital Organization Tokyo Medical Center, Meguro-ku, Tokyo, Japan
- Kobe Eye Center, Next Vision, Kobe, Hyogo, Japan
| | - Kazushige Tsunoda
- Laboratory of Visual Physiology, Division of Vision Research, National Institute of Sensory Organs, National Hospital Organization Tokyo Medical Center, Meguro-ku, Tokyo, Japan
| | - Kazutoshi Yoshitake
- Division of Molecular and Cellular Biology, National Institute of Sensory Organs, National Hospital Organization Tokyo Medical Center, Meguro-ku, Tokyo, Japan
| | - Takeshi Iwata
- Division of Molecular and Cellular Biology, National Institute of Sensory Organs, National Hospital Organization Tokyo Medical Center, Meguro-ku, Tokyo, Japan
| | - Nobuhisa Nao-i
- Department of Ophthalmology, Faculty of Medicine, University of Miyazaki, Kiyotake, Miyazaki, Japan
| | - on behalf of the JEGC study group
- Department of Ophthalmology, Faculty of Medicine, University of Miyazaki, Kiyotake, Miyazaki, Japan
- Laboratory of Visual Physiology, Division of Vision Research, National Institute of Sensory Organs, National Hospital Organization Tokyo Medical Center, Meguro-ku, Tokyo, Japan
- Department of Ophthalmology, Keio University School of Medicine, Tokyo, Japan
- UCL Institute of Ophthalmology, London, UK
- Moorfields Eye Hospital, London, UK
- Southwest Hospital/Southwest Eye Hospital, Third Military Medical University, Chongqing, China
- Graduate School of Health Management, Keio University, Tokyo, Japan
- Division of Public Health, Yokokawa Clinic, Suita, Osaka, Japan
- Department of Ophthalmology, Nagoya University Graduate School of Medicine, Showa-ku, Nagoya, Aichi Japan
- Department of Ophthalmology, The Jikei University School of Medicine, Nishi-Shimbashi, Minato-ku, Tokyo, Japan
- Department of Ophthalmology, Kinki University Faculty of Medicine, Osaka-Sayama City, Osaka, Japan
- Kobe Eye Center, Next Vision, Kobe, Hyogo, Japan
- Division of Molecular and Cellular Biology, National Institute of Sensory Organs, National Hospital Organization Tokyo Medical Center, Meguro-ku, Tokyo, Japan
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Khanna H. More Than Meets the Eye: Current Understanding of RPGR Function. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1074:521-538. [PMID: 29721984 DOI: 10.1007/978-3-319-75402-4_64] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/15/2023]
Abstract
This article summarizes the recent advances in our understanding of a major retinal disease gene RPGR (retinitis pigmentosa GTPase regulator), mutations in which are associated with majority of X-linked forms of retinal degenerations. A great deal of work has been done to uncover the ciliary localization of RPGR and its interacting proteins in the retina. However, the molecular mechanisms of action of RPGR in the photoreceptors are still unclear. Recent studies have begun to shed light on the intracellular pathways in which RPGR is likely involved. The deregulation of such pathways may underlie the pathogenesis of severe retinal degeneration associated with RPGR. With the recent advances in the gene augmentation therapy for RPGR-associated disease, there is a lot of excitement in the field. Patients with RPGR mutations, however, present with clinically heterogeneous manifestations. It is therefore imperative to examine the function of RPGR in detail, so that we can design patient-oriented therapeutic strategies for this disease.
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Affiliation(s)
- Hemant Khanna
- Department of Ophthalmology and Neurobiology, UMASS Medical School, Worcester, MA, USA.
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27
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Wang J, Zhou C, Xiao Y, Liu H. Novel splice receptor-site mutation of RPGR in a Chinese family with X-linked retinitis pigmentosa. Medicine (Baltimore) 2018; 97:e12779. [PMID: 30313097 PMCID: PMC6203575 DOI: 10.1097/md.0000000000012779] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
RATIONALE Retinitis pigmentosa (RP) is a group of clinically and genetically heterogeneous diseases; X-linked retinitis pigmentosa (XLRP) is the most serious type. Mutations in RP GTPase regulator (RPGR) account for over 70% of patients with XLRP. PATIENT CONCERNS We report a Chinese family with RP, 5 males presented with night blindness and decreased vision, and 8 females showed different severities of myopia. DIAGNOSES Targeted exome capture sequencing was performed in 2 affected males, which revealed a novel variant (NM_000328.2, c.470-1G>A) in the RPGR gene. The mis-splicing causes a substitution of the 157th amino acid from glutamic acid to glycine and finally the 165th codon is changed to stop codon, possibly resulting in a truncated protein and/or a nonsense-mediated mRNA decay. The mutation cosegregated with the disease phenotype in the family. INTERVENTIONS Medication and cataract surgery. OUTCOMES The phenotype of affected males is more serious than that of the carrier females, and the effect of clinical treatment is not very well. LESSONS Next-generation sequencing is a suitable method for early detection of pathogenic mutations in RP, which would be helpful for prenatal diagnosis of the disease.
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Affiliation(s)
- Jing Wang
- Department of Obstetrics and Gynecology, West China Second University Hospital
- Key Laboratory of Birth Defects and Related Diseases of Women and Children, Ministry of Education, Sichuan University, Chengdu, China
| | - Cong Zhou
- Department of Obstetrics and Gynecology, West China Second University Hospital
- Key Laboratory of Birth Defects and Related Diseases of Women and Children, Ministry of Education, Sichuan University, Chengdu, China
| | - Yuanyuan Xiao
- Department of Obstetrics and Gynecology, West China Second University Hospital
- Key Laboratory of Birth Defects and Related Diseases of Women and Children, Ministry of Education, Sichuan University, Chengdu, China
| | - Hongqian Liu
- Department of Obstetrics and Gynecology, West China Second University Hospital
- Key Laboratory of Birth Defects and Related Diseases of Women and Children, Ministry of Education, Sichuan University, Chengdu, China
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Wang L, Qi A, Pan H, Liu B, Feng J, Chen W, Wang B. A novel CRX frameshift mutation causing cone-rod dystrophy in a Chinese family: A case report. Medicine (Baltimore) 2018; 97:e11499. [PMID: 30095615 PMCID: PMC6133598 DOI: 10.1097/md.0000000000011499] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/29/2018] [Accepted: 06/20/2018] [Indexed: 01/22/2023] Open
Abstract
BACKGROUND Cone-rod dystrophy (CORD) is an inherited, progressive retinal disorder with genetic and phenotypic heterogeneity. Here, we aimed to identify the pathogenic mutation in affected individuals in a Chinese family with autosomal dominant cone-rod dystrophy (adCORD). METHODS Genomic DNA and clinical examination results were collected from a Chinese family presenting with adCORD. The candidate disease-causing mutations were screened with whole-exome sequencing (WES) and bioinformatics analyses. Sanger sequencing was used for validation and cosegregation analysis. RESULTS A novel frameshift mutation (NM_000554.4; c.538dupG:p.Val180fs) in exon 4 of the CRX gene was identified in all affected individuals in the Chinese family with adCORD. Cosegregation analysis confirmed that this mutation was cosegregated with the disease. This variant, which results in premature termination of the protein, was absent from all public variant databases or internal exome databases. CONCLUSIONS We used whole-exome sequencing to identify a novel CRX mutation causing adCORD in a Chinese family. This study broadens the known pathogenic mutation spectrum of the CRX gene and shows the potential of WES in identifying the pathogenic mutations of CORD disease.
