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Gao Y, Guo L, Wang F, Wang Y, Li P, Zhang D. Development of mitochondrial gene-editing strategies and their potential applications in mitochondrial hereditary diseases: a review. Cytotherapy 2024; 26:11-24. [PMID: 37930294 DOI: 10.1016/j.jcyt.2023.10.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2023] [Revised: 10/12/2023] [Accepted: 10/13/2023] [Indexed: 11/07/2023]
Abstract
Mitochondrial DNA (mtDNA) is a critical genome contained within the mitochondria of eukaryotic cells, with many copies present in each mitochondrion. Mutations in mtDNA often are inherited and can lead to severe health problems, including various inherited diseases and premature aging. The lack of efficient repair mechanisms and the susceptibility of mtDNA to damage exacerbate the threat to human health. Heteroplasmy, the presence of different mtDNA genotypes within a single cell, increases the complexity of these diseases and requires an effective editing method for correction. Recently, gene-editing techniques, including programmable nucleases such as restriction endonuclease, zinc finger nuclease, transcription activator-like effector nuclease, clustered regularly interspaced short palindromic repeats/clustered regularly interspaced short palindromic repeats-associated 9 and base editors, have provided new tools for editing mtDNA in mammalian cells. Base editors are particularly promising because of their high efficiency and precision in correcting mtDNA mutations. In this review, we discuss the application of these techniques in mitochondrial gene editing and their limitations. We also explore the potential of base editors for mtDNA modification and discuss the opportunities and challenges associated with their application in mitochondrial gene editing. In conclusion, this review highlights the advancements, limitations and opportunities in current mitochondrial gene-editing technologies and approaches. Our insights aim to stimulate the development of new editing strategies that can ultimately alleviate the adverse effects of mitochondrial hereditary diseases.
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Affiliation(s)
- Yanyan Gao
- Institute for Translational Medicine, The Affiliated Hospital of Qingdao University, College of Medicine, Qingdao University, Qingdao, China
| | - Linlin Guo
- The Affiliated Cardiovascular Hospital of Qingdao University, Qingdao University, Qingdao, China
| | - Fei Wang
- Institute for Translational Medicine, The Affiliated Hospital of Qingdao University, College of Medicine, Qingdao University, Qingdao, China
| | - Yin Wang
- Institute for Translational Medicine, The Affiliated Hospital of Qingdao University, College of Medicine, Qingdao University, Qingdao, China
| | - Peifeng Li
- Institute for Translational Medicine, The Affiliated Hospital of Qingdao University, College of Medicine, Qingdao University, Qingdao, China
| | - Dejiu Zhang
- Institute for Translational Medicine, The Affiliated Hospital of Qingdao University, College of Medicine, Qingdao University, Qingdao, China.
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2
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Ripolone M, Zanotti S, Napoli L, Ronchi D, Ciscato P, Comi GP, Moggio M, Sciacco M. MERRF Mutation A8344G in a Four-Generation Family without Central Nervous System Involvement: Clinical and Molecular Characterization. J Pers Med 2023; 13:jpm13010147. [PMID: 36675808 PMCID: PMC9865457 DOI: 10.3390/jpm13010147] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Revised: 01/10/2023] [Accepted: 01/10/2023] [Indexed: 01/14/2023] Open
Abstract
A 53-year-old man approached our Neuromuscular Unit following an incidental finding of hyperckemia. Similar to his mother who had died at the age of 77 years, he was diabetic and had a few lipomas. The patient's two sisters, aged 60 and 50 years, did not have any neurological symptoms. Proband's skeletal muscle biopsy showed several COX-negative fibers, many of which were "ragged red". Genetic analysis revealed the presence of the A8344G mtDNA mutation, which is most commonly associated with a maternally inherited multisystem mitochondrial disorder known as MERRF (myoclonus epilepsy with ragged-red fibers). The two sisters also carry the mutation. Family members on the maternal side were reported healthy. Although atypical phenotypes have been reported in association with the A8344G mutation, central nervous system (CSN) manifestations other than myoclonic epilepsy are always reported in the family tree. If present, our four-generation family manifestations are late-onset and do not affect CNS. This could be explained by the fact that the mutational load remains low and therefore prevents tissues/organs from reaching the pathologic threshold. The fact that this occurs throughout generations and that CNS, which has the highest energetic demand, is clinically spared, suggests that regulatory genes and/or pathways affect mitochondrial segregation and replication, and protect organs from progressive dysfunction.
