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Beecher G, Gavrilova RH, Mandrekar J, Naddaf E. Mitochondrial myopathies diagnosed in adulthood: clinico-genetic spectrum and long-term outcomes. Brain Commun 2024; 6:fcae041. [PMID: 38434220 PMCID: PMC10906953 DOI: 10.1093/braincomms/fcae041] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2023] [Revised: 12/14/2023] [Accepted: 02/12/2024] [Indexed: 03/05/2024] Open
Abstract
Mitochondrial myopathies are frequently recognized in childhood as part of a broader multisystem disorder and often overlooked in adulthood. Herein, we describe the phenotypic and genotypic spectrum and long-term outcomes of mitochondrial myopathies diagnosed in adulthood, focusing on neuromuscular features, electrodiagnostic and myopathological findings and survival. We performed a retrospective chart review of adult patients diagnosed with mitochondrial myopathy at Mayo Clinic (2005-21). We identified 94 patients. Median time from symptom onset to diagnosis was 11 years (interquartile range 4-21 years). Median age at diagnosis was 48 years (32-63 years). Primary genetic defects were identified in mitochondrial DNA in 48 patients (10 with single large deletion, 38 with point mutations) and nuclear DNA in 29. Five patients had multiple mitochondrial DNA deletions or depletion without nuclear DNA variants. Twelve patients had histopathological features of mitochondrial myopathy without molecular diagnosis. The most common phenotypes included multisystem disorder (n = 30); mitochondrial encephalomyopathy, lactic acidosis and stroke-like episodes (14); limb myopathy (13); chronic progressive external ophthalmoplegia (12); and chronic progressive external ophthalmoplegia-plus (12). Isolated skeletal muscle manifestations occurred in 27%. Sixty-nine per cent had CNS and 21% had cardiac involvement. Mutations most frequently involved MT-TL1 (27) and POLG (17); however, a wide spectrum of established and novel molecular defects, with overlapping phenotypes, was identified. Electrodiagnostic studies identified myopathy (77%), fibrillation potentials (27%) and axonal peripheral neuropathy (42%, most common with nuclear DNA variants). Among 42 muscle biopsies available, median percentage counts were highest for cytochrome C oxidase negative fibres (5.1%) then ragged blue (1.4%) and ragged red fibres (0.5%). Skeletal muscle weakness was mild and slowly progressive (decline in strength summated score of 0.01/year). Median time to gait assistance was 5.5 years from diagnosis and 17 years from symptom onset. Thirty patients died, with median survival of 33.4 years from symptom onset and 10.9 years from diagnosis. Median age at death was 55 years. Cardiac involvement was associated with increased mortality [hazard ratio 2.36 (1.05, 5.29)]. There was no difference in survival based on genotype or phenotype. Despite the wide phenotypic and genotypic spectrum, mitochondrial myopathies in adults share similar features with slowly progressive limb weakness, contrasting with common multiorgan involvement and high mortality.
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Affiliation(s)
- Grayson Beecher
- Department of Neurology, Mayo Clinic, Rochester, MN 55905, USA
- Division of Neurology, Department of Medicine, University of Alberta, Edmonton, Alberta, Canada T6G 2G3
| | - Ralitza H Gavrilova
- Department of Neurology, Mayo Clinic, Rochester, MN 55905, USA
- Department of Clinical Genomics, Mayo Clinic, Rochester, MN 55905, USA
| | - Jay Mandrekar
- Department of Neurology, Mayo Clinic, Rochester, MN 55905, USA
| | - Elie Naddaf
- Department of Neurology, Mayo Clinic, Rochester, MN 55905, USA
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2
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Hong S, Kim S, Kim K, Lee H. Clinical Approaches for Mitochondrial Diseases. Cells 2023; 12:2494. [PMID: 37887337 PMCID: PMC10605124 DOI: 10.3390/cells12202494] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2023] [Revised: 10/18/2023] [Accepted: 10/19/2023] [Indexed: 10/28/2023] Open
Abstract
Mitochondria are subcontractors dedicated to energy production within cells. In human mitochondria, almost all mitochondrial proteins originate from the nucleus, except for 13 subunit proteins that make up the crucial system required to perform 'oxidative phosphorylation (OX PHOS)', which are expressed by the mitochondria's self-contained DNA. Mitochondrial DNA (mtDNA) also encodes 2 rRNA and 22 tRNA species. Mitochondrial DNA replicates almost autonomously, independent of the nucleus, and its heredity follows a non-Mendelian pattern, exclusively passing from mother to children. Numerous studies have identified mtDNA mutation-related genetic diseases. The consequences of various types of mtDNA mutations, including insertions, deletions, and single base-pair mutations, are studied to reveal their relationship to mitochondrial diseases. Most mitochondrial diseases exhibit fatal symptoms, leading to ongoing therapeutic research with diverse approaches such as stimulating the defective OXPHOS system, mitochondrial replacement, and allotropic expression of defective enzymes. This review provides detailed information on two topics: (1) mitochondrial diseases caused by mtDNA mutations, and (2) the mechanisms of current treatments for mitochondrial diseases and clinical trials.
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Affiliation(s)
- Seongho Hong
- Korea Mouse Phenotyping Center, Seoul National University, Seoul 08826, Republic of Korea;
- Department of Medicine, Korea University College of Medicine, Seoul 02708, Republic of Korea
| | - Sanghun Kim
- Laboratory Animal Resource and Research Center, Korea Research Institute of Bioscience and Biotechnology, Cheongju 28116, Republic of Korea;
- College of Veterinary Medicine and Research Institute of Veterinary Medicine, Chungbuk National University, Cheongju 28644, Republic of Korea
| | - Kyoungmi Kim
- Department of Biomedical Sciences, Korea University College of Medicine, Seoul 02841, Republic of Korea
- Department of Physiology, Korea University College of Medicine, Seoul 02841, Republic of Korea
| | - Hyunji Lee
- Department of Medicine, Korea University College of Medicine, Seoul 02708, Republic of Korea
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Horvath R, Medina J, Reilly MM, Shy ME, Zuchner S. Peripheral neuropathy in mitochondrial disease. HANDBOOK OF CLINICAL NEUROLOGY 2023; 194:99-116. [PMID: 36813324 DOI: 10.1016/b978-0-12-821751-1.00014-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/22/2023]
Abstract
Mitochondria are essential for the health and viability of both motor and sensory neurons and their axons. Processes that disrupt their normal distribution and transport along axons will likely cause peripheral neuropathies. Similarly, mutations in mtDNA or nuclear encoded genes result in neuropathies that either stand alone or are part of multisystem disorders. This chapter focuses on the more common genetic forms and characteristic clinical phenotypes of "mitochondrial" peripheral neuropathies. We also explain how these various mitochondrial abnormalities cause peripheral neuropathy. In a patient with a neuropathy either due to a mutation in a nuclear or an mtDNA gene, clinical investigations aim to characterize the neuropathy and make an accurate diagnosis. In some patients, this may be relatively straightforward, where a clinical assessment and nerve conduction studies followed by genetic testing is all that is needed. In others, multiple investigations including a muscle biopsy, CNS imaging, CSF analysis, and a wide range of metabolic and genetic tests in blood and muscle may be needed to establish diagnosis.
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Affiliation(s)
- Rita Horvath
- Department of Clinical Neurosciences, University of Cambridge, John van Geest Centre for Brain Repair, Cambridge, United Kingdom.
| | - Jessica Medina
- Dr. John T. Macdonald Foundation Department of Human Genetics and John P. Hussman Institute for Human Genomics, University of Miami Miller School of Medicine, Miami, FL, United States
| | - Mary M Reilly
- MRC Centre for Neuromuscular Diseases, UCL Queen Square Institute of Neurology, London, United Kingdom
| | - Michael E Shy
- Department of Neurology, Carver College of Medicine, University of Iowa, Iowa City, IA, United States
| | - Stephan Zuchner
- Dr. John T. Macdonald Foundation Department of Human Genetics and John P. Hussman Institute for Human Genomics, University of Miami Miller School of Medicine, Miami, FL, United States
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Lang-Orsini M, Gonzalez-Perez P. Neuropathic Pain as Main Manifestation of POLG-Related Disease: A Case Report. Front Neurol 2022; 13:846110. [PMID: 35350396 PMCID: PMC8957867 DOI: 10.3389/fneur.2022.846110] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2021] [Accepted: 02/04/2022] [Indexed: 12/05/2022] Open
Abstract
Mutations in nuclear-encoded genes that are involved in mitochondrial DNA replication and maintenance (e.g., POLG) have been associated with chronic progressive external ophthalmoplegia (CPEO) phenotype. These nuclear genome mutations may lead to multiple mitochondrial DNA deletions or mitochondrial DNA depletion. On the other hand, primary genetic defects of mitochondrial DNA (such as single large-scale deletion or point mutations) have also been associated with the CPEO phenotype. Chronic progressive external ophthalmoplegia (CPEO) may be a manifestation of specific syndromes that, when clinically recognized, prompt clinicians to investigate specific genetic defects. Thus, CPEO, as part of Kearns Sayre syndrome, suggests the presence of a large-scale deletion of mitochondrial DNA. However, in pure CPEO or CPEO plus phenotypes, it is more difficult to know whether causative genetic defects affect the nuclear or mitochondrial DNA. Here, we present a patient with a long-standing history of CPEO plus phenotype, in whom the sequencing of mitochondrial DNA from skeletal muscle was normal, and no other genetic defect was suspected at first. At the time of our evaluation, the presence of polyneuropathy and neuropathic pain prompted us to investigate nuclear genetic defects and, specifically, mutations in the POLG gene. Thus, the sequencing of the POLG gene revealed p.Thr251Ile and p.Pro587Leu mutations in one allele, and p.Ala467Thr mutation in another allele. Although one would expect that mutations in POLG lead to multiple mitochondrial DNA deletions or depletion (loss of copies), the absence of mitochondrial DNA abnormalities in tissue may be explained by heteroplasmy, a lack or no significant involvement of biopsied tissue, or a sampling bias. So, the absence of secondary mitochondrial DNA alterations should not discourage clinicians from further investigating mutations in nuclear-encoded genes. Lastly, mitochondrial point mutations and single mitochondrial DNA deletions very rarely cause CPEO associated with polyneuropathy and neuropathic pain, and POLG-related disease should be considered in this scenario, instead.
