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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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2
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Li JK, Li W, Gao FJ, Qu SF, Hu FY, Zhang SH, Li LL, Wang ZW, Qiu Y, Wang LS, Huang J, Wu JH, Chen F. Mutation Screening of mtDNA Combined Targeted Exon Sequencing in a Cohort With Suspected Hereditary Optic Neuropathy. Transl Vis Sci Technol 2020; 9:11. [PMID: 32855858 PMCID: PMC7422818 DOI: 10.1167/tvst.9.8.11] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Accepted: 04/23/2020] [Indexed: 12/02/2022] Open
Abstract
Purpose Leber hereditary optic neuropathy (LHON) and autosomal dominant optic atrophy (ADOA) are the two commonest forms of hereditary optic neuropathy. The aim of this study was to comprehensively investigate the incidence and spectrum of mutations in patients with suspected hereditary optic neuropathy by combining mitochondrial DNA (mtDNA) genome-wide and targeted exon sequencing. Methods A cohort of 1101 subjects were recruited to participate in the study, comprising 177 families (177 probands and their family members, a total of 537 subjects, including 254 patients) and 164 sporadic cases with suspected hereditary optic neuropathy, and 400 unrelated control subjects for genetic analysis: all subjects (including control subjects) underwent a comprehensive ophthalmologic examination and were subjected to sequencing analysis of mtDNA genome-wide and targeted exon. Overall, targeted exon sequencing was used to screen 792 genes associated with common hereditary eye diseases, and the mtDNA genome-wide were screened by next-generation sequencing. Results We found variants detected in 168 (40.2%, 168/418) of the 418 patients screened. Among these, 132 cases (78.6%, 132/168) were detected with known LHON disease-causing mtDNA variants; 40 cases (23.8%, 40/168) were detected with nuclear DNA (ntDNA) variants, which included 36 cases (21.4%, 36/168) with detected OPA1 mutations, 4 patients (2.4%, 4/168) with detected OPA3 mutations, and 2 patients (1.2%, 2/168) with detected TMEM126A homozygous mutation. Coexistence variation (mtDNA/mtDNA [n = 16], ntDNA/ntDNA [n = 4], mtDNA/ntDNA [n = 7]) was found in 27 patients (16.4%, 27/165), including mtDNA/ntDNA coexistence variation that was detected in seven patients. Among these ntDNA mutations, 38 distinct disease-causing variants, including autosomal recessive heterozygous mutations, were detected, which included 22 novel variants and two de novo variants. Total haplogroup distribution showed that 34.5% (29/84) and 28.6% (24/84) of the affected subjects with m.11778G>A belonged to haplogroup D and M, with a high frequency of subhaplogroups D4, D5, and M7. Conclusions The LHON-mtDNA mutations are the commonest genetic defects in this Chinese cohort, followed by the OPA1 mutations. To our knowledge, this is the first comprehensive study of LHON, ADOA, and autosomal recessive optic atrophy combined with mtDNA genome-wide and targeted exon sequencing, as well as haplogroup analysis, in a large cohort of Chinese patients with suspected hereditary optic neuropathy. Our findings provide a powerful basis for genetic counseling in patients with suspected hereditary optic neuropathy. Translational Relevance We applied mtDNA genome-wide sequencing combined with panel-based targeted exon sequencing to explore the pathogenic variation spectrum and genetic characteristics of patients with suspected hereditary optic neuropathy, providing a comprehensive research strategy for clinical assistant diagnosis, treatment, and genetic counseling.
