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Nogueira C, Pereira C, Silva L, Laranjeira M, Lopes A, Neiva R, Rodrigues E, Campos T, Martins E, Bandeira A, Coelho M, Magalhães M, Damásio J, Gaspar A, Janeiro P, Gomes AL, Ferreira AC, Jacinto S, Vieira JP, Diogo L, Santos H, Mendonça C, Vilarinho L. The genetic landscape of mitochondrial diseases in the next-generation sequencing era: a Portuguese cohort study. Front Cell Dev Biol 2024; 12:1331351. [PMID: 38465286 PMCID: PMC10920333 DOI: 10.3389/fcell.2024.1331351] [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: 10/31/2023] [Accepted: 01/30/2024] [Indexed: 03/12/2024] Open
Abstract
Introduction: Rare disorders that are genetically and clinically heterogeneous, such as mitochondrial diseases (MDs), have a challenging diagnosis. Nuclear genes codify most proteins involved in mitochondrial biogenesis, despite all mitochondria having their own DNA. The development of next-generation sequencing (NGS) technologies has revolutionized the understanding of many genes involved in the pathogenesis of MDs. In this new genetic era, using the NGS approach, we aimed to identify the genetic etiology for a suspected MD in a cohort of 450 Portuguese patients. Methods: We examined 450 patients using a combined NGS strategy, starting with the analysis of a targeted mitochondrial panel of 213 nuclear genes, and then proceeding to analyze the whole mitochondrial DNA. Results and Discussion: In this study, we identified disease-related variants in 134 (30%) analyzed patients, 88 with nuclear DNA (nDNA) and 46 with mitochondrial DNA (mtDNA) variants, most of them being pediatric patients (66%), of which 77% were identified in nDNA and 23% in mtDNA. The molecular analysis of this cohort revealed 72 already described pathogenic and 20 novel, probably pathogenic, variants, as well as 62 variants of unknown significance. For this cohort of patients with suspected MDs, the use of a customized gene panel provided a molecular diagnosis in a timely and cost-effective manner. Patients who cannot be diagnosed after this initial approach will be further selected for whole-exome sequencing. Conclusion: As a national laboratory for the study and research of MDs, we demonstrated the power of NGS to achieve a molecular etiology, expanding the mutational spectrum and proposing accurate genetic counseling in this group of heterogeneous diseases without therapeutic options.
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Affiliation(s)
- C. Nogueira
- Research & Development Unit, Human Genetics Department, National Institute of Health Doutor Ricardo Jorge, Lisbon, Portugal
- Newborn Screening, Metabolism & Genetics Unit, Human Genetics Department, National Institute of Health Doutor Ricardo Jorge, Lisbon, Portugal
| | - C. Pereira
- Newborn Screening, Metabolism & Genetics Unit, Human Genetics Department, National Institute of Health Doutor Ricardo Jorge, Lisbon, Portugal
| | - L. Silva
- Research & Development Unit, Human Genetics Department, National Institute of Health Doutor Ricardo Jorge, Lisbon, Portugal
- Newborn Screening, Metabolism & Genetics Unit, Human Genetics Department, National Institute of Health Doutor Ricardo Jorge, Lisbon, Portugal
| | - Mateus Laranjeira
- Research & Development Unit, Human Genetics Department, National Institute of Health Doutor Ricardo Jorge, Lisbon, Portugal
| | - A. Lopes
- Newborn Screening, Metabolism & Genetics Unit, Human Genetics Department, National Institute of Health Doutor Ricardo Jorge, Lisbon, Portugal
| | - R. Neiva
- Newborn Screening, Metabolism & Genetics Unit, Human Genetics Department, National Institute of Health Doutor Ricardo Jorge, Lisbon, Portugal
| | - E. Rodrigues
- Inherited Metabolic Diseases Reference Centre, São João Hospital University Centre, Porto, Portugal
| | - T. Campos