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Affiliation(s)
- Melanie Lang-Orsini
- Department of Pathology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, United States
| | - Paloma Gonzalez-Perez
- Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, United States
- *Correspondence: Paloma Gonzalez-Perez
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Ramón J, Vila-Julià F, Molina-Granada D, Molina-Berenguer M, Melià MJ, García-Arumí E, Torres-Torronteras J, Cámara Y, Martí R. Therapy Prospects for Mitochondrial DNA Maintenance Disorders. Int J Mol Sci 2021; 22:6447. [PMID: 34208592 PMCID: PMC8234938 DOI: 10.3390/ijms22126447] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2021] [Revised: 06/10/2021] [Accepted: 06/11/2021] [Indexed: 02/07/2023] Open
Abstract
Mitochondrial DNA depletion and multiple deletions syndromes (MDDS) constitute a group of mitochondrial diseases defined by dysfunctional mitochondrial DNA (mtDNA) replication and maintenance. As is the case for many other mitochondrial diseases, the options for the treatment of these disorders are rather limited today. Some aggressive treatments such as liver transplantation or allogeneic stem cell transplantation are among the few available options for patients with some forms of MDDS. However, in recent years, significant advances in our knowledge of the biochemical pathomechanisms accounting for dysfunctional mtDNA replication have been achieved, which has opened new prospects for the treatment of these often fatal diseases. Current strategies under investigation to treat MDDS range from small molecule substrate enhancement approaches to more complex treatments, such as lentiviral or adenoassociated vector-mediated gene therapy. Some of these experimental therapies have already reached the clinical phase with very promising results, however, they are hampered by the fact that these are all rare disorders and so the patient recruitment potential for clinical trials is very limited.
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Affiliation(s)
- Javier Ramón
- Research Group on Neuromuscular and Mitochondrial Diseases, Vall d’Hebron Research Institute, Universitat Autònoma de Barcelona, 08035 Barcelona, Spain; (J.R.); (F.V.-J.); (D.M.-G.); (M.M.-B.); (M.J.M.); (E.G.-A.); (J.T.-T.); (Y.C.)
- Biomedical Network Research Centre on Rare Diseases (CIBERER), Instituto de Salud Carlos III, 28029 Madrid, Spain
| | - Ferran Vila-Julià
- Research Group on Neuromuscular and Mitochondrial Diseases, Vall d’Hebron Research Institute, Universitat Autònoma de Barcelona, 08035 Barcelona, Spain; (J.R.); (F.V.-J.); (D.M.-G.); (M.M.-B.); (M.J.M.); (E.G.-A.); (J.T.-T.); (Y.C.)
- Biomedical Network Research Centre on Rare Diseases (CIBERER), Instituto de Salud Carlos III, 28029 Madrid, Spain
| | - David Molina-Granada
- Research Group on Neuromuscular and Mitochondrial Diseases, Vall d’Hebron Research Institute, Universitat Autònoma de Barcelona, 08035 Barcelona, Spain; (J.R.); (F.V.-J.); (D.M.-G.); (M.M.-B.); (M.J.M.); (E.G.-A.); (J.T.-T.); (Y.C.)
- Biomedical Network Research Centre on Rare Diseases (CIBERER), Instituto de Salud Carlos III, 28029 Madrid, Spain
| | - Miguel Molina-Berenguer
- Research Group on Neuromuscular and Mitochondrial Diseases, Vall d’Hebron Research Institute, Universitat Autònoma de Barcelona, 08035 Barcelona, Spain; (J.R.); (F.V.-J.); (D.M.-G.); (M.M.-B.); (M.J.M.); (E.G.-A.); (J.T.-T.); (Y.C.)
- Biomedical Network Research Centre on Rare Diseases (CIBERER), Instituto de Salud Carlos III, 28029 Madrid, Spain
| | - Maria Jesús Melià
- Research Group on Neuromuscular and Mitochondrial Diseases, Vall d’Hebron Research Institute, Universitat Autònoma de Barcelona, 08035 Barcelona, Spain; (J.R.); (F.V.-J.); (D.M.-G.); (M.M.-B.); (M.J.M.); (E.G.-A.); (J.T.-T.); (Y.C.)
- Biomedical Network Research Centre on Rare Diseases (CIBERER), Instituto de Salud Carlos III, 28029 Madrid, Spain
| | - Elena García-Arumí
- Research Group on Neuromuscular and Mitochondrial Diseases, Vall d’Hebron Research Institute, Universitat Autònoma de Barcelona, 08035 Barcelona, Spain; (J.R.); (F.V.-J.); (D.M.-G.); (M.M.-B.); (M.J.M.); (E.G.-A.); (J.T.-T.); (Y.C.)
- Biomedical Network Research Centre on Rare Diseases (CIBERER), Instituto de Salud Carlos III, 28029 Madrid, Spain
| | - Javier Torres-Torronteras
- Research Group on Neuromuscular and Mitochondrial Diseases, Vall d’Hebron Research Institute, Universitat Autònoma de Barcelona, 08035 Barcelona, Spain; (J.R.); (F.V.-J.); (D.M.-G.); (M.M.-B.); (M.J.M.); (E.G.-A.); (J.T.-T.); (Y.C.)
- Biomedical Network Research Centre on Rare Diseases (CIBERER), Instituto de Salud Carlos III, 28029 Madrid, Spain
| | - Yolanda Cámara
- Research Group on Neuromuscular and Mitochondrial Diseases, Vall d’Hebron Research Institute, Universitat Autònoma de Barcelona, 08035 Barcelona, Spain; (J.R.); (F.V.-J.); (D.M.-G.); (M.M.-B.); (M.J.M.); (E.G.-A.); (J.T.-T.); (Y.C.)
- Biomedical Network Research Centre on Rare Diseases (CIBERER), Instituto de Salud Carlos III, 28029 Madrid, Spain
| | - Ramon Martí
- Research Group on Neuromuscular and Mitochondrial Diseases, Vall d’Hebron Research Institute, Universitat Autònoma de Barcelona, 08035 Barcelona, Spain; (J.R.); (F.V.-J.); (D.M.-G.); (M.M.-B.); (M.J.M.); (E.G.-A.); (J.T.-T.); (Y.C.)
- Biomedical Network Research Centre on Rare Diseases (CIBERER), Instituto de Salud Carlos III, 28029 Madrid, Spain
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6
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Macken WL, Vandrovcova J, Hanna MG, Pitceathly RDS. Applying genomic and transcriptomic advances to mitochondrial medicine. Nat Rev Neurol 2021; 17:215-230. [PMID: 33623159 DOI: 10.1038/s41582-021-00455-2] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/06/2021] [Indexed: 02/07/2023]
Abstract
Next-generation sequencing (NGS) has increased our understanding of the molecular basis of many primary mitochondrial diseases (PMDs). Despite this progress, many patients with suspected PMD remain without a genetic diagnosis, which restricts their access to in-depth genetic counselling, reproductive options and clinical trials, in addition to hampering efforts to understand the underlying disease mechanisms. Although they represent a considerable improvement over their predecessors, current methods for sequencing the mitochondrial and nuclear genomes have important limitations, and molecular diagnostic techniques are often manual and time consuming. However, recent advances in genomics and transcriptomics offer realistic solutions to these challenges. In this Review, we discuss the current genetic testing approach for PMDs and the opportunities that exist for increased use of whole-genome NGS of nuclear and mitochondrial DNA (mtDNA) in the clinical environment. We consider the possible role for long-read approaches in sequencing of mtDNA and in the identification of novel nuclear genomic causes of PMDs. We examine the expanding applications of RNA sequencing, including the detection of cryptic variants that affect splicing and gene expression and the interpretation of rare and novel mitochondrial transfer RNA variants.
