1
|
Trinh TT, Blasco H, Maillot F, Bakhos D. Hearing loss in inherited metabolic disorders: A systematic review. Metabolism 2021; 122:154841. [PMID: 34333001 DOI: 10.1016/j.metabol.2021.154841] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/02/2021] [Revised: 07/14/2021] [Accepted: 07/15/2021] [Indexed: 10/20/2022]
Abstract
Inherited metabolic disorders (IMDs) have been observed in individuals with hearing loss (HL), but IMDs are rarely the cause of syndromic HL. With early diagnosis, management of HL is more effective and cortical reorganization is possible with hearing aids or cochlear implants. This review describes relationships between IMDs and HL in terms of incidence, etiology of HL, pathophysiology, and treatment. Forty types of IMDs are described in the literature, mainly in case reports. Management and prognosis are noted where existing. We also describe IMDs with HL given age of occurrence of HL. Reviewing the main IMDs that are associated with HL may provide an additional clinical tool with which to better diagnose syndromic HL.
Collapse
Affiliation(s)
- T-T Trinh
- CHRU de Tours, service ORL et Chirurgie Cervico-Faciale, Tours, France.
| | - H Blasco
- Laboratoire de Biochimie et Biologie Moléculaire, Tours, France; Université François Rabelais, Tours, France; INSERM U1253, Tours, France
| | - F Maillot
- Université François Rabelais, Tours, France; INSERM U1253, Tours, France; CHU de Tours, service de Médecine Interne, Tours, France
| | - D Bakhos
- CHRU de Tours, service ORL et Chirurgie Cervico-Faciale, Tours, France; Université François Rabelais, Tours, France; INSERM U1253, Tours, France
| |
Collapse
|
2
|
Fay A, Garcia Y, Margeta M, Maharjan S, Jürgensen C, Briceño J, Garcia M, Yin S, Bassaganyas L, McMahon T, Hou YM, Fu YH, Ptáček LJ. A Mitochondrial tRNA Mutation Causes Axonal CMT in a Large Venezuelan Family. Ann Neurol 2020; 88:830-842. [PMID: 32715519 DOI: 10.1002/ana.25854] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Revised: 07/20/2020] [Accepted: 07/22/2020] [Indexed: 12/19/2022]
Abstract
OBJECTIVE The objective of this study was to identify the genetic cause for progressive peripheral nerve disease in a Venezuelan family. Despite the growing list of genes associated with Charcot-Marie-Tooth disease, many patients with axonal forms lack a genetic diagnosis. METHODS A pedigree was constructed, based on family clinical data. Next-generation sequencing of mitochondrial DNA (mtDNA) was performed for 6 affected family members. Muscle biopsies from 4 family members were used for analysis of muscle histology and ultrastructure, mtDNA sequencing, and RNA quantification. Ultrastructural studies were performed on sensory nerve biopsies from 2 affected family members. RESULTS Electrodiagnostic testing showed a motor and sensory axonal polyneuropathy. Pedigree analysis revealed inheritance only through the maternal line, consistent with mitochondrial transmission. Sequencing of mtDNA identified a mutation in the mitochondrial tRNAVal (mt-tRNAVal ) gene, m.1661A>G, present at nearly 100% heteroplasmy, which disrupts a Watson-Crick base pair in the T-stem-loop. Muscle biopsies showed chronic denervation/reinnervation changes, whereas biochemical analysis of electron transport chain (ETC) enzyme activities showed reduction in multiple ETC complexes. Northern blots from skeletal muscle total RNA showed severe reduction in abundance of mt-tRNAVal , and mildly increased mt-tRNAPhe , in subjects compared with unrelated age- and sex-matched controls. Nerve biopsies from 2 affected family members demonstrated ultrastructural mitochondrial abnormalities (hyperplasia, hypertrophy, and crystalline arrays) consistent with a mitochondrial neuropathy. CONCLUSION We identify a previously unreported cause of Charcot-Marie-Tooth (CMT) disease, a mutation in the mt-tRNAVal , in a Venezuelan family. This work expands the list of CMT-associated genes from protein-coding genes to a mitochondrial tRNA gene. ANN NEUROL 2020;88:830-842.