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Affiliation(s)
- Michela Ripolone
- Neuromuscular and Rare Diseases Unit, Department of Neuroscience, Foundation IRCCS Ca’ Granda Ospedale Maggiore Policlinico, 20122 Milan, Italy
| | - Simona Zanotti
- Neuromuscular and Rare Diseases Unit, Department of Neuroscience, Foundation IRCCS Ca’ Granda Ospedale Maggiore Policlinico, 20122 Milan, Italy
| | - Laura Napoli
- Neuromuscular and Rare Diseases Unit, Department of Neuroscience, Foundation IRCCS Ca’ Granda Ospedale Maggiore Policlinico, 20122 Milan, Italy
| | - Dario Ronchi
- Dino Ferrari Center, Department of Pathophysiology and Transplantation (DEPT), University of Milan, 20122 Milan, Italy
| | - Patrizia Ciscato
- Neuromuscular and Rare Diseases Unit, Department of Neuroscience, Foundation IRCCS Ca’ Granda Ospedale Maggiore Policlinico, 20122 Milan, Italy
| | - Giacomo Pietro Comi
- Neuromuscular and Rare Diseases Unit, Department of Neuroscience, Foundation IRCCS Ca’ Granda Ospedale Maggiore Policlinico, 20122 Milan, Italy
- Dino Ferrari Center, Department of Pathophysiology and Transplantation (DEPT), University of Milan, 20122 Milan, Italy
| | - Maurizio Moggio
- Neuromuscular and Rare Diseases Unit, Department of Neuroscience, Foundation IRCCS Ca’ Granda Ospedale Maggiore Policlinico, 20122 Milan, Italy
| | - Monica Sciacco
- Neuromuscular and Rare Diseases Unit, Department of Neuroscience, Foundation IRCCS Ca’ Granda Ospedale Maggiore Policlinico, 20122 Milan, Italy
- Correspondence: ; Tel.: +39-0255-036-504
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3
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Štufková H, Kolářová H, Lokvencová K, Honzík T, Zeman J, Hansíková H, Tesařová M. A Novel MTTK Gene Variant m.8315A>C as a Cause of MERRF Syndrome. Genes (Basel) 2022; 13. [PMID: 35886028 DOI: 10.3390/genes13071245] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Revised: 07/11/2022] [Accepted: 07/11/2022] [Indexed: 02/01/2023] Open
Abstract
In this study, we report on a novel heteroplasmic pathogenic variant in mitochondrial DNA (mtDNA). The studied patient had myoclonus, epilepsy, muscle weakness, and hearing impairment and harbored a heteroplasmic m.8315A>C variant in the MTTK gene with a mutation load ranging from 71% to >96% in tested tissues. In muscle mitochondria, markedly decreased activities of respiratory chain complex I + III and complex IV were observed together with mildly reduced amounts of complex I and complex V (with the detection of V*- and free F1-subcomplexes) and a diminished level of complex IV holoenzyme. This pattern was previously seen in other MTTK pathogenic variants. The novel variant was not present in internal and publicly available control databases. Our report further expands the spectrum of MTTK variants associated with mitochondrial encephalopathies in adults.
