1
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Lei Q, Xiang K, Cheng L, Xiang M. Human retinal organoids with an OPA1 mutation are defective in retinal ganglion cell differentiation and function. Stem Cell Reports 2024; 19:68-83. [PMID: 38101398 PMCID: PMC10828684 DOI: 10.1016/j.stemcr.2023.11.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2023] [Revised: 11/15/2023] [Accepted: 11/16/2023] [Indexed: 12/17/2023] Open
Abstract
Autosomal dominant optic atrophy (ADOA), mostly caused by heterozygous OPA1 mutations and characterized by retinal ganglion cell (RGC) loss and optic nerve degeneration, is one of the most common types of inherited optic neuropathies. Previous work using a two-dimensional (2D) differentiation model of induced pluripotent stem cells (iPSCs) has investigated ADOA pathogenesis but failed to agree on the effect of OPA1 mutations on RGC differentiation. Here, we use 3D retinal organoids capable of mimicking in vivo retinal development to resolve the issue. We generated isogenic iPSCs carrying the hotspot OPA1 c.2708_2711delTTAG mutation and found that the mutant variant caused defective initial and terminal differentiation and abnormal electrophysiological properties of organoid-derived RGCs. Moreover, this variant inhibits progenitor proliferation and results in mitochondrial dysfunction. These data demonstrate that retinal organoids coupled with gene editing serve as a powerful tool to definitively identify disease-related phenotypes and provide valuable resources to further investigate ADOA pathogenesis and screen for ADOA therapeutics.
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Affiliation(s)
- Qiannan Lei
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou 510060, China
| | - Kangjian Xiang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou 510060, China
| | - Lin Cheng
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou 510060, China
| | - Mengqing Xiang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou 510060, China; Guangdong Provincial Key Laboratory of Brain Function and Disease, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China.
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2
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Valentin K, Georgi T, Riedl R, Aminfar H, Singer C, Klopstock T, Wedrich A, Schneider M. Idebenone Treatment in Patients with OPA1-Dominant Optic Atrophy: A Prospective Phase 2 Trial. Neuroophthalmology 2023; 47:237-247. [PMID: 38130806 PMCID: PMC10732653 DOI: 10.1080/01658107.2023.2251575] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2023] [Accepted: 07/31/2023] [Indexed: 12/23/2023] Open
Abstract
The aim of this study was to evaluate the therapeutic effect of idebenone in patients with OPA1-dominant optic atrophy (DOA). Sixteen patients with genetically confirmed OPA1-DOA were treated with 900 mg idebenone daily for 12 months. The primary endpoint was the best recovery/least deterioration of visual acuity. Secondary endpoints were the changes of visual acuity, colour vision, contrast sensitivity, visual field, peripapillary retinal nerve fibre layer thickness (pRNFLT), and visual-related quality of life. For the primary endpoint, a significant increase was observed for the right eye (p = .0027), for the left eye (p = .0111) and for the better-seeing eye (p = .0152). For visual fields, a significant improvement was observed for the left eye between baseline and 9 months (p = .0038). Regarding pRNFLT, a significant decrease was found for the left eye between baseline and 3 months (p = .0413) and between baseline and 6 months (p = .0448). In the visual function questionnaire, a significant improvement was observed in the subscale general vision (p = .0156) and in the composite score (p = .0256). In conclusion, best recovery of visual acuity improved, even though the amount of improvement was small. Furthermore, a maintenance of visual function after 12 months of idebenone intake could be observed as well as a significant improvement in vision-related quality of life.Whether this effect is due to idebenone treatment, the placebo effect, or is explainable by the natural progression of DOA, remains unclear. Trial registration: EU Clinical Trials Register, EudraCT Number: 2019-001493-28.
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Affiliation(s)
| | - Thomas Georgi
- Department of Ophthalmology, Medical University of Graz, Graz, Austria
| | - Regina Riedl
- Institute for Medical Informatics, Statistics and Documentation, Medical University of Graz, Graz, Austria
| | - Haleh Aminfar
- Department of Ophthalmology, Medical University of Graz, Graz, Austria
| | - Christoph Singer
- Department of Ophthalmology, Medical University of Graz, Graz, Austria
| | - Thomas Klopstock
- Department of Neurology, Friedrich-Baur-Institute, Ludwig-Maximilians-University, Munich, Germany
| | - Andreas Wedrich
- Department of Ophthalmology, Medical University of Graz, Graz, Austria
| | - Mona Schneider
- Department of Ophthalmology, Medical University of Graz, Graz, Austria
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3
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Pohl KA, Zhang X, Pham AH, Chan JW, Sadun AA, Yang XJ. Establishing induced pluripotent stem cell lines from two dominant optic atrophy patients with distinct OPA1 mutations and clinical pathologies. Front Genet 2023; 14:1251216. [PMID: 37745862 PMCID: PMC10513078 DOI: 10.3389/fgene.2023.1251216] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2023] [Accepted: 08/17/2023] [Indexed: 09/26/2023] Open
Abstract
Dominant optic atrophy (DOA) is an inherited disease that leads to the loss of retinal ganglion cells (RGCs), the projection neurons that relay visual information from the retina to the brain through the optic nerve. The majority of DOA cases can be attributed to mutations in optic atrophy 1 (OPA1), a nuclear gene encoding a mitochondrial-targeted protein that plays important roles in maintaining mitochondrial structure, dynamics, and bioenergetics. Although OPA1 is ubiquitously expressed in all human tissues, RGCs appear to be the primary cell type affected by OPA1 mutations. DOA has not been extensively studied in human RGCs due to the general unavailability of retinal tissues. However, recent advances in stem cell biology have made it possible to produce human RGCs from pluripotent stem cells (PSCs). To aid in establishing DOA disease models based on human PSC-derived RGCs, we have generated iPSC lines from two DOA patients who carry distinct OPA1 mutations and present very different disease symptoms. Studies using these OPA1 mutant RGCs can be correlated with clinical features in the patients to provide insights into DOA disease mechanisms.
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Affiliation(s)
- Katherine A. Pohl
- Department of Ophthalmology, Stein Eye Institute, University of California, Los Angeles, Los Angeles, CA, United States
- Molecular Biology Institute, University of California, Los Angeles, Los Angeles, CA, United States
| | - Xiangmei Zhang
- Department of Ophthalmology, Stein Eye Institute, University of California, Los Angeles, Los Angeles, CA, United States
| | - Anh H. Pham
- Department of Ophthalmology, Doheny Eye Institute, University of California, Los Angeles, Pasadena, CA, United States
| | - Jane W. Chan
- Department of Ophthalmology, Doheny Eye Institute, University of California, Los Angeles, Pasadena, CA, United States
| | - Alfredo A. Sadun
- Department of Ophthalmology, Doheny Eye Institute, University of California, Los Angeles, Pasadena, CA, United States
| | - Xian-Jie Yang
- Department of Ophthalmology, Stein Eye Institute, University of California, Los Angeles, Los Angeles, CA, United States
- Molecular Biology Institute, University of California, Los Angeles, Los Angeles, CA, United States
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4
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Swirski S, May O, Ahlers M, Wissinger B, Greschner M, Jüschke C, Neidhardt J. In Vivo Efficacy and Safety Evaluations of Therapeutic Splicing Correction Using U1 snRNA in the Mouse Retina. Cells 2023; 12:cells12060955. [PMID: 36980294 PMCID: PMC10047704 DOI: 10.3390/cells12060955] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Revised: 03/14/2023] [Accepted: 03/14/2023] [Indexed: 03/30/2023] Open
Abstract
Efficacy and safety considerations constitute essential steps during development of in vivo gene therapies. Herein, we evaluated efficacy and safety of splice factor-based treatments to correct mutation-induced splice defects in an Opa1 mutant mouse line. We applied adeno-associated viruses to the retina. The viruses transduced retinal cells with an engineered U1 snRNA splice factor designed to correct the Opa1 splice defect. We found the treatment to be efficient in increasing wild-type Opa1 transcripts. Correspondingly, Opa1 protein levels increased significantly in treated eyes. Measurements of retinal morphology and function did not reveal therapy-related side-effects supporting the short-term safety of the treatment. Alterations of potential off-target genes were not detected. Our data suggest that treatments of splice defects applying engineered U1 snRNAs represent a promising in vivo therapeutic approach. The therapy increased wild-type Opa1 transcripts and protein levels without detectable morphological, functional or genetic side-effects in the mouse eye. The U1 snRNA-based therapy can be tailored to specific disease gene mutations, hence, raising the possibility of a wider applicability of this promising technology towards treatment of different inherited retinal diseases.
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Affiliation(s)
- Sebastian Swirski
- Human Genetics, Department of Human Medicine, Faculty of Medicine and Health Sciences, University of Oldenburg, Carl-von-Ossietzky-Straße 9-11, 26129 Oldenburg, Germany
| | - Oliver May
- Human Genetics, Department of Human Medicine, Faculty of Medicine and Health Sciences, University of Oldenburg, Carl-von-Ossietzky-Straße 9-11, 26129 Oldenburg, Germany
| | - Malte Ahlers
- Visual Neuroscience, Department of Neuroscience, Faculty of Medicine and Health Sciences, University of Oldenburg, Carl-von-Ossietzky-Straße 9-11, 26129 Oldenburg, Germany
| | - Bernd Wissinger
- Institute for Ophthalmic Research, Centre for Ophthalmology, University of Tübingen, Elfriede-Aulhorn-Straße 7, 72076 Tübingen, Germany
| | - Martin Greschner
- Institute for Ophthalmic Research, Centre for Ophthalmology, University of Tübingen, Elfriede-Aulhorn-Straße 7, 72076 Tübingen, Germany
- Research Center Neurosensory Science, University of Oldenburg, Carl-von-Ossietzky-Straße 9-11, 26129 Oldenburg, Germany
| | - Christoph Jüschke
- Human Genetics, Department of Human Medicine, Faculty of Medicine and Health Sciences, University of Oldenburg, Carl-von-Ossietzky-Straße 9-11, 26129 Oldenburg, Germany
| | - John Neidhardt
- Human Genetics, Department of Human Medicine, Faculty of Medicine and Health Sciences, University of Oldenburg, Carl-von-Ossietzky-Straße 9-11, 26129 Oldenburg, Germany
- Research Center Neurosensory Science, University of Oldenburg, Carl-von-Ossietzky-Straße 9-11, 26129 Oldenburg, Germany
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5
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Eckmann‐Hansen C, Bek T, Sander B, Larsen M. Vision-related quality of life and visual ability in patients with autosomal dominant optic atrophy. Acta Ophthalmol 2022; 100:797-804. [PMID: 35146926 PMCID: PMC9790332 DOI: 10.1111/aos.15102] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Revised: 12/07/2021] [Accepted: 01/20/2022] [Indexed: 12/30/2022]
Abstract
PURPOSE The purpose of the study was to evaluate vision-related quality of life and visual ability in patients with OPA1 autosomal dominant optic atrophy (ADOA). METHODS This cross-sectional, observational study included 145 participants with a mutation in the OPA1 gene associated with ADOA, 63 mutation-free first-degree relatives and 92 healthy subjects unrelated to the families. Participants underwent a clinical eye examination, and adult participants completed the National Eye Institute Visual Function Questionnaire (NEI-VFQ-39), while children completed the Cardiff Visual Ability Questionnaire for Children (CVAQC). RESULTS In adults with ADOA, both mean visual acuity (VA) and mean contrast sensitivity (CS) were significantly inferior to both first-degree relatives and unrelated controls (p < 0.001). In children with ADOA, mean VA was significantly lower compared with first-degree relatives (p = 0.0052), whereas CS was not (0.127). Adults with ADOA scored lower than both comparator groups on composite score (p < 0.001), general health subscale (p = 0.0075) and all vision-related subscales (p < 0.001) except the ocular pain subscale (p = 0.2). In children with ADOA, the median CVAQC logit score was significantly lower compared with first-degree relatives (p = 0.037). The science lessons subscale was significantly lower for children with ADOA compared with first-degree relatives (p = 0.046), as well as the language lessons subscale (p = 0.038). For adults, composite score and subscale scores were significantly associated with both VA, CS and fixation status. CONCLUSION OPA1 mutation is associated with lower quality of life and visual ability in patients with ADOA compared with both first-degree relatives and unrelated controls. VA, CS and fixation status affect quality of life in patients with ADOA.
