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Strong SA, Hirji N, Quartilho A, Kalitzeos A, Michaelides M. Retrospective cohort study exploring whether an association exists between spatial distribution of cystoid spaces in cystoid macular oedema secondary to retinitis pigmentosa and response to treatment with carbonic anhydrase inhibitors. Br J Ophthalmol 2018; 103:233-237. [PMID: 29706600 DOI: 10.1136/bjophthalmol-2017-311392] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2017] [Accepted: 03/28/2018] [Indexed: 11/04/2022]
Abstract
BACKGROUND Carbonic anhydrase inhibitors (CAIs) are frequently used as an initial step to treat retinitis pigmentosa-associated cystoid macular oedema (RP-CMO). Interestingly, it has been postulated that CAIs might reduce outer nuclear layer (ONL) fluid more effectively than inner nuclear layer (INL) fluid due to better access to retinal pigment epithelium basolateral membrane than neurosensory retina. This retrospective cohort study explores if an association between spatial distribution of cystoid spaces in RP-CMO and CAI response exists. METHODS Two independent graders reviewed pretreatment and post-treatment optical coherence tomography (OCT) images of 25 patients (43 eyes) initiated on topical and/or oral CAIs between January 2013 and December 2014. Documentation included the presence/absence of fluid (and layer(s) involved), external limiting membrane, epiretinal membrane (ERM), vitreomacular adhesion/traction, lamellar/full-thickness macular hole and central macular thickness (CMT)/volume. RESULTS INL fluid was found in all study eyes. All 13 'responders' (at least 11% reduction of CMT after treatment) demonstrated pretreatment ONL fluid. In seven patients (four responders and three non-responders), complete clearance of ONL fluid was achieved despite persistence of INL fluid. ERM presence was similar in responders and non-responders. CONCLUSION In this study, INL fluid was found to be the most common spatial distribution of RP-CMO. However, patients who were classed as a 'responder' to CAI treatment all demonstrated coexisting ONL fluid on their pretreatment OCT scans. This may be explained by CAIs having better access to retinal pigment epithelium basolateral membrane than neurosensory retina. Our study also suggests a minimal impact on response to CAIs by ERM.
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Affiliation(s)
- Stacey A Strong
- UCL Institute of Ophthalmology, University College London, London, UK.,Moorfields Eye Hospital NHS Foundation Trust, London, UK
| | - Nashila Hirji
- UCL Institute of Ophthalmology, University College London, London, UK.,Moorfields Eye Hospital NHS Foundation Trust, London, UK
| | - Ana Quartilho
- UCL Institute of Ophthalmology, University College London, London, UK.,Moorfields Eye Hospital NHS Foundation Trust, London, UK
| | - Angelos Kalitzeos
- UCL Institute of Ophthalmology, University College London, London, UK.,Moorfields Eye Hospital NHS Foundation Trust, London, UK
| | - Michel Michaelides
- UCL Institute of Ophthalmology, University College London, London, UK .,Moorfields Eye Hospital NHS Foundation Trust, London, UK
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Athanasiou D, Aguila M, Bellingham J, Li W, McCulley C, Reeves PJ, Cheetham ME. The molecular and cellular basis of rhodopsin retinitis pigmentosa reveals potential strategies for therapy. Prog Retin Eye Res 2018; 62:1-23. [PMID: 29042326 PMCID: PMC5779616 DOI: 10.1016/j.preteyeres.2017.10.002] [Citation(s) in RCA: 217] [Impact Index Per Article: 36.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2017] [Revised: 10/03/2017] [Accepted: 10/13/2017] [Indexed: 12/12/2022]
Abstract
Inherited mutations in the rod visual pigment, rhodopsin, cause the degenerative blinding condition, retinitis pigmentosa (RP). Over 150 different mutations in rhodopsin have been identified and, collectively, they are the most common cause of autosomal dominant RP (adRP). Mutations in rhodopsin are also associated with dominant congenital stationary night blindness (adCSNB) and, less frequently, recessive RP (arRP). Recessive RP is usually associated with loss of rhodopsin function, whereas the dominant conditions are a consequence of gain of function and/or dominant negative activity. The in-depth characterisation of many rhodopsin mutations has revealed that there are distinct consequences on the protein structure and function associated with different mutations. Here we categorise rhodopsin mutations into seven discrete classes; with defects ranging from misfolding and disruption of proteostasis, through mislocalisation and disrupted intracellular traffic to instability and altered function. Rhodopsin adRP offers a unique paradigm to understand how disturbances in photoreceptor homeostasis can lead to neuronal cell death. Furthermore, a wide range of therapies have been tested in rhodopsin RP, from gene therapy and gene editing to pharmacological interventions. The understanding of the disease mechanisms associated with rhodopsin RP and the development of targeted therapies offer the potential of treatment for this currently untreatable neurodegeneration.