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Affiliation(s)
- Lihua Wang
- Department of Ophthalmology, Beijing Haidian Maternal and Child Health Hospital
| | - Anhui Qi
- Graduate School of Peking Union Medical College
- Center for Genetics, National Research Institute for Family Planning, Beijing, China
| | - Hong Pan
- Graduate School of Peking Union Medical College
- Center for Genetics, National Research Institute for Family Planning, Beijing, China
| | - Beihong Liu
- Graduate School of Peking Union Medical College
- Center for Genetics, National Research Institute for Family Planning, Beijing, China
| | - Jingjing Feng
- Department of Ophthalmology, Beijing Haidian Maternal and Child Health Hospital
| | - Wei Chen
- Department of Ophthalmology, Beijing Haidian Maternal and Child Health Hospital
| | - Binbin Wang
- Graduate School of Peking Union Medical College
- Center for Genetics, National Research Institute for Family Planning, Beijing, China
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29
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Clinical and genetic characteristics of 251 consecutive patients with macular and cone/cone-rod dystrophy. Sci Rep 2018; 8:4824. [PMID: 29555955 PMCID: PMC5859282 DOI: 10.1038/s41598-018-22096-0] [Citation(s) in RCA: 150] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2017] [Accepted: 02/16/2018] [Indexed: 12/14/2022] Open
Abstract
Macular and cone/cone-rod dystrophies (MD/CCRD) demonstrate a broad genetic and phenotypic heterogeneity, with retinal alterations solely or predominantly involving the central retina. Targeted next-generation sequencing (NGS) is an efficient diagnostic tool for identifying mutations in patient with retinitis pigmentosa, which shows similar genetic heterogeneity. To detect the genetic causes of disease in patients with MD/CCRD, we implemented a two-tier procedure consisting of Sanger sequencing and targeted NGS including genes associated with clinically overlapping conditions. Disease-causing mutations were identified in 74% of 251 consecutive MD/CCRD patients (33% of the variants were novel). Mutations in ABCA4, PRPH2 and BEST1 accounted for 57% of disease cases. Further mutations were identified in CDHR1, GUCY2D, PROM1, CRX, GUCA1A, CERKL, MT-TL1, KIF11, RP1L1, MERTK, RDH5, CDH3, C1QTNF5, CRB1, JAG1, DRAM2, POC1B, NPHP1 and RPGR. We provide detailed illustrations of rare phenotypes, including autofluorescence and optical coherence tomography imaging. Targeted NGS also identified six potential novel genotype-phenotype correlations for FAM161A, INPP5E, MERTK, FBLN5, SEMA4A and IMPDH1. Clinical reassessment of genetically unsolved patients revealed subgroups with similar retinal phenotype, indicating a common molecular disease cause in each subgroup.
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30
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Martinez-Fernandez De La Camara C, Nanda A, Salvetti AP, Fischer MD, MacLaren RE. Gene therapy for the treatment of X-linked retinitis pigmentosa. Expert Opin Orphan Drugs 2018; 6:167-177. [PMID: 30057863 PMCID: PMC6059358 DOI: 10.1080/21678707.2018.1444476] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
INTRODUCTION X-linked retinitis pigmentosa caused by mutations in the retinitis pigmentosa GTPase regulator (RPGR) gene is the most common form of recessive RP. The phenotype is characterised by its severity and rapid disease progression. Gene therapy using adeno-associated viral vectors is currently the most promising therapeutic approach. However, the construction of a stable vector encoding the full-length RPGR transcript has previously proven to be a limiting step towards gene therapy clinical trials. Recently however, a codon optimised version of RPGR has been shown to increase the stability and fidelity of the sequence, conferring a therapeutic effect in murine and canine animal models. AREAS COVERED This manuscript reviews the natural history of X-linked retinitis pigmentosa and the research performed from the discovery of the causative gene, RPGR, to the preclinical testing of potential therapies that have led to the initiation of three clinical trials. EXPERT OPINION X-linked retinitis pigmentosa is an amenable disease to be treated by gene therapy. Codon optimisation has overcome the challenge of designing an RPGR vector without mutations, and with a therapeutic effect in different animal models. With the RPGR gene therapy clinical trials still in the early stages, the confirmation of the safety, tolerability and potency of the therapy is still ongoing.
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Affiliation(s)
| | - Anika Nanda
- Nuffield Laboratory of Ophthalmology, Department of Clinical Neurosciences, John Radcliffe Hospital, Oxford, UK
- Oxford Eye Hospital, Oxford University Hospitals NHS Trust, John Radcliffe Hospital, Oxford, UK
| | - Anna Paola Salvetti
- Nuffield Laboratory of Ophthalmology, Department of Clinical Neurosciences, John Radcliffe Hospital, Oxford, UK
- Department of Biomedical and Clinical Sciences “Luigi Sacco”, Sacco Hospital, University of Milan, Milano, Italy
| | - M. Dominik Fischer
- Nuffield Laboratory of Ophthalmology, Department of Clinical Neurosciences, John Radcliffe Hospital, Oxford, UK
- Centre for Ophthalmology Tübingen, University Eye Hospital, Tübingen, Germany
| | - Robert E. MacLaren
- Nuffield Laboratory of Ophthalmology, Department of Clinical Neurosciences, John Radcliffe Hospital, Oxford, UK
- Oxford Eye Hospital, Oxford University Hospitals NHS Trust, John Radcliffe Hospital, Oxford, UK
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31
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Li J, Zhang Q. Insight into the molecular genetics of myopia. Mol Vis 2017; 23:1048-1080. [PMID: 29386878 PMCID: PMC5757860] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2017] [Accepted: 12/29/2017] [Indexed: 11/18/2022] Open
Abstract
Myopia is the most common cause of visual impairment worldwide. Genetic and environmental factors contribute to the development of myopia. Studies on the molecular genetics of myopia are well established and have implicated the important role of genetic factors. With linkage analysis, association studies, sequencing analysis, and experimental myopia studies, many of the loci and genes associated with myopia have been identified. Thus far, there has been no systemic review of the loci and genes related to non-syndromic and syndromic myopia based on the different approaches. Such a systemic review of the molecular genetics of myopia will provide clues to identify additional plausible genes for myopia and help us to understand the molecular mechanisms underlying myopia. This paper reviews recent genetic studies on myopia, summarizes all possible reported genes and loci related to myopia, and suggests implications for future studies on the molecular genetics of myopia.
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Affiliation(s)
- Jiali Li
- 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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32
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Jensen VL, Leroux MR. Gates for soluble and membrane proteins, and two trafficking systems (IFT and LIFT), establish a dynamic ciliary signaling compartment. Curr Opin Cell Biol 2017; 47:83-91. [PMID: 28432921 DOI: 10.1016/j.ceb.2017.03.012] [Citation(s) in RCA: 60] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2017] [Revised: 02/18/2017] [Accepted: 03/21/2017] [Indexed: 12/28/2022]
Abstract
Primary cilia are microtubule-based organelles found on most mammalian cell surfaces. They possess a soluble matrix and membrane contiguous with the cell body cytosol and plasma membrane, and yet, have distinct compositions that can be modulated to enable dynamic signal transduction. Here, we discuss how specialized ciliary compartments are established using a coordinated network of gating, trafficking and targeting activities. Cilium homeostasis is maintained by a size-selective molecular mesh that limits soluble protein entry, and by a membrane diffusion barrier localized at the transition zone. Bidirectional protein shuttling between the cell body and cilium uses IntraFlagellar Transport (IFT), and prenylated ciliary protein delivery is achieved through Lipidated protein IntraFlagellar Targeting (LIFT). Elucidating how these gates and transport systems function will help reveal the roles that cilia play in ciliary signaling and the growing spectrum of disorders termed ciliopathies.