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Affiliation(s)
- Christina Eckmann‐Hansen
- Department of OphthalmologyRigshospitaletGlostrupDenmark,Faculty of Health and Medical SciencesUniversity of CopenhagenCopenhagenDenmark
| | - Toke Bek
- Department of OphthalmologyAarhus University HospitalAarhusDenmark
| | - Birgit Sander
- Department of OphthalmologyRigshospitaletGlostrupDenmark
| | - Michael Larsen
- Department of OphthalmologyRigshospitaletGlostrupDenmark,Faculty of Health and Medical SciencesUniversity of CopenhagenCopenhagenDenmark
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6
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Han J, Li Y, You Y, Fan K, Lei B. Autosomal dominant optic atrophy caused by six novel pathogenic OPA1 variants and genotype-phenotype correlation analysis. BMC Ophthalmol 2022; 22:322. [PMID: 35883160 PMCID: PMC9327245 DOI: 10.1186/s12886-022-02546-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2021] [Accepted: 07/20/2022] [Indexed: 11/10/2022] Open
Abstract
PURPOSE To describe the genetic and clinical features of nineteen patients from eleven unrelated Chinese pedigrees with OPA1-related autosomal dominant optic atrophy (ADOA) and define the phenotype-genotype correlations. METHODS Detailed ophthalmic examinations were performed. Targeted next-generation sequencing (NGS) was conducted in the eleven probands using a custom designed panel PS400. Sanger sequencing and cosegregation were used to verify the identified variants. The pathogenicity of gene variants was evaluated according to American College of Medical Genetics and Genomics (ACMG) guidelines. RESULTS Nineteen patients from the eleven unrelated Chinese ADOA pedigrees had impaired vision and optic disc pallor. Optical coherence tomography showed significant thinning of the retinal nerve fiber layer. The visual field showed varying degrees of central or paracentral scotoma. The onset of symptoms occurred between 3 and 24 years of age (median age 6 years). Eleven variants in OPA1 were identified in the cohort, and nine novel variants were identified. Among the novel variants, two splicing variants c.984 + 1_984 + 2delGT, c.1194 + 2 T > C, two stop-gain variants c.1937C > G, c.2830G > T, and one frameshift variant c.2787_2794del8, were determined to be pathogenic based on ACMG. A novel splicing variant c.1316-10 T > G was determined to be likely pathogenic. In addition, a novel missense c.1283A > C (p.N428T) and two novel splicing variants c.2496G > A and c.1065 + 5G > C were of uncertain significance. CONCLUSIONS Six novel pathogenic variants were identified. The findings will facilitate genetic counselling by expanding the pathogenic mutation spectrum of OPA1.
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Affiliation(s)
- Jinfeng Han
- Department of Ophthalmology, Zhengzhou University People's Hospital, Henan Provincial People's Hospital, Zhengzhou University, Zheng-zhou, 450003, China.,Academy of Medical Sciences, Zhengzhou University, Zhengzhou, 450000, China
| | - Ya Li
- Department of Ophthalmology, Zhengzhou University People's Hospital, Henan Provincial People's Hospital, Zhengzhou University, Zheng-zhou, 450003, China.,Henan Eye Institute, Henan Eye Hospital, Henan Provincial People's Hospital, 7 Weiwu Road, Zhengzhou, 450003, Henan, China
| | - Ya You
- Department of Ophthalmology, Zhengzhou University People's Hospital, Henan Provincial People's Hospital, Zhengzhou University, Zheng-zhou, 450003, China.,Henan Eye Institute, Henan Eye Hospital, Henan Provincial People's Hospital, 7 Weiwu Road, Zhengzhou, 450003, Henan, China
| | - Ke Fan
- Department of Ophthalmology, Zhengzhou University People's Hospital, Henan Provincial People's Hospital, Zhengzhou University, Zheng-zhou, 450003, China.,Henan Eye Institute, Henan Eye Hospital, Henan Provincial People's Hospital, 7 Weiwu Road, Zhengzhou, 450003, Henan, China
| | - Bo Lei
- Department of Ophthalmology, Zhengzhou University People's Hospital, Henan Provincial People's Hospital, Zhengzhou University, Zheng-zhou, 450003, China. .,Academy of Medical Sciences, Zhengzhou University, Zhengzhou, 450000, China. .,Henan Eye Institute, Henan Eye Hospital, Henan Provincial People's Hospital, 7 Weiwu Road, Zhengzhou, 450003, Henan, China.
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7
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Cesareo M, Giannini C, Di Marino M, Aloe G, Martucci A, Aiello F, Cusumano A, Mancino R, Ricci F, Sorge RP, Nucci C. Optical coherence tomography angiography in the multimodal assessment of the retinal posterior pole in autosomal dominant optic atrophy. Acta Ophthalmol 2022; 100:e798-e806. [PMID: 34250739 DOI: 10.1111/aos.14972] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Accepted: 06/17/2021] [Indexed: 01/25/2023]
Abstract
PURPOSE To assess retinal vascular involvement in patients with autosomal dominant optic atrophy (ADOA) genetically confirmed by the presence of the OPA1 (Optic Atrophy 1) gene mutation using a multimodal protocol of investigation of retinal posterior pole. METHODS In this cross-sectional, case-control, observational study, both eyes of 13 patients with a genetic diagnosis of ADOA were compared with both eyes of 13 healthy controls (HCs). All subjects underwent full ophthalmological examination, spectral domain-optical coherence tomography (SD-OCT), fundus perimetry (FP) and OCT angiography (OCTA). RESULTS Vessel density (VD) of the superficial and deep macular vascular plexi and of the radial peripapillary capillary plexus were significantly decreased (p ≤ 0.001) in ADOA patients compared with HCs. The area under the receiver operating characteristics analysis also revealed high values of sensitivity and specificity of OCTA parameters in distinguish between patients and HCs. A strong correlation (Pearson Coefficient, r = 0.91) emerged between OCTA VD of the superficial retinal plexus and the average Ganglion Cell Layer (GCL) thickness as measured by SD-OCT; a slightly lower correlation (Pearson Coefficient, r = 0.89) was also found between VD of the deep plexus and the average GCL thickness of the same eyes in patients with ADOA. The correlation among values of differential light sensitivity (DLS) measured by FP with VD and GCL thickness parameters was also investigated. The correlation analysis among DLS and the VD parameters showed from low-to-moderate correlation (ranging from r = 0.29 for the deep fovea VD to r = 0.59 for the deep whole image VD). The correlation coefficient between the mean DLS and the average thickness of GCL was more significant (Pearson Coefficient, r = 0.75). A significant correlation emerged also between the VD and the visual acuity, in terms of LogMAR BCVA (best-corrected visual acuity), especially for the VD of the deep capillary plexus (Pearson Coefficient for the Deep whole Image VD and LogMAR BCVA r = -0.75; for the Deep parafovea VD and LogMAR BCVA r = -0.78). CONCLUSION Retinal microvascular assessment by OCTA angiography can provide relevant clinical information on retinal involvement in ADOA patients. In patients with genetically confirmed OPA1-related ADOA, there is a decrease in retinal vessel density associated with GCL thinning and DLS reduction.
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Affiliation(s)
- Massimo Cesareo
- Ophthalmology Unit, Department of Experimental Medicine, University of Rome Tor Vergata, Rome, Italy
| | - Clarissa Giannini
- Ophthalmology Unit, Department of Experimental Medicine, University of Rome Tor Vergata, Rome, Italy
| | - Matteo Di Marino
- Ophthalmology Unit, Department of Experimental Medicine, University of Rome Tor Vergata, Rome, Italy
| | - Gianluca Aloe
- Ophthalmology Unit, Department of Experimental Medicine, University of Rome Tor Vergata, Rome, Italy
| | - Alessio Martucci
- Ophthalmology Unit, Department of Experimental Medicine, University of Rome Tor Vergata, Rome, Italy
| | - Francesco Aiello
- Ophthalmology Unit, Department of Experimental Medicine, University of Rome Tor Vergata, Rome, Italy
| | - Andrea Cusumano
- Ophthalmology Unit, Department of Experimental Medicine, University of Rome Tor Vergata, Rome, Italy
| | - Raffaele Mancino
- Ophthalmology Unit, Department of Experimental Medicine, University of Rome Tor Vergata, Rome, Italy
| | - Federico Ricci
- Ophthalmology Unit, Department of Experimental Medicine, University of Rome Tor Vergata, Rome, Italy
| | - Roberto Pietro Sorge
- Laboratory of Biometry, Department of Systems Medicine, University of Rome "Tor Vergata", Rome, Italy
| | - Carlo Nucci
- Ophthalmology Unit, Department of Experimental Medicine, University of Rome Tor Vergata, Rome, Italy
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8
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Sun Z, Wu S, Zhu T, Wei X, Han X, Zou X, Sui R. Generation of a human induced pluripotent stem cell line PUMCHi019-A from a dominant optic atrophy patient with an OPA1 mutation. Stem Cell Res 2022; 60:102705. [DOI: 10.1016/j.scr.2022.102705] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/05/2021] [Revised: 02/03/2022] [Accepted: 02/06/2022] [Indexed: 11/26/2022] Open
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9
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Zou W, Ji D, Zhang Z, Yang L, Cao Y. Players in Mitochondrial Dynamics and Female Reproduction. Front Mol Biosci 2021; 8:717328. [PMID: 34708072 PMCID: PMC8542886 DOI: 10.3389/fmolb.2021.717328] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Accepted: 09/07/2021] [Indexed: 01/16/2023] Open
Abstract
Mitochondrial dynamics (fission and fusion) are essential physiological processes for mitochondrial metabolic function, mitochondrial redistribution, and mitochondrial quality control. Various proteins are involved in regulating mitochondrial dynamics. Aberrant expression of these proteins interferes with mitochondrial dynamics and induces a range of diseases. Multiple therapeutic approaches have been developed to treat the related diseases in recent years, but their curative effects are limited. Meanwhile, the role of mitochondrial dynamics in female reproductive function has attracted progressively more attention, including oocyte development and maturation, fertilization, and embryonic development. Here, we reviewed the significance of mitochondrial dynamics, proteins involved in mitochondrial dynamics, and disorders resulting from primary mitochondrial dynamic dysfunction. We summarized the latest therapeutic approaches of hereditary mitochondrial fusion-fission abnormalities and reviewed the recent advances in female reproductive mitochondrial dynamics.
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Affiliation(s)
- Weiwei Zou
- Reproductive Medicine Center, Department of Obstetrics and Gynecology, The First Affiliated Hospital of Anhui Medical University, Hefei, China.,NHC Key Laboratory of Study on Abnormal Gametes and Reproductive Tract (Anhui Medical University), Hefei, China.,Key Laboratory of Population Health Across Life Cycle (Anhui Medical University), Ministry of Education of the People's Republic of China, Hefei, China
| | - Dongmei Ji
- Reproductive Medicine Center, Department of Obstetrics and Gynecology, The First Affiliated Hospital of Anhui Medical University, Hefei, China.,Anhui Province Key Laboratory of Reproductive Health and Genetics, Hefei, China.,Biopreservation and Artificial Organs, Anhui Provincial Engineering Research Center, Anhui Medical University, Hefei, China
| | - Zhiguo Zhang
- Reproductive Medicine Center, Department of Obstetrics and Gynecology, The First Affiliated Hospital of Anhui Medical University, Hefei, China.,Anhui Province Key Laboratory of Reproductive Health and Genetics, Hefei, China.,Biopreservation and Artificial Organs, Anhui Provincial Engineering Research Center, Anhui Medical University, Hefei, China
| | - Li Yang
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China
| | - Yunxia Cao
- Reproductive Medicine Center, Department of Obstetrics and Gynecology, The First Affiliated Hospital of Anhui Medical University, Hefei, China.,NHC Key Laboratory of Study on Abnormal Gametes and Reproductive Tract (Anhui Medical University), Hefei, China.,Key Laboratory of Population Health Across Life Cycle (Anhui Medical University), Ministry of Education of the People's Republic of China, Hefei, China
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10
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Sanz-Morello B, Ahmadi H, Vohra R, Saruhanian S, Freude KK, Hamann S, Kolko M. Oxidative Stress in Optic Neuropathies. Antioxidants (Basel) 2021; 10:1538. [PMID: 34679672 PMCID: PMC8532958 DOI: 10.3390/antiox10101538] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2021] [Revised: 09/07/2021] [Accepted: 09/12/2021] [Indexed: 01/23/2023] Open
Abstract
Increasing evidence indicates that changes in the redox system may contribute to the pathogenesis of multiple optic neuropathies. Optic neuropathies are characterized by the neurodegeneration of the inner-most retinal neurons, the retinal ganglion cells (RGCs), and their axons, which form the optic nerve. Often, optic neuropathies are asymptomatic until advanced stages, when visual impairment or blindness is unavoidable despite existing treatments. In this review, we describe systemic and, whenever possible, ocular redox dysregulations observed in patients with glaucoma, ischemic optic neuropathy, optic neuritis, hereditary optic neuropathies (i.e., Leber's hereditary optic neuropathy and autosomal dominant optic atrophy), nutritional and toxic optic neuropathies, and optic disc drusen. We discuss aspects related to anti/oxidative stress biomarkers that need further investigation and features related to study design that should be optimized to generate more valuable and comparable results. Understanding the role of oxidative stress in optic neuropathies can serve to develop therapeutic strategies directed at the redox system to arrest the neurodegenerative processes in the retina and RGCs and ultimately prevent vision loss.