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4
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Emmanuele V, Ganesh J, Vladutiu G, Haas R, Kerr D, Saneto RP, Cohen BH, Van Hove JLK, Scaglia F, Hoppel C, Rosales XQ, Barca E, Buchsbaum R, Thompson JL, DiMauro S, Hirano M. Time to harmonize mitochondrial syndrome nomenclature and classification: A consensus from the North American Mitochondrial Disease Consortium (NAMDC). Mol Genet Metab 2022; 136:125-131. [PMID: 35606253 PMCID: PMC9341219 DOI: 10.1016/j.ymgme.2022.05.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/13/2022] [Revised: 05/03/2022] [Accepted: 05/07/2022] [Indexed: 11/17/2022]
Abstract
OBJECTIVE To harmonize terminology in mitochondrial medicine, we propose revised clinical criteria for primary mitochondrial syndromes. METHODS The North American Mitochondrial Disease Consortium (NAMDC) established a Diagnostic Criteria Committee comprised of members with diverse expertise. It included clinicians, researchers, diagnostic laboratory directors, statisticians, and data managers. The Committee conducted a comprehensive literature review, an evaluation of current clinical practices and diagnostic modalities, surveys, and teleconferences to reach consensus on syndrome definitions for mitochondrial diseases. The criteria were refined after manual application to patients enrolled in the NAMDC Registry. RESULTS By building upon published diagnostic criteria and integrating recent advances, NAMDC has generated updated consensus criteria for the clinical definition of classical mitochondrial syndromes. CONCLUSIONS Mitochondrial diseases are clinically, biochemically, and genetically heterogeneous and therefore challenging to classify and diagnose. To harmonize terminology, we propose revised criteria for the clinical definition of mitochondrial disorders. These criteria are expected to standardize the diagnosis and categorization of mitochondrial diseases, which will facilitate future natural history studies and clinical trials.
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Affiliation(s)
- Valentina Emmanuele
- Department of Neurology, Columbia University Medical Center, New York, NY, USA
| | - Jaya Ganesh
- Division of Genetics, Department of Pediatrics, Mount Sinai School of Medicine, New York, NY, USA
| | - Georgirene Vladutiu
- Departments of Pediatrics, Neurology, and Pathology and Anatomical Sciences, Jacobs School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, NY, USA
| | - Richard Haas
- Departments of Neurosciences and Pediatrics, University of California San Diego, La Jolla, CA, USA
| | - Douglas Kerr
- Department of Pediatrics, Case Western Reserve University, Cleveland, OH, USA
| | - Russell P Saneto
- Department of Neurology, Division of Pediatric Neurology, Seattle Children's Hospital/University of Washington, Seattle, WA, USA
| | - Bruce H Cohen
- Department of Pediatrics, Children's Hospital Medical Center of Akron and Northeast Ohio Medical University, Akron, OH, USA
| | - Johan L K Van Hove
- Department of Pediatrics, Section of Clinical Genetics and Metabolism, University of Colorado School of Medicine, Aurora, CO, USA
| | - Fernando Scaglia
- Department of Molecular and Human Genetics, Baylor College of Medicine and Texas Children's Hospital, Houston, TX, USA; Texas Children's Hospital, Houston, TX, USA; Joint BCM-CUHK Center of Medical Genetics, Prince of Wales Hospital, ShaTin, Hong Kong Special Administrative Region
| | - Charles Hoppel
- Center for Mitochondrial Disease, School of Medicine, Case Western Reserve University, Cleveland, OH, United States of America
| | - Xiomara Q Rosales
- Department of Neurology, Columbia University Medical Center, New York, NY, USA
| | - Emanuele Barca
- Department of Neurology, Columbia University Medical Center, New York, NY, USA
| | - Richard Buchsbaum
- Department of Biostatistics, Mailman School of Public Health, Columbia University, New York, NY, United States
| | - John L Thompson
- Department of Neurology, Columbia University Medical Center, New York, NY, USA; Department of Biostatistics, Mailman School of Public Health, Columbia University, New York, NY, United States
| | - Salvatore DiMauro
- Department of Neurology, Columbia University Medical Center, New York, NY, USA
| | - Michio Hirano
- Department of Neurology, Columbia University Medical Center, New York, NY, USA.
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5
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Lopriore P, Ricciarini V, Siciliano G, Mancuso M, Montano V. Mitochondrial Ataxias: Molecular Classification and Clinical Heterogeneity. Neurol Int 2022; 14:337-356. [PMID: 35466209 PMCID: PMC9036286 DOI: 10.3390/neurolint14020028] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Revised: 03/26/2022] [Accepted: 03/28/2022] [Indexed: 01/25/2023] Open
Abstract
Ataxia is increasingly being recognized as a cardinal manifestation in primary mitochondrial diseases (PMDs) in both paediatric and adult patients. It can be caused by disruption of cerebellar nuclei or fibres, its connection with the brainstem, or spinal and peripheral lesions leading to proprioceptive loss. Despite mitochondrial ataxias having no specific defining features, they should be included in hereditary ataxias differential diagnosis, given the high prevalence of PMDs. This review focuses on the clinical and neuropathological features and genetic background of PMDs in which ataxia is a prominent manifestation.