Collapse
Affiliation(s)
- Alexander Fay
- Department of Neurology, University of California, San Francisco, CA, USA
| | - Yngo Garcia
- Department of Biochemistry, Faculty of Medicine, University of The Andes, Mérida, Venezuela.,Unit of Surgery, Neurosurgery Service, Medical Surgery Clinical Institute, Mérida, Venezuela
| | - Marta Margeta
- Department of Pathology, University of California, San Francisco, CA, USA
| | - Sunita Maharjan
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, Philadelphia, PA, USA
| | - Claudia Jürgensen
- Department of Biology, Faculty of Science, University of The Andes, Mérida, Venezuela
| | - Jose Briceño
- Physiotherapy and Rehabilitation Service, University Hospital of The Andes, Mérida, Venezuela
| | - Mariaelena Garcia
- Department of Biology, Faculty of Science, University of The Andes, Mérida, Venezuela
| | - Sitao Yin
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, Philadelphia, PA, USA
| | - Laia Bassaganyas
- Department of Medical Genetics, University of Cambridge and Cardiovascular Research Institute, University of California, San Francisco, CA, USA
| | - Thomas McMahon
- Department of Neurology, University of California, San Francisco, CA, USA
| | - Ya-Ming Hou
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, Philadelphia, PA, USA
| | - Ying-Hui Fu
- Department of Neurology, University of California, San Francisco, CA, USA
| | - Louis J Ptáček
- Department of Neurology, University of California, San Francisco, CA, USA
| |
Collapse
|
3
|
Cruz S, Taipa R, Nogueira C, Pereira C, Almeida LS, Neiva R, Geraldes T, Guimarães A, Melo‐Pires M, Vilarinho L. Clinical, biochemical, molecular, and histological features of 65 Portuguese patients with mitochondrial disorders. Muscle Nerve 2017; 56:868-872. [DOI: 10.1002/mus.25593] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/23/2017] [Indexed: 11/12/2022]
Affiliation(s)
- Simão Cruz
- Neurology DepartmentHospital Prof. Doutor Fernando FonsecaIC 19, 2720‐276, Amadora Portugal
| | - Ricardo Taipa
- Neuropathology UnitHospital Santo António / Centro Hospitalar do PortoPorto Portugal
| | - Célia Nogueira
- Newborn screening, Metabolism and Genetics Unit, Human Genetics DepartmentDr. Ricardo Jorge National Health InstitutePorto Portugal
| | - Cristina Pereira
- Newborn screening, Metabolism and Genetics Unit, Human Genetics DepartmentDr. Ricardo Jorge National Health InstitutePorto Portugal
| | - Lígia S. Almeida
- Newborn screening, Metabolism and Genetics Unit, Human Genetics DepartmentDr. Ricardo Jorge National Health InstitutePorto Portugal
| | - Raquel Neiva
- Newborn screening, Metabolism and Genetics Unit, Human Genetics DepartmentDr. Ricardo Jorge National Health InstitutePorto Portugal
| | - Tiago Geraldes
- Neurology DepartmentHospital Garcia de OrtaAlmada Portugal
| | - António Guimarães
- Neuropathology UnitHospital Santo António / Centro Hospitalar do PortoPorto Portugal
| | - Manuel Melo‐Pires
- Neuropathology UnitHospital Santo António / Centro Hospitalar do PortoPorto Portugal
| | - Laura Vilarinho
- Newborn screening, Metabolism and Genetics Unit, Human Genetics DepartmentDr. Ricardo Jorge National Health InstitutePorto Portugal
| |
Collapse
|
4
|
Abstract
Mitochondrial diseases are a clinically heterogeneous group of disorders that ultimately result from dysfunction of the mitochondrial respiratory chain. There is some evidence to suggest that mitochondrial dysfunction plays a role in neuropsychiatric illness; however, the data are inconclusive. This article summarizes the available literature published in the area of neuropsychiatric manifestations in both children and adults with primary mitochondrial disease, with a focus on autism spectrum disorder in children and mood disorders and schizophrenia in adults.