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Affiliation(s)
- Jian-Kang Li
- BGI Education Center, University of Chinese Academy of Sciences, Shenzhen, China.,Department of Computer Science, City University of Hong Kong, Kowloon, Hong Kong.,BGI-Shenzhen, Shenzhen, China
| | - Wei Li
- BGI Education Center, University of Chinese Academy of Sciences, Shenzhen, China.,BGI-Shenzhen, Shenzhen, China
| | - Feng-Juan Gao
- Eye Institute, Eye, Ear, Nose and Throat Hospital, College of Medicine, Fudan University, Shanghai, China.,Shanghai Key Laboratory of Visual Impairment and Restoration, Science and Technology Commission of Shanghai Municipality, Shanghai, China
| | - Shou-Fang Qu
- National Institutes for Food and Drug Control, Tiantan Xili Dongcheng District, Beijing, China
| | - Fang-Yuan Hu
- Eye Institute, Eye, Ear, Nose and Throat Hospital, College of Medicine, Fudan University, Shanghai, China.,Shanghai Key Laboratory of Visual Impairment and Restoration, Science and Technology Commission of Shanghai Municipality, Shanghai, China
| | - Sheng-Hai Zhang
- Eye Institute, Eye, Ear, Nose and Throat Hospital, College of Medicine, Fudan University, Shanghai, China.,Shanghai Key Laboratory of Visual Impairment and Restoration, Science and Technology Commission of Shanghai Municipality, Shanghai, China
| | - Li-Li Li
- National Institutes for Food and Drug Control, Tiantan Xili Dongcheng District, Beijing, China
| | - Zi-Wei Wang
- BGI Education Center, University of Chinese Academy of Sciences, Shenzhen, China.,BGI-Shenzhen, Shenzhen, China
| | - Yong Qiu
- BGI-Shenzhen, Shenzhen, China.,MGI, BGI-Shenzhen, Shenzhen, China
| | - Lu-Sheng Wang
- Department of Computer Science, City University of Hong Kong, Kowloon, Hong Kong.,BGI-Shenzhen, Shenzhen, China
| | - Jie Huang
- National Institutes for Food and Drug Control, Tiantan Xili Dongcheng District, Beijing, China
| | - Ji-Hong Wu
- Eye Institute, Eye, Ear, Nose and Throat Hospital, College of Medicine, Fudan University, Shanghai, China.,Shanghai Key Laboratory of Visual Impairment and Restoration, Science and Technology Commission of Shanghai Municipality, Shanghai, China
| | - Fang Chen
- BGI-Shenzhen, Shenzhen, China.,MGI, BGI-Shenzhen, Shenzhen, China
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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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4
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Del Dotto V, Fogazza M, Musiani F, Maresca A, Aleo SJ, Caporali L, La Morgia C, Nolli C, Lodi T, Goffrini P, Chan D, Carelli V, Rugolo M, Baruffini E, Zanna C. Deciphering OPA1 mutations pathogenicity by combined analysis of human, mouse and yeast cell models. Biochim Biophys Acta Mol Basis Dis 2018; 1864:3496-3514. [PMID: 30293569 DOI: 10.1016/j.bbadis.2018.08.004] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2018] [Revised: 07/24/2018] [Accepted: 08/01/2018] [Indexed: 11/19/2022]
Abstract
OPA1 is the major gene responsible for Dominant Optic Atrophy (DOA) and the syndromic form DOA "plus". Over 370 OPA1 mutations have been identified so far, although their pathogenicity is not always clear. We have analyzed one novel and a set of known OPA1 mutations to investigate their impact on protein functions in primary skin fibroblasts and in two "ad hoc" generated cell systems: the MGM1/OPA1 chimera yeast model and the Opa1-/- MEFs model expressing the mutated human OPA1 isoform 1. The yeast model allowed us to confirm the deleterious effects of these mutations and to gain information on their dominance/recessivity. The MEFs model enhanced the phenotypic alteration caused by mutations, nicely correlating with the clinical severity observed in patients, and suggested that the DOA "plus" phenotype could be induced by the combinatorial effect of mitochondrial network fragmentation with variable degrees of mtDNA depletion. Overall, the two models proved to be valuable tools to functionally assess and define the deleterious mechanism and the pathogenicity of novel OPA1 mutations, and useful to testing new therapeutic interventions.