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Affiliation(s)
- Victor L Jensen
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, Canada; Centre for Cell Biology, Development and Disease, Simon Fraser University, Burnaby, Canada
| | - Michel R Leroux
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, Canada; Centre for Cell Biology, Development and Disease, Simon Fraser University, Burnaby, Canada.
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Analysis of RP2 and RPGR Mutations in Five X-Linked Chinese Families with Retinitis Pigmentosa. Sci Rep 2017; 7:44465. [PMID: 28294154 PMCID: PMC5353642 DOI: 10.1038/srep44465] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2016] [Accepted: 02/08/2017] [Indexed: 11/08/2022] Open
Abstract
Mutations in RP2 and RPGR genes are responsible for the X-linked retinitis pigmentosa (XLRP). In this study, we analyzed the RP2 and RPGR gene mutations in five Han Chinese families with XLRP. An approximately 17Kb large deletion including the exon 4 and exon 5 of RP2 gene was found in an XLRP family. In addition, four frameshift mutations including three novel mutations of c.1059 + 1 G > T, c.2002dupC and c.2236_2237del CT, as well as a previously reported mutation of c.2899delG were detected in the RPGR gene in the other four families. Our study further expands the mutation spectrum of RP2 and RPGR, and will be helpful for further study molecular pathogenesis of XLRP.
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Identification of novel X-linked gain-of-function RPGR-ORF15 mutation in Italian family with retinitis pigmentosa and pathologic myopia. Sci Rep 2016; 6:39179. [PMID: 27995965 PMCID: PMC5171904 DOI: 10.1038/srep39179] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2016] [Accepted: 11/18/2016] [Indexed: 11/09/2022] Open
Abstract
The aim of this study was to describe a new pathogenic variant in the mutational hot spot exon ORF15 of retinitis pigmentosa GTPase regulator (RPGR) gene within an Italian family with X-linked retinitis pigmentosa (RP), detailing its distinctive genotype-phenotype correlation with pathologic myopia (PM). All members of this RP-PM family underwent a complete ophthalmic examination. The entire open reading frames of RPGR and retinitis pigmentosa 2 genes were analyzed by Sanger sequencing. A novel frame-shift mutation in exon ORF15 of RPGR gene (c.2091_2092insA; p.A697fs) was identified as hemizygous variant in the male proband with RP, and as heterozygous variant in the females of this pedigree who invariably exhibited symmetrical PM in both eyes. The c.2091_2092insA mutation coherently co-segregated with the observed phenotypes. These findings expand the spectrum of X-linked RP variants. Interestingly, focusing on Caucasian ethnicity, just three RPGR mutations are hitherto reported in RP-PM families: one of these is located in exon ORF15, but none appears to be characterized by a high penetrance of PM trait as observed in the present, relatively small, pedigree. The geno-phenotypic attributes of this heterozygosity suggest that gain-of-function mechanism could give rise to PM via a degenerative cell-cell remodeling of the retinal structures.
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Charng J, Cideciyan AV, Jacobson SG, Sumaroka A, Schwartz SB, Swider M, Roman AJ, Sheplock R, Anand M, Peden MC, Khanna H, Heon E, Wright AF, Swaroop A. Variegated yet non-random rod and cone photoreceptor disease patterns in RPGR-ORF15-associated retinal degeneration. Hum Mol Genet 2016; 25:5444-5459. [PMID: 27798110 PMCID: PMC6078602 DOI: 10.1093/hmg/ddw361] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2016] [Revised: 10/16/2016] [Accepted: 10/18/2016] [Indexed: 12/13/2022] Open
Abstract
Mutations in the ORF15 exon of the RPGR gene cause a common form of X-linked retinitis pigmentosa, which often results in severe loss of vision. In dogs and mice, gene augmentation therapy has been shown to arrest the progressive degeneration of rod and cone photoreceptors. However, the distribution of potentially treatable photoreceptors across the human retinas and the rate of degeneration are not known. Here, we have defined structural and functional features of the disease in 70 individuals with ORF15 mutations. We also correlated the features observed in patients with those of three Rpgr-mutant (Rpgr-ko, Rd9, and Rpgr-cko) mice. In patients, there was pronounced macular disease. Across the retina, rod and cone dysfunction showed a range of patterns and a spectrum of severity between individuals, but a high symmetry was observed between eyes of each individual. Genotype was not related to disease expression. In the Rpgr-ko mice, there were intra-retinal differences in rhodopsin and cone opsin trafficking. In Rd9 and Rpgr-cko mice, retinal degeneration showed inter-ocular symmetry. Longitudinal results in patients revealed localized rod and cone dysfunction with progression rates of 0.8 to 1.3 log per decade in sensitivity loss. Relatively retained rod and cone photoreceptors in mid- and far-peripheral temporal-inferior and nasal-inferior visual field regions should be good targets for future localized gene therapies in patients.
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Affiliation(s)
- Jason Charng
- Scheie Eye Institute, Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, PA, USA
| | - Artur V. Cideciyan
- Scheie Eye Institute, Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, PA, USA
| | - Samuel G. Jacobson
- Scheie Eye Institute, Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, PA, USA
| | - Alexander Sumaroka
- Scheie Eye Institute, Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, PA, USA
| | - Sharon B. Schwartz
- Scheie Eye Institute, Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, PA, USA
| | - Malgorzata Swider
- Scheie Eye Institute, Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, PA, USA
| | - Alejandro J. Roman
- Scheie Eye Institute, Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, PA, USA
| | - Rebecca Sheplock
- Scheie Eye Institute, Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, PA, USA
| | - Manisha Anand
- Department of Ophthalmology, University of Massachusetts Medical School, Worcester, Massachusetts, MA, USA
| | - Marc C. Peden
- Retina Associates of Florida, Tampa, Florida, FL, USA
| | - Hemant Khanna
- Department of Ophthalmology, University of Massachusetts Medical School, Worcester, Massachusetts, MA, USA
| | - Elise Heon
- Department of Ophthalmology and Vision Sciences, The Hospital for Sick Children, University of Toronto, Toronto, Canada
| | - Alan F. Wright
- MRC Human Genetics Unit, MRC IGMM, University of Edinburgh, Edinburgh, Scotland, UK
| | - Anand Swaroop
- Neurobiology-Neurodegeneration & Repair Laboratory, National Eye Institute, National Institutes of Health, Bethesda, Maryland, MD, USA
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Dutta N, Seo S. RPGR, a prenylated retinal ciliopathy protein, is targeted to cilia in a prenylation- and PDE6D-dependent manner. Biol Open 2016; 5:1283-9. [PMID: 27493202 PMCID: PMC5051646 DOI: 10.1242/bio.020461] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
RPGR (retinitis pigmentosa GTPase regulator) is a ciliary protein associated with several forms of inherited retinal degenerative diseases. PDE6D is a ubiquitously expressed prenyl-binding protein and involved in ciliary targeting of prenylated proteins. The current working model for the RPGR function depicts that RPGR acts as a scaffold protein to recruit cargo-loaded PDE6D to primary cilia. Here, we present evidence demonstrating an alternative relationship between RPGR and PDE6D, in which RPGR is a cargo of PDE6D for ciliary targeting. We found that the constitutive isoform of RPGR, which is prenylated, requires prenylation for its ciliary localization. We also found that there are at least two independent ciliary targeting signals in RPGR: one within the N-terminal region that contains the RCC1-like domain and the other near the prenylation site at the C-terminus. Ablation of PDE6D blocked ciliary targeting of RPGR. Our study indicates that prenylated RPGR is one of the cargos of PDE6D for ciliary trafficking and provides insight into the mechanisms by which RPGR is targeted to cilia. Summary: RPGR is a ciliary protein that functions as a scaffold to recruit cargo-loaded PDE6D to cilia. Our study shows that RPGR is also a cargo of PDE6D.