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Affiliation(s)
- William L Macken
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology and The National Hospital for Neurology and Neurosurgery, London, UK
| | - Jana Vandrovcova
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology and The National Hospital for Neurology and Neurosurgery, London, UK
| | - Michael G Hanna
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology and The National Hospital for Neurology and Neurosurgery, London, UK
| | - Robert D S Pitceathly
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology and The National Hospital for Neurology and Neurosurgery, London, UK.
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Abstract
Objectives: Generally, neuropathies of peripheral nerves are a frequent condition (prevalence 2–3%) and most frequently due to alcoholism, diabetes, renal insufficiency, malignancy, toxins, or drugs. However, the vast majority of neuropathies has orphan status. This review focuses on the etiology, frequency, diagnosis, and treatment of orphan neuropathies. Methods: Literature review Results: Rareness of diseases is not uniformly defined but in the US an orphan disease is diagnosed if the prevalence is <1:200000, in Europe if <5:10000. Most acquired and hereditary neuropathies are orphan diseases. Often the causative variant has been reported only in a single patient or family, particularly the ones that are newly detected (e.g. SEPT9, SORD). Among the complex neuropathies (hereditary multisystem disorders with concomitant neuropathies) orphan forms have been reported among mitochondrial disorders (e.g. NARP, MNGIE, SANDO), spinocerebellar ataxias (e.g. TMEM240), hereditary spastic paraplegias (e.g UBAP1), lysosomal storage disease (e.g. Schindler disease), peroxisomal disorders, porphyrias, and other types (e.g. giant axonal neuropathy, Tangier disease). Orphan acquired neuropathies include the metabolic neuropathies (e.g. vitamin-B1, folic acid), toxic neuropathies (e.g. copper, lithium, lead, arsenic, thallium, mercury), infectious neuropathies, immune-mediated (e.g. Bruns-Garland syndrome), and neoplastic/paraneoplastic neuropathies. Conclusions: Though orphan neuropathies are rare per definition they constitute the majority of neuropathies and should be considered as some of them are easy to identify and potentially treatable, as clarification of the underlying cause may contribute to the knowledge about etiology and pathophysiology of these conditions, and as the true prevalence may become obvious only if all ever diagnosed cases are reported.
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Affiliation(s)
| | | | - Julia Wanschitz
- Department of Neurology, Medical University, Innsbruck, Austria
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van den Ameele J, Fuge J, Pitceathly RDS, Berry S, McIntyre Z, Hanna MG, Lee M, Chinnery PF. Chronic pain is common in mitochondrial disease. Neuromuscul Disord 2020; 30:413-419. [PMID: 32334903 PMCID: PMC7306151 DOI: 10.1016/j.nmd.2020.02.017] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2019] [Revised: 02/24/2020] [Accepted: 02/25/2020] [Indexed: 12/13/2022]
Abstract
Chronic pain is common in patients with mitochondrial disease. Pain due to mitochondrial disease is primarily of neuropathic nature. Distribution, intensity and type of pain are genetically determined.
In the absence of cure, the main objectives in the management of patients with mitochondrial disease are symptom control and prevention of complications. While pain is a complicating symptom in many chronic diseases and is known to have a clear impact on quality of life, its prevalence and severity in people with mitochondrial disease is unknown. We conducted a survey of pain symptoms in patients with genetically confirmed mitochondrial disease from two UK mitochondrial disease specialist centres. The majority (66.7%) of patients had chronic pain which was primarily of neuropathic nature. Presence of pain did not significantly impact overall quality of life. The m.3243A>G MTTL1 mutation was associated with higher pain severity and increased the likelihood of neuropathic pain compared to other causative nuclear and mitochondrial gene mutations. Although previously not considered a core symptom in people with mitochondrial disease, pain is a common clinical manifestation, frequently of neuropathic nature, and influenced by genotype. Therefore, pain-related symptoms should be carefully characterised and actively managed in this patient population.
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Affiliation(s)
- Jelle van den Ameele
- Department of Clinical Neurosciences, University of Cambridge, Cambridge Biomedical Campus, Cambridge CB2 0QQ, UK; WT/CRUK Gurdon Institute, Tennis Court Road, Cambridge CB2 1QN, UK.
| | - Joshua Fuge
- Department of Clinical Neurosciences, University of Cambridge, Cambridge Biomedical Campus, Cambridge CB2 0QQ, UK
| | - Robert D S Pitceathly
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology and The National Hospital for Neurology and Neurosurgery, London WC1N 3BG, UK
| | - Sarah Berry
- Department of Clinical Neurosciences, University of Cambridge, Cambridge Biomedical Campus, Cambridge CB2 0QQ, UK
| | - Zoe McIntyre
- Department of Clinical Neurosciences, University of Cambridge, Cambridge Biomedical Campus, Cambridge CB2 0QQ, UK
| | - Michael G Hanna
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology and The National Hospital for Neurology and Neurosurgery, London WC1N 3BG, UK
| | - Michael Lee
- Division of Anaesthesia, University of Cambridge, Cambridge CB2 2QQ, UK
| | - Patrick F Chinnery
- Department of Clinical Neurosciences, University of Cambridge, Cambridge Biomedical Campus, Cambridge CB2 0QQ, UK; MRC Mitochondrial Biology Unit, University of Cambridge, Cambridge CB2 0XY, UK.
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O'Donnell L, Blakely EL, Baty K, Alexander M, Bogdanova-Mihaylova P, Craig J, Walsh R, Brett F, Taylor RW, Murphy SM. Chronic Progressive External Ophthalmoplegia due to a Rare de novo m.12334G>A MT-TL2 Mitochondrial DNA Variant1. J Neuromuscul Dis 2020; 7:355-360. [PMID: 32310184 DOI: 10.3233/jnd-200486] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
We describe a patient with chronic progressive external ophthalmoplegia (CPEO) due to a rare mitochondrial genetic variant. Muscle biopsy revealed numerous cytochrome c oxidase (COX)-deficient fibres, prompting sequencing of the entire mitochondrial genome in muscle which revealed a rare m.12334G>A variant in the mitochondrial (mt-) tRNALeu(CUN)(MT-TL2) gene. Analysis of several tissues showed this to be a de novo mutational event. Single fibre studies confirmed the segregation of high m.12334G>A heteroplasmy levels with the COX histochemical defect, confirming pathogenicity of the m.12334G>A MT-TL2 variant. This case illustrates the importance of pursuing molecular genetic analysis in clinically-affected tissues when mitochondrial disease is suspected.
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Affiliation(s)
- Luke O'Donnell
- Department of Neurology, Tallaght University Hospital, Tallaght, Dublin, Ireland
| | - Emma L Blakely
- Wellcome Centre for Mitochondrial Research, Translational and Clinical Research Institute, Newcastle University, Newcastle upon Tyne, United Kingdom
- NHS Highly Specialised Mitochondrial Diagnostic Laboratory, Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne, United Kingdom
| | - Karen Baty
- Wellcome Centre for Mitochondrial Research, Translational and Clinical Research Institute, Newcastle University, Newcastle upon Tyne, United Kingdom
- NHS Highly Specialised Mitochondrial Diagnostic Laboratory, Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne, United Kingdom
| | - Michael Alexander
- Department of Neurophysiology, Tallaght University Hospital, Tallaght, Dublin, Ireland
- Academic Unit of Neurology, Trinity College Dublin, The University of Dublin, Dublin, Ireland
| | | | - John Craig
- Department of Neurology, Belfast Health and Social Care Trust, Belfast, United Kingdom
| | - Ronan Walsh
- Department of Neurology, Hermitage Medical Clinic, Dublin, Ireland
| | - Francesca Brett
- Department of Neuropathology, Beaumont Hospital, Dublin, Ireland
| | - Robert W Taylor
- Wellcome Centre for Mitochondrial Research, Translational and Clinical Research Institute, Newcastle University, Newcastle upon Tyne, United Kingdom
- NHS Highly Specialised Mitochondrial Diagnostic Laboratory, Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne, United Kingdom
| | - Sinead M Murphy
- Department of Neurology, Tallaght University Hospital, Tallaght, Dublin, Ireland
- Academic Unit of Neurology, Trinity College Dublin, The University of Dublin, Dublin, Ireland
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Iwanicka-Pronicka K, Ciara E, Piekutowska-Abramczuk D, Halat P, Pajdowska M, Pronicki M. Congenital cochlear deafness in mitochondrial diseases related to RRM2B and SERAC1 gene defects. A study of the mitochondrial patients of the CMHI hospital in Warsaw, Poland. Int J Pediatr Otorhinolaryngol 2019; 121:143-149. [PMID: 30909120 DOI: 10.1016/j.ijporl.2019.03.015] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/18/2018] [Revised: 03/07/2019] [Accepted: 03/10/2019] [Indexed: 01/11/2023]
Abstract
OBJECTIVES Although hearing loss is a well-known symptom of mitochondria-related disorders, it is not clear how often it is a congenital and cochlear impairment. The Newborn Hearing Screening Program (NHSP) enables to distinguish congenital cochlear deafness from an acquired hearing deficit. The initial aim of the study was to research the frequency of the congenital cochlear hearing loss among patients with various gene defects resulting in mitochondrial disorders. The research process brought on an additional gain: basing on our preliminary study group of 80 patients, in 12 patients altogether we identified two defected genes responsible for mitochondrial disorders, whose carriers did not pass the NHSP. Finally, these patients were diagnosed with the congenital cochlear deafness. MATERIAL AND METHODS The results of the NHSP in the patients with mitochondrial disorders diagnosed in our tertiary reference center were analyzed. Only the cases with confirmed mutations were qualified for the study group. The NHSP database included 80 patients with mutations in 31 different genes: 25 nuclear-encoded and 6 mtDNA-encoded. We searched the literature for the presence of a congenital hearing impairment (CHI) in mitochondrial disorders caused by changes in 278 already known genes. RESULTS For 68 patients from the study group the NHSP test indicated a proper cochlear function and thus suggested normal hearing. For 12 mitochondrial patients, the NHSP test indicated the requirement for the further audiological diagnosis, and finally CHI was confirmed in 8 of them. This latter subset included patients with pathogenic variants in RRM2B and SERAC1, known as "deafness-causing genes". Contrary to our initial expectations, the patients carrying mutations in other "deafness-causing genes": MPV17, POLG, COX10, as well as other mitochondria-related genes, all reported in literature, did not indicate any CHI following the NHSP test. CONCLUSION Our study indicates that the cochlear CHI is a phenotypic feature of the RRM2B and SERAC1 related defects. The diagnosis of the CHI following the NHSP allows to early distinguish those defects from other mitochondria-related disorders in which the NHSP test result is correct. Wider studies are needed to assess the significance of this observation.