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Mahmud S, Biswas S, Afrose S, Mita MA, Hasan MR, Shimu MSS, Paul GK, Chung S, Saleh MA, Alshehri S, Ghoneim MM, Alruwaily M, Kim B. Use of Next-Generation Sequencing for Identifying Mitochondrial Disorders. Curr Issues Mol Biol 2022; 44:1127-48. [PMID: 35723297 PMCID: PMC8947152 DOI: 10.3390/cimb44030074] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2022] [Revised: 02/18/2022] [Accepted: 02/24/2022] [Indexed: 12/06/2022] Open
Abstract
Mitochondria are major contributors to ATP synthesis, generating more than 90% of the total cellular energy production through oxidative phosphorylation (OXPHOS): metabolite oxidation, such as the β-oxidation of fatty acids, and the Krebs’s cycle. OXPHOS inadequacy due to large genetic lesions in mitochondrial as well as nuclear genes and homo- or heteroplasmic point mutations in mitochondrially encoded genes is a characteristic of heterogeneous, maternally inherited genetic disorders known as mitochondrial disorders that affect multisystemic tissues and organs with high energy requirements, resulting in various signs and symptoms. Several traditional diagnostic approaches, including magnetic resonance imaging of the brain, cardiac testing, biochemical screening, variable heteroplasmy genetic testing, identifying clinical features, and skeletal muscle biopsies, are associated with increased risks, high costs, a high degree of false-positive or false-negative results, or a lack of precision, which limits their diagnostic abilities for mitochondrial disorders. Variable heteroplasmy levels, mtDNA depletion, and the identification of pathogenic variants can be detected through genetic sequencing, including the gold standard Sanger sequencing. However, sequencing can be time consuming, and Sanger sequencing can result in the missed recognition of larger structural variations such as CNVs or copy-number variations. Although each sequencing method has its own limitations, genetic sequencing can be an alternative to traditional diagnostic methods. The ever-growing roster of possible mutations has led to the development of next-generation sequencing (NGS). The enhancement of NGS methods can offer a precise diagnosis of the mitochondrial disorder within a short period at a reasonable expense for both research and clinical applications.
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7
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Mustafa MF, Fakurazi S, Abdullah MA, Maniam S. Pathogenic Mitochondria DNA Mutations: Current Detection Tools and Interventions. Genes (Basel) 2020; 11:genes11020192. [PMID: 32059522 PMCID: PMC7074468 DOI: 10.3390/genes11020192] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2019] [Revised: 12/10/2019] [Accepted: 12/11/2019] [Indexed: 02/07/2023] Open
Abstract
Mitochondria are best known for their role in energy production, and they are the only mammalian organelles that contain their own genomes. The mitochondrial genome mutation rate is reported to be 10–17 times higher compared to nuclear genomes as a result of oxidative damage caused by reactive oxygen species during oxidative phosphorylation. Pathogenic mitochondrial DNA mutations result in mitochondrial DNA disorders, which are among the most common inherited human diseases. Interventions of mitochondrial DNA disorders involve either the transfer of viable isolated mitochondria to recipient cells or genetically modifying the mitochondrial genome to improve therapeutic outcome. This review outlines the common mitochondrial DNA disorders and the key advances in the past decade necessary to improve the current knowledge on mitochondrial disease intervention. Although it is now 31 years since the first description of patients with pathogenic mitochondrial DNA was reported, the treatment for mitochondrial disease is often inadequate and mostly palliative. Advancements in diagnostic technology improved the molecular diagnosis of previously unresolved cases, and they provide new insight into the pathogenesis and genetic changes in mitochondrial DNA diseases.