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Affiliation(s)
- Nirmal Dutta
- Department of Ophthalmology and Visual Sciences, University of Iowa College of Medicine, Iowa City, IA 52242, USA
| | - Seongjin Seo
- Department of Ophthalmology and Visual Sciences, University of Iowa College of Medicine, Iowa City, IA 52242, USA
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37
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Tee JJL, Smith AJ, Hardcastle AJ, Michaelides M. RPGR-associated retinopathy: clinical features, molecular genetics, animal models and therapeutic options. Br J Ophthalmol 2016; 100:1022-7. [PMID: 26843488 DOI: 10.1136/bjophthalmol-2015-307698] [Citation(s) in RCA: 64] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2015] [Accepted: 01/02/2016] [Indexed: 11/04/2022]
Abstract
Retinitis pigmentosa GTPase regulator (RPGR) gene sequence variants account for the vast majority of X linked retinitis pigmentosa (RP), which is one of the most severe forms of RP. Symptoms of nyctalopia typically begin in childhood, with increasing loss of peripheral visual field during teenage years, and progressive central visual loss during the second to fourth decade of life. There is however marked intrafamilial and interfamilial phenotypic heterogeneity in affected males and carrier females. There is now a far greater understanding of the range of phenotypes associated with variants in this gene; including rod-cone dystrophy, cone-rod dystrophy, cone dystrophy, macular dystrophy and non-ocular phenotypes. There are also increasingly established genotype-phenotype associations and structure-function correlations. RPGR is involved in ciliary function, with ciliary dysfunction now recognised as the mechanism underlying a large proportion of inherited retinal disease. There has been significant progress in identifying naturally occurring animal models and developing novel models to define the underlying disease mechanisms and to test gene replacement therapy, in addition to advances in human retinal imaging, culminating in completed and planned clinical trials. These significant developments will be discussed.
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Affiliation(s)
- James J L Tee
- UCL Institute of Ophthalmology, University College London, London, UK Moorfields Eye Hospital, London, UK
| | - Alexander J Smith
- UCL Institute of Ophthalmology, University College London, London, UK Moorfields Eye Hospital, London, UK
| | - Alison J Hardcastle
- UCL Institute of Ophthalmology, University College London, London, UK Moorfields Eye Hospital, London, UK
| | - Michel Michaelides
- UCL Institute of Ophthalmology, University College London, London, UK Moorfields Eye Hospital, London, UK
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38
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Rao KN, Li L, Zhang W, Brush RS, Rajala RVS, Khanna H. Loss of human disease protein retinitis pigmentosa GTPase regulator (RPGR) differentially affects rod or cone-enriched retina. Hum Mol Genet 2016; 25:1345-56. [PMID: 26908598 DOI: 10.1093/hmg/ddw017] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2015] [Accepted: 01/18/2016] [Indexed: 01/13/2023] Open
Abstract
It is unclear how genes, such as RPGR (retinitis pigmentosa guanine triphosphatase regulator) that are expressed in both rods and cones, cause variable disease pathogenesis. Using transcriptomic analysis, we show that loss of RPGR in a rod-dominant mouse retina (Rpgr(ko)) results in predominant alterations in genes involved in actin cytoskeletal dynamics, prior to onset of degeneration. We validated these findings and found an increase in activated RhoA-GTP levels and polymerized F-actin in the Rpgr(ko) mouse retina. To assess the effect of the loss of RPGR in the all-cone region of the human retina, we used Nrl(-/-) (neural retina leucine zipper) mice, to generate Rpgr(ko)::Nrl(-/-) double-knock-out (Rpgr-DKO) mice. These mice exhibited supranormal cone response to light and substantially retained retinal architecture. Transcriptomic analysis revealed predominant up-regulation of retinal pigmented epithelium (RPE)-specific genes associated with visual cycle, whereas fatty acid analysis showed mild decrease in docosahexaenoic acid in the retina of the Rpgr-DKO mice when compared with the Nrl(-/-) mice. Our data reveal new insights into distinct intracellular pathways that are involved in RPGR-associated rod and cone dysfunction and provide a platform to design new treatment modalities.
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Affiliation(s)
- Kollu N Rao
- Department of Ophthalmology, University of Massachusetts Medical School, 368 Plantation St, Albert Sherman Center AS6-2043, Worcester, MA 01605, USA and
| | - Linjing Li
- Department of Ophthalmology, University of Massachusetts Medical School, 368 Plantation St, Albert Sherman Center AS6-2043, Worcester, MA 01605, USA and
| | - Wei Zhang
- Department of Ophthalmology, University of Massachusetts Medical School, 368 Plantation St, Albert Sherman Center AS6-2043, Worcester, MA 01605, USA and
| | - Richard S Brush
- University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
| | - Raju V S Rajala
- University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
| | - Hemant Khanna
- Department of Ophthalmology, University of Massachusetts Medical School, 368 Plantation St, Albert Sherman Center AS6-2043, Worcester, MA 01605, USA and
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Lu QK, Zhao N, Lv YS, Gong WK, Wang HY, Tong QH, Lai XM, Liu RR, Fang MY, Zhang JG, Du ZF, Zhang XN. A novel CRX mutation by whole-exome sequencing in an autosomal dominant cone-rod dystrophy pedigree. Int J Ophthalmol 2015; 8:1112-7. [PMID: 26682157 DOI: 10.3980/j.issn.2222-3959.2015.06.06] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2015] [Accepted: 03/30/2015] [Indexed: 11/02/2022] Open
Abstract
AIM To identify the disease-causing gene mutation in a Chinese pedigree with autosomal dominant cone-rod dystrophy (adCORD). METHODS A southern Chinese adCORD pedigree including 9 affected individuals was studied. Whole-exome sequencing (WES), coupling the Agilent whole-exome capture system to the Illumina HiSeq 2000 DNA sequencing platform was used to search the specific gene mutation in 3 affected family members and 1 unaffected member. After a suggested variant was found through the data analysis, the putative mutation was validated by Sanger DNA sequencing of samples from all available family members. RESULTS The results of both WES and Sanger sequencing revealed a novel nonsense mutation c.C766T (p.Q256X) within exon 5 of CRX gene which was pathogenic for adCORD in this family. The mutation could affect photoreceptor-specific gene expression with a dominant-negative effect and resulted in loss of the OTX tail, thus the mutant protein occupies the CRX-binding site in target promoters without establishing an interaction and, consequently, may block transactivation. CONCLUSION All modes of Mendelian inheritance in CORD have been observed, and genetic heterogeneity is a hallmark of CORD. Therefore, conventional genetic diagnosis of CORD would be time-consuming and labor-intensive. Our study indicated the robustness and cost-effectiveness of WES in the genetic diagnosis of CORD.