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Affiliation(s)
- Katarzyna Iwanicka-Pronicka
- - Department of Audiology and Phoniatrics, The Children's Memorial Health Institute, Al. Dzieci Polskich 20, Warsaw, Poland; - Department of Medical Genetics, The Children's Memorial Health Institute, Al. Dzieci Polskich 20, Warsaw, Poland.
| | - Elżbieta Ciara
- - Department of Medical Genetics, The Children's Memorial Health Institute, Al. Dzieci Polskich 20, Warsaw, Poland
| | - Dorota Piekutowska-Abramczuk
- - Department of Medical Genetics, The Children's Memorial Health Institute, Al. Dzieci Polskich 20, Warsaw, Poland
| | - Paulina Halat
- - Department of Medical Genetics, The Children's Memorial Health Institute, Al. Dzieci Polskich 20, Warsaw, Poland
| | - Magdalena Pajdowska
- - Department of Clinical Biochemistry, Radioimmunology, and Experimental Medicine, The Children's Memorial Health Institute, Al. Dzieci Polskich 20, Warsaw, Poland
| | - Maciej Pronicki
- - Department of Pathology, The Children's Memorial Health Institute, Al. Dzieci Polskich 20, Warsaw, Poland
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Sui Y, Nguyen HB, Thai TQ, Ikenaka K, Ohno N. Mitochondrial Dynamics in Physiology and Pathology of Myelinated Axons. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1190:145-163. [PMID: 31760643 DOI: 10.1007/978-981-32-9636-7_10] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Mitochondria play essential roles in neurons and abnormal functions of mitochondria have been implicated in neurological disorders including myelin diseases. Since mitochondrial functions are regulated and maintained by their dynamic behavior involving localization, transport, and fusion/fission, modulation of mitochondrial dynamics would be involved in physiology and pathology of myelinated axons. In fact, the integration of multimodal imaging in vivo and in vitro revealed that mitochondrial localization and transport are differentially regulated in nodal and internodal regions in response to the changes of metabolic demand in myelinated axons. In addition, the mitochondrial behavior in axons is modulated as adaptive responses to demyelination irrespective of the cause of myelin loss, and the behavioral modulation is partly through interactions with cytoskeletons and closely associated with the pathophysiology of demyelinating diseases. Furthermore, the behavior and functions of axonal mitochondria are modulated in congenital myelin disorders involving impaired interactions between axons and myelin-forming cells, and, together with the inflammatory environment, implicated in axonal degeneration and disease phenotypes. Further studies on the regulatory mechanisms of the mitochondrial dynamics in myelinated axons would provide deeper insights into axo-glial interactions mediated through myelin ensheathment, and effective manipulations of the dynamics may lead to novel therapeutic strategies protecting axonal and neuronal functions and survival in primary diseases of myelin.
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Affiliation(s)
- Yang Sui
- Division of Neurobiology and Bioinformatics, National Institute for Physiological Sciences, Okazaki, Aichi, Japan.,Departments of Anatomy and Structural Biology, Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, Chuo, Yamanashi, Japan
| | - Huy Bang Nguyen
- Division of Neurobiology and Bioinformatics, National Institute for Physiological Sciences, Okazaki, Aichi, Japan.,Departments of Anatomy and Structural Biology, Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, Chuo, Yamanashi, Japan
| | - Truc Quynh Thai
- Division of Neurobiology and Bioinformatics, National Institute for Physiological Sciences, Okazaki, Aichi, Japan.,Departments of Anatomy and Structural Biology, Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, Chuo, Yamanashi, Japan
| | - Kazuhiro Ikenaka
- Division of Neurobiology and Bioinformatics, National Institute for Physiological Sciences, Okazaki, Aichi, Japan
| | - Nobuhiko Ohno
- Division of Neurobiology and Bioinformatics, National Institute for Physiological Sciences, Okazaki, Aichi, Japan. .,Department of Anatomy, Division of Histology and Cell Biology, Jichi Medical University, School of Medicine, Shimotsuke, Japan.
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12
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Kozak I, Oystreck DT, Abu-Amero KK, Nowilaty SR, Alkhalidi H, Elkhamary SM, Mohamed S, Hamad MHA, Salih MA, Blakely EL, Taylor RW, Bosley TM. NEW OBSERVATIONS REGARDING THE RETINOPATHY OF GENETICALLY CONFIRMED KEARNS-SAYRE SYNDROME. Retin Cases Brief Rep 2018; 12:349-358. [PMID: 28296806 DOI: 10.1097/icb.0000000000000503] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
PURPOSE To report novel retinal findings in Kearns-Sayre syndrome and correlate degree of retinopathy with other clinical findings. METHODS Observational case series of patients from Saudi Arabia with retinal and neuroophthalmologic examinations, medical chart review, and mitochondrial genetic evaluation. RESULTS The three unrelated patients had progressive external ophthalmoplegia and pigmentary retinopathy bilaterally. Muscle biopsy in two of the cases revealed mitochondrial myopathy. All three had abnormal findings on neuroimaging and modestly reduced visual acuity in both eyes with a variable pigmentary retinopathy. One of the patients had bilateral subretinal fibrosis with a full-thickness macular hole in the right eye. All three patients had single, large-scale mitochondrial DNA (mtDNA) deletions (5.0-7.6 kb in size) with blood mtDNA heteroplasmy levels ranging from below 20% to 57%. Severity of pigmentary retinopathy did not correlate with severity of progressive external ophthalmoplegia, but did correspond grossly with electroretinographic abnormalities, just as the degree of ocular motility restriction and ptosis in each patient correlated with the size of their extraocular muscles on neuroimaging. In addition, the size of the single, large-scale mtDNA deletion and level of mtDNA heteroplasmy corresponded with degree of ocular motility restriction but not with severity of retinopathy. CONCLUSION Subretinal fibrosis and macular hole are novel retinal observations which expand clinical profile in Kearns-Sayre syndrome. Genetic testing for mtDNA deletions and heteroplasmy in blood, muscle biopsy, careful ocular and retinal examination including electroretinography, and imaging are indispensable tests for this condition.
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Affiliation(s)
- Igor Kozak
- King Khaled Eye Specialist Hospital, Riyadh, Saudi Arabia
| | - Darren T Oystreck
- Department of Ophthalmology, College of Medicine, King Saud University, Riyadh, Saudi Arabia
- The Division of Ophthalmology, Faculty of Health Sciences, University of Stellenbosch, Tygerberg, South Africa
| | - Khaled K Abu-Amero
- Department of Ophthalmology, College of Medicine, King Saud University, Riyadh, Saudi Arabia
- Department of Ophthalmology, College of Medicine, University of Florida, Jacksonville, Florida
| | | | | | | | - Sarar Mohamed
- Pediatrics, College of Medicine, King Saud University Riyadh, Saudi Arabia
| | | | - Mustafa A Salih
- Pediatrics, College of Medicine, King Saud University Riyadh, Saudi Arabia
| | - Emma L Blakely
- The Wellcome Trust Centre for Mitochondrial Research, Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Robert W Taylor
- The Wellcome Trust Centre for Mitochondrial Research, Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Thomas M Bosley
- Department of Ophthalmology, College of Medicine, King Saud University, Riyadh, Saudi Arabia
- The Wilmer Eye Institute, Johns Hopkins University, Baltimore, Maryland
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13
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Alves CAPF, Gonçalves FG, Grieb D, Lucato LT, Goldstein AC, Zuccoli G. Neuroimaging of Mitochondrial Cytopathies. Top Magn Reson Imaging 2018; 27:219-240. [PMID: 30086109 DOI: 10.1097/rmr.0000000000000173] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Mitochondrial diseases are a complex and heterogeneous group of genetic disorders that occur as a result of either nuclear DNA or mitochondrial DNA pathogenic variants, leading to a decrease in oxidative phosphorylation and cellular energy (ATP) production. Increasing knowledge about molecular, biochemical, and genetic abnormalities related to mitochondrial dysfunction has expanded the neuroimaging phenotypes of mitochondrial disorders. As a consequence of this growing field, the imaging recognition patterns of mitochondrial cytopathies are continually evolving. In this review, we describe the main neuroimaging characteristics of pediatric mitochondrial diseases, ranging from classical to more recent and challenging features. Due to the increased knowledge about the imaging findings of mitochondrial cytopathies, the pediatric neuroradiologist plays a crucial role in the diagnosis and evaluation of these patients.