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Affiliation(s)
- Berta Sanz-Morello
- Eye Translational Research Unit, Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, 2100 Copenhagen, Denmark; (B.S.-M.); (H.A.); (R.V.)
| | - Hamid Ahmadi
- Eye Translational Research Unit, Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, 2100 Copenhagen, Denmark; (B.S.-M.); (H.A.); (R.V.)
- Department of Ophthalmology, Rigshospitalet, 2600 Glostrup, Denmark;
| | - Rupali Vohra
- Eye Translational Research Unit, Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, 2100 Copenhagen, Denmark; (B.S.-M.); (H.A.); (R.V.)
- Group of Stem Cell Models for Studies of Neurodegenerative Diseases, Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, 1870 Frederiksberg, Denmark; (S.S.); (K.K.F.)
| | - Sarkis Saruhanian
- Group of Stem Cell Models for Studies of Neurodegenerative Diseases, Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, 1870 Frederiksberg, Denmark; (S.S.); (K.K.F.)
| | - Kristine Karla Freude
- Group of Stem Cell Models for Studies of Neurodegenerative Diseases, Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, 1870 Frederiksberg, Denmark; (S.S.); (K.K.F.)
| | - Steffen Hamann
- Department of Ophthalmology, Rigshospitalet, 2600 Glostrup, Denmark;
| | - Miriam Kolko
- Eye Translational Research Unit, Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, 2100 Copenhagen, Denmark; (B.S.-M.); (H.A.); (R.V.)
- Department of Ophthalmology, Rigshospitalet, 2600 Glostrup, Denmark;
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11
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Raviskanthan S, Ahuja P, Mortensen PW, Milea D, Lee AG. Delayed diagnosis of autosomal dominant optic atrophy until seventh decade of life. Can J Ophthalmol 2021; 57:e96-e100. [PMID: 34534508 DOI: 10.1016/j.jcjo.2021.08.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Revised: 08/05/2021] [Accepted: 08/17/2021] [Indexed: 11/16/2022]
Affiliation(s)
| | - Pranati Ahuja
- School of Medicine, University of Texas Medical Branch, Galveston, Tex
| | | | - Dan Milea
- Singapore National Eye Center, Singapore;; Singapore Eye Research Institute, Singapore;; Duke-NUS Medical School, Singapore;; Copenhagen University Hospital, Copenhagen, Denmark
| | - Andrew G Lee
- Blanton Eye Institute, Houston Methodist Hospital, Houston, Tex.;; Weill Cornell Medicine, New York, NY;; University of Texas Medical Branch, Galveston, Tex.;; University of Texas MD Anderson Cancer Center, Houston, Tex.;; Texas A&M College of Medicine, Bryan, Tex.;; University of Iowa Hospitals and Clinics, Iowa City, Iowa;.
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12
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Weisschuh N, Schimpf-Linzenbold S, Mazzola P, Kieninger S, Xiao T, Kellner U, Neuhann T, Kelbsch C, Tonagel F, Wilhelm H, Kohl S, Wissinger B. Mutation spectrum of the OPA1 gene in a large cohort of patients with suspected dominant optic atrophy: Identification and classification of 48 novel variants. PLoS One 2021; 16:e0253987. [PMID: 34242285 PMCID: PMC8270428 DOI: 10.1371/journal.pone.0253987] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Accepted: 06/17/2021] [Indexed: 12/18/2022] Open
Abstract
Autosomal dominant optic atrophy is one of the most common inherited optic neuropathies. This disease is genetically heterogeneous, but most cases are due to pathogenic variants in the OPA1 gene: depending on the population studied, 32–90% of cases harbor pathogenic variants in this gene. The aim of this study was to provide a comprehensive overview of the entire spectrum of likely pathogenic variants in the OPA1 gene in a large cohort of patients. Over a period of 20 years, 755 unrelated probands with a diagnosis of bilateral optic atrophy were referred to our laboratory for molecular genetic investigation. Genetic testing of the OPA1 gene was initially performed by a combined analysis using either single-strand conformation polymorphism or denaturing high performance liquid chromatography followed by Sanger sequencing to validate aberrant bands or melting profiles. The presence of copy number variations was assessed using multiplex ligation-dependent probe amplification. Since 2012, genetic testing was based on next-generation sequencing platforms. Genetic screening of the OPA1 gene revealed putatively pathogenic variants in 278 unrelated probands which represent 36.8% of the entire cohort. A total of 156 unique variants were identified, 78% of which can be considered null alleles. Variant c.2708_2711del/p.(V903Gfs*3) was found to constitute 14% of all disease-causing alleles. Special emphasis was placed on the validation of splice variants either by analyzing cDNA derived from patients´ blood samples or by heterologous splice assays using minigenes. Splicing analysis revealed different aberrant splicing events, including exon skipping, activation of exonic or intronic cryptic splice sites, and the inclusion of pseudoexons. Forty-eight variants that we identified were novel. Nine of them were classified as pathogenic, 34 as likely pathogenic and five as variant of uncertain significance. Our study adds a significant number of novel variants to the mutation spectrum of the OPA1 gene and will thereby facilitate genetic diagnostics of patients with suspected dominant optic atrophy.
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Affiliation(s)
- Nicole Weisschuh
- Institute for Ophthalmic Research, Centre for Ophthalmology, University of Tübingen, Tübingen, Germany
| | - Simone Schimpf-Linzenbold
- Institute for Ophthalmic Research, Centre for Ophthalmology, University of Tübingen, Tübingen, Germany.,CeGaT GmbH and Praxis für Humangenetik Tübingen, Tübingen, Germany
| | - Pascale Mazzola
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Tübingen, Germany
| | - Sinja Kieninger
- Institute for Ophthalmic Research, Centre for Ophthalmology, University of Tübingen, Tübingen, Germany
| | - Ting Xiao
- Institute for Ophthalmic Research, Centre for Ophthalmology, University of Tübingen, Tübingen, Germany
| | - Ulrich Kellner
- Zentrum für seltene Netzhauterkrankungen, AugenZentrum Siegburg, MVZ Augenärztliches Diagnostik- und Therapiecentrum Siegburg GmbH, Siegburg, Germany.,RetinaScience, Bonn, Germany
| | | | - Carina Kelbsch
- Centre for Ophthalmology, University Eye Hospital, University of Tübingen, Tübingen, Germany
| | - Felix Tonagel
- Centre for Ophthalmology, University Eye Hospital, University of Tübingen, Tübingen, Germany
| | - Helmut Wilhelm
- Centre for Ophthalmology, University Eye Hospital, University of Tübingen, Tübingen, Germany
| | - Susanne Kohl
- Institute for Ophthalmic Research, Centre for Ophthalmology, University of Tübingen, Tübingen, Germany
| | - Bernd Wissinger
- Institute for Ophthalmic Research, Centre for Ophthalmology, University of Tübingen, Tübingen, Germany
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13
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Senthil S, Nakka M, Sachdeva V, Goyal S, Sahoo N, Choudhari N. Glaucoma Mimickers: A major review of causes, diagnostic evaluation, and recommendations. Semin Ophthalmol 2021; 36:692-712. [PMID: 33689583 DOI: 10.1080/08820538.2021.1897855] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Background: Glaucoma is characterized by chronic progressive optic neuropathy with corresponding visual field changes, with or without raised intraocular pressure (IOP). When diagnosing glaucoma or monitoring its progression, the examiner has to rely on the appearance of the optic disc, characteristic retinal nerve fiber layer defects, and corresponding visual field defects. However, similar changes and symptoms may be observed in several other disorders of the optic nerve and retina that may mimic glaucoma, often leading to misdiagnosis. Methods and result: The consequences of misdiagnosis not only result in improper treatment that may impact vision but also would negatively affect the overall health, psychological well-being of the patient, and may have considerable economic implications.Conclusion: The current review describes various conditions that mimic glaucoma and the features that help differentiate these conditions from glaucoma.
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Affiliation(s)
- Sirisha Senthil
- VST Glaucoma Center, L V Prasad Eye Institute, Hyderabad, India
| | - Mamata Nakka
- VST Glaucoma Center, L V Prasad Eye Institute, Hyderabad, India
| | - Virender Sachdeva
- Nimmagada Prasad Children's Eye Care Centre, GMRV Campus, L V Prasad Eye Institute, Visakhapatnam, India
| | - Shaveta Goyal
- VST Glaucoma Center, L V Prasad Eye Institute, Hyderabad, India
| | - Nibedita Sahoo
- MTC Campus, L V Prasad Eye Institute, Bhubaneswar, India
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14
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Lock JH, Irani NK, Newman NJ. Neuro-ophthalmic manifestations of mitochondrial disorders and their management. Taiwan J Ophthalmol 2020; 11:39-52. [PMID: 33767954 PMCID: PMC7971441 DOI: 10.4103/tjo.tjo_68_20] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Accepted: 09/23/2020] [Indexed: 12/30/2022] Open
Abstract
The visual system has high metabolic requirements and is therefore particularly vulnerable to mitochondrial dysfunction. The most commonly affected tissues include the extraocular muscles, photoreceptors, retinal pigment epithelium, optic nerve and visual cortex. Hence, the most common manifestations of mitochondrial disorders are progressive external ophthalmoplegia, macular pattern dystrophy, pigmentary retinopathy, optic neuropathy and retrochiasmal visual field loss. With the exception of Leber hereditary optic neuropathy and stroke-like episodes seen in mitochondrial encephalopathy, lactic acidosis and stroke-like episodes, the majority of neuro-ophthalmic manifestations have an insidious onset. As such, some patients may not recognize subtle progressive visual symptoms. When mitochondrial disorders are highly suspected, meticulous examination performed by an ophthalmologist with targeted ancillary testing can help confirm the diagnosis. Similarly, neuro-ophthalmic symptoms and signs may be the first indication of mitochondrial disease and should prompt systemic investigations for potentially life-threatening associations, such as cardiac conduction defects. Finally, the ophthalmologist can offer symptomatic treatments for some of the most disabling manifestations of these disorders.
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Affiliation(s)
- Jane H Lock
- Department of Ophthalmology, Royal Perth Hospital, Perth, WA, Australia.,Department of Ophthalmology, Sir Charles Gairdner Hospital, Perth, WA, Australia.,Department of Ophthalmology, Perth's Children's Hospital, Perth, WA, Australia
| | - Neha K Irani
- Department of Ophthalmology, Royal Perth Hospital, Perth, WA, Australia.,Department of Neurology, Fiona Stanley Hospital, Perth, WA, Australia.,Department of Neurology, Joondalup Health Campus, Perth, WA, Australia
| | - Nancy J Newman
- Department of Ophthalmology, Emory University School of Medicine, Atlanta, GA, USA.,Department of Neurology, Emory University School of Medicine, Atlanta, GA, USA.,Department of Neurological Surgery, Emory University School of Medicine, Atlanta, GA, USA
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15
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Gibson S, Azamian MS, Lalani SR, Yen KG, Sutton VR, Scott DA. Recessive ACO2 variants as a cause of isolated ophthalmologic phenotypes. Am J Med Genet A 2020; 182:1960-1966. [PMID: 32449285 DOI: 10.1002/ajmg.a.61634] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2020] [Revised: 04/15/2020] [Accepted: 05/04/2020] [Indexed: 12/20/2022]
Abstract
The mitochondrial aconitase gene (ACO2) encodes an enzyme that catalyzes the conversion of citrate to isocitrate in the tricarboxylic acid cycle. Biallelic variants in ACO2 are purported to cause two distinct disorders: infantile cerebellar-retinal degeneration (ICRD) which is characterized by CNS abnormalities, neurodevelopmental phenotypes, optic atrophy and retinal degeneration; and optic atrophy 9 (OPA9), characterized by isolated ophthalmologic phenotypes including optic atrophy and low vision. However, some doubt remains as to whether biallelic ACO2 variants can cause isolated ophthalmologic phenotypes. A review of the literature revealed five individuals from three families who carry biallelic ACO2 variants whose phenotypes are consistent with OPA9. Here, we describe a brother and sister with OPA9 who are compound heterozygous for novel missense variants in ACO2; c.[487G>T];[1894G>A], p.[(Val163Leu)];[(Val632Met)]. A review of pathogenic ACO2 variants revealed that those associated with OPA9 are distinct from those associated with ICRD. Missense variants associated with either OPA9 or ICRD do not cluster in distinct ACO2 domains, making it difficult to predict the severity of a variant based on position alone. We conclude that biallelic variants in ACO2 can cause the milder OPA9 phenotype, and that the OPA9-related ACO2 variants identified to date are distinct from those that cause ICRD.