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MESH Headings
- Acidosis, Lactic/congenital
- Acidosis, Lactic/genetics
- Acidosis, Lactic/metabolism
- DNA Mutational Analysis
- DNA, Mitochondrial/genetics
- DNA, Mitochondrial/metabolism
- Epilepsies, Myoclonic/congenital
- Epilepsies, Myoclonic/genetics
- Epilepsies, Myoclonic/therapy
- Gene Editing/methods
- Genetic Therapy/methods
- Humans
- Leigh Disease/genetics
- Leigh Disease/metabolism
- Leigh Disease/therapy
- Mitochondria/genetics
- Mitochondria/metabolism
- Mitochondria/pathology
- Mitochondrial Diseases/genetics
- Mitochondrial Diseases/metabolism
- Mitochondrial Diseases/therapy
- Mitochondrial Encephalomyopathies/congenital
- Mitochondrial Encephalomyopathies/genetics
- Mitochondrial Encephalomyopathies/metabolism
- Mutation
- Optic Atrophy, Hereditary, Leber/genetics
- Optic Atrophy, Hereditary, Leber/metabolism
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Affiliation(s)
- Mohd Fazirul Mustafa
- Department of Human Anatomy, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor Darul Ehsan, Malaysia
| | - Sharida Fakurazi
- Department of Human Anatomy, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor Darul Ehsan, Malaysia
| | - Maizaton Atmadini Abdullah
- Department of Pathology, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor Darul Ehsan, Malaysia
- Laboratory of Molecular Medicine, Institute of Bioscience, University Putra Malaysia, 43400 UPM Serdang Selangor Darul Ehsan, Malaysia
| | - Sandra Maniam
- Department of Human Anatomy, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor Darul Ehsan, Malaysia
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8
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Ryzhkova AI, Sazonova MA, Sinyov VV, Galitsyna EV, Chicheva MM, Melnichenko AA, Grechko AV, Postnov AY, Orekhov AN, Shkurat TP. Mitochondrial diseases caused by mtDNA mutations: a mini-review. Ther Clin Risk Manag 2018; 14:1933-1942. [PMID: 30349272 PMCID: PMC6186303 DOI: 10.2147/tcrm.s154863] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
There are several types of mitochondrial cytopathies, which cause a set of disorders, arise as a result of mitochondria’s failure. Mitochondria’s functional disruption leads to development of physical, growing and cognitive disabilities and includes multiple organ pathologies, essentially disturbing the nervous and muscular systems. The origins of mitochondrial cytopathies are mutations in genes of nuclear DNA encoding mitochondrial proteins or in mitochondrial DNA. Nowadays, numerous mtDNA mutations significant to the appearance and progress of pathologies in humans are detected. In this mini-review, we accent on the mitochondrial cytopathies related to mutations of mtDNA. As well known, there are definite set of symptoms of mitochondrial cytopathies distinguishing or similar for different syndromes. The present article contains data about mutations linked with cytopathies that facilitate diagnosis of different syndromes by using genetic analysis methods. In addition, for every individual, more effective therapeutic approach could be developed after wide-range mutant background analysis of mitochondrial genome.
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Affiliation(s)
- Anastasia I Ryzhkova
- Laboratory of Medical Genetics, National Medical Research Center of Cardiology, Moscow, Russian Federation, .,Department of Virology, K.I. Skryabin Moscow State Academy of Veterinary Medicine and Biotechnology-MVA, Moscow, Russian Federation,
| | - Margarita A Sazonova
- Laboratory of Medical Genetics, National Medical Research Center of Cardiology, Moscow, Russian Federation, .,Laboratory of Angiopathology, Institute of General Pathology and Pathophysiology, Moscow, Russian Federation
| | - Vasily V Sinyov
- Laboratory of Medical Genetics, National Medical Research Center of Cardiology, Moscow, Russian Federation,
| | - Elena V Galitsyna
- Department of Genetics, Southern Federal University, Rostov-on-Don, Russian Federation