- Inherited Metabolic Diseases Reference Centre, São João Hospital University Centre, Porto, Portugal
| | - E. Martins
- Inherited Metabolic Diseases Reference Centre, Santo António Hospital University Centre, Porto, Portugal
| | - A. Bandeira
- Inherited Metabolic Diseases Reference Centre, Santo António Hospital University Centre, Porto, Portugal
| | - M. Coelho
- Inherited Metabolic Diseases Reference Centre, Santo António Hospital University Centre, Porto, Portugal
| | - M. Magalhães
- Neurology Department, Santo António Hospital University Centre, Porto, Portugal
| | - J. Damásio
- Neurology Department, Santo António Hospital University Centre, Porto, Portugal
| | - A. Gaspar
- Inherited Metabolic Diseases Reference Centre, Lisboa Norte Hospital University Centre, Lisboa, Portugal
| | - P Janeiro
- Inherited Metabolic Diseases Reference Centre, Lisboa Norte Hospital University Centre, Lisboa, Portugal
| | - A. Levy Gomes
- Neurology Department, Lisboa Norte Hospital University Centre, Lisboa, Portugal
| | - A. C. Ferreira
- Inherited Metabolic Diseases Reference Centre, Lisboa Central Hospital Centre, Lisboa, Portugal
| | - S. Jacinto
- Inherited Metabolic Diseases Reference Centre, Lisboa Central Hospital Centre, Lisboa, Portugal
| | - J. P. Vieira
- Inherited Metabolic Diseases Reference Centre, Lisboa Central Hospital Centre, Lisboa, Portugal
| | - L. Diogo
- Inherited Metabolic Diseases Reference Centre, Coimbra Hospital and University Centre, Coimbra, Portugal
| | - H. Santos
- Inherited Metabolic Diseases Reference Centre, Vila Nova de Gaia Hospital Centre, Vila Nova de Gaia, Portugal
| | - C. Mendonça
- Pediatric Department, Faro Hospital and University Centre, Faro, Portugal
| | - L. Vilarinho
- Research & Development Unit, Human Genetics Department, National Institute of Health Doutor Ricardo Jorge, Lisbon, Portugal
- Newborn Screening, Metabolism & Genetics Unit, Human Genetics Department, National Institute of Health Doutor Ricardo Jorge, Lisbon, Portugal
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Qi Y, Wu Z, Bai Y, Jiao Y, Li P. Screening for Mitochondrial tRNA Mutations in 318 Patients with Dilated Cardiomyopathy. Hum Hered 2022; 87:000521615. [PMID: 34991096 DOI: 10.1159/000521615] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2021] [Accepted: 11/25/2021] [Indexed: 11/19/2022] Open
Abstract
OBJECTIVES Dilated cardiomyopathy (DCM) is a complex cardiovascular disease with unknown etiology. Although nuclear genes play active roles in DCM, mitochondrial dysfunction was believed to be involved in the pathogenesis of DCM. The objective of this study is to analysis the association between mitochondrial tRNA (mt-tRNA) mutations and DCM. MATERIAL AND METHODS We performed a mutational analysis of mt-tRNA genes in a cohort of 318 patients with DCM and 200 age- and gender-matched control subjects. To further assess their pathogenicity, phylogenetic analysis and mitochondrial functions including mtDNA copy number, ATP and ROS were analyzed. RESULTS 7 possible pathogenic mutations: MT-TL1 3302A>G, MT-TI 4295A>G, MT-TM 4435A>G, MT-TA 5655T>C, MT-TH 12201T>C, MT-TE 14692A>G and MT-TT 15927G>A were identified in DCM group but absent in controls. These mutations occurred at extremely conserved nucleotides of corresponding tRNAs, and led to the failure in tRNAs metabolism. Moreover, a significant reduction in ATP and mtDNA copy number, whereas a markedly increased in ROS level were observed in polymononuclear leukocytes (PMNs) derived from the DCM patients carrying these mt-tRNA mutations, suggesting that these mutations may cause mitochondrial dysfunction that was responsible for DCM. CONCLUSIONS Our data indicated that mt-tRNA mutations may be the molecular basis for DCM, which shaded novel insight into the pathophysiology of DCM that was manifestated by mitochondrial dysfunction.