Collapse
Affiliation(s)
- Samantha E Marin
- Department of Neurosciences, University of California, San Diego (UCSD), 9500 Gilman Drive #0935, La Jolla, CA 92093-0935, USA
| | - Russell P Saneto
- Department of Neurology, Seattle Children's Hospital, University of Washington, 4800 Sand Point Way Northeast, Seattle, WA 98105, USA; Department of Pediatrics, Seattle Children's Hospital, University of Washington, 4800 Sand Point Way Northeast, Seattle, WA 98105, USA.
| |
Collapse
|
5
|
Altmann J, Büchner B, Nadaj-Pakleza A, Schäfer J, Jackson S, Lehmann D, Deschauer M, Kopajtich R, Lautenschläger R, Kuhn KA, Karle K, Schöls L, Schulz JB, Weis J, Prokisch H, Kornblum C, Claeys KG, Klopstock T. Expanded phenotypic spectrum of the m.8344A>G "MERRF" mutation: data from the German mitoNET registry. J Neurol 2016; 263:961-972. [PMID: 26995359 DOI: 10.1007/s00415-016-8086-3] [Citation(s) in RCA: 61] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2015] [Revised: 02/28/2016] [Accepted: 02/29/2016] [Indexed: 11/24/2022]
Abstract
The m.8344A>G mutation in the MTTK gene, which encodes the mitochondrial transfer RNA for lysine, is traditionally associated with myoclonic epilepsy and ragged-red fibres (MERRF), a multisystemic mitochondrial disease that is characterised by myoclonus, seizures, cerebellar ataxia, and mitochondrial myopathy with ragged-red fibres. We studied the clinical and paraclinical phenotype of 34 patients with the m.8344A>G mutation, mainly derived from the nationwide mitoREGISTER, the multicentric registry of the German network for mitochondrial disorders (mitoNET). Mean age at symptom onset was 24.5 years ±10.9 (6-48 years) with adult onset in 75 % of the patients. In our cohort, the canonical features seizures, myoclonus, cerebellar ataxia and ragged-red fibres that are traditionally associated with MERRF, occurred in only 61, 59, 70, and 63 % of the patients, respectively. In contrast, other features such as hearing impairment were even more frequently present (72 %). Other common features in our cohort were migraine (52 %), psychiatric disorders (54 %), respiratory dysfunction (45 %), gastrointestinal symptoms (38 %), dysarthria (36 %), and dysphagia (35 %). Brain MRI revealed cerebral and/or cerebellar atrophy in 43 % of our patients. There was no correlation between the heteroplasmy level in blood and age at onset or clinical phenotype. Our findings further broaden the clinical spectrum of the m.8344A>G mutation, document the large clinical variability between carriers of the same mutation, even within families and indicate an overlap of the phenotype with other mitochondrial DNA-associated syndromes.
Collapse
Affiliation(s)
- Judith Altmann
- Department of Neurology, RWTH Aachen University, Aachen, Germany.,Institute of Neuropathology, RWTH Aachen University, Aachen, Germany
| | - Boriana Büchner
- Department of Neurology, Friedrich-Baur-Institute, Ludwig-Maximilians-University, München, Germany
| | | | - Jochen Schäfer
- Department of Neurology, University Hospital Carl Gustav Carus, Dresden, Germany
| | - Sandra Jackson
- Department of Neurology, University Hospital Carl Gustav Carus, Dresden, Germany
| | - Diana Lehmann
- Department of Neurology, University of Halle-Wittenberg, Halle/Saale, Germany
| | - Marcus Deschauer
- Department of Neurology, University of Halle-Wittenberg, Halle/Saale, Germany.,Department of Neurology, University of Technology München, München, Germany
| | - Robert Kopajtich
- Institute of Human Genetics, Helmholtz Centre München, München, Germany.,Institute of Human Genetics, Technical University München, München, Germany
| | - Ronald Lautenschläger
- Institute for Medical Statistics and Epidemiology, University of Technology München, München, Germany
| | - Klaus A Kuhn
- Institute for Medical Statistics and Epidemiology, University of Technology München, München, Germany
| | - Kathrin Karle
- Institute of Clinical Neurogenetics, Department of Neurology and Hertie Institute for Clinical Brain Research, Tübingen, Germany
| | - Ludger Schöls
- Institute of Clinical Neurogenetics, Department of Neurology and Hertie Institute for Clinical Brain Research, Tübingen, Germany
| | - Jörg B Schulz
- Department of Neurology, RWTH Aachen University, Aachen, Germany.,JARA - Translational Brain Medicine, Aachen, Germany
| | - Joachim Weis
- Institute of Neuropathology, RWTH Aachen University, Aachen, Germany
| | - Holger Prokisch
- Institute of Human Genetics, Helmholtz Centre München, München, Germany.,Institute of Human Genetics, Technical University München, München, Germany
| | - Cornelia Kornblum
- Department of Neurology, University Hospital of Bonn, Bonn, Germany.,Center for Rare Diseases Bonn (ZSEB), University Hospital of Bonn, Bonn, Germany
| | - Kristl G Claeys
- Department of Neurology, RWTH Aachen University, Aachen, Germany. .,Institute of Neuropathology, RWTH Aachen University, Aachen, Germany. .,Department of Neurology, University Hospitals Leuven and University of Leuven (KU Leuven), Leuven, Belgium.