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Affiliation(s)
- Qin-Kang Lu
- Ophthalmology Center, Yinzhou People's Hospital, Yinzhou Hospital Affiliated to Medical School of Ningbo University, Ningbo 315040, Zhejiang Province, China
| | - Na Zhao
- Ophthalmology Center, Yinzhou People's Hospital, Yinzhou Hospital Affiliated to Medical School of Ningbo University, Ningbo 315040, Zhejiang Province, China
| | - Ya-Su Lv
- Department of Cell Biology and Medical Genetics, Research Center for Molecular Medicine, Institute of Cell Biology, Zhejiang University School of Medicine, Hangzhou 310058, Zhejiang Province, China
| | - Wei-Kun Gong
- Ophthalmology Center, Yinzhou People's Hospital, Yinzhou Hospital Affiliated to Medical School of Ningbo University, Ningbo 315040, Zhejiang Province, China
| | - Hui-Yun Wang
- Ophthalmology Center, Yinzhou People's Hospital, Yinzhou Hospital Affiliated to Medical School of Ningbo University, Ningbo 315040, Zhejiang Province, China
| | - Qi-Hu Tong
- Ophthalmology Center, Yinzhou People's Hospital, Yinzhou Hospital Affiliated to Medical School of Ningbo University, Ningbo 315040, Zhejiang Province, China
| | - Xiao-Ming Lai
- Ophthalmology Center, Yinzhou People's Hospital, Yinzhou Hospital Affiliated to Medical School of Ningbo University, Ningbo 315040, Zhejiang Province, China
| | - Rong-Rong Liu
- Department of Cell Biology and Medical Genetics, Research Center for Molecular Medicine, Institute of Cell Biology, Zhejiang University School of Medicine, Hangzhou 310058, Zhejiang Province, China
| | - Ming-Yan Fang
- BGI-Shenzhen, Shenzhen 518083, Guangdong Province, China
| | - Jian-Guo Zhang
- BGI-Shenzhen, Shenzhen 518083, Guangdong Province, China
| | - Zhen-Fang Du
- Department of Cell Biology and Medical Genetics, Research Center for Molecular Medicine, Institute of Cell Biology, Zhejiang University School of Medicine, Hangzhou 310058, Zhejiang Province, China
| | - Xian-Ning Zhang
- Department of Cell Biology and Medical Genetics, Research Center for Molecular Medicine, Institute of Cell Biology, Zhejiang University School of Medicine, Hangzhou 310058, Zhejiang Province, China
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Veleri S, Lazar CH, Chang B, Sieving PA, Banin E, Swaroop A. Biology and therapy of inherited retinal degenerative disease: insights from mouse models. Dis Model Mech 2015; 8:109-29. [PMID: 25650393 PMCID: PMC4314777 DOI: 10.1242/dmm.017913] [Citation(s) in RCA: 179] [Impact Index Per Article: 19.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Retinal neurodegeneration associated with the dysfunction or death of photoreceptors is a major cause of incurable vision loss. Tremendous progress has been made over the last two decades in discovering genes and genetic defects that lead to retinal diseases. The primary focus has now shifted to uncovering disease mechanisms and designing treatment strategies, especially inspired by the successful application of gene therapy in some forms of congenital blindness in humans. Both spontaneous and laboratory-generated mouse mutants have been valuable for providing fundamental insights into normal retinal development and for deciphering disease pathology. Here, we provide a review of mouse models of human retinal degeneration, with a primary focus on diseases affecting photoreceptor function. We also describe models associated with retinal pigment epithelium dysfunction or synaptic abnormalities. Furthermore, we highlight the crucial role of mouse models in elucidating retinal and photoreceptor biology in health and disease, and in the assessment of novel therapeutic modalities, including gene- and stem-cell-based therapies, for retinal degenerative diseases.
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Affiliation(s)
- Shobi Veleri
- Neurobiology-Neurodegeneration and Repair Laboratory, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Csilla H Lazar
- Neurobiology-Neurodegeneration and Repair Laboratory, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA. Molecular Biology Center, Interdisciplinary Research Institute on Bio-Nano Sciences, Babes-Bolyai-University, Cluj-Napoca, 400271, Romania
| | - Bo Chang
- The Jackson Laboratory, Bar Harbor, ME 04609, USA
| | - Paul A Sieving
- National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Eyal Banin
- Neurobiology-Neurodegeneration and Repair Laboratory, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA. Center for Retinal and Macular Degenerations, Department of Ophthalmology, Hadassah-Hebrew University Medical Center, Jerusalem 91120, Israel
| | - Anand Swaroop
- Neurobiology-Neurodegeneration and Repair Laboratory, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA.
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41
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Photoreceptor rescue by an abbreviated human RPGR gene in a murine model of X-linked retinitis pigmentosa. Gene Ther 2015; 23:196-204. [PMID: 26348595 PMCID: PMC4863462 DOI: 10.1038/gt.2015.93] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2015] [Revised: 07/05/2015] [Accepted: 08/21/2015] [Indexed: 11/08/2022]
Abstract
The X-linked RP3 gene codes for the ciliary protein RPGR and accounts for over 10% of inherited retinal degenerations. The critical RPGR-ORF15 splice variant contains a highly repetitive purine-rich linker region that renders it unstable and difficult to adapt for gene therapy. To test the hypothesis that the precise length of the linker region is not critical for function, we evaluated whether AAV-mediated replacement gene therapy with a human ORF15 variant containing in-frame shortening of the linker region could reconstitute RPGR function in vivo. We delivered human RPGR-ORF15 replacement genes with deletion of most (314-codons, “short form”) or 1/3 (126-codons, “long form”) of the linker region to Rpgr null mice. Human RPGR-ORF15 expression was detected post-treatment with both forms of ORF15 transgenes. However, only the long form correctly localized to the connecting cilia and led to significant functional and morphological rescue of rods and cones. Thus the highly repetitive region of RPGR is functionally important but that moderate shortening of its length, which confers the advantage of added stability, preserves its function. These findings provide a theoretical basis for optimizing replacement gene design in clinical trials for X-linked RP3.