| | - Mariya M Chicheva
- Department of Genetics, Southern Federal University, Rostov-on-Don, Russian Federation
| | | | - Andrey V Grechko
- Federal Research and Clinical Center of Reanimatology and Rehabilitology, Moscow, Russian Federation
| | - Anton Yu Postnov
- Laboratory of Medical Genetics, National Medical Research Center of Cardiology, Moscow, Russian Federation,
| | - Alexander N Orekhov
- Laboratory of Angiopathology, Institute of General Pathology and Pathophysiology, Moscow, Russian Federation.,Institute for Atherosclerosis Research, Skolkovo Innovative Centre, Moscow Region, Russian Federation
| | - Tatiana P Shkurat
- Department of Genetics, Southern Federal University, Rostov-on-Don, Russian Federation
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Affiliation(s)
- Shweta Bhat
- Department of Biological Sciences and Bioengineering, Indian Institute of Technology, Kanpur, India
| | - Subramaniam Ganesh
- Department of Biological Sciences and Bioengineering, Indian Institute of Technology, Kanpur, India
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10
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Park SY, Kim SH, Lee YM. Molecular Diagnosis of Myoclonus Epilepsy Associated with Ragged-Red Fibers Syndrome in the Absence of Ragged Red Fibers. Front Neurol 2017; 8:520. [PMID: 29033892 PMCID: PMC5626808 DOI: 10.3389/fneur.2017.00520] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2017] [Accepted: 09/19/2017] [Indexed: 11/13/2022] Open
Abstract
Myoclonus epilepsy with ragged-red fibers (MERRFs), an inherited mitochondrial disorder, has characteristic morphological changes of ragged-red fibers (RRFs) in muscle biopsy, in the absence of which mitochondrial etiology is usually not considered in patients with phenotypes suggestive of MERRF. In these circumstances, MERRF can only be diagnosed using genetic analyses. The symptoms, pathological findings, and imaging results being age dependent, we can construct a protocol based on these characteristics to understand the disease’s natural course and to manage patients more effectively. The absence of RRFs should not preclude a MERRF diagnosis.
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Affiliation(s)
- Sun Yeong Park
- Departments of Pediatrics, Yonsei University College of Medicine, Seoul, South Korea
| | - Se Hoon Kim
- Departments of Pathology, Yonsei University College of Medicine, Seoul, South Korea
| | - Young-Mock Lee
- Departments of Pediatrics, Yonsei University College of Medicine, Seoul, South Korea
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11
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Lorenzoni PJ, Scola RH, Kay CSK, Silvado CES, Werneck LC. When should MERRF (myoclonus epilepsy associated with ragged-red fibers) be the diagnosis? Arq Neuropsiquiatr 2015; 72:803-11. [PMID: 25337734 DOI: 10.1590/0004-282x20140124] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2014] [Accepted: 07/22/2014] [Indexed: 11/22/2022]
Abstract
Myoclonic epilepsy associated with ragged red fibers (MERRF) is a rare mitochondrial disorder. Diagnostic criteria for MERRF include typical manifestations of the disease: myoclonus, generalized epilepsy, cerebellar ataxia and ragged red fibers (RRF) on muscle biopsy. Clinical features of MERRF are not necessarily uniform in the early stages of the disease, and correlations between clinical manifestations and physiopathology have not been fully elucidated. It is estimated that point mutations in the tRNALys gene of the DNAmt, mainly A8344G, are responsible for almost 90% of MERRF cases. Morphological changes seen upon muscle biopsy in MERRF include a substantive proportion of RRF, muscle fibers showing a deficient activity of cytochrome c oxidase (COX) and the presence of vessels with a strong reaction for succinate dehydrogenase and COX deficiency. In this review, we discuss mainly clinical and laboratory manifestations, brain images, electrophysiological patterns, histology and molecular findings as well as some differential diagnoses and treatments.