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Affiliation(s)
- Shelley Gibson
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, USA
| | - Mahshid S Azamian
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, USA
- Texas Children's Hospital, Houston, Texas, USA
| | - Seema R Lalani
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, USA
- Texas Children's Hospital, Houston, Texas, USA
| | - Kimberly G Yen
- Texas Children's Hospital, Houston, Texas, USA
- Department of Ophthalmology, Baylor College of Medicine, Houston, Texas, USA
| | - V Reid Sutton
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, USA
- Texas Children's Hospital, Houston, Texas, USA
| | - Daryl A Scott
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, USA
- Texas Children's Hospital, Houston, Texas, USA
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, Texas, USA
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16
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Mitochondrial disorders and the eye. Surv Ophthalmol 2019; 65:294-311. [PMID: 31783046 DOI: 10.1016/j.survophthal.2019.11.001] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2019] [Revised: 11/16/2019] [Accepted: 11/18/2019] [Indexed: 01/27/2023]
Abstract
Mitochondria are cellular organelles that play a key role in energy metabolism and oxidative phosphorylation. Malfunctioning of mitochondria has been implicated as the cause of many disorders with variable inheritance, heterogeneity of systems involved, and varied phenotype. Metabolically active tissues are more likely to be affected, causing an anatomic and physiologic disconnect in the treating physicians' mind between presentation and underlying pathophysiology. We shall focus on disorders of mitochondrial metabolism relevant to an ophthalmologist. These disorders can affect all parts of the visual pathway (crystalline lens, extraocular muscles, retina, optic nerve, and retrochiasm). After the introduction reviewing mitochondrial structure and function, each disorder is reviewed in detail, including approaches to its diagnosis and most current management guidelines.
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17
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Le Roux B, Lenaers G, Zanlonghi X, Amati-Bonneau P, Chabrun F, Foulonneau T, Caignard A, Leruez S, Gohier P, Procaccio V, Milea D, den Dunnen JT, Reynier P, Ferré M. OPA1: 516 unique variants and 831 patients registered in an updated centralized Variome database. Orphanet J Rare Dis 2019; 14:214. [PMID: 31500643 PMCID: PMC6734442 DOI: 10.1186/s13023-019-1187-1] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2019] [Accepted: 08/30/2019] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The dysfunction of OPA1, a dynamin GTPase involved in mitochondrial fusion, is responsible for a large spectrum of neurological disorders, each of which includes optic neuropathy. The database dedicated to OPA1 ( https://www.lovd.nl/OPA1 ), created in 2005, has now evolved towards a centralized and more reliable database using the Global Variome shared Leiden Open-source Variation Database (LOVD) installation. RESULTS The updated OPA1 database, which registers all the patients from our center as well as those reported in the literature, now covers a total of 831 patients: 697 with isolated dominant optic atrophy (DOA), 47 with DOA "plus", and 83 with asymptomatic or unclassified DOA. It comprises 516 unique OPA1 variants, of which more than 80% (414) are considered pathogenic. Full clinical data for 118 patients are documented using the Human Phenotype Ontology, a standard vocabulary for referencing phenotypic abnormalities. Contributors may now make online submissions of phenotypes related to OPA1 mutations, giving clinical and molecular descriptions together with detailed ophthalmological and neurological data, according to an international thesaurus. CONCLUSIONS The evolution of the OPA1 database towards the LOVD, using unified nomenclature, should ensure its interoperability with other databases and prove useful for molecular diagnoses based on gene-panel sequencing, large-scale mutation statistics, and genotype-phenotype correlations.
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Affiliation(s)
- Bastien Le Roux
- Département d'Ophtalmologie, Centre Hospitalier Universitaire d'Angers, Angers, France
| | - Guy Lenaers
- Unité Mixte de Recherche MITOVASC, CNRS 6015/INSERM 1083, Université d'Angers, Angers, France
| | - Xavier Zanlonghi
- Centre de Compétence Maladie Rare, Clinique Jules Verne, Nantes, France
| | - Patrizia Amati-Bonneau
- Unité Mixte de Recherche MITOVASC, CNRS 6015/INSERM 1083, Université d'Angers, Angers, France.,Département de Biochimie et Génétique, Centre Hospitalier Universitaire d'Angers, Angers, France
| | - Floris Chabrun
- Unité Mixte de Recherche MITOVASC, CNRS 6015/INSERM 1083, Université d'Angers, Angers, France.,Département de Biochimie et Génétique, Centre Hospitalier Universitaire d'Angers, Angers, France
| | - Thomas Foulonneau
- Unité Mixte de Recherche MITOVASC, CNRS 6015/INSERM 1083, Université d'Angers, Angers, France
| | - Angélique Caignard
- Département d'Ophtalmologie, Centre Hospitalier Universitaire d'Angers, Angers, France
| | - Stéphanie Leruez
- Département d'Ophtalmologie, Centre Hospitalier Universitaire d'Angers, Angers, France
| | - Philippe Gohier
- Département d'Ophtalmologie, Centre Hospitalier Universitaire d'Angers, Angers, France
| | - Vincent Procaccio
- Unité Mixte de Recherche MITOVASC, CNRS 6015/INSERM 1083, Université d'Angers, Angers, France.,Département de Biochimie et Génétique, Centre Hospitalier Universitaire d'Angers, Angers, France
| | - Dan Milea
- Singapore National Eye Center, Singapore Eye Research Institute, Duke-NUS, Singapore, Singapore
| | - Johan T den Dunnen
- Human Genetics and Clinical Genetics, Leiden University Medical Center, Leiden, The Netherlands
| | - Pascal Reynier
- Unité Mixte de Recherche MITOVASC, CNRS 6015/INSERM 1083, Université d'Angers, Angers, France.,Département de Biochimie et Génétique, Centre Hospitalier Universitaire d'Angers, Angers, France
| | - Marc Ferré
- Unité Mixte de Recherche MITOVASC, CNRS 6015/INSERM 1083, Université d'Angers, Angers, France.
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18
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19
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Ham M, Han J, Osann K, Smith M, Kimonis V. Meta-analysis of genotype-phenotype analysis of OPA1 mutations in autosomal dominant optic atrophy. Mitochondrion 2018; 46:262-269. [PMID: 30165240 DOI: 10.1016/j.mito.2018.07.006] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2018] [Revised: 05/20/2018] [Accepted: 07/31/2018] [Indexed: 01/21/2023]
Abstract
Autosomal Dominant Optic Atrophy (ADOA) is a neuro-ophthalmic disease characterized by progressive bilateral vision loss, pallor of the optic disc, central vision loss, and impairment of color vision. Additionally, a small percentage of patients experience hearing loss and ataxia, while recent studies suggest disruption of cardiac and neuromuscular functions. In order to obtain a better understanding of the genotype-phenotype correlation of the various mutations in the optic atrophy 1 (OPA1) gene, we obtained both clinical and genetic information of ADOA patients from published reports. We conducted a systematic review of published OPA1 literature and identified 408 individuals with confirmed OPA1 mutations, 120 of whom reported extra-ocular (ADOA 'plus') manifestations through their descriptions of visual and multi-systemic symptoms. Our results show that there is a significant variation in frequency of the specific exons involved between the ADOA classic and ADOA 'plus' patients. Classic ADOA groups were more likely to have mutations in exon 8 and 9, while ADOA 'plus' groups were more likely to have mutations in exons 14, 15 and 17. Additional comparisons revealed significant differences between mutation types/domains and specific ADOA 'plus' manifestations. We also found that individuals with maternally inherited OPA1 mutations were significantly more likely to develop 'plus' manifestations than those with paternally inherited mutations. Overall, this study provides novel information regarding genotype-phenotype correlations of ADOA which warrants additional recommendations added to the current clinical management of ADOA patients.
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Affiliation(s)
- Michelle Ham
- Division of Genetics and Genomic Medicine, Department of Pediatrics, University of California, Irvine, CA, USA
| | - Julia Han
- Division of Genetics and Genomic Medicine, Department of Pediatrics, University of California, Irvine, CA, USA
| | - Kathryn Osann
- Department of Medicine, Division of Hematology-Oncology, University of California, Irvine, CA, USA
| | - Moyra Smith
- Division of Genetics and Genomic Medicine, Department of Pediatrics, University of California, Irvine, CA, USA
| | - Virginia Kimonis
- Division of Genetics and Genomic Medicine, Department of Pediatrics, University of California, Irvine, CA, USA.
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20
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Li H, Jones EM, Li H, Yang L, Sun Z, Yuan Z, Chen R, Dong F, Sui R. Clinical and genetic features of eight Chinese autosomal-dominant optic atrophy pedigrees with six novel OPA1 pathogenic variants. Ophthalmic Genet 2018; 39:569-576. [PMID: 29952689 DOI: 10.1080/13816810.2018.1466337] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
BACKGROUND Autosomal-dominant optic atrophy (ADOA) is one of the most common types of inherited optic atrophy. We identify OPA1 pathogenic variants and assess the clinical features of a cohort of Chinese ADOA patients Materials and Methods: Detailed clinical evaluations were performed and genomic DNA was extracted from peripheral blood for all the participants. Sanger sequencing was used to analyze all exons and exon/intron junctions of OPA1 for eight pedigrees. Target exome capture plus next-generation sequencing (NGS) were applied for one atypical family with photophobia. Reverse transcription polymerase chain reaction was carried out to further characterize the mRNA change of selected splicing alteration. RESULTS All 17 patients had impaired vision and optic-disk pallor; however, the clinical severity varied markedly. Two patients complicated with hearing loss. Six novel and two reported pathogenic variants in OPA1 (GenBank Accession No. NM_130837.2) were identified including four nonsynonymous variants (c.2400T > G, c.1468T > C, c.1567A > G and c.1466T > C), two splicing variants (c.2984-1_2986delGAGA and c.2983 + 5G > A), one small deletion (c.2960_2968delGCGTTCAAC), and one small insertion (c.3009_3010insA). RNA analysis revealed the splicing variant c.2984-1_2986delGAGA caused small deletion of mRNA (r.2983_2988del). CONCLUSIONS ADOA patients presented variable clinical manifestations. Novel OPA1 pathogenic variants are the main genetic defect for Chinese ADOA cases. NGS may be a useful molecular testing tool for atypical ADOA.
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Affiliation(s)
- Huajin Li
- a Department of Ophthalmology , Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences , Beijing , China
| | - Evan M Jones
- b Department of Molecular and Human Genetics , Baylor College of Medicine , Houston , TX , USA
| | - Hui Li
- a Department of Ophthalmology , Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences , Beijing , China
| | - Lizhu Yang
- a Department of Ophthalmology , Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences , Beijing , China
| | - Zixi Sun
- a Department of Ophthalmology , Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences , Beijing , China
| | - Zhisheng Yuan
- a Department of Ophthalmology , Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences , Beijing , China
| | - Rui Chen
- b Department of Molecular and Human Genetics , Baylor College of Medicine , Houston , TX , USA
| | - Fangtian Dong
- a Department of Ophthalmology , Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences , Beijing , China
| | - Ruifang Sui
- a Department of Ophthalmology , Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences , Beijing , China
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21
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Liskova P, Tesarova M, Dudakova L, Svecova S, Kolarova H, Honzik T, Seto S, Votruba M. OPA1 analysis in an international series of probands with bilateral optic atrophy. Acta Ophthalmol 2017; 95:363-369. [PMID: 27860320 DOI: 10.1111/aos.13285] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2016] [Accepted: 09/02/2016] [Indexed: 01/16/2023]
Abstract
PURPOSE To determine the molecular genetic cause in previously unreported probands with optic atrophy from the United Kingdom, Czech Republic and Canada. METHODS OPA1 coding regions and flanking intronic sequences were screened by direct sequencing in 82 probands referred with a diagnosis of bilateral optic atrophy. Detected rare variants were assessed for pathogenicity by in silico analysis. Segregation of the identified variants was performed in available first degree relatives. RESULTS A total of 29 heterozygous mutations evaluated as pathogenic were identified in 42 probands, of these seven were novel. In two probands, only variants of unknown significance were found. 76% of pathogenic mutations observed in 30 (71%) of 42 probands were evaluated to lead to unstable transcripts resulting in haploinsufficiency. Three probands with the following disease-causing mutations c.1230+1G>A, c.1367G>A and c.2965dup were documented to suffer from hearing loss and/or neurological impairment. CONCLUSIONS OPA1 gene screening in patients with bilateral optic atrophy is an important part of clinical evaluation as it may establish correct clinical diagnosis. Our study expands the spectrum of OPA1 mutations causing dominant optic atrophy and supports the fact that haploinsufficiency is the most common disease mechanism.