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Affiliation(s)
| | | | - Dominik Grieb
- Department of Radiology and Neuroradiology, Sana Kliniken Duisburg, Germany
| | - Leandro Tavares Lucato
- Neuroradiology Section, Hospital das Clínicas- HCFMUSP, Faculdade de Medicina, Universidade de Sao Paulo, Sao Paulo, SP, Brazil
| | - Amy C Goldstein
- Division of Human Genetics, Children's Hospital of Philadelphia, University of Pennsylvania, Philadelphia, PA
| | - Giulio Zuccoli
- Department of Radiology, University of Pittsburgh School of Medicine, Director of Pediatric Neuroradiology, Children Hospital of Pittsburgh, Pittsburgh, PA
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14
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Luigetti M, Primiano G, Cuccagna C, Bernardo D, Sauchelli D, Vollono C, Servidei S. Small fibre neuropathy in mitochondrial diseases explored with sudoscan. Clin Neurophysiol 2018; 129:1618-1623. [DOI: 10.1016/j.clinph.2018.04.755] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2017] [Revised: 03/30/2018] [Accepted: 04/29/2018] [Indexed: 01/16/2023]
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15
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Work-up for mitochondrial small fiber neuropathy requires application of skin biopsies. Clin Neurophysiol 2018; 129:2051-2052. [PMID: 30025802 DOI: 10.1016/j.clinph.2018.06.025] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2018] [Accepted: 06/20/2018] [Indexed: 11/23/2022]
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16
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17
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Cortese A, Laurà M, Casali C, Nishino I, Hayashi YK, Magri S, Taroni F, Stuani C, Saveri P, Moggio M, Ripolone M, Prelle A, Pisciotta C, Sagnelli A, Pichiecchio A, Reilly MM, Buratti E, Pareyson D. Altered TDP-43-dependent splicing in HSPB8-related distal hereditary motor neuropathy and myofibrillar myopathy. Eur J Neurol 2017; 25:154-163. [PMID: 29029362 DOI: 10.1111/ene.13478] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2017] [Accepted: 09/07/2017] [Indexed: 11/29/2022]
Abstract
BACKGROUND AND PURPOSE Mutations in the small heat-shock protein 22 gene (HSPB8) have been associated with Charcot-Marie-Tooth disease type 2L, distal hereditary motor neuropathy (dHMN) type IIa and, more recently, distal myopathy/myofibrillar myopathy (MFM) with protein aggregates and TDP-43 inclusions. The aim was to report a novel family with HSPB8K141E -related dHMN/MFM and to investigate, in a patient muscle biopsy, whether the presence of protein aggregates was paralleled by altered TDP-43 function. METHODS We reviewed clinical and genetic data. We assessed TDP-43 expression by qPCR and alternative splicing of four previously validated direct TDP-43 target exons in four genes by reverse transcriptase-polymerase chain reaction. RESULTS The triplets and their mother presented in the second to third decade of life with progressive weakness affecting distal and proximal lower limb and truncal muscles. Nerve conduction study showed a motor axonal neuropathy. The clinical features, moderately raised creatin kinase levels, selective pattern of muscle involvement on magnetic resonance imaging and pathological changes on muscle biopsy, including the presence of protein aggregates, supported the diagnosis of a contemporary primary muscle involvement. In affected muscle tissue we observed a consistent alteration of TDP-43-dependent splicing in three out of four TDP-43-target transcripts (POLDIP3, FNIP1 and BRD8), as well as a significant decrease of TDP-43 mRNA levels. CONCLUSIONS Our study confirmed the role of mutated HSPB8 as a cause of a combined neuromuscular disorder encompassing dHMN and MFM with protein aggregates. We identified impaired RNA metabolism, secondary to TDP-43 loss of function, as a possible pathological mechanism of HSPB8K141E toxicity, leading to muscle and nerve degeneration.
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Affiliation(s)
- A Cortese
- C. Mondino National Neurological Institute Foundation, IRCCS, Pavia, Italy.,MRC Centre for Neuromuscular Diseases, UCL Institute of Neurology, London, UK
| | - M Laurà
- MRC Centre for Neuromuscular Diseases, UCL Institute of Neurology, London, UK
| | - C Casali
- Department of Medical and Surgical Sciences and Biotechnologies, Sapienza University of Rome, Latina, Italy
| | - I Nishino
- Department of Neuromuscular Research, National Center of Neurology and Psychiatry, National Institute of Neuroscience, Tokyo, Japan
| | - Y K Hayashi
- Department of Pathophysiology, Tokyo Medical University, Tokyo, Japan
| | - S Magri
- Unit of Rare Neurodegenerative and Neurometabolic Diseases, IRCCS Foundation, C. Besta Neurological Institute, Milan, Italy
| | - F Taroni
- Unit of Rare Neurodegenerative and Neurometabolic Diseases, IRCCS Foundation, C. Besta Neurological Institute, Milan, Italy
| | - C Stuani
- International Centre for Genetic Engineering and Biotechnology (ICGEB), Trieste, Italy
| | - P Saveri
- Unit of Rare Neurodegenerative and Neurometabolic Diseases, IRCCS Foundation, C. Besta Neurological Institute, Milan, Italy
| | - M Moggio
- Neuromuscular and Rare Diseases Unit, Department of Neuroscience, Fondazione IRCCS Ca' Granda, Ospedale Maggiore Policlinico, Milan, Italy
| | - M Ripolone
- Neuromuscular and Rare Diseases Unit, Department of Neuroscience, Fondazione IRCCS Ca' Granda, Ospedale Maggiore Policlinico, Milan, Italy
| | - A Prelle
- Department of Neurology, Ospedale Maggiore, Crema, Italy
| | - C Pisciotta
- Unit of Rare Neurodegenerative and Neurometabolic Diseases, IRCCS Foundation, C. Besta Neurological Institute, Milan, Italy
| | - A Sagnelli
- Unit of Rare Neurodegenerative and Neurometabolic Diseases, IRCCS Foundation, C. Besta Neurological Institute, Milan, Italy
| | - A Pichiecchio
- C. Mondino National Neurological Institute Foundation, IRCCS, Pavia, Italy
| | - M M Reilly
- MRC Centre for Neuromuscular Diseases, UCL Institute of Neurology, London, UK
| | - E Buratti
- International Centre for Genetic Engineering and Biotechnology (ICGEB), Trieste, Italy
| | - D Pareyson
- Unit of Rare Neurodegenerative and Neurometabolic Diseases, IRCCS Foundation, C. Besta Neurological Institute, Milan, Italy
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Lv ZY, Xu XM, Cao XF, Wang Q, Sun DF, Tian WJ, Yang Y, Wang YZ, Hao YL. Mitochondrial mutations in 12S rRNA and 16S rRNA presenting as chronic progressive external ophthalmoplegia (CPEO) plus: A case report. Medicine (Baltimore) 2017; 96:e8869. [PMID: 29310369 PMCID: PMC5728770 DOI: 10.1097/md.0000000000008869] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
RATIONALE Chronic progressive external ophthalmoplegia (CPEO) is a classical mitochondrial ocular disorder characterized by bilateral progressive ptosis and ophthalmoplegia. Kearns -Sayre syndrome (KSS) is a multisystem disorder with PEO, cardiac conduction block, and pigmentary retinopathy. A few individuals with CPEO have other manifestations of KSS, but do not meet all the clinical diagnosis criteria, and this is called "CPEO plus." PATIENT CONCERNS We report a 48-year-old woman exhibiting limb weakness, ptosis, ophthalmoparesis, and cerebellar dysfunctions. DIAGNOSES The patient was diagnosed as exhibiting CPEO plus syndrome. INTERVENTIONS The patient underwent clinical, genetic, histological, and histochemical analysis. She was treated orally with CoQ10, vitamin Bs, L-carnitine, and vitamin E. OUTCOMES The patient's serum creatine kinase levels, electrocardiography, and nerve conduction study results were normal; an electromyogram revealed myopathic findings. Magnetic resonance imaging showed global brain atrophy, particularly in the brainstem and cerebellum areas. A muscle biopsy showed the presence of abundant ragged red fibers. Sequencing of the mitochondrial DNA from the skeletal muscle biopsy revealed C960del mutation in 12S rRNA and homozygous mutation C2835T in 16S rRNA. She took medicines on schedule, the clinical features were similar as 2 years ago. LESSONS This is the first report of 2 rRNA mutations in a patient with MRI findings showing global brain atrophy, particularly in brainstem and cerebellum areas. Early recognition and appropriate treatment is crucial. This case highlights the cerebellar ataxia can occur in CPEO plus.