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Affiliation(s)
- Valentina Del Dotto
- Unit of Neurology, Department of Biomedical and NeuroMotor Sciences (DIBINEM), University of Bologna, 40139 Bologna, Italy
| | - Mario Fogazza
- Department of Pharmacy and Biotechnology (FABIT), University of Bologna, 40126 Bologna, Italy
| | - Francesco Musiani
- Department of Pharmacy and Biotechnology (FABIT), University of Bologna, 40126 Bologna, Italy
| | - Alessandra Maresca
- IRCCS Institute of Neurological Sciences of Bologna, Bellaria Hospital, 40139 Bologna, Italy
| | - Serena J Aleo
- Department of Pharmacy and Biotechnology (FABIT), University of Bologna, 40126 Bologna, Italy
| | - Leonardo Caporali
- IRCCS Institute of Neurological Sciences of Bologna, Bellaria Hospital, 40139 Bologna, Italy
| | - Chiara La Morgia
- Unit of Neurology, Department of Biomedical and NeuroMotor Sciences (DIBINEM), University of Bologna, 40139 Bologna, Italy; IRCCS Institute of Neurological Sciences of Bologna, Bellaria Hospital, 40139 Bologna, Italy
| | - Cecilia Nolli
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, 43124 Parma, Italy
| | - Tiziana Lodi
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, 43124 Parma, Italy
| | - Paola Goffrini
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, 43124 Parma, Italy
| | - David Chan
- Division of Biology and Biological Engineering, California Institute of Technology (CALTECH), Pasadena, CA 91125, USA
| | - Valerio Carelli
- Unit of Neurology, Department of Biomedical and NeuroMotor Sciences (DIBINEM), University of Bologna, 40139 Bologna, Italy; IRCCS Institute of Neurological Sciences of Bologna, Bellaria Hospital, 40139 Bologna, Italy
| | - Michela Rugolo
- Department of Pharmacy and Biotechnology (FABIT), University of Bologna, 40126 Bologna, Italy
| | - Enrico Baruffini
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, 43124 Parma, Italy
| | - Claudia Zanna
- Department of Pharmacy and Biotechnology (FABIT), University of Bologna, 40126 Bologna, Italy.
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5
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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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6
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Chevrollier A, Cassereau J, Ferré M, Alban J, Desquiret-Dumas V, Gueguen N, Amati-Bonneau P, Procaccio V, Bonneau D, Reynier P. Standardized mitochondrial analysis gives new insights into mitochondrial dynamics and OPA1 function. Int J Biochem Cell Biol 2012; 44:980-8. [DOI: 10.1016/j.biocel.2012.03.006] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2011] [Revised: 03/07/2012] [Accepted: 03/08/2012] [Indexed: 01/03/2023]
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Hamahata T, Fujimaki T, Fujiki K, Miyazaki A, Mizota A, Murakami A. OPA1 mutations in Japanese patients suspected to have autosomal dominant optic atrophy. Jpn J Ophthalmol 2011; 56:91-7. [PMID: 22042570 DOI: 10.1007/s10384-011-0096-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2010] [Accepted: 07/25/2011] [Indexed: 11/29/2022]
Abstract
PURPOSE To report three types of heterozygous mutations in the OPA1 gene in five patients from three families with autosomal dominant optic atrophy (ADOA, MIM#165500). METHODS DNA was extracted from the leukocytes of the peripheral blood. For mtDNA, mutations were examined at positions 11778, 3460 and 14484. For the OPA1 gene, the exons were amplified by PCR and mutations were detected by restriction enzymes or the dye terminator method. RESULTS We detected three types of OPA1 mutation but no mtDNA mutations. In the OPA1 gene, heterozygous frameshift mutations from codon 903 due to a four-base pair deletion in exon 27 were detected in three patients from one family (c.2708_2711delTTAG, p.V903GfsX905). A heterozygous mutation due to a three-base pair deletion in exon 17, leading to a one-amino acid deletion (c.1618_1620delACT, p.T540del), and a heterozygous mutation due to a one-base substitution in exon 11, leading to a stop codon (c.1084G>T, p.E362X), were detected in sporadic cases. CONCLUSION OPA1 mutations existed in three Japanese families with ADOA. After a detailed clinical assessment of the proband, the screening of the OPA1 gene may be helpful for precise diagnosis of ADOA, provided the relevant information of the family members is limited.
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Affiliation(s)
- Tetsuya Hamahata
- Department of Ophthalmology, Juntendo University School of Medicine, 3-1-3 Hongo, Bunkyo-ku, Tokyo 113-8431, Japan.