| | - Thomas Klopstock
- Department of Neurology, Friedrich-Baur-Institute, Ludwig-Maximilians-University, München, Germany.,German Center for Neurodegenerative Diseases (DZNE), München, Germany.,Munich Cluster for Systems Neurology (SyNergy), München, Germany
| |
Collapse
|
6
|
Scheibye-Knudsen M, Fang EF, Croteau DL, Wilson DM, Bohr VA. Protecting the mitochondrial powerhouse. Trends Cell Biol 2015; 25:158-70. [PMID: 25499735 PMCID: PMC5576887 DOI: 10.1016/j.tcb.2014.11.002] [Citation(s) in RCA: 230] [Impact Index Per Article: 25.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2014] [Revised: 11/07/2014] [Accepted: 11/10/2014] [Indexed: 01/21/2023]
Abstract
Mitochondria are the oxygen-consuming power plants of cells. They provide a critical milieu for the synthesis of many essential molecules and allow for highly efficient energy production through oxidative phosphorylation. The use of oxygen is, however, a double-edged sword that on the one hand supplies ATP for cellular survival, and on the other leads to the formation of damaging reactive oxygen species (ROS). Different quality control pathways maintain mitochondria function including mitochondrial DNA (mtDNA) replication and repair, fusion-fission dynamics, free radical scavenging, and mitophagy. Further, failure of these pathways may lead to human disease. We review these pathways and propose a strategy towards a treatment for these often untreatable disorders.
Collapse
Affiliation(s)
- Morten Scheibye-Knudsen
- Laboratory of Molecular Gerontology, National Institute on Aging (NIA), National Institutes of Health (NIH), Baltimore, MD 21224, USA
| | - Evandro F Fang
- Laboratory of Molecular Gerontology, National Institute on Aging (NIA), National Institutes of Health (NIH), Baltimore, MD 21224, USA
| | - Deborah L Croteau
- Laboratory of Molecular Gerontology, National Institute on Aging (NIA), National Institutes of Health (NIH), Baltimore, MD 21224, USA
| | - David M Wilson
- Laboratory of Molecular Gerontology, National Institute on Aging (NIA), National Institutes of Health (NIH), Baltimore, MD 21224, USA
| | - Vilhelm A Bohr
- Laboratory of Molecular Gerontology, National Institute on Aging (NIA), National Institutes of Health (NIH), Baltimore, MD 21224, USA.
| |
Collapse
|
7
|
Limongelli G, Masarone D, D’Alessandro R, Elliott PM. Mitochondrial diseases and the heart: an overview of molecular basis, diagnosis, treatment and clinical course. Future Cardiol 2012; 8:71-88. [DOI: 10.2217/fca.11.79] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The mitochondrion is the main site of production of ATP that represents the source of energy for a large number of cellular processes. Mitochondrial diseases that result in a deficit in ATP production can affect almost every organ system with a large spectrum of clinical phenotypes. Cardiomyocytes are particularly vulnerable to limited ATP supply because of their large energy requirement. Abnormalities in the mitochondrial function are increasingly recognized in association with dilated and hypertrophic cardiomyopathy, cardiac conduction defects, endothelial dysfunction and coronary artery disease. Cardiologists should, therefore, be alerted to symptoms and signs suggestive of mitochondrial diseases and become familiar with the general issues related to multisystem disease management, genetic counseling and testing.