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Affiliation(s)
- Petra Liskova
- Institute of Inherited Metabolic Disorders; First Faculty of Medicine; Charles University and General University Hospital in Prague; Prague Czech Republic
- Department of Ophthalmology; First Faculty of Medicine; Charles University and General University Hospital in Prague; Prague Czech Republic
| | - Marketa Tesarova
- Department of Paediatrics and Adolescent Medicine; First Faculty of Medicine; Charles University and General University Hospital in Prague; Prague Czech Republic
| | - Lubica Dudakova
- Institute of Inherited Metabolic Disorders; First Faculty of Medicine; Charles University and General University Hospital in Prague; Prague Czech Republic
| | - Stepanka Svecova
- Department of Paediatrics and Adolescent Medicine; First Faculty of Medicine; Charles University and General University Hospital in Prague; Prague Czech Republic
| | - Hana Kolarova
- Department of Paediatrics and Adolescent Medicine; First Faculty of Medicine; Charles University and General University Hospital in Prague; Prague Czech Republic
| | - Tomas Honzik
- Department of Paediatrics and Adolescent Medicine; First Faculty of Medicine; Charles University and General University Hospital in Prague; Prague Czech Republic
| | - Sharon Seto
- Cardiff Eye Unit; University Hospital of Wales; Cardiff UK
- School of Optometry & Vision Sciences; Cardiff University; Cardiff UK
| | - Marcela Votruba
- Cardiff Eye Unit; University Hospital of Wales; Cardiff UK
- School of Optometry & Vision Sciences; Cardiff University; Cardiff UK
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22
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Kamel K, Farrell M, O'Brien C. Mitochondrial dysfunction in ocular disease: Focus on glaucoma. Mitochondrion 2017; 35:44-53. [PMID: 28499981 DOI: 10.1016/j.mito.2017.05.004] [Citation(s) in RCA: 59] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2016] [Revised: 03/08/2017] [Accepted: 05/08/2017] [Indexed: 12/21/2022]
Abstract
Mitochondrial dysfunction commonly presents with ocular findings as a part of a systemic disorder. These ophthalmic manifestations can be the first sign of a mitochondrial abnormality, which highlights the key role of a comprehensive ophthalmic assessment. On the other hand, a number of visually disabling genetic and acquired eye diseases with no curative treatment show abnormal mitochondrial function. Recent advances in mitochondrial research have improved our understanding of previously unexplained ocular disorders utilising better diagnostic approaches. Further studies on mitochondrial dysfunction and novel modalities of treatment will help to improve outcomes of these conditions. In this review article we discuss the clinical picture of common mitochondrial-related eye diseases, diagnostic approaches and possible treatment options including a very recent interesting report about gene therapy, with a particular focus on glaucoma.
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Affiliation(s)
- Khalid Kamel
- Institute of Ophthalmology, Mater Misericordiae University Hospital, Dublin, Ireland
| | | | - Colm O'Brien
- Institute of Ophthalmology, Mater Misericordiae University Hospital, Dublin, Ireland.
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23
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Assessment of the retinal posterior pole in dominant optic atrophy by spectral-domain optical coherence tomography and microperimetry. PLoS One 2017; 12:e0174560. [PMID: 28358911 PMCID: PMC5373574 DOI: 10.1371/journal.pone.0174560] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2016] [Accepted: 03/11/2017] [Indexed: 11/24/2022] Open
Abstract
Background To assess posterior pole (PP) retinal structure in patients with genetically confirmed autosomal dominant optic atrophy (ADOA) using new spectral domain optical coherence tomography (SD-OCT) segmentation technology. To analyze retinal PP thickness in relation to retinal sensitivity data from microperimetry (MP) in ADOA patients. Methods and findings This prospective cross-sectional study included 11 patients with ADOA and 11 age-matched healthy subjects. All participants underwent both a “Posterior Pole” and “peripapillary RNFL (pRNFL)” scanning protocol using SD-OCT. Functional mapping of the PP was also performed using MP. A customized program was implemented in order to achieve accurate superimposition of MP sensitivity map onto SD-OCT map. The thickness of the PP different retinal layers and pRNFL was obtained and measured for each eye. Mean retinal sensitivity values and fixation stability were obtained and compared between ADOA patients and healthy subjects. Correlation analysis was performed on a point-to-point basis to evaluate the association between mean thickness and retinal sensitivity of each retinal layer. Total retinal thickness (TRT), Retinal Nerve Fiber Layer (RNFL), Ganglion Cell Layer (GCL), Inner Plexiform Layer (IPL), Inner Nuclear Layer (INL) and Inner Retinal Layers (IRL) at the posterior pole as well as pRNFL were significantly thinner in ADOA patients (P < 0.0001). On the contrary, the Outer Plexiform Layer (OPL) and the Outer Nuclear Layer (ONL) were significantly thicker in the ADOA group (P < 0.001). No significant differences were found in Retinal Pigment Epithelium (RPE) and Outer Retinal Layers (ORL) thickness between ADOA and controls. The average PP retinal sensitivity was significantly reduced in ADOA patients compared with controls (P < 0.001), as measured by microperimeter Nidek MP-1 (MP1). Fixation stability was significantly worse in the ADOA group (P = 0.01). The most severe sensitivity defects in ADOA patients were found at the level of the papillo-macular bundle (PMB). Conclusions Inner retinal layers showed pathological changes in ADOA patients. In addition, the whole retinal PP (not only the PMB) was significantly altered in ADOA, both in terms of retinal thickness and sensitivity.
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Characterization of two novel intronic OPA1 mutations resulting in aberrant pre-mRNA splicing. BMC MEDICAL GENETICS 2017; 18:22. [PMID: 28245802 PMCID: PMC5331656 DOI: 10.1186/s12881-017-0383-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/06/2016] [Accepted: 02/17/2017] [Indexed: 12/24/2022]
Abstract
BACKGROUND We report two novel splice region mutations in OPA1 in two unrelated families presenting with autosomal-dominant optic atrophy type 1 (ADOA1) (ADOA or Kjer type optic atrophy). Mutations in OPA1 encoding a mitochondrial inner membrane protein are a major cause of ADOA. METHODS We analyzed two unrelated families including four affected individuals clinically suspicious of ADOA. Standard ocular examinations were performed in affected individuals of both families. All coding exons, as well as exon-intron boundaries of the OPA1 gene were sequenced. In addition, multiplex ligation-dependent probe amplification (MLPA) was performed to uncover copy number variations in OPA1. mRNA processing was monitored using RT-PCR and subsequent cDNA analysis. RESULTS We report two novel splice region mutations in OPA1 in two unrelated individuals and their affected relatives, which were previously not described in the literature. In one family the heterozygous insertion and deletion c.[611-37_611-38insACTGGAGAATGTAAAGGGCTTT;611-6_611-16delCATATTTATCT] was found in all investigated family members leading to the activation of an intronic cryptic splice site. In the second family sequencing of OPA1 disclosed a de novo heterozygous deletion c.2012+4_2012+7delAGTA resulting in exon 18 and 19 skipping, which was not detected in healthy family members. CONCLUSION We identified two novel intronic mutations in OPA1 affecting the correct OPA1 pre-mRNA splicing, which was confirmed by OPA1 cDNA analysis. This study shows the importance of transcript analysis to determine the consequences of unclear intronic mutations in OPA1 in proximity to the intron-exon boundaries.
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Inoue M, Himori N, Kunikata H, Takeshita T, Aizawa N, Shiga Y, Omodaka K, Nishiguchi KM, Takahashi H, Nakazawa T. The reduction of temporal optic nerve head microcirculation in autosomal dominant optic atrophy. Acta Ophthalmol 2016; 94:e580-e585. [PMID: 26936288 DOI: 10.1111/aos.12999] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2015] [Accepted: 12/28/2015] [Indexed: 11/29/2022]
Abstract
PURPOSE To evaluate the optic nerve head (ONH) microcirculation in autosomal dominant optic atrophy (ADOA) patients. METHODS This study comprised 22 eyes of 12 ADOA patients, diagnosed according to clinical findings including family history and the presence of mutations in the OPA1 gene. Twenty-four normal eyes of 24 age-matched subjects, with either the right or left eye randomly selected for use, served as controls. Circumpapillary retinal nerve fibre layer thickness (cpRNFLT) and mean blur rate (MBR) in the ONH were determined with optical coherence tomography (OCT) and laser speckle flowgraphy (LSFG), respectively. For each ONH quadrant (superior, temporal, inferior and nasal), the MBR and cpRNFLT ratio was also calculated by dividing tissue MBR in that quadrant by tissue MBR in the entire ONH and by dividing cpRNFLT in that quadrant by cpRNFLT in the entire ONH respectively. RESULTS Mean blur rate (MBR) in all quadrants was significantly lower in the ADOA patients than in the controls (p < 0.001 in each). The MBR ratio was significantly lower in the ADOA patients only in the temporal quadrant (p < 0.001). Similarly, cpRNFLT was lower in the ADOA patients in all quadrants (p < 0.001 in each), and the cpRNFLT ratio was lower in the temporal quadrant (p < 0.001). CONCLUSION Reduced blood flow in the temporal optic disc in ADOA patients is associated with reduced temporal cpRNFLT, suggesting that both are caused by damage to the papillomacular bundle. The anatomical characteristics of the papillomacular bundle may make it especially susceptible to mitochondrial dysfunction-induced damage, which occurs in ADOA.
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Affiliation(s)
- Maki Inoue
- Department of Ophthalmology; Tohoku University Graduate School of Medicine; Sendai Japan
| | - Noriko Himori
- Department of Ophthalmology; Tohoku University Graduate School of Medicine; Sendai Japan
| | - Hiroshi Kunikata
- Department of Ophthalmology; Tohoku University Graduate School of Medicine; Sendai Japan
- Department of Retinal Disease Control; Tohoku University Graduate School of Medicine; Sendai Japan
| | - Takayuki Takeshita
- Department of Ophthalmology; Tohoku University Graduate School of Medicine; Sendai Japan
| | - Naoko Aizawa
- Department of Ophthalmology; Tohoku University Graduate School of Medicine; Sendai Japan
| | - Yukihiro Shiga
- Department of Ophthalmology; Tohoku University Graduate School of Medicine; Sendai Japan
| | - Kazuko Omodaka
- Department of Ophthalmology; Tohoku University Graduate School of Medicine; Sendai Japan
| | - Koji M Nishiguchi
- Department of Advanced Ophthalmic Medicine; Tohoku University Graduate School of Medicine; Sendai Japan
| | - Hidetoshi Takahashi
- Department of Ophthalmology; Tohoku University Graduate School of Medicine; Sendai Japan
| | - Toru Nakazawa
- Department of Ophthalmology; Tohoku University Graduate School of Medicine; Sendai Japan
- Department of Retinal Disease Control; Tohoku University Graduate School of Medicine; Sendai Japan
- Department of Advanced Ophthalmic Medicine; Tohoku University Graduate School of Medicine; Sendai Japan
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Rönnbäck C, Nissen C, Almind GJ, Grønskov K, Milea D, Larsen M. Genotype-phenotype heterogeneity of ganglion cell and inner plexiform layer deficit in autosomal-dominant optic atrophy. Acta Ophthalmol 2015; 93:762-6. [PMID: 26385429 DOI: 10.1111/aos.12835] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2015] [Accepted: 07/22/2015] [Indexed: 12/01/2022]
Abstract
PURPOSE To describe the thickness of the combined ganglion cell and inner plexiform layers (GC-IPL) and the peripapillary retinal nerve fibre layer (RNFL) in patients with OPA1 c.983A>G or c.2708_2711delTTAG autosomal-dominant optic atrophy (ADOA). METHODS The study included 20 individuals with c.983A>G and nine individuals with c.2708_2711delTTAG. Data for comparison were drawn from 49, previously published, individuals with OPA1 c.2826_2836delinsGGATGCTCCA and 51 individuals with no OPA1 mutation. Subjects underwent refraction, best-corrected visual acuity assessment, axial length measurement and high-definition optical coherence tomography. RESULTS There was overlap in GC-IPL thickness in subjects younger than 20-30 years between the two new groups of ADOA patients and controls. Numerical decreases in GC-IPL thickness with age did not reach statistical significance in individuals with c.983A>G (p = 0.18) or in healthy controls (p = 0.22), but it did in individuals with c.2708_2711delTTAG (p = 0.02). Visual acuity decreased with decreasing GC-IPL thickness (p = 0.0006 in c.983A>G and p = 0.0084 in c.2708_2711delTTAG). Unlike c.2826_2836delinsGGATGCTCCA, individuals with c.983A>G or c.2708_2711delTTAG did not show a pattern of maximum GC-IPL deficit inferonasal of the fovea. CONCLUSION Genotype-phenotype heterogeneity in OPA1 ADOA is evident when inner retinal atrophy is examined as a function of age. Thus, a pronounced decline with age in GC-IPL thickness is observed in c.2708_2711delTTAG ADOA, an intermediate decline with age is observed in c.983A>G ADOA, whereas little or no change with age is observed in c.2826_2836delinsGGATGCTCCA ADOA. This genotype-phenotype heterogeneity may explain why some patients have progressive visual loss while others have a relatively stable prognosis.