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Zarrouk S, Finsterer J, Mehri S, Ourda F, Ben Arab S, Boussada R. Dilated Cardiomyopathy due to the Novel MT-CYB Missense Mutation m.14757T>C. J Med Cases 2021; 12:455-459. [PMID: 34804306 PMCID: PMC8577615 DOI: 10.14740/jmc3787] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2021] [Accepted: 10/13/2021] [Indexed: 12/03/2022] Open
Abstract
Mitochondrial DNA (mtDNA) mutations frequently manifest with multisystem disease, including cardiomyopathy (CM). Various studies described mutations in protein-encoding mtDNA genes, such as cytochrome-b, manifesting with CM. A detailed clinical, biochemical, and molecular genetic analysis was performed in a 40-year-old male with dilated CM (DCM) to detect the underlying mtDNA defect. Muscle biopsy showed complex-III deficiency, and sequencing of the cytochrome-b gene revealed the pathogenic variant m.14757T>C in MT-CYB, resulting in the replacement of the hydrophobic methionine by the polar threonine (M4T). By application of the PolyPhen algorithm the variant was predicted as pathogenic. The mutation was not found in 100 healthy controls and never reported as a neutral polymorphism despite extensive sequencing of the cytochrome-b gene in 2,704 normal healthy controls from different ethnic backgrounds. In conclusion, the novel variant m.14757T>C in MT-CYB is associated with DCM suggesting a pathophysiologic role of the variant in the development of DCM.
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Affiliation(s)
- Sinda Zarrouk
- Department of Genetic and Molecular Epidemiology, Medical University of Tunis, Tunisia
| | - Josef Finsterer
- City Hospital Landstrasse, Messerli Institute, Vienna, Austria
| | - Sounira Mehri
- Department of Genetic and Molecular Epidemiology, Medical University of Tunis, Tunisia
| | - Fatma Ourda
- Department of Functional Cardiology, La Rabta Hospital of Tunis, Tunisia
| | - Saida Ben Arab
- Department of Genetic and Molecular Epidemiology, Medical University of Tunis, Tunisia
| | - Raafik Boussada
- Department of Functional Cardiology, La Rabta Hospital of Tunis, Tunisia
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mtDNA in the Pathogenesis of Cardiovascular Diseases. DISEASE MARKERS 2021; 2021:7157109. [PMID: 34795807 PMCID: PMC8595034 DOI: 10.1155/2021/7157109] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/21/2021] [Revised: 10/06/2021] [Accepted: 10/24/2021] [Indexed: 12/14/2022]
Abstract
The incidence rate of cardiovascular disease (CVD) has been increasing year by year and has become the main cause for the increase of mortality. Mitochondrial DNA (mtDNA) plays a crucial role in the pathogenesis of CVD, especially in heart failure and ischemic heart diseases. With the deepening of research, more and more evidence showed that mtDNA is related to the occurrence and development of CVD. Current studies mainly focus on how mtDNA copy number, an indirect biomarker of mitochondrial function, contributes to CVD and its underlying mechanisms including mtDNA autophagy, the effect of mtDNA on cardiac inflammation, and related metabolic functions. However, no relevant studies have been conducted yet. In this paper, we combed the current research status of the mechanism related to the influence of mtDNA on the occurrence, development, and prognosis of CVD, so as to find whether these mechanisms have something in common, or is there a correlation between each mechanism for the development of CVD?