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Fraser JA, Biousse V, Newman NJ. The neuro-ophthalmology of mitochondrial disease. Surv Ophthalmol 2010; 55:299-334. [PMID: 20471050 PMCID: PMC2989385 DOI: 10.1016/j.survophthal.2009.10.002] [Citation(s) in RCA: 177] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2009] [Revised: 09/21/2009] [Accepted: 10/01/2009] [Indexed: 01/16/2023]
Abstract
Mitochondrial diseases frequently manifest neuro-ophthalmologic symptoms and signs. Because of the predilection of mitochondrial disorders to involve the optic nerves, extraocular muscles, retina, and even the retrochiasmal visual pathways, the ophthalmologist is often the first physician to be consulted. Disorders caused by mitochondrial dysfunction can result from abnormalities in either the mitochondrial DNA or in nuclear genes which encode mitochondrial proteins. Inheritance of these mutations will follow patterns specific to their somatic or mitochondrial genetics. Genotype-phenotype correlations are inconstant, and considerable overlap may occur among these syndromes. The diagnostic approach to the patient with suspected mitochondrial disease entails a detailed personal and family history, careful ophthalmic, neurologic, and systemic examination, directed investigations, and attention to potentially life-threatening sequelae. Although curative treatments for mitochondrial disorders are currently lacking, exciting research advances are being made, particularly in the area of gene therapy. Leber hereditary optic neuropathy, with its window of opportunity for timely intervention and its accessibility to directed therapy, offers a unique model to study future therapeutic interventions. Most patients and their relatives benefit from informed genetic counseling.
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Affiliation(s)
- J. Alexander Fraser
- Departments of Ophthalmology (J.A.F., V.B., N.J.N.), Neurology (V.B., N.J.N.), and Neurological Surgery (N.J.N.), Emory University School of Medicine, Atlanta, GA
| | - Valérie Biousse
- Departments of Ophthalmology (J.A.F., V.B., N.J.N.), Neurology (V.B., N.J.N.), and Neurological Surgery (N.J.N.), Emory University School of Medicine, Atlanta, GA
| | - Nancy J. Newman
- Departments of Ophthalmology (J.A.F., V.B., N.J.N.), Neurology (V.B., N.J.N.), and Neurological Surgery (N.J.N.), Emory University School of Medicine, Atlanta, GA
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Yen MY, Wang AG, Lin YC, Fann MJ, Hsiao KJ. Novel mutations of the OPA1 gene in Chinese dominant optic atrophy. Ophthalmology 2009; 117:392-6.e1. [PMID: 19969356 DOI: 10.1016/j.ophtha.2009.07.019] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2009] [Revised: 06/27/2009] [Accepted: 07/01/2009] [Indexed: 11/16/2022] Open
Abstract
PURPOSE To investigate OPA1 gene mutations in Chinese patients with autosomal dominant optic atrophy and sporadic optic atrophy. DESIGN Molecular genetic studies and observational case series. PARTICIPANTS Twenty-four patients from 10 unrelated Chinese pedigrees of autosomal-dominant optic atrophy, 35 isolated cases with bilateral optic atrophy of unknown cause, and 50 unrelated normal controls. METHODS Genomic DNA was extracted from peripheral blood leukocytes. All 28 coding exons of the OPA1 gene and flanking intron splice sites were sequenced. Putative mutations were reexamined for segregation in the respective families by direct sequencing. Further characterization of selected splicing site mutations was performed by reverse transcription-polymerase chain reaction (PCR) of each patient's leukocyte mRNA. MAIN OUTCOME MEASURES Direct sequencing of the OPA1 gene. RESULTS Four OPA1 gene mutations were detected, including 2 splicing site mutations (c.1065+2T>C on intron 10 and c.1212+2insT on intron 12), 1 deletion (c.1776_1778delACT on exon 19), and 1 missense mutation (c.2846 T>C on exon 28). The c.1212+2insT, c.1776_1778delACT, and c.2846T>C mutations were newly identified OPA1 mutations. Reverse transcription (RT)-PCR and direct sequencing revealed that the splicing site mutations on c.1065+2T>C and c.1212+2insT caused skipping of exons 10 and 12, respectively. The c.1776_1778delACT mutation led to a deletion of the Leu amino acid on residue 593. OPA1 mutations were found in 4 of 10 familial cases (40 %) and in 1 of 35 sporadic cases of optic atrophy. CONCLUSIONS OPA1 gene mutations are causative in Chinese autosomal-dominant optic atrophy and sporadic optic atrophy. Screening for OPA1 gene mutations in patients with childhood onset optic atrophy who have no affected relatives is useful in making the diagnosis.