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Affiliation(s)
| | - Monica Aguila
- UCL Institute of Ophthalmology, 11-43 Bath Street, London EC1V 9EL, UK
| | - James Bellingham
- UCL Institute of Ophthalmology, 11-43 Bath Street, London EC1V 9EL, UK
| | - Wenwen Li
- UCL Institute of Ophthalmology, 11-43 Bath Street, London EC1V 9EL, UK
| | - Caroline McCulley
- UCL Institute of Ophthalmology, 11-43 Bath Street, London EC1V 9EL, UK
| | - Philip J Reeves
- School of Biological Sciences, University of Essex, Wivenhoe Park, Essex CO4 3SQ, UK.
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Tsang SH, Sharma T. Retinitis Pigmentosa (Non-syndromic). ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2018; 1085:125-130. [PMID: 30578498 DOI: 10.1007/978-3-319-95046-4_25] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Most of the genes causing autosomal recessive retinitis pigmentosa (AR-RP) are rare and cause 1% of all cases. Some of the genes, like PDE6 (PDE6A, PDE6B, PDE6G), RP25, and RPE65, have higher prevalence, about 2-5% of all cases. Overall, autosomal recessive RP accounts for about 15-20% of all cases of RP. Clinically, it shows all the classic features of RP, such as attenuated retinal blood vessels, intraretinal pigmentation, waxy pallor of the optic disc, and hyperfluorescent rings on fundus autofluorescence (FAF) (Figs. 25.1, 25.2 and 25.3). The ring is suggestive of increased metabolic burden of the corresponding retinal pigment epithelium (RPE).
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Affiliation(s)
- Stephen H Tsang
- Jonas Children's Vision Care, Bernard & Shirlee Brown Glaucoma Laboratory, Columbia Stem Cell Initiative-Departments of Ophthalmology, Biomedical Engineering, Pathology & Cell Biology, Institute of Human Nutrition, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY, USA
- Department of Ophthalmology, Columbia University, Edward S. Harkness Eye Institute, NewYork-Presbyterian Hospital, New York, NY, USA
| | - Tarun Sharma
- Department of Ophthalmology, Columbia University, Edward S. Harkness Eye Institute, NewYork-Presbyterian Hospital, New York, NY, USA.
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Bryant L, Lozynska O, Maguire AM, Aleman TS, Bennett J. Prescreening whole exome sequencing results from patients with retinal degeneration for variants in genes associated with retinal degeneration. Clin Ophthalmol 2017; 12:49-63. [PMID: 29343940 PMCID: PMC5749571 DOI: 10.2147/opth.s147684] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Background Accurate clinical diagnosis and prognosis of retinal degeneration can be aided by the identification of the disease-causing genetic variant. It can confirm the clinical diagnosis as well as inform the clinician of the risk for potential involvement of other organs such as kidneys. It also aids in genetic counseling for affected individuals who want to have a child. Finally, knowledge of disease-causing variants informs laboratory investigators involved in translational research. With the advent of next-generation sequencing, identifying pathogenic mutations is becoming easier, especially the identification of novel pathogenic variants. Methods We used whole exome sequencing on a cohort of 69 patients with various forms of retinal degeneration and in whom screens for previously identified disease-causing variants had been inconclusive. All potential pathogenic variants were verified by Sanger sequencing and, when possible, segregation analysis of immediate relatives. Potential variants were identified by using a semi-masked approach in which rare variants in candidate genes were identified without knowledge of the clinical diagnosis (beyond "retinal degeneration") or inheritance pattern. After the initial list of genes was prioritized, genetic diagnosis and inheritance pattern were taken into account. Results We identified the likely pathogenic variants in 64% of the subjects. Seven percent had a single heterozygous mutation identified that would cause recessive disease and 13% had no obviously pathogenic variants and no family members available to perform segregation analysis. Eleven subjects are good candidates for novel gene discovery. Two de novo mutations were identified that resulted in dominant retinal degeneration. Conclusion Whole exome sequencing allows for thorough genetic analysis of candidate genes as well as novel gene discovery. It allows for an unbiased analysis of genetic variants to reduce the chance that the pathogenic mutation will be missed due to incomplete or inaccurate family history or analysis at the early stage of a syndromic form of retinal degeneration.