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5
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Bayona-Bafaluy MP, Iglesias E, López-Gallardo E, Emperador S, Pacheu-Grau D, Labarta L, Montoya J, Ruiz-Pesini E. Genetic aspects of the oxidative phosphorylation dysfunction in dilated cardiomyopathy. MUTATION RESEARCH-REVIEWS IN MUTATION RESEARCH 2020; 786:108334. [PMID: 33339579 DOI: 10.1016/j.mrrev.2020.108334] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2020] [Revised: 08/19/2020] [Accepted: 08/20/2020] [Indexed: 12/27/2022]
Abstract
Dilated cardiomyopathy is a frequent and extremely heterogeneous medical condition. Deficits in the oxidative phosphorylation system have been described in patients suffering from dilated cardiomyopathy. Hence, mutations in proteins related to this biochemical pathway could be etiological factors for some of these patients. Here, we review the clinical phenotypes of patients harboring pathological mutations in genes related to the oxidative phosphorylation system, either encoded in the mitochondrial or in the nuclear genome, presenting with dilated cardiomyopathy. In addition to the clinical heterogeneity of these patients, the large genetic heterogeneity has contributed to an improper allocation of pathogenicity for many candidate mutations. We suggest criteria to avoid incorrect assignment of pathogenicity to newly found mutations and discuss possible therapies targeting the oxidative phosphorylation function.
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Affiliation(s)
- M Pilar Bayona-Bafaluy
- Departamento de Bioquímica, Biología Molecular y Celular, Universidad de Zaragoza. C/ Miguel Servet, 177. 50013, Zaragoza, Spain; Instituto de Investigación Sanitaria (IIS) de Aragón, Av. San Juan Bosco, 13., 50009, Zaragoza, Spain; Centro de Investigaciones Biomédicas en Red de Enfermedades Raras (CIBERER), Av. Monforte de Lemos, 3-5, 28029, Madrid, Spain.
| | - Eldris Iglesias
- Departamento de Bioquímica, Biología Molecular y Celular, Universidad de Zaragoza. C/ Miguel Servet, 177. 50013, Zaragoza, Spain; Instituto de Investigación Sanitaria (IIS) de Aragón, Av. San Juan Bosco, 13., 50009, Zaragoza, Spain.
| | - Ester López-Gallardo
- Departamento de Bioquímica, Biología Molecular y Celular, Universidad de Zaragoza. C/ Miguel Servet, 177. 50013, Zaragoza, Spain; Instituto de Investigación Sanitaria (IIS) de Aragón, Av. San Juan Bosco, 13., 50009, Zaragoza, Spain; Centro de Investigaciones Biomédicas en Red de Enfermedades Raras (CIBERER), Av. Monforte de Lemos, 3-5, 28029, Madrid, Spain.
| | - Sonia Emperador
- Departamento de Bioquímica, Biología Molecular y Celular, Universidad de Zaragoza. C/ Miguel Servet, 177. 50013, Zaragoza, Spain; Instituto de Investigación Sanitaria (IIS) de Aragón, Av. San Juan Bosco, 13., 50009, Zaragoza, Spain; Centro de Investigaciones Biomédicas en Red de Enfermedades Raras (CIBERER), Av. Monforte de Lemos, 3-5, 28029, Madrid, Spain.
| | - David Pacheu-Grau
- Department of Cellular Biochemistry, University Medical Center, Georg-August University,Humboldtalle, 23., 37073, Göttingen, Germany.
| | - Lorenzo Labarta
- Unidad de Cuidados Intensivos, Hospital San Jorge, Av. Martínez de Velasco, 36., 22004, Huesca, Spain.
| | - Julio Montoya
- Departamento de Bioquímica, Biología Molecular y Celular, Universidad de Zaragoza. C/ Miguel Servet, 177. 50013, Zaragoza, Spain; Instituto de Investigación Sanitaria (IIS) de Aragón, Av. San Juan Bosco, 13., 50009, Zaragoza, Spain; Centro de Investigaciones Biomédicas en Red de Enfermedades Raras (CIBERER), Av. Monforte de Lemos, 3-5, 28029, Madrid, Spain.
| | - Eduardo Ruiz-Pesini
- Departamento de Bioquímica, Biología Molecular y Celular, Universidad de Zaragoza. C/ Miguel Servet, 177. 50013, Zaragoza, Spain; Instituto de Investigación Sanitaria (IIS) de Aragón, Av. San Juan Bosco, 13., 50009, Zaragoza, Spain; Centro de Investigaciones Biomédicas en Red de Enfermedades Raras (CIBERER), Av. Monforte de Lemos, 3-5, 28029, Madrid, Spain; Fundación ARAID, Av. de Ranillas, 1-D., 50018, Zaragoza, Spain.