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Affiliation(s)
- May-Yung Yen
- Department of Ophthalmology, Taipei Veterans General Hospital, Taipei, Taiwan.
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10
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Jourdain A, Martinou JC. Mitochondrial outer-membrane permeabilization and remodelling in apoptosis. Int J Biochem Cell Biol 2009; 41:1884-9. [PMID: 19439192 DOI: 10.1016/j.biocel.2009.05.001] [Citation(s) in RCA: 88] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2009] [Revised: 05/01/2009] [Accepted: 05/04/2009] [Indexed: 11/18/2022]
Abstract
Many human pathologies are associated with defects in mitochondria such as diabetes, neurodegenerative diseases or cancer. This tiny organelle is involved in a plethora of processes in mammalian cells, including energy production, lipid metabolism and cell death. In the so-called intrinsic apoptotic pathway, the outer mitochondrial membrane (MOM) is premeabilized by the pro-apoptotic Bcl-2 members Bax and Bak, allowing the release of apoptogenic factors such as cytochrome c from the inter-membrane space into the cytosol. At the same time, mitochondria fragment in response to Drp-1 activation suggesting that mitochondrial fission could play a role in mitochondrial outer-membrane permeabilization (MOMP). In this review, we will discuss the link that could exist between mitochondrial fission and fusion machinery, Bcl-2 family members and MOMP.
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Affiliation(s)
- Alexis Jourdain
- Department of Cell Biology, University of Geneva, Quai Ernest-Ansermet 30, 1211 Geneva 4, Switzerland
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11
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Hudson G, Amati-Bonneau P, Blakely EL, Stewart JD, He L, Schaefer AM, Griffiths PG, Ahlqvist K, Suomalainen A, Reynier P, McFarland R, Turnbull DM, Chinnery PF, Taylor RW. Mutation of OPA1 causes dominant optic atrophy with external ophthalmoplegia, ataxia, deafness and multiple mitochondrial DNA deletions: a novel disorder of mtDNA maintenance. ACTA ACUST UNITED AC 2007; 131:329-37. [PMID: 18065439 DOI: 10.1093/brain/awm272] [Citation(s) in RCA: 306] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Mutations in nuclear genes involved in mitochondrial DNA (mtDNA) maintenance cause a wide range of clinical phenotypes associated with the secondary accumulation of multiple mtDNA deletions in affected tissues. The majority of families with autosomal dominant progressive external ophthalmoplegia (PEO) harbour mutations in genes encoding one of three well-characterized proteins--pol gamma, Twinkle or Ant 1. Here we show that a heterozygous mis-sense mutation in OPA1 leads to multiple mtDNA deletions in skeletal muscle and a mosaic defect of cytochrome c oxidase (COX). The disorder presented with visual failure and optic atrophy in childhood, followed by PEO, ataxia, deafness and a sensory-motor neuropathy in adult life. COX-deficient skeletal muscle fibres contained supra-threshold levels of multiple mtDNA deletions, and genetic linkage, sequencing and expression analysis excluded POLG1, PEO1 and SLC25A4, the gene encoding Ant 1, as the cause. This demonstrates the importance of OPA1 in mtDNA maintenance, and implicates OPA1 in diseases associated with secondary defects of mtDNA.