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Affiliation(s)
- Laura Bryant
- Center for Advanced Retinal and Ocular Therapeutics (CAROT), FM Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Olga Lozynska
- Center for Advanced Retinal and Ocular Therapeutics (CAROT), FM Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Albert M Maguire
- Center for Advanced Retinal and Ocular Therapeutics (CAROT), FM Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.,Department of Ophthalmology, The Children's Hospital of Philadelphia, Philadelphia, PA, USA.,Department of Ophthalmology, Scheie Eye Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Tomas S Aleman
- Center for Advanced Retinal and Ocular Therapeutics (CAROT), FM Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.,Department of Ophthalmology, The Children's Hospital of Philadelphia, Philadelphia, PA, USA.,Department of Ophthalmology, Scheie Eye Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Jean Bennett
- Center for Advanced Retinal and Ocular Therapeutics (CAROT), FM Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.,Department of Ophthalmology, The Children's Hospital of Philadelphia, Philadelphia, PA, USA.,Department of Ophthalmology, Scheie Eye Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
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Jerath NU, Mankodi A, Crawford TO, Grunseich C, Baloui H, Nnamdi-Emeratom C, Schindler AB, Heiman-Patterson T, Chrast R, Shy ME. Charcot-Marie-Tooth Disease type 4C: Novel mutations, clinical presentations, and diagnostic challenges. Muscle Nerve 2017; 57:749-755. [PMID: 28981955 DOI: 10.1002/mus.25981] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/03/2017] [Indexed: 12/15/2022]
Abstract
INTRODUCTION This study analyzes and describes atypical presentations of Charcot-Marie-Tooth disease type 4C (CMT4C). METHODS We present clinical and physiologic features of 5 patients with CMT4C caused by biallelic private mutations of SH3TC2. RESULTS All patients manifested scoliosis, and nerve conduction study indicated results in the demyelinating range. All patients exhibited signs of motor impairment within the first years of life. We describe 2 or more different genetic diseases in the same patient, atypical presentations of CMT, and 3 new mutations in CMT4C patients. DISCUSSION A new era of unbiased genetic testing has led to this small case series of individuals with CMT4C and highlights the recognition of different genetic diseases in CMT4C patients for accurate diagnosis, genetic risk identification, and therapeutic intervention. The phenotype of CMT4C, in addition, appears to be enriched by a number of features unusual for the broad CMT category. Muscle Nerve 57: 749-755, 2018.
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Affiliation(s)
- Nivedita U Jerath
- Department of Neurology, University of Iowa Carver College of Medicine, 200 Hawkins Drive Iowa City, Iowa, 52242, USA.,Department of Neurology, University of Florida, PO Box 100236 Gainesville, FL, 32610
| | - Ami Mankodi
- Neurogenetics Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, USA
| | - Thomas O Crawford
- Department of Pediatric Neurology, Johns Hopkins University, Baltimore, Maryland, USA
| | - Christopher Grunseich
- Neurogenetics Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, USA
| | - Hasna Baloui
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden.,Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Chioma Nnamdi-Emeratom
- Neurogenetics Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, USA
| | - Alice B Schindler
- Neurogenetics Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, USA
| | - Terry Heiman-Patterson
- Department of Neurology, Drexel University College of Medicine, Philadelphia, Pennsylvania, USA
| | - Roman Chrast
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden.,Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Michael E Shy
- Department of Neurology, University of Iowa Carver College of Medicine, 200 Hawkins Drive Iowa City, Iowa, 52242, USA
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