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19
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Rossor AM, Carr AS, Devine H, Chandrashekar H, Pelayo-Negro AL, Pareyson D, Shy ME, Scherer SS, Reilly MM. Peripheral neuropathy in complex inherited diseases: an approach to diagnosis. J Neurol Neurosurg Psychiatry 2017; 88:846-863. [PMID: 28794150 DOI: 10.1136/jnnp-2016-313960] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/06/2017] [Revised: 03/07/2017] [Accepted: 03/08/2017] [Indexed: 12/14/2022]
Abstract
Peripheral neuropathy is a common finding in patients with complex inherited neurological diseases and may be subclinical or a major component of the phenotype. This review aims to provide a clinical approach to the diagnosis of this complex group of patients by addressing key questions including the predominant neurological syndrome associated with the neuropathy, for example, spasticity, the type of neuropathy and the other neurological and non-neurological features of the syndrome. Priority is given to the diagnosis of treatable conditions. Using this approach, we associated neuropathy with one of three major syndromic categories: (1) ataxia, (2) spasticity and (3) global neurodevelopmental impairment. Syndromes that do not fall easily into one of these three categories can be grouped according to the predominant system involved in addition to the neuropathy, for example, cardiomyopathy and neuropathy. We also include a separate category of complex inherited relapsing neuropathy syndromes, some of which may mimic Guillain-Barré syndrome, as many will have a metabolic aetiology and be potentially treatable.
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Affiliation(s)
- Alexander M Rossor
- MRC Centre for Neuromuscular Diseases, UCL Institute of Neurology and National Hospital for Neurology and Neurosurgery, London, UK
| | - Aisling S Carr
- MRC Centre for Neuromuscular Diseases, UCL Institute of Neurology and National Hospital for Neurology and Neurosurgery, London, UK
| | - Helen Devine
- MRC Centre for Neuromuscular Diseases, UCL Institute of Neurology and National Hospital for Neurology and Neurosurgery, London, UK
| | - Hoskote Chandrashekar
- Lysholm Department of Neuroradiology, National Hospital for Neurology and Neurosurgery, London, UK
| | - Ana Lara Pelayo-Negro
- MRC Centre for Neuromuscular Diseases, UCL Institute of Neurology and National Hospital for Neurology and Neurosurgery, London, UK
| | - Davide Pareyson
- Unit of Neurological Rare Diseases of Adulthood, Carlo Besta Neurological Institute IRCCS Foundation, Milan, Italy
| | - Michael E Shy
- Department of Neurology, University of Iowa, Iowa City, USA
| | - Steven S Scherer
- Department of Neurology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Mary M Reilly
- MRC Centre for Neuromuscular Diseases, UCL Institute of Neurology and National Hospital for Neurology and Neurosurgery, London, UK
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20
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Finsterer J, Zarrouk-Mahjoub S. Axonal hyperexcitability due to Schwann cell involvement in chronic progressive external ophthalmoplegia. Clin Neurophysiol 2017; 128:2096-2097. [PMID: 28811105 DOI: 10.1016/j.clinph.2017.06.260] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2017] [Accepted: 06/14/2017] [Indexed: 01/07/2023]
Affiliation(s)
| | - Sinda Zarrouk-Mahjoub
- University of Tunis El Manar and Genomics Platform, Pasteur Institute of Tunis, Tunisia
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21
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Ruggiero L, Fiorillo C, Nesti C, Manganelli F, Iodice R, Esposito M, Santorelli FM, Santoro L. Sporadic chronic progressive external ophthalmoplegia with single large mitochondrial DNA deletion and neurogenic findings. J Neurol 2017; 264:597-599. [PMID: 28175988 DOI: 10.1007/s00415-017-8409-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2016] [Revised: 01/26/2017] [Accepted: 01/29/2017] [Indexed: 11/27/2022]
Affiliation(s)
- Lucia Ruggiero
- Department of Neurosciences, Reproductive and Odontostomatological Sciences, University Federico II of Naples, Naples, Italy.
| | - Chiara Fiorillo
- Center of Myology and Neurodegenerative Disorders, Department of Neuroscience, Istituto G. Gaslini, Largo Gaslini 5, 16147, Genoa, Italy
| | - Claudia Nesti
- Molecular Medicine, IRCCS Stella Maris, Via dei Giacinti 2, 56128, Pisa, Italy
| | - Fiore Manganelli
- Department of Neurosciences, Reproductive and Odontostomatological Sciences, University Federico II of Naples, Naples, Italy
| | - Rosa Iodice
- Department of Neurosciences, Reproductive and Odontostomatological Sciences, University Federico II of Naples, Naples, Italy
| | - Marcello Esposito
- Department of Neurosciences, Reproductive and Odontostomatological Sciences, University Federico II of Naples, Naples, Italy
| | | | - Lucio Santoro
- Department of Neurosciences, Reproductive and Odontostomatological Sciences, University Federico II of Naples, Naples, Italy
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22
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Kidd DP. Case 7. Neuroophthalmology 2017. [DOI: 10.1007/978-1-4471-2410-8_7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022] Open
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Lehmann D, Kornhuber ME, Clajus C, Alston CL, Wienke A, Deschauer M, Taylor RW, Zierz S. Peripheral neuropathy in patients with CPEO associated with single and multiple mtDNA deletions. NEUROLOGY-GENETICS 2016; 2:e113. [PMID: 27822509 PMCID: PMC5089902 DOI: 10.1212/nxg.0000000000000113] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/14/2016] [Accepted: 09/07/2016] [Indexed: 11/15/2022]
Abstract
Objective: To characterize peripheral nerve involvement in patients with chronic progressive external ophthalmoplegia (CPEO) with single and multiple mitochondrial DNA (mtDNA) deletions, based on clinical scores and detailed nerve conduction studies. Methods: Peripheral nerve involvement was prospectively investigated in 33 participants with CPEO (single deletions n = 18 and multiple deletions n = 15). Clinically, a modified Total Neuropathy Score (mTNS) and a modified International Cooperative Ataxia Rating Scale (mICARS) were used. Nerve conduction studies included Nn. suralis, superficialis radialis, tibialis, and peroneus mot. Early somatosensory evoked potentials were obtained by N. tibialis stimulation. Results: Participants with multiple deletions had higher mTNS and mICARS scores than those with single deletions. Electrophysiologically in both sensory nerves (N. suralis and N. radialis superficialis), compound action potential (CAP) amplitudes and nerve conduction velocities were lower and mostly abnormal in multiple deletions than those in single deletions. Early somatosensory evoked potentials of N. tibialis revealed increased P40 latencies and decreased N35-P40 amplitudes in multiple deletions. Both sensory nerves had higher areas under the receiver operating characteristic curves for the decreased CAP amplitudes than the 2 motor nerves. The N. suralis had the best Youden index, indicating a sensitivity of 93.3% and a specificity of 72.2% to detect multiple deletions. Conclusions: Peripheral nerve involvement in participants with multiple mtDNA deletions is an axonal type of predominant sensory neuropathy. This is clinically consistent with higher mTNS and mICARS scores. Sensory nerve involvement in participants with multiple deletions was not correlated with age at onset and duration of disease.