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Boulanger-Scemama E, El Shamieh S, Démontant V, Condroyer C, Antonio A, Michiels C, Boyard F, Saraiva JP, Letexier M, Souied E, Mohand-Saïd S, Sahel JA, Zeitz C, Audo I. Next-generation sequencing applied to a large French cone and cone-rod dystrophy cohort: mutation spectrum and new genotype-phenotype correlation. Orphanet J Rare Dis 2015; 10:85. [PMID: 26103963 PMCID: PMC4566196 DOI: 10.1186/s13023-015-0300-3] [Citation(s) in RCA: 79] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2014] [Accepted: 06/15/2015] [Indexed: 12/21/2022] Open
Abstract
Background Cone and cone-rod dystrophies are clinically and genetically heterogeneous inherited retinal disorders with predominant cone impairment. They should be distinguished from the more common group of rod-cone dystrophies (retinitis pigmentosa) due to their more severe visual prognosis with early central vision loss. The purpose of our study was to document mutation spectrum of a large French cohort of cone and cone-rod dystrophies. Methods We applied Next-Generation Sequencing targeting a panel of 123 genes implicated in retinal diseases to 96 patients. A systematic filtering approach was used to identify likely disease causing variants, subsequently confirmed by Sanger sequencing and co-segregation analysis when possible. Results Overall, the likely causative mutations were detected in 62.1 % of cases, revealing 33 known and 35 novel mutations. This rate was higher for autosomal dominant (100 %) than autosomal recessive cases (53.8 %). Mutations in ABCA4 and GUCY2D were responsible for 19.2 % and 29.4 % of resolved cases with recessive and dominant inheritance, respectively. Furthermore, unexpected genotype-phenotype correlations were identified, confirming the complexity of inherited retinal disorders with phenotypic overlap between cone-rod dystrophies and other retinal diseases. Conclusions In summary, this time-efficient approach allowed mutation detection in the most important cohort of cone-rod dystrophies investigated so far covering the largest number of genes. Association of known gene defects with novel phenotypes and mode of inheritance were established. Electronic supplementary material The online version of this article (doi:10.1186/s13023-015-0300-3) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Elise Boulanger-Scemama
- INSERM, U968, Paris, F-75012, France.,Institut de la Vision, Sorbonne Universités, UPMC Univ Paris 06, UMR_S 968, 17, rue Moreau, Paris, F-75012, France.,CNRS, UMR_7210, Paris, F-75012, France
| | - Said El Shamieh
- INSERM, U968, Paris, F-75012, France.,Institut de la Vision, Sorbonne Universités, UPMC Univ Paris 06, UMR_S 968, 17, rue Moreau, Paris, F-75012, France.,CNRS, UMR_7210, Paris, F-75012, France
| | - Vanessa Démontant
- INSERM, U968, Paris, F-75012, France.,Institut de la Vision, Sorbonne Universités, UPMC Univ Paris 06, UMR_S 968, 17, rue Moreau, Paris, F-75012, France.,CNRS, UMR_7210, Paris, F-75012, France
| | - Christel Condroyer
- INSERM, U968, Paris, F-75012, France.,Institut de la Vision, Sorbonne Universités, UPMC Univ Paris 06, UMR_S 968, 17, rue Moreau, Paris, F-75012, France.,CNRS, UMR_7210, Paris, F-75012, France
| | - Aline Antonio
- INSERM, U968, Paris, F-75012, France.,Institut de la Vision, Sorbonne Universités, UPMC Univ Paris 06, UMR_S 968, 17, rue Moreau, Paris, F-75012, France.,CNRS, UMR_7210, Paris, F-75012, France.,Centre Hospitalier National d'Ophtalmologie des Quinze-Vingts, DHU ViewMaintain, INSERM-DHOS CIC 1423, Paris, F-75012, France
| | - Christelle Michiels
- INSERM, U968, Paris, F-75012, France.,Institut de la Vision, Sorbonne Universités, UPMC Univ Paris 06, UMR_S 968, 17, rue Moreau, Paris, F-75012, France.,CNRS, UMR_7210, Paris, F-75012, France
| | - Fiona Boyard
- INSERM, U968, Paris, F-75012, France.,Institut de la Vision, Sorbonne Universités, UPMC Univ Paris 06, UMR_S 968, 17, rue Moreau, Paris, F-75012, France.,CNRS, UMR_7210, Paris, F-75012, France
| | - Jean-Paul Saraiva
- IntegraGen SA, Genopole CAMPUS 1 bat G8 FR-91030 EVRY, Paris, France
| | - Mélanie Letexier
- IntegraGen SA, Genopole CAMPUS 1 bat G8 FR-91030 EVRY, Paris, France
| | - Eric Souied
- Centre Hospitalier Intercommunal de Créteil, Department of Ophthalmology, Université Paris-Est Créteil, 94000, Créteil, France
| | - Saddek Mohand-Saïd
- INSERM, U968, Paris, F-75012, France.,Institut de la Vision, Sorbonne Universités, UPMC Univ Paris 06, UMR_S 968, 17, rue Moreau, Paris, F-75012, France.,CNRS, UMR_7210, Paris, F-75012, France.,Centre Hospitalier National d'Ophtalmologie des Quinze-Vingts, DHU ViewMaintain, INSERM-DHOS CIC 1423, Paris, F-75012, France
| | - José-Alain Sahel
- INSERM, U968, Paris, F-75012, France.,Institut de la Vision, Sorbonne Universités, UPMC Univ Paris 06, UMR_S 968, 17, rue Moreau, Paris, F-75012, France.,CNRS, UMR_7210, Paris, F-75012, France.,Centre Hospitalier National d'Ophtalmologie des Quinze-Vingts, DHU ViewMaintain, INSERM-DHOS CIC 1423, Paris, F-75012, France.,Fondation Ophtalmologique Adolphe de Rothschild, 75019, Paris, France.,Académie des Sciences-Institut de France, 75006, Paris, France.,University College London Institute of Ophthalmology, 11-43 Bath Street, London, EC1V 9EL, UK
| | - Christina Zeitz
- INSERM, U968, Paris, F-75012, France. .,Institut de la Vision, Sorbonne Universités, UPMC Univ Paris 06, UMR_S 968, 17, rue Moreau, Paris, F-75012, France. .,CNRS, UMR_7210, Paris, F-75012, France.
| | - Isabelle Audo
- INSERM, U968, Paris, F-75012, France. .,Institut de la Vision, Sorbonne Universités, UPMC Univ Paris 06, UMR_S 968, 17, rue Moreau, Paris, F-75012, France. .,CNRS, UMR_7210, Paris, F-75012, France. .,Centre Hospitalier National d'Ophtalmologie des Quinze-Vingts, DHU ViewMaintain, INSERM-DHOS CIC 1423, Paris, F-75012, France. .,University College London Institute of Ophthalmology, 11-43 Bath Street, London, EC1V 9EL, UK.
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Nash BM, Wright DC, Grigg JR, Bennetts B, Jamieson RV. Retinal dystrophies, genomic applications in diagnosis and prospects for therapy. Transl Pediatr 2015; 4:139-63. [PMID: 26835369 PMCID: PMC4729094 DOI: 10.3978/j.issn.2224-4336.2015.04.03] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Retinal dystrophies (RDs) are degenerative diseases of the retina which have marked clinical and genetic heterogeneity. Common presentations among these disorders include night or colour blindness, tunnel vision and subsequent progression to complete blindness. The known causative disease genes have a variety of developmental and functional roles with mutations in more than 120 genes shown to be responsible for the phenotypes. In addition, mutations within the same gene have been shown to cause different disease phenotypes, even amongst affected individuals within the same family highlighting further levels of complexity. The known disease genes encode proteins involved in retinal cellular structures, phototransduction, the visual cycle, and photoreceptor structure or gene regulation. This review aims to demonstrate the high degree of genetic complexity in both the causative disease genes and their associated phenotypes, highlighting the more common clinical manifestation of retinitis pigmentosa (RP). The review also provides insight to recent advances in genomic molecular diagnosis and gene and cell-based therapies for the RDs.
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Affiliation(s)
- Benjamin M Nash
- 1 Eye Genetics Research Group, Children's Medical Research Institute, University of Sydney, The Children's Hospital at Westmead and Save Sight Institute, Sydney, NSW, Australia ; 2 Sydney Genome Diagnostics, The Children's Hospital at Westmead, Sydney, NSW, Australia ; 3 Discipline of Paediatrics and Child Health, Sydney Medical School, University of Sydney, NSW, Australia
| | - Dale C Wright
- 1 Eye Genetics Research Group, Children's Medical Research Institute, University of Sydney, The Children's Hospital at Westmead and Save Sight Institute, Sydney, NSW, Australia ; 2 Sydney Genome Diagnostics, The Children's Hospital at Westmead, Sydney, NSW, Australia ; 3 Discipline of Paediatrics and Child Health, Sydney Medical School, University of Sydney, NSW, Australia
| | - John R Grigg
- 1 Eye Genetics Research Group, Children's Medical Research Institute, University of Sydney, The Children's Hospital at Westmead and Save Sight Institute, Sydney, NSW, Australia ; 2 Sydney Genome Diagnostics, The Children's Hospital at Westmead, Sydney, NSW, Australia ; 3 Discipline of Paediatrics and Child Health, Sydney Medical School, University of Sydney, NSW, Australia
| | - Bruce Bennetts
- 1 Eye Genetics Research Group, Children's Medical Research Institute, University of Sydney, The Children's Hospital at Westmead and Save Sight Institute, Sydney, NSW, Australia ; 2 Sydney Genome Diagnostics, The Children's Hospital at Westmead, Sydney, NSW, Australia ; 3 Discipline of Paediatrics and Child Health, Sydney Medical School, University of Sydney, NSW, Australia
| | - Robyn V Jamieson
- 1 Eye Genetics Research Group, Children's Medical Research Institute, University of Sydney, The Children's Hospital at Westmead and Save Sight Institute, Sydney, NSW, Australia ; 2 Sydney Genome Diagnostics, The Children's Hospital at Westmead, Sydney, NSW, Australia ; 3 Discipline of Paediatrics and Child Health, Sydney Medical School, University of Sydney, NSW, Australia
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Beltran WA, Cideciyan AV, Lewin AS, Hauswirth WW, Jacobson SG, Aguirre GD. Gene augmentation for X-linked retinitis pigmentosa caused by mutations in RPGR. Cold Spring Harb Perspect Med 2014; 5:a017392. [PMID: 25301933 DOI: 10.1101/cshperspect.a017392] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
X-linked retinitis pigmentosa (XLRP) caused by mutations in the RPGR gene is a severe and early onset form of retinal degeneration, and no treatment is currently available. Recent evidence in two clinically relevant canine models shows that adeno-associated viral (AAV)-mediated RPGR gene transfer to rods and cones can prevent disease onset and rescue photoreceptors at early- and mid-stages of degeneration. There is thus a strong incentive for conducting long-term, preclinical efficacy and safety studies, while concomitantly pursuing the detailed phenotypic characterization of XLRP disease in patients that may benefit from such corrective therapy.