Collapse
Affiliation(s)
- Giuseppe Limongelli
- Monaldi Hospital Second University of Naples (SUN), Naples, Italy
- The Heart Hospital, University College of London (UCL), London, UK
| | - Daniele Masarone
- Monaldi Hospital Second University of Naples (SUN), Naples, Italy
| | | | - Perry M Elliott
- The Heart Hospital, University College of London (UCL), London, UK
| |
Collapse
|
8
|
Wang J, Venegas V, Li F, Wong L. Analysis of Mitochondrial DNA Point Mutation Heteroplasmy by ARMS Quantitative PCR. ACTA ACUST UNITED AC 2011; Chapter 19:Unit 19.6.. [DOI: 10.1002/0471142905.hg1906s68] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Jing Wang
- Baylor College of Medicine Houston Texas
| | | | | | | |
Collapse
|
9
|
Moustris A, Edwards MJ, Bhatia KP. Movement disorders and mitochondrial disease. HANDBOOK OF CLINICAL NEUROLOGY 2011; 100:173-92. [PMID: 21496577 DOI: 10.1016/b978-0-444-52014-2.00010-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Affiliation(s)
- Andreas Moustris
- Sobell Department of Motor Neuroscience and Movement Disorders, UCL Institute of Neurology, London, UK
| | | | | |
Collapse
|
10
|
Thajeb P, Dai DF. Current Opinion on the Clinical Approach to the Diagnosis of Mitochondrial Disease. INT J GERONTOL 2007. [DOI: 10.1016/s1873-9598(08)70020-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
|
11
|
Disorders of the mitochondrial respiratory chain. NEURODEGENER DIS 2005. [DOI: 10.1017/cbo9780511544873.063] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
|
12
|
Rahim F, Gupta D, Bertorini TE, Ledoux MS. Dropped head presentation of mitochondrial myopathy. J Clin Neuromuscul Dis 2003; 5:108-114. [PMID: 19078729 DOI: 10.1097/00131402-200312000-00007] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Dropped head secondary to weakness of the neck extensors has been reported in a wide assortment of neuromuscular disorders. Infrequently, dropped head can be the first sign of disease. We describe two patients with dropped head as the presenting manifestation of mitochondrial myopathy. In both patients, serum lactate was elevated and muscle biopsy showed mitochondrial proliferation. Mitochondrial myopathy should be considered in the differential diagnosis of dropped head syndrome, particularly when other, more common causes such as myasthenia gravis, polymyositis, and amyotrophic lateral sclerosis have been excluded by appropriate laboratory and electrophysiological studies.
Collapse
Affiliation(s)
- Fazal Rahim
- From the Department of Neurology, University of Tennessee Health Science Center Memphis
| | | | | | | |
Collapse
|
13
|
Graf WD, Marin-Garcia J, Gao HG, Pizzo S, Naviaux RK, Markusic D, Barshop BA, Courchesne E, Haas RH. Autism associated with the mitochondrial DNA G8363A transfer RNA(Lys) mutation. J Child Neurol 2000; 15:357-61. [PMID: 10868777 DOI: 10.1177/088307380001500601] [Citation(s) in RCA: 114] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
We report a family with a heterogeneous group of neurologic disorders associated with the mitochondrial DNA G8363A transfer ribonucleic acid (RNA)Lys mutation. The phenotype of one child in the family was consistent with autism. During his second year of life, he lost previously acquired language skills and developed marked hyperactivity with toe-walking, abnormal reciprocal social interaction, stereotyped mannerisms, restricted interests, self-injurious behavior, and seizures. Brain magnetic resonance imaging (MRI) and repeated serum lactate studies were normal. His older sister developed signs of Leigh syndrome with progressive ataxia, myoclonus, seizures, and cognitive regression. Her laboratory studies revealed increased MRI T2-weighted signal in the putamen and posterior medulla, elevated lactate in serum and cerebrospinal fluid, and absence of cytochrome c oxidase staining in muscle histochemistry. Molecular analysis in her revealed the G8363A mutation of the mitochondrial transfer RNA(Lys) gene in blood (82% mutant mitochondrial DNA) and muscle (86%). The proportions of mutant mitochondrial DNA from her brother with autism were lower (blood 60%, muscle 61%). It is likely that the origin of his autism phenotype is the pathogenic G8363A mitochondrial DNA mutation. This observation suggests that certain mitochondrial point mutations could be the basis for autism in some individuals.