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6
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Schaffer AE, Pinkard O, Coller JM. tRNA Metabolism and Neurodevelopmental Disorders. Annu Rev Genomics Hum Genet 2019; 20:359-387. [PMID: 31082281 DOI: 10.1146/annurev-genom-083118-015334] [Citation(s) in RCA: 51] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
tRNAs are short noncoding RNAs required for protein translation. The human genome includes more than 600 putative tRNA genes, many of which are considered redundant. tRNA transcripts are subject to tightly controlled, multistep maturation processes that lead to the removal of flanking sequences and the addition of nontemplated nucleotides. Furthermore, tRNAs are highly structured and posttranscriptionally modified. Together, these unique features have impeded the adoption of modern genomics and transcriptomics technologies for tRNA studies. Nevertheless, it has become apparent from human neurogenetic research that many tRNA biogenesis proteins cause brain abnormalities and other neurological disorders when mutated. The cerebral cortex, cerebellum, and peripheral nervous system show defects, impairment, and degeneration upon tRNA misregulation, suggesting that they are particularly sensitive to changes in tRNA expression or function. An integrated approach to identify tRNA species and contextually characterize tRNA function will be imperative to drive future tool development and novel therapeutic design for tRNA-associated disorders.
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Affiliation(s)
- Ashleigh E Schaffer
- Department of Genetics and Genome Sciences and Center for RNA Science and Therapeutics, Case Western Reserve University, Cleveland, Ohio 44106, USA;
| | - Otis Pinkard
- Department of Genetics and Genome Sciences and Center for RNA Science and Therapeutics, Case Western Reserve University, Cleveland, Ohio 44106, USA;
| | - Jeffery M Coller
- Department of Genetics and Genome Sciences and Center for RNA Science and Therapeutics, Case Western Reserve University, Cleveland, Ohio 44106, USA;
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7
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Stefano GB, Bjenning C, Wang F, Wang N, Kream RM. Mitochondrial Heteroplasmy. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 982:577-594. [PMID: 28551808 DOI: 10.1007/978-3-319-55330-6_30] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Genetic polymorphisms, in concert with well-characterized etiology and progression of major pathologies, plays a significant role in aberrant processes afflicting human populations. Mitochondrial heteroplasmy represents a dynamically determined co-expression of inherited polymorphisms and somatic pathology in varying ratios within individual mitochondrial DNA (mtDNA) genomes with repetitive patterns of tissue specificity. The ratios of the MtDNA genomes represent a balance between healthy and pathological cellular outcomes. Mechanistically, cardiomyopathies have profound alterations of normative mitochondrial function. Certain allele imbalances in the nuclear mitochondrial genome are associated with key energy mitochondrial proteins. Mitochondrial heteroplasmy may manifest itself at critical protein expression points, e.g., cytochrome c oxidase (COX). Pathological mtDNA mutations also are associated with the development of congestive heart failure. Interestingly, mitochondrial 'normal vs. abnormal' ratios of various heteroplasmic populations may occur in families. In the translational context of human health and disease, we discuss the need for determining critical foci to probe multiple biological roles of mitochondrial heteroplasmy in cardiomyopathy.
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Affiliation(s)
- George B Stefano
- International Scientific Information, Inc., 150 Broadhollow Rd, Ste 114, Melville, NY, 11747, USA.