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Affiliation(s)
- Gavin Hudson
- Mitochondrial Research Group, School of Neurology, Neurobiology and Psychiatry, The Medical School, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK
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Ban Y, Yoshida Y, Kawasaki S, Mochida C. A novel mutation of the OPA1 gene in a Japanese patient with autosomal dominant optic atrophy. Graefes Arch Clin Exp Ophthalmol 2007; 245:1581-3. [PMID: 17579882 DOI: 10.1007/s00417-007-0598-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2006] [Revised: 02/20/2007] [Accepted: 04/12/2007] [Indexed: 11/29/2022] Open
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Hayashi T, Takeuchi T, Gekka T, Kitahara K. Dominant optic atrophy in a Japanese family with OPA1 frameshift mutation (V942fsX966). Eur J Ophthalmol 2007; 17:253-8. [PMID: 17415700 DOI: 10.1177/112067210701700216] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
PURPOSE The authors report the ophthalmic characteristics of a male proband in a Japanese family with autosomal dominant optic atrophy (DOA) harboring a frameshift mutation in the OPA1 gene. METHODS Conventional ophthalmologic examinations including static automated perimetry were performed, as well as assessment of the three-generation family history. The peripapillary retinal nerve fiber layer (RNFL) was evaluated using scanning laser polarimetry. Mutation screening of the OPA1 gene was performed with polymerase chain reaction amplification and direct sequencing. RESULTS A frameshift mutation (p.V942fsX966) was identified in the proband and his mother. In comparison with the adolescent onset of visual loss in the proband and his maternal grandfather, the mother presented with only subtle temporal disc pallor and has never been aware of any visual disturbances. Symmetric thinned peripapillary RNFL was detected in the proband, whose visual field abnormalities were limited to central scotomas and were without mean deviation worsening between 11 to 17 years of age in both eyes. The proband's logMAR visual acuity (0.52 to 0.7) has remained almost unchanged for more than 10 years since initial evaluation at age 10. CONCLUSIONS The OPA1 mutation may be correlated with slow progression of DOA, and with phenotypic variations within the family. Further study is necessary to determine whether symmetric thinned peripapillary RNFL represents a feature of DOA.
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Affiliation(s)
- T Hayashi
- Department of Ophthalmology, Jikei University School of Medicine, 3-25-8 Nishi-shinbashi, Minato-ku, Tokyo 105-8461, Japan.
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Cohn AC, Toomes C, Potter C, Towns KV, Hewitt AW, Inglehearn CF, Craig JE, Mackey DA. Autosomal dominant optic atrophy: penetrance and expressivity in patients with OPA1 mutations. Am J Ophthalmol 2007; 143:656-62. [PMID: 17306754 DOI: 10.1016/j.ajo.2006.12.038] [Citation(s) in RCA: 89] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2006] [Revised: 12/12/2006] [Accepted: 12/17/2006] [Indexed: 10/23/2022]
Abstract
PURPOSE We identified families with autosomal dominant optic atrophy (ADOA), determined the number and type of OPA1 mutations, and investigated the phenotypic variation and penetrance in ADOA Australian pedigrees. DESIGN Cross-sectional genetics study. METHODS Probands were identified on the basis of characteristic clinical features of ADOA. We screened the OPA1 gene using single-strand conformational polymorphism, heteroduplex analysis (SSCP/HA), or by direct sequencing. Penetrance for pedigrees in which a mutation of OPA1 had been identified was calculated initially using all recruited individuals, and subanalysis was performed using only those families for which there was total recruitment of siblings. RESULTS A total of 406 patients from 17 pedigrees were recruited, and OPA1 mutations were identified in 11/17 (65%) of these. The mean age at clinical examination was 38.2 +/- 19.9 years (median age, 35 years; range, four to 83 years). The median best-corrected visual acuity in OPA1-mutation carriers was 20/70 (range, 20/16 to hand movements [HM]). The penetrance in Australian ADOA pedigrees in the families with complete sibling recruitment was 82.5%. On the other hand, overall penetrance for all individuals harboring an OPA1 mutation was 88%. CONCLUSIONS OPA1 mutations were identified in 11/17 (65%) of the ADOA pedigrees in this study. The penetrance in our cohort was lower than originally described (82.5% vs 98%) but higher than some recent studies since the availability of genotyping. It is anticipated that this figure would be even lower as more asymptomatic individuals are identified. There are likely to be other genetic and environmental modifiers influencing disease penetrance.
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Affiliation(s)
- Amy C Cohn
- Ocular Diagnostic Clinic, Royal Victorian Eye and Ear Hospital, Melbourne, Australia
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