Collapse
Affiliation(s)
- W D Graf
- Department of Pediatrics, University of Washington, Seattle, USA.
| | | | | | | | | | | | | | | | | |
Collapse
|
14
|
Serra G, Piccinnu R, Tondi M, Muntoni F, Zeviani M, Mastropaolo C. Clinical and EEG findings in eleven patients affected by mitochondrial encephalomyopathy with MERRF-MELAS overlap. Brain Dev 1996; 18:185-91. [PMID: 8836498 DOI: 10.1016/0387-7604(95)00147-6] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
A study of mitochondrial DNA disease was carried out on 12 members belonging to three generations of a family from northern Sardinia. On the basis of the diagnostic criteria currently used in the classification of mitochondrial diseases a typical MERRF-MELAS overlap phenotype was seen in 11 patients with the mtDNA tRNA(lys) mutation at nucleotide position 8356. Clinical and instrumental investigations (EEG in particular) were made. Patients were divided into two groups: severely and mildly affected cases. The follow-up was reported. The aim of this study was to identify, through EEG, the early signs of the disease. The EEG findings recorded during the clinical evolution allowed us to recognize four degrees of cerebral involvement, and could also suggest the prognosis.
Collapse
Affiliation(s)
- G Serra
- Institute of Child Neuropsychiatry, University of Sassari, Italy
| | | | | | | | | | | |
Collapse
|
15
|
Abstract
We present here a report on a 5-year experience in clinical investigation, diagnostic management and molecular genetic studies of neuromitochondrial disorders, defined on the basis of morphological, biochemical and genetic findings. Leigh disease is the most frequent clinical presentation in infancy and childhood, but symptoms at onset are poorly informative. In paediatric cases, lactic acidosis and neuroradiological abnormalities are frequent, and can be of help for the diagnostic orientation. In the adult population, muscle weakness, ophthalmoplegia with ragged-red fibres, retinitis pigmentosa, progressive myoclonal ataxia, and early-onset stroke-like episodes, are frequently combined in complex syndromes that are often familial (maternally inherited) and/or associated with well-established mutations in mitochondrial DNA (mtDNA). However, the presence of overlap syndromes and features common to many neuromitochondrial diseases can complicate the clinical evaluation and the diagnostic approach. The pathogenicity of a given mtDNA mutation can frequently be ascertained by correlating the degree of heteroplasmy with the clinical or biochemical phenotypes. Moreover, transmitochondrial cybrids can be used to test the effects of either mitochondrial or nuclear gene abnormalities in a fully controlled, user-friendly and highly informative system.
Collapse
Affiliation(s)
- M Zeviani
- Division of Biochemistry & Genetics, Istituto Nazionale Neurologico C. Besta, Milan, Italy
| | | | | |
Collapse
|
16
|
Ozawa M, Goto Y, Sakuta R, Tanno Y, Tsuji S, Nonaka I. The 8,344 mutation in mitochondrial DNA: a comparison between the proportion of mutant DNA and clinico-pathologic findings. Neuromuscul Disord 1995; 5:483-8. [PMID: 8580730 DOI: 10.1016/0960-8966(95)00009-c] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Ten patients, two men and eight women with mitochondrial encephalomyopathy, had an A-G mutation at nucleotide pair 8,344 in the mitochondrial DNA, the most common genetic defect in myoclonus epilepsy with ragged-red fibers (MERRF). Eight patients had the clinical and pathologic characteristics of MERRF including myoclonus, seizures, cerebellar ataxia and myopathy with ragged-red fibers. Two patients had atypical symptoms such as early onset of fatal cardiac failure and late onset of rapid mental deterioration, respectively. The striking feature in our patients with the 8,344 mutation cardiac involvement and two developed progressive heart failure. In the typical MERRF patients, the proportion of mutant mitochondrial DNA in their skeletal muscles, quantified by a single strand conformation polymorphism analysis, was above 85%. However, there was no significant correlation between clinical severity, histopathological findings and the proportion of mutant mtDNA in muscle biopsy samples, suggesting that non-ragged-red fibers play an important role in the phenotype expression of the mutants.