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Affiliation(s)
- Cecilia Rönnbäck
- Department of Ophthalmology; Glostrup Hospital; Glostrup Denmark
- Faculty of Health Sciences; University of Copenhagen; Copenhagen Denmark
| | - Claus Nissen
- Department of Ophthalmology; Glostrup Hospital; Glostrup Denmark
- Faculty of Health Sciences; University of Copenhagen; Copenhagen Denmark
| | - Gitte J. Almind
- Faculty of Health Sciences; University of Copenhagen; Copenhagen Denmark
- Kennedy Center; Clinical Genetic Clinic; Copenhagen Denmark
| | - Karen Grønskov
- Faculty of Health Sciences; University of Copenhagen; Copenhagen Denmark
- Kennedy Center; Clinical Genetic Clinic; Copenhagen Denmark
| | - Dan Milea
- Department of Ophthalmology; Glostrup Hospital; Glostrup Denmark
- Singapore Eye Research Institute; Singapore National Eye Centre and Duke-NUS; Singapore Singapore
| | - Michael Larsen
- Department of Ophthalmology; Glostrup Hospital; Glostrup Denmark
- Faculty of Health Sciences; University of Copenhagen; Copenhagen Denmark
- Kennedy Center; National Eye Clinic; Copenhagen Denmark
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Galvez-Ruiz A. Clinical variability in hereditary optic neuropathies: Two novel mutations in two patients with dominant optic atrophy and Wolfram syndrome. Saudi J Ophthalmol 2015; 29:307-11. [PMID: 26586986 PMCID: PMC4625377 DOI: 10.1016/j.sjopt.2015.03.003] [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: 10/22/2014] [Revised: 03/11/2015] [Accepted: 03/30/2015] [Indexed: 11/30/2022] Open
Abstract
Dominant optic atrophy (DOA) and Wolfram syndrome share a great deal of clinical variability, including an association with hearing loss and the presence of optic atrophy at similar ages. The objective of this paper was to discuss the phenotypic variability of these syndromes with respect to the presentation of two clinical cases. We present two patients, each with either DOA or Wolfram syndrome, and contribute to the research literature through our findings of two novel mutations. The overlapping of several clinical characteristics in hereditary optic neuropathies can complicate the differential diagnosis. Future studies are needed to better determine the genotype-phenotype correlation for these diseases.
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Affiliation(s)
- Alberto Galvez-Ruiz
- Neuro-ophthalmology Unit, King Khaled Eye Specialist Hospital, P.O. Box 7191. Riyadh 11462, Saudi Arabia
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Agarwal N, Hanumunthadu D, Afrasiabi M, Malaguarnera G, Cordeiro MF. Clinical update in optic nerve disorders. EXPERT REVIEW OF OPHTHALMOLOGY 2015. [DOI: 10.1586/17469899.2015.1003544] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Nissen C, Rönnbäck C, Sander B, Herbst K, Milea D, Larsen M, Lund-Andersen H. Dissociation of Pupillary Post-Illumination Responses from Visual Function in Confirmed OPA1 c.983A > G and c.2708_2711delTTAG Autosomal Dominant Optic Atrophy. Front Neurol 2015; 6:5. [PMID: 25699009 PMCID: PMC4316714 DOI: 10.3389/fneur.2015.00005] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2014] [Accepted: 01/09/2015] [Indexed: 12/03/2022] Open
Abstract
Purpose: To test whether the melanopsin-containing, intrinsically photosensitive retinal ganglion cells (ipRGCs), as evaluated by examination of the pupillary light reflex (PLR), are preserved in genetically confirmed autosomal dominant optic atrophy (ADOA). Method: Twenty-nine patients with either the c.983A > G (n = 14) or the c.2708_ 2711delTTAG mutation (n = 15) were examined with monochromatic pupillometry, using isoluminant (300 cd/m2), red (660 nm) or blue (470 nm) light, optical coherence tomography, automated visual field analysis, and with determination of best corrected visual acuity (BCVA). Since we examined two different mutations, initially we compared all outcome variables between the two, and finding no statistically significant difference, pooled them. Results: Despite a poor BCVA (56 letters, ETDRS) in the ADOA patients, their post-illuminatory pupil responses did not differ significantly from those of healthy controls (blue, p = 0.45, red, p = 0.49, t-test), and no statistically significant effect was noted of peripapillary retinal nerve fiber layer thickness, ganglion cell-inner plexiform layer thickness, or age. Conclusion: The PLR to blue light of high luminance (300 cd/m2) was preserved in both c.983A > G and c.2708_2711delTTAG ADOA despite severe visual loss and optic nerve atrophy. The study confirms, in a large sample of two genetically homogenous groups, that the ipRGCs are spared in ADOA.
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Affiliation(s)
- Claus Nissen
- Department of Ophthalmology, Glostrup Hospital, University of Copenhagen , Copenhagen , Denmark
| | - Cecilia Rönnbäck
- Department of Ophthalmology, Glostrup Hospital, University of Copenhagen , Copenhagen , Denmark
| | - Birgit Sander
- Department of Ophthalmology, Glostrup Hospital, University of Copenhagen , Copenhagen , Denmark
| | - Kristina Herbst
- Department of Ophthalmology, Glostrup Hospital, University of Copenhagen , Copenhagen , Denmark
| | - Dan Milea
- Department of Ophthalmology, Glostrup Hospital, University of Copenhagen , Copenhagen , Denmark ; Singapore National Eye Centre, Singapore Eye Research Institute, Duke-NUS Graduate Medical School Singapore , Singapore , Singapore ; Angers University Hospital , Angers , France
| | - Michael Larsen
- Department of Ophthalmology, Glostrup Hospital, University of Copenhagen , Copenhagen , Denmark
| | - Henrik Lund-Andersen
- Department of Ophthalmology, Glostrup Hospital, University of Copenhagen , Copenhagen , Denmark
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Fülöp L, Rajki A, Maka E, Molnár MJ, Spät A. Mitochondrial Ca2+ uptake correlates with the severity of the symptoms in autosomal dominant optic atrophy. Cell Calcium 2015; 57:49-55. [DOI: 10.1016/j.ceca.2014.11.008] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2014] [Revised: 11/28/2014] [Accepted: 11/29/2014] [Indexed: 12/22/2022]
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Ferré M, Caignard A, Milea D, Leruez S, Cassereau J, Chevrollier A, Amati-Bonneau P, Verny C, Bonneau D, Procaccio V, Reynier P. Improved Locus-Specific Database forOPA1Mutations Allows Inclusion of Advanced Clinical Data. Hum Mutat 2014; 36:20-5. [DOI: 10.1002/humu.22703] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2014] [Accepted: 09/12/2014] [Indexed: 11/09/2022]
Affiliation(s)
- Marc Ferré
- CNRS 6214/INSERM 1083; Angers University; Angers France
- Department of Biochemistry and Genetics; University Hospital; Angers France
| | - Angélique Caignard
- CNRS 6214/INSERM 1083; Angers University; Angers France
- Department of Ophthalmology; University Hospital; Angers France
| | - Dan Milea
- CNRS 6214/INSERM 1083; Angers University; Angers France
- Department of Ophthalmology; University Hospital; Angers France
- Singapore National Eye Centre, Singapore Eye Research Institute; Duke-NUS Singapore
| | - Stéphanie Leruez
- CNRS 6214/INSERM 1083; Angers University; Angers France
- Department of Ophthalmology; University Hospital; Angers France
| | - Julien Cassereau
- CNRS 6214/INSERM 1083; Angers University; Angers France
- Department of Neurology; University Hospital; Angers France
| | | | - Patrizia Amati-Bonneau
- CNRS 6214/INSERM 1083; Angers University; Angers France
- Department of Biochemistry and Genetics; University Hospital; Angers France
| | - Christophe Verny
- CNRS 6214/INSERM 1083; Angers University; Angers France
- Department of Neurology; University Hospital; Angers France
| | - Dominique Bonneau
- CNRS 6214/INSERM 1083; Angers University; Angers France
- Department of Biochemistry and Genetics; University Hospital; Angers France
| | - Vincent Procaccio
- CNRS 6214/INSERM 1083; Angers University; Angers France
- Department of Biochemistry and Genetics; University Hospital; Angers France
| | - Pascal Reynier
- CNRS 6214/INSERM 1083; Angers University; Angers France
- Department of Biochemistry and Genetics; University Hospital; Angers France
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Zhang L, Shi W, Song L, Zhang X, Cheng L, Wang Y, Ge X, Li W, Zhang W, Min Q, Jin ZB, Qu J, Gu F. A recurrent deletion mutation in OPA1 causes autosomal dominant optic atrophy in a Chinese family. Sci Rep 2014; 4:6936. [PMID: 25374051 PMCID: PMC4221781 DOI: 10.1038/srep06936] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2014] [Accepted: 10/20/2014] [Indexed: 11/23/2022] Open
Abstract
Autosomal dominant optic atrophy (ADOA) is the most frequent form of hereditary optic neuropathy and occurs due to the degeneration of the retinal ganglion cells. To identify the genetic defect in a family with putative ADOA, we performed capture next generation sequencing (CNGS) to screen known retinal disease genes. However, six exons failed to be sequenced by CNGS in optic atrophy 1 gene (OPA1). Sequencing of those exons identified a 4 bp deletion mutation (c.2983-1_2985del) in OPA1. Furthermore, we sequenced the transcripts of OPA1 from the patient skin fibroblasts and found there is six-nucleotide deletion (c.2984-c.2989, AGAAAG). Quantitative-PCR and Western blotting showed that OPA1 mRNA and its protein expression have no obvious difference between patient skin fibroblast and control. The analysis of protein structure by molecular modeling suggests that the mutation may change the structure of OPA1 by formation of an alpha helix protruding into an existing pocket. Taken together, we identified an OPA1 mutation in a family with ADOA by filling the missing CNGS data. We also showed that this mutation affects the structural intactness of OPA1. It provides molecular insights for clinical genetic diagnosis and treatment of optic atrophy.
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Affiliation(s)
- Liping Zhang
- School of Ophthalmology and Optometry, Eye Hospital, Wenzhou Medical University, State Key Laboratory Cultivation Base and Key Laboratory of Vision Science, Ministry of Health and Zhejiang Provincial Key Laboratory of Ophthalmology and Optometry, Wenzhou, Zhejiang 325027 China
| | - Wei Shi
- National Key Discipline of Pediatrics, Ministry of Education, Department of Ophthalmology, Beijing Children's Hospital, Capital Medical University, Beijing 100045, China
| | - Liming Song
- Department of Urology, Beijing Chao-yang Hospital, Capital Medical University, Beijing 100020 China
| | - Xiao Zhang
- School of Ophthalmology and Optometry, Eye Hospital, Wenzhou Medical University, State Key Laboratory Cultivation Base and Key Laboratory of Vision Science, Ministry of Health and Zhejiang Provincial Key Laboratory of Ophthalmology and Optometry, Wenzhou, Zhejiang 325027 China
| | - Lulu Cheng
- School of Ophthalmology and Optometry, Eye Hospital, Wenzhou Medical University, State Key Laboratory Cultivation Base and Key Laboratory of Vision Science, Ministry of Health and Zhejiang Provincial Key Laboratory of Ophthalmology and Optometry, Wenzhou, Zhejiang 325027 China
| | - Yanfang Wang
- Zhejiang Key Laboratory of Medical Genetics, School of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou, Zhejiang 325035 China
| | - Xianglian Ge
- School of Ophthalmology and Optometry, Eye Hospital, Wenzhou Medical University, State Key Laboratory Cultivation Base and Key Laboratory of Vision Science, Ministry of Health and Zhejiang Provincial Key Laboratory of Ophthalmology and Optometry, Wenzhou, Zhejiang 325027 China
| | - Wei Li
- Zhejiang Key Laboratory of Medical Genetics, School of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou, Zhejiang 325035 China
| | - Wei Zhang
- Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101 China
| | - Qingjie Min
- Institute of Genomic Medicine, Wenzhou Medical University, Wenzhou, Zhejiang 325027 China
| | - Zi-Bing Jin
- School of Ophthalmology and Optometry, Eye Hospital, Wenzhou Medical University, State Key Laboratory Cultivation Base and Key Laboratory of Vision Science, Ministry of Health and Zhejiang Provincial Key Laboratory of Ophthalmology and Optometry, Wenzhou, Zhejiang 325027 China
| | - Jia Qu
- School of Ophthalmology and Optometry, Eye Hospital, Wenzhou Medical University, State Key Laboratory Cultivation Base and Key Laboratory of Vision Science, Ministry of Health and Zhejiang Provincial Key Laboratory of Ophthalmology and Optometry, Wenzhou, Zhejiang 325027 China
| | - Feng Gu
- School of Ophthalmology and Optometry, Eye Hospital, Wenzhou Medical University, State Key Laboratory Cultivation Base and Key Laboratory of Vision Science, Ministry of Health and Zhejiang Provincial Key Laboratory of Ophthalmology and Optometry, Wenzhou, Zhejiang 325027 China
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Rönnbäck C, Grønskov K, Larsen M. Retinal vessel diameters decrease with macular ganglion cell layer thickness in autosomal dominant optic atrophy and in healthy subjects. Acta Ophthalmol 2014; 92:670-4. [PMID: 24612963 DOI: 10.1111/aos.12378] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2013] [Accepted: 01/29/2014] [Indexed: 11/27/2022]
Abstract
PURPOSE To investigate retinal trunk vessel diameters in subjects with autosomal dominant optic atrophy (ADOA) and mutation-free healthy relatives. METHODS This cross-sectional study included 52 ADOA patients with the optic atrophy 1 (OPA1) exon 28 (c.2826_2836delinsGGATGCTCCA) mutation (age 8.6-83.5 years) (best-corrected visual acuity (BCVA) 8-94 Early Treatment Diabetic Retinopathy Study (ETDRS) letters) and 55 mutation-free first-degree healthy relatives (age 8.9-68.7 years, BCVA 80-99). Analysis of fundus photographs provided integrated magnification-corrected measures of retinal vessel diameters (central retinal artery equivalent, CRAE, and central retinal vein equivalent, CRVE). Statistical analysis was corrected for age, gender, spherical equivalent refraction, axial length and mean arterial blood pressure (MABP) in a mixed model analysis. RESULTS Retinal arteries and veins were thinner in ADOA than in healthy controls (CRAE (mean ± 2 standard deviations (SD)) 153.9 ± 41.0 μm and CRVE 236.1 ± 42.0 μm in ADOA, CRAE 172.5 ± 25.0 μm (p = 0.0004) and CRVE 254.2 ± 37.6 μm (p = 0.0019) in healthy controls). MABP was comparable in the two groups (p = 0.18), and in both groups, CRAE decreased with increasing MABP (p = 0.01 and p < 0.0001, respectively). In ADOA, CRAE and CRVE decreased with age (p = 0.011 and p = 0.020, respectively) and CRAE decreased with decreasing BCVA (p = 0.011). In patients with ADOA and in healthy controls, CRAE decreased with decreasing average macular ganglion cell-inner plexiform layer (GC-IPL) thickness (p = 0.0017 and p = 0.0057, respectively). CONCLUSION Narrow retinal arteries and veins were associated not only with the severity of ADOA but with ganglion cell volume in patients with ADOA and in healthy subjects. This suggests that narrow vessels are a consequence rather than the cause of inner retinal hypoplasia or atrophy, although longitudinal studies are needed to confirm this hypothesis.