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Affiliation(s)
- Diana Lehmann
- Form the Department of Neurology (D.L., M.E.K., C.C., S.Z.), Institute of Medical Epidemiology, Biometrics and Informatics (A.W.), University of Halle-Wittenberg, Halle/Saale, Germany; Wellcome Trust Centre for Mitochondrial Research (C.L.A., R.W.T.), Institute of Neuroscience, The Medical School, Newcastle University, UK; and Department of Neurology (M.D.), Technical University Munich, Germany
| | - Malte E Kornhuber
- Form the Department of Neurology (D.L., M.E.K., C.C., S.Z.), Institute of Medical Epidemiology, Biometrics and Informatics (A.W.), University of Halle-Wittenberg, Halle/Saale, Germany; Wellcome Trust Centre for Mitochondrial Research (C.L.A., R.W.T.), Institute of Neuroscience, The Medical School, Newcastle University, UK; and Department of Neurology (M.D.), Technical University Munich, Germany
| | - Carolina Clajus
- Form the Department of Neurology (D.L., M.E.K., C.C., S.Z.), Institute of Medical Epidemiology, Biometrics and Informatics (A.W.), University of Halle-Wittenberg, Halle/Saale, Germany; Wellcome Trust Centre for Mitochondrial Research (C.L.A., R.W.T.), Institute of Neuroscience, The Medical School, Newcastle University, UK; and Department of Neurology (M.D.), Technical University Munich, Germany
| | - Charlotte L Alston
- Form the Department of Neurology (D.L., M.E.K., C.C., S.Z.), Institute of Medical Epidemiology, Biometrics and Informatics (A.W.), University of Halle-Wittenberg, Halle/Saale, Germany; Wellcome Trust Centre for Mitochondrial Research (C.L.A., R.W.T.), Institute of Neuroscience, The Medical School, Newcastle University, UK; and Department of Neurology (M.D.), Technical University Munich, Germany
| | - Andreas Wienke
- Form the Department of Neurology (D.L., M.E.K., C.C., S.Z.), Institute of Medical Epidemiology, Biometrics and Informatics (A.W.), University of Halle-Wittenberg, Halle/Saale, Germany; Wellcome Trust Centre for Mitochondrial Research (C.L.A., R.W.T.), Institute of Neuroscience, The Medical School, Newcastle University, UK; and Department of Neurology (M.D.), Technical University Munich, Germany
| | - Marcus Deschauer
- Form the Department of Neurology (D.L., M.E.K., C.C., S.Z.), Institute of Medical Epidemiology, Biometrics and Informatics (A.W.), University of Halle-Wittenberg, Halle/Saale, Germany; Wellcome Trust Centre for Mitochondrial Research (C.L.A., R.W.T.), Institute of Neuroscience, The Medical School, Newcastle University, UK; and Department of Neurology (M.D.), Technical University Munich, Germany
| | - Robert W Taylor
- Form the Department of Neurology (D.L., M.E.K., C.C., S.Z.), Institute of Medical Epidemiology, Biometrics and Informatics (A.W.), University of Halle-Wittenberg, Halle/Saale, Germany; Wellcome Trust Centre for Mitochondrial Research (C.L.A., R.W.T.), Institute of Neuroscience, The Medical School, Newcastle University, UK; and Department of Neurology (M.D.), Technical University Munich, Germany
| | - Stephan Zierz
- Form the Department of Neurology (D.L., M.E.K., C.C., S.Z.), Institute of Medical Epidemiology, Biometrics and Informatics (A.W.), University of Halle-Wittenberg, Halle/Saale, Germany; Wellcome Trust Centre for Mitochondrial Research (C.L.A., R.W.T.), Institute of Neuroscience, The Medical School, Newcastle University, UK; and Department of Neurology (M.D.), Technical University Munich, Germany
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Neurophysiological profile of peripheral neuropathy associated with childhood mitochondrial disease. Mitochondrion 2016; 30:162-7. [PMID: 27475922 DOI: 10.1016/j.mito.2016.07.014] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2016] [Revised: 07/22/2016] [Accepted: 07/26/2016] [Indexed: 12/22/2022]
Abstract
INTRODUCTION Peripheral nerve involvement is common in mitochondrial disease but often unrecognised due to the prominent central nervous system features. Identification of the underlying neuropathy may assist syndrome classification, targeted genetic testing and rehabilitative interventions. METHODS Clinical data and the results of nerve conduction studies were obtained retrospectively from the records of four tertiary children's hospital metabolic disease, neuromuscular or neurophysiology services. Nerve conductions studies were also performed prospectively on children attending a tertiary metabolic disease service. Results were classified and analysed according to the underlying genetic cause. RESULTS Nerve conduction studies from 27 children with mitochondrial disease were included in the study (mitochondrial DNA (mtDNA) - 7, POLG - 7, SURF1 - 10, PDHc deficiency - 3). Four children with mtDNA mutations had a normal study while three had mild abnormalities in the form of an axonal sensorimotor neuropathy when not acutely unwell. One child with MELAS had a severe acute axonal motor neuropathy during an acute stroke-like episode that resolved over 12months. Five children with POLG mutations and disease onset beyond infancy had a sensory ataxic neuropathy with an onset in the second decade of life, while the two infants with POLG mutations had a demyelinating neuropathy. Seven of the 10 children with SURF1 mutations had a demyelinating neuropathy. All three children with PDHc deficiency had an axonal sensorimotor neuropathy. Unlike CMT, the neuropathy associated with mitochondrial disease was not length-dependent. CONCLUSIONS This is the largest study to date of peripheral neuropathy in genetically- classified childhood mitochondrial disease. Characterising the underlying neuropathy may assist with the diagnosis of the mitochondrial syndrome and should be an integral part of the assessment of children with suspected mitochondrial disease.
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25
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The wide POLG-related spectrum: An integrated view. J Neurol Sci 2016; 368:70-6. [PMID: 27538604 DOI: 10.1016/j.jns.2016.06.062] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2015] [Revised: 06/05/2016] [Accepted: 06/27/2016] [Indexed: 01/21/2023]
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Bilic E, Delimar V, Desnica L, Pulanic D, Bilic E, Bakovic M, Curtis LM, Seiwerth RS, Stipetic MM, Ceovic R, Pulanic TK, Aleric I, Milos O, Vrhovac R, Nemet D, Pavletic SZ. High prevalence of small- and large-fiber neuropathy in a prospective cohort of patients with moderate to severe chronic GvHD. Bone Marrow Transplant 2016; 51:1513-1517. [PMID: 27272447 DOI: 10.1038/bmt.2016.158] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- E Bilic
- Department of Neurology, University Hospital Centre Zagreb, Zagreb, Croatia.,University of Zagreb School of Medicine, Zagreb, Croatia
| | - V Delimar
- Department of Neurology, University Hospital Centre Zagreb, Zagreb, Croatia
| | - L Desnica
- Division of Haematology, Department of Internal Medicine, University Hospital Centre Zagreb, Zagreb, Croatia
| | - D Pulanic
- University of Zagreb School of Medicine, Zagreb, Croatia.,Division of Haematology, Department of Internal Medicine, University Hospital Centre Zagreb, Zagreb, Croatia.,Faculty of Medicine Osijek, JJ Strossmayer University of Osijek, Osijek, Croatia
| | - E Bilic
- University of Zagreb School of Medicine, Zagreb, Croatia.,Department of Pediatric Haematology and Oncology, University Hospital Centre Zagreb, Zagreb, Croatia
| | - M Bakovic
- Institute of Forensic Medicine and Criminalistics, University of Zagreb School of Medicine, Zagreb, Croatia
| | - L M Curtis
- Experimental Transplantation & Immunology Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | - R S Seiwerth
- Division of Haematology, Department of Internal Medicine, University Hospital Centre Zagreb, Zagreb, Croatia
| | - M M Stipetic
- University of Zagreb, School of Dental Medicine, Zagreb, Croatia.,University Dental Clinic, Clinical Department of Oral Medicine, University Hospital Centre Zagreb, Zagreb, Croatia
| | - R Ceovic
- University of Zagreb School of Medicine, Zagreb, Croatia.,Department of Dermatology and Venerology, University Hospital Centre Zagreb, Zagreb, Croatia
| | - T K Pulanic
- Gynecology Department, Community Health Center Zagreb East, Zagreb, Croatia
| | - I Aleric
- Faculty of Medicine Osijek, JJ Strossmayer University of Osijek, Osijek, Croatia.,Department of Pulmology, University Hospital Centre Zagreb, Zagreb, Croatia
| | - O Milos
- Department of Neurology, University Hospital Centre Zagreb, Zagreb, Croatia
| | - R Vrhovac
- University of Zagreb School of Medicine, Zagreb, Croatia.,Division of Haematology, Department of Internal Medicine, University Hospital Centre Zagreb, Zagreb, Croatia
| | - D Nemet
- University of Zagreb School of Medicine, Zagreb, Croatia.,Division of Haematology, Department of Internal Medicine, University Hospital Centre Zagreb, Zagreb, Croatia.,Faculty of Medicine Osijek, JJ Strossmayer University of Osijek, Osijek, Croatia
| | - S Z Pavletic
- Experimental Transplantation & Immunology Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
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"Mitochondrial neuropathies": A survey from the large cohort of the Italian Network. Neuromuscul Disord 2016; 26:272-6. [PMID: 27020842 DOI: 10.1016/j.nmd.2016.02.008] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2015] [Revised: 02/10/2016] [Accepted: 02/15/2016] [Indexed: 11/21/2022]
Abstract
Involvement of the peripheral nervous system in mitochondrial disorders has been previously reported. However, the prevalence of peripheral neuropathy in mitochondrial disorders is still unclear. Based on the large database of the "Nation-wide Italian Collaborative Network of Mitochondrial Diseases", we reviewed the clinical data of 1200 patients, with special regard to peripheral neuropathy (mean age at onset 24.3 ± 20.1 years; age at last evaluation 39.8 ± 22.3 years; females 52.7%; childhood onset [before age 16 years] 43.1%). Peripheral neuropathy was present in 143/1156 patients (12.4%), being one of the ten most common signs and symptoms. POLG mutations cause a potentially painful, axonal/mixed, mainly sensory polyneuropathy; TYMP mutations lead to a demyelinating sensory-motor polyneuropathy; SURF1 mutations are associated with a demyelinating/mixed sensory-motor polyneuropathy. The only mtDNA mutation consistently associated with peripheral neuropathy (although less severely than in the above-considered nuclear genes) was the m.8993T > G (or the rarer T > C) changes, which lead to an axonal, mainly sensory polyneuropathy. In conclusion, peripheral neuropathy is one of the most common features of a mitochondrial disorder, and may negatively impact on the quality of life of these patients. Furthermore, the presence or absence of peripheral neuropathy, as well as its specific forms and the association with neuropathic pain (indicative of a POLG-associated disease) can guide the molecular analysis.