| | - Christina Bjenning
- Cardiometabolic Designs LLC, 160 W15th Ave, Suite 303, Sea Cliff, NY, 11579, USA
| | - Fuzhou Wang
- Division of Neuroscience, Bonoi Academy of Science & Education, Chapel Hill, NC, 27510, USA
| | - Nan Wang
- Department of Anesthesiology, Affiliated Hospital of OB/GYN, Nanjing Medical University, Nanjing, 210004, China
| | - Richard M Kream
- International Scientific Information, Inc., 150 Broadhollow Rd, Ste 114, Melville, NY, 11747, USA
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8
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Abstract
Ischaemic heart disease and stroke are vascular events with serious health consequences worldwide. Recent genetic and epigenetic techniques have revealed many genetic determinants of these vascular events and simplified the approaches to research focused on ischaemic heart disease and stroke. The pathogenetic mechanisms of ischaemic heart disease and stroke are complex, with mitochondrial involvement (partially or entirely) recently gaining substantial support. Not only can mitochondrial reactive oxygen species give rise to ischaemic heart disease and stroke by production of oxidised low-density lipoprotein and induction of apoptosis, but the impact on pericytes contributes directly to the pathogenesis. Over the past two decades, publications implicate the causative role of nuclear genes in the development of ischaemic heart disease and stroke, in contrast to the potential role of mitochondrial DNA (mtDNA) in the pathophysiology of the disorders, which is much less understood, although recent studies do demonstrate that the involvement of mitochondria and mtDNA in the development of ischaemic heart disease and stroke is likely to be larger than originally thought, with the novel discovery of links among mitochondria, mtDNA and vascular events. Here we explore the molecular events and mtDNA alterations in relation to the role of mitochondria in ischaemic heart disease and stroke.
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9
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Wilson IJ, Carling PJ, Alston CL, Floros VI, Pyle A, Hudson G, Sallevelt SCEH, Lamperti C, Carelli V, Bindoff LA, Samuels DC, Wonnapinij P, Zeviani M, Taylor RW, Smeets HJM, Horvath R, Chinnery PF. Mitochondrial DNA sequence characteristics modulate the size of the genetic bottleneck. Hum Mol Genet 2016; 25:1031-41. [PMID: 26740552 PMCID: PMC4754047 DOI: 10.1093/hmg/ddv626] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2015] [Accepted: 12/22/2015] [Indexed: 01/03/2023] Open
Abstract
With a combined carrier frequency of 1:200, heteroplasmic mitochondrial DNA (mtDNA) mutations cause human disease in ∼1:5000 of the population. Rapid shifts in the level of heteroplasmy seen within a single generation contribute to the wide range in the severity of clinical phenotypes seen in families transmitting mtDNA disease, consistent with a genetic bottleneck during transmission. Although preliminary evidence from human pedigrees points towards a random drift process underlying the shifting heteroplasmy, some reports describe differences in segregation pattern between different mtDNA mutations. However, based on limited observations and with no direct comparisons, it is not clear whether these observations simply reflect pedigree ascertainment and publication bias. To address this issue, we studied 577 mother–child pairs transmitting the m.11778G>A, m.3460G>A, m.8344A>G, m.8993T>G/C and m.3243A>G mtDNA mutations. Our analysis controlled for inter-assay differences, inter-laboratory variation and ascertainment bias. We found no evidence of selection during transmission but show that different mtDNA mutations segregate at different rates in human pedigrees. m.8993T>G/C segregated significantly faster than m.11778G>A, m.8344A>G and m.3243A>G, consistent with a tighter mtDNA genetic bottleneck in m.8993T>G/C pedigrees. Our observations support the existence of different genetic bottlenecks primarily determined by the underlying mtDNA mutation, explaining the different inheritance patterns observed in human pedigrees transmitting pathogenic mtDNA mutations.