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Affiliation(s)
- Cecilia Rönnbäck
- Department of Ophthalmology; Glostrup Hospital; Glostrup Denmark
- Faculty of Health Sciences; University of Copenhagen; Copenhagen Denmark
| | - Karen Grønskov
- Faculty of Health Sciences; University of Copenhagen; Copenhagen Denmark
- Applied Human Molecular Genetics; Kennedy Center; Rigshospitalet; Copenhagen Denmark
| | - Michael Larsen
- Department of Ophthalmology; Glostrup Hospital; Glostrup Denmark
- Faculty of Health Sciences; University of Copenhagen; Copenhagen Denmark
- National Eye Clinic; Kennedy Center; Rigshospitalet; Copenhagen Denmark
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Mitochondrial dysfunction affecting visual pathways. Rev Neurol (Paris) 2014; 170:344-54. [DOI: 10.1016/j.neurol.2014.03.009] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2014] [Revised: 03/08/2014] [Accepted: 03/26/2014] [Indexed: 01/08/2023]
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Hereditäre Optikusatrophien. MED GENET-BERLIN 2014. [DOI: 10.1007/s11825-014-0435-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Zusammenfassung
Bei hereditären Optikusatrophien werden 2 Untergruppen differenziert: isolierte hereditäre Optikusatrophien und hereditäre Optikusatrophien als Teil von syndromalen Erkrankungen. In der 1. Gruppe ist die Beeinträchtigung des N. opticus typischerweise die einzige Manifestation. Diese Gruppe umfasst insbesondere autosomal-dominante und autosomal-rezessive Optikusatrophien, darüber hinaus auch die mitochondrial vererbte hereditäre Leber-Optikusneuropathie (LHON).
In der 2. Gruppe, die die syndromalen Erkrankungen umfasst, wird eine Vielzahl neurologischer und anderer systemischer Auffälligkeiten beobachtet. Am häufigsten sind hier Veränderungen der mitochondrialen DNA (mtDNA) ursächlich. Weiterhin ist eine Optikusatrophie Symptom von einigen erblichen peripheren Neuropathien bzw. Charcot-Marie-Tooth-Erkrankungen (CMT2A2, CMTX5), hereditären sensorischen Neuropathie Typ 3 (HSAN3), Friedreich-Ataxie, Leukodystrophien, Sphingolipidosen, Zeroidlipofuszinosen und Eisenspeichererkrankungen („neurodegeneration with brain iron accumulation“, NBIA). Im vorliegenden Beitrag werden die zugrundeliegenden genetischen Prädispositionen und die klinischen Phänotypen erläutert.
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Imaging of the Macula Indicates Early Completion of Structural Deficit in Autosomal-Dominant Optic Atrophy. Ophthalmology 2013; 120:2672-2677. [DOI: 10.1016/j.ophtha.2013.08.008] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2013] [Revised: 07/23/2013] [Accepted: 08/07/2013] [Indexed: 11/23/2022] Open
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High-resolution en face images of microcystic macular edema in patients with autosomal dominant optic atrophy. BIOMED RESEARCH INTERNATIONAL 2013; 2013:676803. [PMID: 24369534 PMCID: PMC3863472 DOI: 10.1155/2013/676803] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/07/2013] [Revised: 10/21/2013] [Accepted: 11/04/2013] [Indexed: 11/24/2022]
Abstract
The purpose of this study was to investigate the characteristics of microcystic macular edema (MME) determined from the en face images obtained by an adaptive optics (AO) fundus camera in patients with autosomal dominant optic atrophy (ADOA) and to try to determine the mechanisms underlying the degeneration of the inner retinal cells and RNFL by using the advantage of AO. Six patients from 4 families with ADOA underwent detailed ophthalmic examinations including spectral domain optical coherence tomography (SD-OCT). Mutational screening of all coding and flanking intron sequences of the OPA1 gene was performed by DNA sequencing. SD-OCT showed a severe reduction in the retinal nerve fiber layer (RNFL) thickness in all patients. A new splicing defect and two new frameshift mutations with premature termination of the Opa1 protein were identified in three families. A reported nonsense mutation was identified in one family. SD-OCT of one patient showed MME in the inner nuclear layer (INL) of the retina. AO images showed microcysts in the en face images of the INL. Our data indicate that AO is a useful method to identify MME in neurodegenerative diseases and may also help determine the mechanisms underlying the degeneration of the inner retinal cells and RNFL.
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Alavi MV, Fuhrmann N. Dominant optic atrophy, OPA1, and mitochondrial quality control: understanding mitochondrial network dynamics. Mol Neurodegener 2013; 8:32. [PMID: 24067127 PMCID: PMC3856479 DOI: 10.1186/1750-1326-8-32] [Citation(s) in RCA: 88] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2013] [Accepted: 09/16/2013] [Indexed: 12/13/2022] Open
Abstract
Mitochondrial quality control is fundamental to all neurodegenerative diseases, including the most prominent ones, Alzheimer’s Disease and Parkinsonism. It is accomplished by mitochondrial network dynamics – continuous fission and fusion of mitochondria. Mitochondrial fission is facilitated by DRP1, while MFN1 and MFN2 on the mitochondrial outer membrane and OPA1 on the mitochondrial inner membrane are essential for mitochondrial fusion. Mitochondrial network dynamics are regulated in highly sophisticated ways by various different posttranslational modifications, such as phosphorylation, ubiquitination, and proteolytic processing of their key-proteins. By this, mitochondria process a wide range of different intracellular and extracellular parameters in order to adapt mitochondrial function to actual energetic and metabolic demands of the host cell, attenuate mitochondrial damage, recycle dysfunctional mitochondria via the mitochondrial autophagy pathway, or arrange for the recycling of the complete host cell by apoptosis. Most of the genes coding for proteins involved in this process have been associated with neurodegenerative diseases. Mutations in one of these genes are associated with a neurodegenerative disease that originally was described to affect retinal ganglion cells only. Since more and more evidence shows that other cell types are affected as well, we would like to discuss the pathology of dominant optic atrophy, which is caused by heterozygous sequence variants in OPA1, in the light of the current view on OPA1 protein function in mitochondrial quality control, in particular on its function in mitochondrial fusion and cytochrome C release. We think OPA1 is a good example to understand the molecular basis for mitochondrial network dynamics.
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Affiliation(s)
- Marcel V Alavi
- Department of Ophthalmology, University of California, San Francisco, 10 Koret Way, 94143-0730 San Francisco, CA, USA.
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First cases of dominant optic atrophy in Saudi Arabia: report of two novel OPA1 mutations. J Neuroophthalmol 2013; 33:349-53. [PMID: 24051421 DOI: 10.1097/wno.0b013e31829ffb9a] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND Fifty to 60% of patients with dominant optic atrophy (DOA) have mutations of the OPA1 gene, which encodes dynamin-related GTPase, a protein of the internal mitochondrial membrane. To date, more than 200 OPA1 mutations in the OPA1 gene have been described. However, DOA is genetically heterogeneous with certain families linked to other chromosomal loci, that is, OPA3, OPA4, OPA5, and OPA7. METHODS This study describes a clinical series of 40 patients from Saudi Arabia with a positive DOA phenotype (i.e., decreased visual acuity during the first 2 decades of life, temporal or global optic disc pallor, and absence of other neurological or ophthalmological diseases that could explain the optic neuropathy) who underwent molecular genetic testing for OPA1 (and, in some cases, for OPA3). RESULTS This study describes for the first time 4 OPA1 mutations in DOA patients from Saudi Arabia, including 2 novel OPA1 mutations in 2 different patients. CONCLUSION The question remains whether certain patients in Saudi Arabia with a clearly defined DOA phenotype may be due to mutations in chromosomal loci other than OPA1 and OPA3. It is likely that genetic alterations associated with different loci will be discovered in the future.
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Neuhann T, Rautenstrauss B. Genetic and phenotypic variability of optic neuropathies. Expert Rev Neurother 2013; 13:357-67. [PMID: 23545052 DOI: 10.1586/ern.13.19] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Hereditary optic neuropathies comprise a group of clinically and genetically heterogeneous disorders. Two subgroups can be formed: isolated hereditary optic atrophies and optic neuropathy as part of complex disorders. In group 1 of hereditary optic neuropathies, optic nerve dysfunction is typically the only manifestation of the disease. This group comprises autosomal dominant, autosomal recessive and X-linked recessive optic atrophy and the maternally inherited Leber's hereditary optic neuropathy. Among the autosomal-dominant forms of optic atrophy, Kjer's disease is most frequently observed. In the second group of complex disorders, various neurologic and other systemic abnormalities are regularly observed. Most frequent in this group are mtDNA mutations, inherited peripheral neuropathies, Charcot-Marie-Tooth disorders (CMT2A2, CMTX5), hereditary sensory neuropathy type 3 (HSAN3), Friedreich's ataxia, leukodystrophies, sphingolipidoses, ceroid-lipofuscinoses and neurodegeneration with brain iron accumulation. We review current knowledge about the underlying genetic predispositions, the most urgent open questions and how this may affect our management of this heterogeneous group of disorders in the future.
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Affiliation(s)
- Teresa Neuhann
- Medizinisch Genetisches Zentrum, Munich, Bayerstrasse 3-5, Munich 80335, Germany.
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Kaden TR, Li W. AUTOPHAGY, MITOCHONDRIAL DYNAMICS AND RETINAL DISEASES. Asia Pac J Ophthalmol (Phila) 2013; 2:S2162-0989(23)01010-1. [PMID: 24205447 PMCID: PMC3816775 DOI: 10.1097/apo.0b013e31829d3e33] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Affiliation(s)
- Talia R. Kaden
- National Eye Institute, National Institutes of Health, Bethesda, MD, USA
- Yale University School of Medicine, New Haven, CT, USA
| | - Wei Li
- National Eye Institute, National Institutes of Health, Bethesda, MD, USA
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Liskova P, Ulmanova O, Tesina P, Melsova H, Diblik P, Hansikova H, Tesarova M, Votruba M. Novel OPA1 missense mutation in a family with optic atrophy and severe widespread neurological disorder. Acta Ophthalmol 2013; 91:e225-31. [PMID: 23387428 DOI: 10.1111/aos.12038] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
PURPOSE To identify the underlying molecular genetic cause in a Czech family with optic atrophy, deafness, ptosis, ophthalmoplegia, polyneuropathy and ataxia transmitted as an autosomal dominant trait. METHODS Ophthalmological and neurological examination followed by molecular genetic analyses. RESULTS Seven family members were clinically affected. There was a variable but progressive visual, hearing and neurological disability across the family as a whole. The majority of subjects presented with impairment of visual function and a variable degree of ptosis and/or ophthalmoplegia from the first to the third decade of life. Deafness, neuropathy and ataxia appeared later, in the third and fourth decade. Migraine, tachycardia, intention tremor, nystagmus and cervical dystonia were observed in isolated individuals. A significant overall feature was the high level of neurological disability leading to 3 of 4 members being unable to walk or stand unaided before the age of 60 years. A novel missense mutation c.1345A>C (p.Thr449Pro) in OPA1 segregating with the disease phenotype over three generations was detected. In silico analysis supported pathogenicity of the identified sequence variant. CONCLUSION Our work expands the spectrum of mutation in OPA1, which may lead to severe multisystem neurological disorder. The molecular genetic cause of dominant optic atrophy in the Czech population is reported for the first time. We propose that regular cardiac follow-up in patients diagnosed with dominant optic atrophy and widespread neurological disease should be considered.