Collapse
Affiliation(s)
- M Ozawa
- Department of Laboratory Medicine, National Center of Neurology and Psychiatry (NCNP), Tokyo, Japan
| | | | | | | | | | | |
Collapse
|
17
|
Oldfors A, Holme E, Tulinius M, Larsson NG. Tissue distribution and disease manifestations of the tRNA(Lys) A-->G(8344) mitochondrial DNA mutation in a case of myoclonus epilepsy and ragged red fibres. Acta Neuropathol 1995; 90:328-33. [PMID: 8525809 DOI: 10.1007/bf00296519] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
This man with myoclonus epilepsy and ragged red fibres (MERRF) syndrome due to the tRNA(Lys) A-->G(8344) mutation of mitochondrial DNA (mtDNA) died of bronchopneumonia at 18 years of age. He had progressive clinical symptoms from 6 months of age manifesting as ataxia, myoclonic seizures, and muscle weakness. A post-mortem examination revealed 91-99% mutated mtDNA in all 32 examined tissue samples, including various organs and different brain regions. The brain appeared without macroscopic changes, but microscopic examination showed degeneration with loss of nerve cells and gliosis affecting the globus pallidus, substantia nigra, red nucleus, dentate nucleus, inferior olivary nucleus, cerebellar cortex, and the spinal cord. Skeletal muscle showed cytochrome c oxidase deficient muscle fibres with proliferation of mitochondria. In addition to pathological changes of muscle and brain there were few morphological changes that could be attributed to his mitochondrial disease. These data support the concept that in patients with the tRNA(Lys) A-->G(8344) mutation who are manifesting disease there are high levels of mutated mtDNA in all tissues, but only some tissues and brain regions are vulnerable.
Collapse
Affiliation(s)
- A Oldfors
- Department of Pathology, Sahlgrenska Hospital, Göteborg, Sweden
| | | | | | | |
Collapse
|
18
|
Hanna MG, Nelson IP, Morgan-Hughes JA, Harding AE. Impaired mitochondrial translation in human myoblasts harbouring the mitochondrial DNA tRNA lysine 8344 A-->G (MERRF) mutation: relationship to proportion of mutant mitochondrial DNA. J Neurol Sci 1995; 130:154-60. [PMID: 8586979 DOI: 10.1016/0022-510x(95)00022-t] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The mitochondrial DNA transfer RNA lysine A8344G mutation is commonly associated with the MERRF (myoclonus epilepsy with ragged red fibre) phenotype. The molecular pathogenesis of disease associated with this mutation is unclear. Theoretically, a mitochondrial tRNA mutation might affect transcription or translation, or both. We therefore studied these processes in cloned primary human myoblast cultures containing different proportions of mutant mtDNA. No abnormality of transcription was observed. However, there was a progressive decrease in mitochondrially encoded protein synthesis as the proportion of mutant mtDNA increased. Furthermore, there was evidence that subunits were differentially affected, based on selective reduction of cytochrome c oxidase subunits with relatively low proportions of mutant mtDNA.
Collapse
Affiliation(s)
- M G Hanna
- University Department of Clinical Neurology, Institute of Neurology, London, UK
| | | | | | | |
Collapse
|
19
|
Masucci JP, Davidson M, Koga Y, Schon EA, King MP. In vitro analysis of mutations causing myoclonus epilepsy with ragged-red fibers in the mitochondrial tRNA(Lys)gene: two genotypes produce similar phenotypes. Mol Cell Biol 1995; 15:2872-81. [PMID: 7739567 PMCID: PMC230518 DOI: 10.1128/mcb.15.5.2872] [Citation(s) in RCA: 93] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Cytoplasts from patients with myoclonus epilepsy with ragged-red fibers harboring a pathogenic point mutation at either nucleotide 8344 or 8356 in the human mitochondrial tRNA(Lys) gene were fused with human cells lacking endogenous mitochondrial DNA (mtDNA). For each mutation, cytoplasmic hybrid (cybrid) cell lines containing 0 or 100% mutated mtDNAs were isolated and their genetic, biochemical, and morphological characteristics were examined. Both mutations resulted in the same biochemical and molecular genetic phenotypes. Specifically, cybrids containing 100% mutated mtDNAs, but not those containing the corresponding wild-type mtDNAs, exhibited severe defects in respiratory chain activity, in the rates of protein synthesis, and in the steady-state levels of mitochondrial translation products. In addition, aberrant mitochondrial translation products were detected with both mutations. No significant alterations were observed in the processing of polycistronic RNA precursor transcripts derived from the region containing the tRNA(Lys) gene. These results demonstrate that two different mtDNA mutations in tRNA(Lys), both associated with the same mitochondrial disorder, result in fundamentally identical defects at the cellular level and strongly suggest that specific protein synthesis abnormalities contribute to the pathogenesis of myoclonus epilepsy with ragged-red fibers.