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Affiliation(s)
- Paulo José Lorenzoni
- Departamento de Neurologia, Hospital de Clínicas, Universidade Federal do Paraná, Curitiba, PR, Brazil
| | - Rosana Herminia Scola
- Departamento de Neurologia, Hospital de Clínicas, Universidade Federal do Paraná, Curitiba, PR, Brazil
| | - Cláudia Suemi Kamoi Kay
- Departamento de Neurologia, Hospital de Clínicas, Universidade Federal do Paraná, Curitiba, PR, Brazil
| | - Carlos Eduardo S Silvado
- Departamento de Neurologia, Hospital de Clínicas, Universidade Federal do Paraná, Curitiba, PR, Brazil
| | - Lineu Cesar Werneck
- Departamento de Neurologia, Hospital de Clínicas, Universidade Federal do Paraná, Curitiba, PR, Brazil
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12
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Catteruccia M, Sauchelli D, Della Marca G, Primiano G, Cuccagna C, Bernardo D, Leo M, Camporeale A, Sanna T, Cianfoni A, Servidei S. "Myo-cardiomyopathy" is commonly associated with the A8344G "MERRF" mutation. J Neurol 2015; 262:701-10. [PMID: 25559684 DOI: 10.1007/s00415-014-7632-0] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2014] [Revised: 12/22/2014] [Accepted: 12/24/2014] [Indexed: 10/24/2022]
Abstract
The objective of the study was to better characterize the clinical phenotype associated with the A8344G "MERRF" mutation of mitochondrial DNA. Fifteen mutated patients were extensively investigated. The frequency of main clinical features was: exercise intolerance and/or muscle weakness 67 %, respiratory involvement 67 %, lactic acidosis 67 %, cardiac abnormalities 53 %, peripheral neuropathy 47 %, myoclonus 40 %, epilepsy 40 %, ataxia 13 %. A restrictive respiratory insufficiency requiring ventilatory support was observed in about half of our patients. One patient developed a severe and rapidly progressive cardiomyopathy requiring cardioverter-defibrillator implantation. Five patients died of overwhelming, intractable lactic acidosis. Serial muscle MRIs identified a consistent pattern of muscle involvement and progression. Cardiac MRI showed non-ischemic late gadolinium enhancement in the left ventricle inferolateral part as early sign of myocardial involvement. Brain spectroscopy demonstrated increased peak of choline and reduction of N-acetylaspartate. Lactate was never detected in brain areas, while it could be documented in ventricles. We confirm that muscle involvement is the most frequent clinical feature associated with A8443G mutation. In contrast with previous reports, however, about half of our patients did not develop signs of CNS involvement even in later stages of the disease. The difference may be related to the infrequent investigation of A8344G mutation in 'pure' mitochondrial myo-cardiomyopathy, representing a bias and a possible cause of syndrome's underestimation. Our study highlights the importance of lactic acidosis and respiratory muscle insufficiency as critical prognostic factors. Muscle and cardiac MRI and brain spectroscopy may be useful tools in diagnosis and follow-up of MERRF.
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Abstract
The mitochondrial DNA (mtDNA) is a compact genome inherited through the maternal lineage. Mutations in mtDNA lead to many of the earliest identified syndromic mitochondrial diseases and display a diverse range of age of onset, symptoms, and outcomes-from isolated childhood onset vision or hearing loss to a multisystemic neurodegenerative disorder with strokes, neuropathy, ophthalmoparesis, and epilepsy beginning at any age. As a heterogeneous group, mitochondrial diseases represent one of the most common metabolic disorders in children and adults, frequently seen by both pediatric and adult specialists. Although the myriad of diseases can make diagnosis seems daunting, the need for extensive supportive care and treatment (the latter for at least a select few mitochondrial disorders) and a rapid and accurate recognition of these disorders is necessary. Here, we provide a review of the most common mitochondrial disease syndromes due to mtDNA mutations.
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Affiliation(s)
- Suzanne Debrosse
- Center for Human Genetics, University Hospitals, Case Medical Center, Cleveland, OH 44195, USA
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14
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Abstract
A previously healthy 10-year-old girl presented with subacute onset of ataxia and acute-onset cardiac and pulmonary failure. Magnetic resonance imaging (MRI) of the brain showed symmetric T2 fluid-attenuated inversion recovery hyperintensities in the dorsal pons, medulla, and inferior cerebellar peduncles; nerve conduction velocities and electromyography demonstrated a sensorimotor axonal neuropathy consistent with Friedreich ataxia. Within 12 months, the patient fully recovered and molecular testing of the frataxin gene was unremarkable. Two years later, the patient returned with acute neurologic decompensation and died one month later from progressive demyelination of the brainstem. Mitochondrial DNA sequencing revealed a mutation at 8344A>G in transfer RNA lysine with heteroplasmy at 98% consistent with a diagnosis of a primary mitochondrial disorder.