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Affiliation(s)
- Petra Liskova
- Laboratory of the Biology and Pathology of the Eye, Institute of Inherited Metabolic Disorders, First Faculty of Medicine, Charles University in Prague and General University Hospital in Prague, Prague, Czech Republic
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Abstract
The hereditary optic neuropathies are inherited disorders in which optic nerve dysfunction is a prominent feature in the phenotypic expression of disease. Optic neuropathy may be primarily an isolated finding, such as in Leber hereditary optic neuropathy and dominant optic atrophy, or part of a multisystem disorder. The pathophysiological mechanisms underlying the hereditary optic neuropathies involve mitochondrial dysfunction owing to mutations in mitochondrial or nuclear DNA that encodes proteins essential to mitochondrial function. Effective treatments are limited, and current management includes therapies directed at enhancing mitochondrial function and preventing oxidative damage, as well as genetic counselling, and supportive and symptomatic measures. New therapies, including gene therapy, are emerging via animal models and human clinical trials. Leber hereditary optic neuropathy, in particular, provides a unique model for testing promising treatments owing to its characteristic sequential bilateral involvement and the accessibility of target tissue within the eye. Lessons learned from treatment of the hereditary optic neuropathies may have therapeutic implications for other disorders of presumed mitochondrial dysfunction. In this Review, the natural history of the common inherited optic neuropathies, the presumed pathogenesis of several of these disorders, and the literature to date regarding potential therapies are summarized.
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Affiliation(s)
- Nancy J Newman
- Neuro-ophthalmology Unit, Department of Ophthalmology, Neurology and Neurological Surgery, Emory University School of Medicine, 1365-B Clifton Road NE, Atlanta, GA 30322, USA
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Debattisti V, Scorrano L. D. melanogaster, mitochondria and neurodegeneration: small model organism, big discoveries. Mol Cell Neurosci 2012; 55:77-86. [PMID: 22940086 DOI: 10.1016/j.mcn.2012.08.007] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2012] [Revised: 08/10/2012] [Accepted: 08/15/2012] [Indexed: 10/28/2022] Open
Abstract
In developed countries, increased life expectancy is accompanied by an increased prevalence of age-related disorders like cancer and neurodegenerative diseases. Albeit the molecular mechanisms behind the clinically, pathologically and etiologically heterogeneous forms of neurodegeneration are often unclear, impairment of mitochondrial fusion-fission and dynamics emerged in recent years as a feature of neuronal dysfunction and death, pinpointing the need for animal models to investigate the relationship between mitochondrial shape and neurodegeneration. While research on mammalian models is slowed down by the complexity of the organisms and their genomes, the long latency of the symptoms and by the difficulty to generate and analyze large cohorts, the lower metazoan Drosophila melanogaster overcomes these problems, proving to be a suitable model to study neurodegenerative diseases and mitochondria-shaping proteins. Here we will summarize our current knowledge on the link between mitochondrial shape and models of neurodegeneration in the fruitfly. This article is part of a Special Issue entitled 'Mitochondrial function and dysfunction in neurodegeneration'.
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Affiliation(s)
- Valentina Debattisti
- Dulbecco-Telethon Institute, Venetian Institute of Molecular Medicine, Via Orus 2 35129 Padova, Italy
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Reis A, Mateus C, Viegas T, Florijn R, Bergen A, Silva E, Castelo-Branco M. Physiological evidence for impairment in autosomal dominant optic atrophy at the pre-ganglion level. Graefes Arch Clin Exp Ophthalmol 2012; 251:221-34. [DOI: 10.1007/s00417-012-2112-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2012] [Revised: 06/08/2012] [Accepted: 07/02/2012] [Indexed: 11/28/2022] Open
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Almind GJ, Ek J, Rosenberg T, Eiberg H, Larsen M, Lucamp L, Brøndum-Nielsen K, Grønskov K. Dominant optic atrophy in Denmark - report of 15 novel mutations in OPA1, using a strategy with a detection rate of 90%. BMC MEDICAL GENETICS 2012; 13:65. [PMID: 22857269 PMCID: PMC3507804 DOI: 10.1186/1471-2350-13-65] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/11/2012] [Accepted: 07/26/2012] [Indexed: 11/25/2022]
Abstract
Background Investigation of the OPA1 mutation spectrum in autosomal dominant optic atrophy (ADOA) in Denmark. Methods Index patients from 93 unrelated ADOA families were assessed for a common Danish founder mutation (c.2826_2836delinsGGATGCTCCA) inOPA1. If negative, direct DNA sequencing of the coding sequence and multiplex ligation-dependent probe amplification (MLPA) were performed. Results from MLPA analysis have been previously reported. Haplotype analysis was carried out analysing single nucleotide polymorphisms (SNP). Retrospective clinical data were retrieved from medical files. Results Probably causative mutations were identified in 84 out of 93 families (90%) including 15 novel mutations. Three mutations c.983A > G, c.2708_2711delTTAG and c.2826_2836delinsGGATGCTCCA, were responsible for ADOA in10, 11 and 28 families, respectively, corresponding to 11%, 12% and 30%. A common haplotype in nine of ten c.983A > G families suggests that they descend from a single founder. The c.2708_2711delTTAG mutation was present on at least two haplotypes and has been repeatedly reported in various ethnic groups,thus represents a mutational hotspot. Clinical examinations of index patients with the two latter mutations demonstrated large inter- and intra-familial variations apparently. Conclusions Genetic testing for OPA1mutations assist in the diagnosis. We have identified mutations in OPA1 in 90% of families including 15 novel mutations. Both DNA sequencing and MLPA analysis are necessary to achieve a high detection rate. More than half of the affected families in Denmark are represented by three common mutations, at least two of which are due to a founder effect, which may account for the high prevalence of ADOA in Denmark.
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Affiliation(s)
- Gitte J Almind
- Center for Applied Human Molecular Genetics, Kennedy Center, Glostrup, Denmark.
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Lenaers G, Hamel C, Delettre C, Amati-Bonneau P, Procaccio V, Bonneau D, Reynier P, Milea D. Dominant optic atrophy. Orphanet J Rare Dis 2012; 7:46. [PMID: 22776096 PMCID: PMC3526509 DOI: 10.1186/1750-1172-7-46] [Citation(s) in RCA: 171] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2011] [Accepted: 03/15/2012] [Indexed: 11/18/2022] Open
Abstract
Definition of the disease Dominant Optic Atrophy (DOA) is a neuro-ophthalmic condition characterized by a bilateral degeneration of the optic nerves, causing insidious visual loss, typically starting during the first decade of life. The disease affects primary the retinal ganglion cells (RGC) and their axons forming the optic nerve, which transfer the visual information from the photoreceptors to the lateral geniculus in the brain. Epidemiology The prevalence of the disease varies from 1/10000 in Denmark due to a founder effect, to 1/30000 in the rest of the world. Clinical description DOA patients usually suffer of moderate visual loss, associated with central or paracentral visual field deficits and color vision defects. The severity of the disease is highly variable, the visual acuity ranging from normal to legal blindness. The ophthalmic examination discloses on fundoscopy isolated optic disc pallor or atrophy, related to the RGC death. About 20% of DOA patients harbour extraocular multi-systemic features, including neurosensory hearing loss, or less commonly chronic progressive external ophthalmoplegia, myopathy, peripheral neuropathy, multiple sclerosis-like illness, spastic paraplegia or cataracts. Aetiology Two genes (OPA1, OPA3) encoding inner mitochondrial membrane proteins and three loci (OPA4, OPA5, OPA8) are currently known for DOA. Additional loci and genes (OPA2, OPA6 and OPA7) are responsible for X-linked or recessive optic atrophy. All OPA genes yet identified encode mitochondrial proteins embedded in the inner membrane and ubiquitously expressed, as are the proteins mutated in the Leber Hereditary Optic Neuropathy. OPA1 mutations affect mitochondrial fusion, energy metabolism, control of apoptosis, calcium clearance and maintenance of mitochondrial genome integrity. OPA3 mutations only affect the energy metabolism and the control of apoptosis. Diagnosis Patients are usually diagnosed during their early childhood, because of bilateral, mild, otherwise unexplained visual loss related to optic discs pallor or atrophy, and typically occurring in the context of a family history of DOA. Optical Coherence Tomography further discloses non-specific thinning of retinal nerve fiber layer, but a normal morphology of the photoreceptors layers. Abnormal visual evoked potentials and pattern ERG may also reflect the dysfunction of the RGCs and their axons. Molecular diagnosis is provided by the identification of a mutation in the OPA1 gene (75% of DOA patients) or in the OPA3 gene (1% of patients). Prognosis Visual loss in DOA may progress during puberty until adulthood, with very slow subsequent chronic progression in most of the cases. On the opposite, in DOA patients with associated extra-ocular features, the visual loss may be more severe over time. Management To date, there is no preventative or curative treatment in DOA; severely visually impaired patients may benefit from low vision aids. Genetic counseling is commonly offered and patients are advised to avoid alcohol and tobacco consumption, as well as the use of medications that may interfere with mitochondrial metabolism. Gene and pharmacological therapies for DOA are currently under investigation.
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Affiliation(s)
- Guy Lenaers
- Institut des Neurosciences de Montpellier, U1051 de l'INSERM, Université de Montpellier I et II, BP 74103, F-34091 Montpellier cedex 05, France.
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Federico A, Cardaioli E, Da Pozzo P, Formichi P, Gallus GN, Radi E. Mitochondria, oxidative stress and neurodegeneration. J Neurol Sci 2012; 322:254-62. [PMID: 22669122 DOI: 10.1016/j.jns.2012.05.030] [Citation(s) in RCA: 517] [Impact Index Per Article: 43.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2012] [Revised: 05/10/2012] [Accepted: 05/12/2012] [Indexed: 02/06/2023]
Abstract
Mitochondria are involved in ATP supply to cells through oxidative phosphorylation (OXPHOS), synthesis of key molecules and response to oxidative stress, as well as in apoptosis. They contain many redox enzymes and naturally occurring inefficiencies of oxidative phosphorylation generate reactive oxygen species (ROS). CNS functions depend heavily on efficient mitochondrial function, since brain tissue has a high energy demand. Mutations in mitochondrial DNA (mtDNA), generation and presence of ROS and environmental factors may contribute to energy failure and lead to neurodegenerative diseases. Many rare metabolic disorders have been associated with mitochondrial dysfunction. More than 300 pathogenic mtDNA mutations involve proteins that regulate OXPHOS and mitochondrial structural integrity, and have also been described in neurodegenerative diseases with autosomal inheritance. Mitochondria may have an important role in ageing-related neurodegenerative disorders like Parkinson's disease (PD), Alzheimer's disease (AD), Huntington's disease (HD) and amyotrophic lateral sclerosis (ALS). In primary mitochondrial and neurodegenerative disorders, there is strong evidence that mitochondrial dysfunction occurs early and has a primary role in pathogenesis. In the present review, we discuss several mitochondrial diseases as models of neurodegeneration.
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Affiliation(s)
- Antonio Federico
- Department of Neurological, Neurosurgical and Behavioural Sciences, Medical School, University of Siena, Italy.
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Zhang J, Yuan Y, Lin B, Feng H, Li Y, Dai X, Zhou H, Dong X, Liu XL, Guan MX. A novel OPA1 mutation in a Chinese family with autosomal dominant optic atrophy. Biochem Biophys Res Commun 2012; 419:670-5. [PMID: 22382025 DOI: 10.1016/j.bbrc.2012.02.073] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2012] [Accepted: 02/13/2012] [Indexed: 12/01/2022]
Abstract
A large four-generation Chinese family with autosomal dominant optic atrophy (ADOA) was investigated in the present study. Eight of the family members were affected in this pedigree. The affected family members exhibited early-onset and progressive visual impairment, resulting in mild to profound loss of visual acuity. The average age-at-onset was 15.9years. A new heterozygous mutation c.C1198G was identified by sequence analysis of the 12th exon of the OPA1 gene. This mutation resulted in a proline to alanine substitution at codon 400, which was located in an evolutionarily conserved region. This missense mutation in the GTPase domain was supposed to result in a loss of function for the encoded protein and act through a dominant negative effect. No other mutations associated with optic atrophy were found in our present study. The c.C1198G heterozygous mutation in the OPA1 gene may be a novel key pathogenic mutation in this pedigree with ADOA. Furthermore, additional nuclear modifier genes, environmental factors, and psychological factors may also contribute to the phenotypic variability of ADOA in this pedigree.
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Affiliation(s)
- Juanjuan Zhang
- School of Ophthalmology and Optometry, Wenzhou Medical College, Wenzhou 325027, Zhejiang, China
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