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Luigetti M, Sauchelli D, Primiano G, Cuccagna C, Bernardo D, Lo Monaco M, Servidei S. Peripheral neuropathy is a common manifestation of mitochondrial diseases: a single-centre experience. Eur J Neurol 2016; 23:1020-7. [DOI: 10.1111/ene.12954] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2015] [Accepted: 11/26/2015] [Indexed: 12/16/2022]
Affiliation(s)
- M. Luigetti
- Department of Geriatrics; Neurosciences and Orthopedics; Institute of Neurology; Catholic University of the Sacred Heart; Rome Italy
| | - D. Sauchelli
- Department of Geriatrics; Neurosciences and Orthopedics; Institute of Neurology; Catholic University of the Sacred Heart; Rome Italy
| | - G. Primiano
- Department of Geriatrics; Neurosciences and Orthopedics; Institute of Neurology; Catholic University of the Sacred Heart; Rome Italy
| | - C. Cuccagna
- Department of Geriatrics; Neurosciences and Orthopedics; Institute of Neurology; Catholic University of the Sacred Heart; Rome Italy
| | - D. Bernardo
- Department of Geriatrics; Neurosciences and Orthopedics; Institute of Neurology; Catholic University of the Sacred Heart; Rome Italy
| | - M. Lo Monaco
- Department of Geriatrics; Neurosciences and Orthopedics; Institute of Neurology; Catholic University of the Sacred Heart; Rome Italy
| | - S. Servidei
- Department of Geriatrics; Neurosciences and Orthopedics; Institute of Neurology; Catholic University of the Sacred Heart; Rome Italy
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Ng YS, Turnbull DM. Mitochondrial disease: genetics and management. J Neurol 2016; 263:179-91. [PMID: 26315846 PMCID: PMC4723631 DOI: 10.1007/s00415-015-7884-3] [Citation(s) in RCA: 78] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2015] [Revised: 08/18/2015] [Accepted: 08/18/2015] [Indexed: 12/14/2022]
Abstract
Mitochondrial disease is one of the most common groups of genetic diseases with a minimum prevalence of greater than 1 in 5000 in adults. Whilst multi-system involvement is often evident, neurological manifestation is the principal presentation in most cases. The multiple clinical phenotypes and the involvement of both the mitochondrial and nuclear genome make mitochondrial disease particularly challenging for the clinician. In this review article we cover mitochondrial genetics and common neurological presentations associated with adult mitochondrial disease. In addition, specific and supportive treatments are discussed.
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Affiliation(s)
- Yi Shiau Ng
- Wellcome Trust Centre for Mitochondrial Research, Institute of Neuroscience, The Medical School, Newcastle University, Framlington Place, Newcastle upon Tyne, NE2 4HH, UK
| | - Doug M Turnbull
- Wellcome Trust Centre for Mitochondrial Research, Institute of Neuroscience, The Medical School, Newcastle University, Framlington Place, Newcastle upon Tyne, NE2 4HH, UK.
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Abstract
Mitochondrial dysfunction underlies many human disorders, including those that affect the visual system. The retinal ganglion cells, whose axons form the optic nerve, are often damaged by mitochondrial-related diseases which result in blindness. Both mitochondrial DNA (mtDNA) and nuclear gene mutations impacting many different mitochondrial processes can result in optic nerve disease. Of particular importance are mutations that impair mitochondrial network dynamics (fusion and fission), oxidative phosphorylation (OXPHOS), and formation of iron-sulfur complexes. Current genetic knowledge can inform genetic counseling and suggest strategies for novel gene-based therapies. Identifying new optic neuropathy-causing genes and defining the role of current and novel genes in disease will be important steps toward the development of effective and potentially neuroprotective therapies.
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Affiliation(s)
- Janey L Wiggs
- Department of Ophthalmology, Harvard Medical School and Massachusetts Eye and Ear, Boston, Massachusetts 02114;
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32
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Alves CJ, Maximino JR, Chadi G. Dysregulated expression of death, stress and mitochondrion related genes in the sciatic nerve of presymptomatic SOD1(G93A) mouse model of Amyotrophic Lateral Sclerosis. Front Cell Neurosci 2015; 9:332. [PMID: 26339226 PMCID: PMC4555015 DOI: 10.3389/fncel.2015.00332] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2015] [Accepted: 08/10/2015] [Indexed: 12/11/2022] Open
Abstract
Schwann cells are the main source of paracrine support to motor neurons. Oxidative stress and mitochondrial dysfunction have been correlated to motor neuron death in Amyotrophic Lateral Sclerosis (ALS). Despite the involvement of Schwann cells in early neuromuscular disruption in ALS, detailed molecular events of a dying-back triggering are unknown. Sciatic nerves of presymptomatic (60-day-old) SOD1(G93A) mice were submitted to a high-density oligonucleotide microarray analysis. DAVID demonstrated the deregulated genes related to death, stress and mitochondrion, which allowed the identification of Cell cycle, ErbB signaling, Tryptophan metabolism and Rig-I-like receptor signaling as the most representative KEGG pathways. The protein-protein interaction networks based upon deregulated genes have identified the top hubs (TRAF2, H2AFX, E2F1, FOXO3, MSH2, NGFR, TGFBR1) and bottlenecks (TRAF2, E2F1, CDKN1B, TWIST1, FOXO3). Schwann cells were enriched from the sciatic nerve of presymptomatic mice using flow cytometry cell sorting. qPCR showed the up regulated (Ngfr, Cdnkn1b, E2f1, Traf2 and Erbb3, H2afx, Cdkn1a, Hspa1, Prdx, Mapk10) and down-regulated (Foxo3, Mtor) genes in the enriched Schwann cells. In conclusion, molecular analyses in the presymptomatic sciatic nerve demonstrated the involvement of death, oxidative stress, and mitochondrial pathways in the Schwann cell non-autonomous mechanisms in the early stages of ALS.
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Affiliation(s)
- Chrystian J Alves
- Department of Neurology, Neuroregeneration Center, University of São Paulo School of Medicine São Paulo, Brazil
| | - Jessica R Maximino
- Department of Neurology, Neuroregeneration Center, University of São Paulo School of Medicine São Paulo, Brazil
| | - Gerson Chadi
- Department of Neurology, Neuroregeneration Center, University of São Paulo School of Medicine São Paulo, Brazil
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Mancuso M, Orsucci D, Angelini C, Bertini E, Carelli V, Comi GP, Donati MA, Federico A, Minetti C, Moggio M, Mongini T, Santorelli FM, Servidei S, Tonin P, Toscano A, Bruno C, Bello L, Caldarazzo Ienco E, Cardaioli E, Catteruccia M, Da Pozzo P, Filosto M, Lamperti C, Moroni I, Musumeci O, Pegoraro E, Ronchi D, Sauchelli D, Scarpelli M, Sciacco M, Valentino ML, Vercelli L, Zeviani M, Siciliano G. Redefining phenotypes associated with mitochondrial DNA single deletion. J Neurol 2015; 262:1301-9. [PMID: 25808502 DOI: 10.1007/s00415-015-7710-y] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2014] [Revised: 03/13/2015] [Accepted: 03/13/2015] [Indexed: 10/23/2022]
Abstract
Progressive external ophthalmoplegia (PEO), Kearns-Sayre syndrome (KSS) and Pearson syndrome are the three sporadic clinical syndromes classically associated with single large-scale deletions of mitochondrial DNA (mtDNA). PEO plus is a term frequently utilized in the clinical setting to identify patients with PEO and some degree of multisystem involvement, but a precise definition is not available. The purpose of the present study is to better define the clinical phenotypes associated with a single mtDNA deletion, by a retrospective study on a large cohort of 228 patients from the database of the "Nation-wide Italian Collaborative Network of Mitochondrial Diseases". In our database, single deletions account for about a third of all patients with mtDNA-related disease, more than previously recognized. We elaborated new criteria for the definition of PEO and "KSS spectrum" (a category of which classic KSS represents the most severe extreme). The criteria for "KSS spectrum" include the resulting multisystem clinical features associated with the KSS features, and which therefore can predict their presence or subsequent development. With the new criteria, we were able to classify nearly all our single-deletion patients: 64.5% PEO, 31.6% KSS spectrum (including classic KSS 6.6%) and 2.6% Pearson syndrome. The deletion length was greater in KSS spectrum than in PEO, whereas heteroplasmy was inversely related with age at onset. We believe that the new phenotype definitions implemented here may contribute to a more homogeneous patient categorization, which will be useful in future cohort studies of natural history and clinical trials.
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