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Affiliation(s)
- William A Beltran
- Section of Ophthalmology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104
| | - Artur V Cideciyan
- Scheie Eye Institute, Department of Ophthalmology, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania 19104
| | - Alfred S Lewin
- Department of Molecular Genetics & Microbiology, University of Florida, Gainesville, Florida 32610
| | - William W Hauswirth
- Department of Ophthalmology, University of Florida, Gainesville, Florida 32610
| | - Samuel G Jacobson
- Scheie Eye Institute, Department of Ophthalmology, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania 19104
| | - Gustavo D Aguirre
- Section of Ophthalmology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104
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Tzu JH, Arguello T, Berrocal AM, Berrocal M, Weisman AD, Liu M, Hess D, Caputo M, Goldberg JL, Feuer WJ, Stone EM, Lam BL. Clinical and Electrophysiologic Characteristics of a Large Kindred with X-Linked Retinitis Pigmentosa Associated with the RPGR Locus. Ophthalmic Genet 2014; 36:321-6. [PMID: 24555744 DOI: 10.3109/13816810.2014.886267] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
PURPOSE To phenotypically and genotypically characterize a large Puerto Rican kindred with X-linked retinitis pigmentosa associated with a novel RP GTPase regulator (RPGR) genotype. METHODS A total of 100 family members of a single kindred with X-linked RP were evaluated with ophthalmic examinations and blood DNA analysis. Visual fields, OCT, and full-field ERG were obtained on all affected males and carriers. RESULTS Of the 100 family members examined, 13 were affected males and 18 were carriers. A deletion of 2 base pair of the RPGR gene in the ORF15 region at position c.2267-2268 (Lys756del2aaAG hemi) was identified with the affected and carriers. Best eye visual acuity was correlated with age (Spearman coefficient = 0.95) with hand-motion acuity by age 35 and light perception to no light perception by age 50-60. Visual fields were minimally plottable by age 40, and ERG responses reached non-detectable levels by late teens. Carriers had no or mild visual symptoms. All carriers had visual acuity of at least 20/50 or better in one eye, and the amount of retinal degeneration was variable with ERG responses ranging from severely impaired to normal. CONCLUSIONS Profound visual loss occurred by the second decade of life with progression to near no light perception by age 60 in this kindred of X-linked RP associated with the RPGR genotype. Female carriers maintained visual acuity with age and were identifiable by clinical and ERG examination. The information from this study is important to determine the optimal age for intervention, as new RP treatments are being developed and tested.
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Affiliation(s)
- Jonathan H Tzu
- a Bascom Palmer Eye Institute, University of Miami Miller School of Medicine , Miami , FL , USA
| | - Tania Arguello
- a Bascom Palmer Eye Institute, University of Miami Miller School of Medicine , Miami , FL , USA
| | - Audina M Berrocal
- a Bascom Palmer Eye Institute, University of Miami Miller School of Medicine , Miami , FL , USA
| | | | - Alejandra D Weisman
- a Bascom Palmer Eye Institute, University of Miami Miller School of Medicine , Miami , FL , USA
| | - Mu Liu
- a Bascom Palmer Eye Institute, University of Miami Miller School of Medicine , Miami , FL , USA
| | - Ditte Hess
- a Bascom Palmer Eye Institute, University of Miami Miller School of Medicine , Miami , FL , USA
| | - Michelle Caputo
- a Bascom Palmer Eye Institute, University of Miami Miller School of Medicine , Miami , FL , USA
| | - Jeffrey L Goldberg
- a Bascom Palmer Eye Institute, University of Miami Miller School of Medicine , Miami , FL , USA
| | - William J Feuer
- a Bascom Palmer Eye Institute, University of Miami Miller School of Medicine , Miami , FL , USA
| | - Edwin M Stone
- c Department of Ophthalmology and Visual Sciences , University of Iowa , IA , USA , and.,d Howard Hughes Medical Institute, University of Iowa Carver College of Medicine , Iowa City , IA , USA
| | - Byron L Lam
- a Bascom Palmer Eye Institute, University of Miami Miller School of Medicine , Miami , FL , USA
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Yang L, Yin X, Feng L, You D, Wu L, Chen N, Li A, Li G, Ma Z. Novel mutations of RPGR in Chinese retinitis pigmentosa patients and the genotype-phenotype correlation. PLoS One 2014; 9:e85752. [PMID: 24454928 PMCID: PMC3893273 DOI: 10.1371/journal.pone.0085752] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2013] [Accepted: 11/30/2013] [Indexed: 11/19/2022] Open
Abstract
X-linked Retinitis Pigmentosa (XLRP) accounts for 10–20% of all RP cases, and represents the most severe subtype of this disease. Mutations in the Retinitis Pigmentosa GTPase Regulator (RPGR) gene are the most common causes of XLRP, accounting for over 70–75% of all XLRP cases. In this work, we analyzed all the exons of RPGR gene with Sanger sequencing in seven Chinese XLRP families, two of these with a provisional diagnosis of adRP but without male-to-male transmission. Three novel deletions (c.2233_34delAG; c.2236_37delGA and c.2403_04delAG) and two known nonsense mutations (c.851C→G and c.2260G→T) were identified in five families. Two novel deletions (c.2233_34delAG and c.2236_37delGA) resulted in the same frame shift (p.E746RfsX22), created similar phenotype in Family 3 and 4. The novel deletion (c.2403_04delAG; p.E802GfsX31) resulted in both XLRP and x-linked cone-rod dystrophy within the male patients of family 5, which suggested the presence of either genetic or environmental modifiers, or both, play a substantial role in disease expression. Genotype-phenotype correlation analysis suggested that (1) both patients and female carriers with mutation in Exon 8 (Family 1) manifest more severe disease than did those with ORF15 mutations (Family 2&3&4); (2) mutation close to downstream of ORF15 (Family 5) demonstrate the early preferential loss of cone function with moderate loss of rod function.