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Affiliation(s)
- Justyna A Chevallier
- Department of Pediatrics, Division of Child and Adolescent Neurology, University of Texas Health Science Center, Houston, TX, USA
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15
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Affiliation(s)
- Andreas Moustris
- Sobell Department of Motor Neuroscience and Movement Disorders, UCL Institute of Neurology, London, UK
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Mancuso M, Orsucci D, Ali G, Lo Gerfo A, Fontanini G, Siciliano G. Advances in molecular diagnostics for mitochondrial diseases. Expert Opin Med Diagn 2009; 3:557-569. [PMID: 23495985 DOI: 10.1517/17530050902967610] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
BACKGROUND Mitochondrial disorders (MD) are diseases caused by impairment of the mitochondrial respiratory chain. Phenotypes are polymorphous and may range from pure myopathy to multisystemic disorders. The genetic defect can be located on mitochondrial or nuclear DNA. At present, diagnosis of MD requires a complex approach: measurement of serum lactate, electromyography, muscle histology and enzymology, and genetic analysis. Magnetic resonance spectroscopy allows the assessment of tissue metabolic alterations, thus providing useful information for the diagnosis and monitoring of MD. Molecular soluble markers of mitochondrial dysfunction, at rest and during exercise, can identify the impairment of the aerobic system in MD, but a reliable biomarker for the screening or diagnosis of MD is still needed. OBJECTIVE Molecular and genetic characterization of MD, together with other experimental approaches, contribute to add new insights to these diseases. Here, the role and advances of diagnostic techniques for MD are reviewed. CONCLUSION Possible applications of the results obtained by new molecular investigative approaches could in future guide therapeutic strategies.
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Affiliation(s)
- Michelangelo Mancuso
- University of Pisa, Neurological Clinic, Department of Neuroscience, Via Roma 67, 56126 Pisa, Italy +0039 050 992440 ; +0039 050 554808 ;
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Du W, Li W, Chen G, Cao H, Tang H, Tang X, Jin Q, Sun Z, Zhao H, Zhou W, He S, Lv Y, Zhao J, Zhang X. Detection of known base substitution mutations in human mitochondrial DNA of MERRF and MELAS by biochip technology. Biosens Bioelectron 2008; 24:2371-6. [PMID: 19155171 DOI: 10.1016/j.bios.2008.12.008] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2008] [Revised: 11/07/2008] [Accepted: 12/03/2008] [Indexed: 11/25/2022]
Abstract
We developed a DNA biochip specialized for detection of known base substitution mutations in mitochondrial DNA causing mitochondrial encephalomyopathy, lactic acidosis and stroke-like episodes (MELAS) and myoclonic epilepsy associated with ragged-red fibers (MERRF). A set of probes sharing a given allele-specific sequence with a single base substitution near the middle of the sequence was covalently immobilized. Cy5-labeled DNA targets were amplified from sample DNAs containing 31 potential MELAS and/or MERRF mutations by a multiplex PCR method. Detection parameters for the DNA biochip-based assay were accordingly optimized. Seven clinically confirmed patients with MELAS, 5 patients with MERRF, 1 suspected MERRF case and 25 healthy controls were tested using the DNA biochip. For discriminating of homoplasmic and heteroplasmic point mutations in mtDNA, a diagnostic factor based on the ratio between the hybridization signals from the reference and test targets with each probe was used. The results showed that all the cases with MELAS had a causal heteroplasmic A3243G tRNA(Leu(UUR)) mutation. In the MERRF patients, four cases were found to be a homoplasmic A8344G tRNA(Lys) mutation and one case was a heteroplasmic T8356C tRNA(Lys) mutation. None of the healthy controls carried the potential mutations. The results of the DNA biochip were completely consistent with those by DNA sequencing. Thus, the DNA biochip would potentially become a valuable tool in clinical specific screening of the mtDNA point mutations associated with MELAS and/or MERRF syndrome.
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Affiliation(s)
- Weidong Du
- Key Lab of Gene Resource Utilization for Severe Hereditary Diseases of Ministry of Education of China, Anhui Medical University, Hefei 230032, China.
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Bibliography. Current world literature. Neuro-muscular diseases: nerve. Curr Opin Neurol 2007; 20:600-4. [PMID: 17885452 DOI: 10.1097/WCO.0b013e3282efeb3b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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