Collapse
Affiliation(s)
- J P Masucci
- Department of Genetics and Development, Columbia University, New York, New York 10032, USA
| | | | | | | | | |
Collapse
|
20
|
Anan R, Nakagawa M, Miyata M, Higuchi I, Nakao S, Suehara M, Osame M, Tanaka H. Cardiac involvement in mitochondrial diseases. A study on 17 patients with documented mitochondrial DNA defects. Circulation 1995; 91:955-61. [PMID: 7850981 DOI: 10.1161/01.cir.91.4.955] [Citation(s) in RCA: 186] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
BACKGROUND Mutations of mitochondrial DNA have been demonstrated as causes of human mitochondrial diseases. While these disorders typically involve multiple organs, the effect of mitochondrial mutations on the heart has not been systematically studied. METHODS AND RESULTS We studied mitochondrial mutations and cardiac changes in 17 patients with Kearns-Sayre syndrome; ocular myopathy; myoclonus epilepsy with ragged red fibers (MERRF); and mitochondrial myopathy, encephalopathy, lactic acidosis, and strokelike episodes (MELAS). Cardiac involvement was evaluated by chest radiograph, ECG, His-bundle electrogram, and echocardiogram. All 3 patients with Kearns-Sayre syndrome had large deletions of mitochondrial DNA and disturbances in cardiac conduction. ECG abnormalities were found in 2 of 6 patients with ocular myopathy who showed large deletions of mitochondrial DNA. All 3 patients with MERRF had an A-to-G mutation at nucleotide position 8344; 2 had cardiomegaly, asymmetrical septal hypertrophy, and diffuse hypokinesis of the left ventricle. One patient with asymmetrical septal hypertrophy developed dilated cardiomyopathy 2 years later. All 5 patients with MELAS had an A-to-G mutation at nucleotide position 3243, and 2 had symmetrical left ventricular hypertrophy with or without abnormal wall motion. CONCLUSIONS The clinical features of cardiac involvement in mitochondrial diseases vary in the different subgroups of these disorders. Particular mitochondrial mutations can cause characteristic cardiac abnormalities.
Collapse
Affiliation(s)
- R Anan
- First Department of Internal Medicine, Faculty of Medicine, Kagoshima University, Japan
| | | | | | | | | | | | | | | |
Collapse
|
21
|
Natowicz MR, Bejjani B. Genetic disorders that masquerade as multiple sclerosis. AMERICAN JOURNAL OF MEDICAL GENETICS 1994; 49:149-69. [PMID: 8116663 DOI: 10.1002/ajmg.1320490202] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
There are many genetic disorders that have signs and symptoms suggestive of multiple sclerosis and that may easily be overlooked in the evaluation of both adult and pediatric multiple sclerosis patients. The recognition of a genetic disorder as the cause of a patient's "multiple sclerosis" phenotype has important implications not only for the patient, but often also for others in the patient's family who may be at risk for the same disease. We present here a review of single gene disorders that can masquerade as multiple sclerosis. For each disorder, the major clinical and biochemical characteristics are discussed, together with the appropriate testing to screen for and confirm the diagnosis. In addition, guidelines are presented for when to suspect an underlying genetic condition in a patient with a diagnosis of definite or probable multiple sclerosis. The great variety of genetic disorders that can masquerade as multiple sclerosis and the many implications of a genetic diagnosis underscore the importance of recognizing genocopies of multiple sclerosis.
Collapse
Affiliation(s)
- M R Natowicz
- Division of Medical Genetics, Shriver Center for Mental Retardation, Waltham, MA 02254
| | | |
Collapse
|