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Affiliation(s)
- Liping Yang
- Department of Ophthalmology, Peking University Third Hospital, Key Laboratory of Vision Loss and Restoration, Ministry of Education, Beijing, P. R. China
| | - Xiaobei Yin
- Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing, P. R. China
| | - Lina Feng
- Department of Ophthalmology, Peking University Third Hospital, Key Laboratory of Vision Loss and Restoration, Ministry of Education, Beijing, P. R. China
| | - Debo You
- Department of Ophthalmology, Peking University Third Hospital, Key Laboratory of Vision Loss and Restoration, Ministry of Education, Beijing, P. R. China
| | - Lemeng Wu
- Department of Ophthalmology, Peking University Third Hospital, Key Laboratory of Vision Loss and Restoration, Ministry of Education, Beijing, P. R. China
| | - Ningning Chen
- Department of Ophthalmology, Peking University Third Hospital, Key Laboratory of Vision Loss and Restoration, Ministry of Education, Beijing, P. R. China
| | - Aijun Li
- Department of Ophthalmology, Peking University Third Hospital, Key Laboratory of Vision Loss and Restoration, Ministry of Education, Beijing, P. R. China
| | - Genlin Li
- Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing, P. R. China
- * E-mail: (GL); (ZM)
| | - Zhizhong Ma
- Department of Ophthalmology, Peking University Third Hospital, Key Laboratory of Vision Loss and Restoration, Ministry of Education, Beijing, P. R. China
- * E-mail: (GL); (ZM)
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Chen X, Liu Y, Sheng X, Tam POS, Zhao K, Chen X, Rong W, Liu Y, Liu X, Pan X, Chen LJ, Zhao Q, Vollrath D, Pang CP, Zhao C. PRPF4 mutations cause autosomal dominant retinitis pigmentosa. Hum Mol Genet 2014; 23:2926-39. [PMID: 24419317 DOI: 10.1093/hmg/ddu005] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Retinitis pigmentosa (RP), a disease characterized by progressive loss of photoreceptors, exhibits significant genetic heterogeneity. Several genes associated with U4/U6-U5 triple small nuclear ribonucleoprotein (tri-snRNP) complex of the spliceosome have been implicated in autosomal dominant RP (adRP). HPrp4, encoded by PRPF4, regulates the stability of U4/U6 di-snRNP, which is essential for continuous splicing. Here, we identified two heterozygous variants in PRPF4, including c.-114_-97del in a simplex RP patient and c.C944T (p.Pro315Leu), which co-segregates with disease phenotype in a family with adRP. Both variants were absent in 400 unrelated controls. The c.-114_-97del, predicted to affect two transcription factor binding sites, was shown to down-regulate the promoter activity of PRPF4 by a luciferase assay, and was associated with a significant reduction of PRPF4 expression in the blood cells of the patient. In fibroblasts from an affected individual with the p.Pro315Leu variant, the expression levels of several tri-snRNP components, including PRPF4 itself, were up-regulated, with altered expression pattern of SC35, a spliceosome marker. The same alterations were also observed in cells over expressing hPrp4(Pro315Leu), suggesting that they arose as a compensatory response to a compromised splicing mechanism caused by hPrp4 dysfunction. Further, over expression of hPrp4(Pro315Leu), but not hPrp4(WT), triggered systemic deformities in wild-type zebrafish embryos with the retina primarily affected, and dramatically augmented death rates in morphant embryos, in which orthologous zebrafish prpf4 gene was silenced. We conclude that mutations of PRPF4 cause RP via haploinsufficiency and dominant-negative effects, and establish PRPF4 as a new U4/U6-U5 snRNP component associated with adRP.
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Affiliation(s)
- Xue Chen
- Department of Ophthalmology, The First Affiliated Hospital of Nanjing Medical University and State Key Laboratory of Reproductive Medicine, Nanjing Medical University, Nanjing 210029, China
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Zahid S, Khan N, Branham K, Othman M, Karoukis AJ, Sharma N, Moncrief A, Mahmood MN, Sieving PA, Swaroop A, Heckenlively JR, Jayasundera T. Phenotypic conservation in patients with X-linked retinitis pigmentosa caused by RPGR mutations. JAMA Ophthalmol 2013; 131:1016-25. [PMID: 23681342 DOI: 10.1001/jamaophthalmol.2013.120] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
IMPORTANCE For patients with X-linked retinitis pigmentosa and clinicians alike, phenotypic variability can be challenging because it complicates counseling regarding patients' likely visual prognosis. OBJECTIVE To evaluate the clinical findings from patients with X-linked retinitis pigmentosa with 13 distinct RPGR mutations and assess for phenotypic concordance or variability. DESIGN Retrospective medical record review of data collected from 1985 to 2011. SETTING Kellogg Eye Center, University of Michigan. PATIENTS A total of 42 patients with X-linked retinitis pigmentosa with mutations in RPGR. Age at first visit ranged from 4 to 53 years, with follow-up ranging from 1 to 11 visits (median follow-up time, 5.5 years; range, 1.4-32.7 years, for 23 patients with >1 visit). MAIN OUTCOMES AND MEASURES Clinical data assessed for concordance included visual acuity (VA), Goldmann visual fields (GVFs), and full-field electroretinography (ERG). Electroretinography phenotype (cone-rod vs rod-cone dysfunction) was defined by the extent of photopic vs scotopic abnormality. Qualitative GVF phenotype was determined by the GVF pattern, where central or peripheral loss suggested cone or rod dysfunction, respectively. Goldmann visual fields were also quantified and compared among patients. RESULTS Each mutation was detected in 2 or more related or unrelated patients. Five mutations in 11 patients displayed strong concordance of VA, while 4 mutations in 16 patients revealed moderate concordance of VA. A definitive cone-rod or rod-cone ERG pattern consistent among patients was found in 6 of 13 mutations (46.2%); the remaining mutations were characterized by patients demonstrating both phenotypes or who had limited data or nonrecordable ERG values. Concordant GVF phenotypes (7 rod-cone pattern vs 4 cone-rod pattern) were seen in 11 of 13 mutations (84.6%). All 6 mutations displaying a constant ERG pattern within the mutation group revealed a GVF phenotype consistent with the ERG findings. CONCLUSIONS AND RELEVANCE While VA and ERG phenotypes are concordant in only some patients carrying identical mutations, assessment of GVF phenotypes revealed stronger phenotypic conservation. Phenotypic concordance is important for establishing proper counseling of patients diagnosed as having X-linked retinitis pigmentosa, as well as for establishing accurate patient selection and efficacy monitoring in therapeutic trials.
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Affiliation(s)
- Sarwar Zahid
- Department of Ophthalmology and Visual Sciences, Kellogg Eye Center, University of Michigan, Ann Arbor, MI 48105, USA
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A novel large in-frame deletion within the CACNA1F gene associates with a cone-rod dystrophy 3-like phenotype. PLoS One 2013; 8:e76414. [PMID: 24124559 PMCID: PMC3790679 DOI: 10.1371/journal.pone.0076414] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2013] [Accepted: 08/25/2013] [Indexed: 01/18/2023] Open
Abstract
Cone-rod dystrophies (CORDs) represent a heterogeneous group of monogenic diseases leading to early impairment of vision. The majority of CORD entities show autosomal modes of inheritance and X-linked traits are comparably rare. So far, three X-chromosomal entities were reported (CORDX1, -X2 and -X3). In this study, we analysed a large family of German origin with solely affected males over three generations showing a CORDX-like phenotype. Due to the heterogeneity of cone-rod dystrophies, we performed a combined linkage and X-exome sequencing approach and identified a novel large intragenic in-frame deletion encompassing exons 18 to 26 within the CACNA1F gene. CACNA1F is described causative for CORDX3 in a single family originating from Finland and alterations in this gene have not yet been reported in other CORDX pedigrees. Our data independently confirm CACNA1F as the causative gene for CORDX3-like phenotypes and detailed clinical characterization of the family expands the knowledge about the phenotypic spectrum of deleterious CACNA1F alterations.
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