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Affiliation(s)
| | - Phillipa J Carling
- Institute of Genetic Medicine, Wellcome Trust Centre for Mitochondrial Research and
| | - Charlotte L Alston
- Wellcome Trust Centre for Mitochondrial Research and Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, UK
| | - Vasileios I Floros
- Medical Research Council Mitochondrial Biology Unit, Cambridge, UK, Department of Clinical Neurosciences, School of Clinical Medicine, University of Cambridge, Cambridge, UK
| | - Angela Pyle
- Institute of Genetic Medicine, Wellcome Trust Centre for Mitochondrial Research and
| | - Gavin Hudson
- Institute of Genetic Medicine, Wellcome Trust Centre for Mitochondrial Research and
| | - Suzanne C E H Sallevelt
- Department of Clinical Genetics, Research Schools GROW/CARIM, Maastricht University Medical Center, Maastricht, Netherlands
| | - Costanza Lamperti
- Division of Molecular Neurogenetics, National Neurological Institute 'C. Besta', Milano, Italy
| | - Valerio Carelli
- IRCCS Institute of Neurological Sciences of Bologna, Bellaria Hospital, Bologna, Italy, Unit of Neurology, Department of Biomedical and NeuroMotor Sciences (DIBINEM), University of Bologna, Bologna, Italy
| | - Laurence A Bindoff
- Department of Neurology, Haukeland University Hospital, Bergen, Norway, Department of Clinical Medicine (K1), University of Bergen, Bergen, Norway
| | - David C Samuels
- Vanderbilt Genetics Institute, Department of Molecular Physiology and Biophysics, Vanderbilt School of Medicine, Nashville, TN, USA and
| | - Passorn Wonnapinij
- Department of Genetics, Faculty of Science, Kasetsart University, Bangkok, Thailand
| | - Massimo Zeviani
- Medical Research Council Mitochondrial Biology Unit, Cambridge, UK, Division of Molecular Neurogenetics, National Neurological Institute 'C. Besta', Milano, Italy
| | - Robert W Taylor
- Wellcome Trust Centre for Mitochondrial Research and Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, UK
| | - Hubert J M Smeets
- Department of Clinical Genetics, Research Schools GROW/CARIM, Maastricht University Medical Center, Maastricht, Netherlands
| | - Rita Horvath
- Institute of Genetic Medicine, Wellcome Trust Centre for Mitochondrial Research and
| | - Patrick F Chinnery
- Wellcome Trust Centre for Mitochondrial Research and Medical Research Council Mitochondrial Biology Unit, Cambridge, UK, Department of Clinical Neurosciences, School of Clinical Medicine, University of Cambridge, Cambridge, UK,
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Sugiura K, Takahashi A, Kubo T, Tanioka K, Morita Y, Osaki Y, Yamasaki N, Furuya H, Kitaoka H. A case of mitochondrial disease in the elderly. ACTA ACUST UNITED AC 2015; 104:2589-93. [PMID: 28530376 DOI: 10.2169/naika.104.2589] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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11
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Alila OF, Rebai EM, Tabebi M, Tej A, Chamkha I, Tlili A, Bouguila J, Tilouche S, Soyah N, Boughamoura L, Fakhfakh F. Whole mitochondrial genome analysis in two families with dilated mitochondrial cardiomyopathy: detection of mutations in MT-ND2 and MT-TL1 genes. Mitochondrial DNA A DNA Mapp Seq Anal 2015; 27:2873-80. [PMID: 26258512 DOI: 10.3109/19401736.2015.1060417] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Pathogenic mitochondrial DNA (mtDNA) mutations leading to mitochondrial dysfunction can cause cardiomyopathy and heart failure. These mutations were described in the mt-tRNA genes and in the mitochondrial protein-coding genes. The aim of this study was to identify the genetic defect in two patients belonging to two families with cardiac dysfunction associated to a wide spectrum of clinical phenotypes. The sequencing analysis of the whole mitochondrial DNA in the two patients and their parents revealed the presence of known polymorphisms associated to cardiomyopathy and two pathogenic mutations in DNA extracted from blood leucocytes: the heteroplasmic m.3243A > G mutation in the MT-TL1 gene in patient A; and the homoplasmic m.5182C > T mutation in the ND2 gene in patient B. Secondary structure analysis of the ND2 protein further supported the deleterious role of the m.5182C > T mutation, as it was found to be involved an extended imbalance in its hydrophobicity and affect its function. In addition, the mitochondrial variants identified in patients A and B classify both of them in the same haplogroup H2a2a1.
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Affiliation(s)
- Olfa Fersi Alila
- a Laboratoire de Génétique Moléculaire Humaine, Faculté de Médecine de Sfax , Sfax , Tunisia
| | - Emna Mkaouar Rebai
- a Laboratoire de Génétique Moléculaire Humaine, Faculté de Médecine de Sfax , Sfax , Tunisia
| | - Mouna Tabebi
- a Laboratoire de Génétique Moléculaire Humaine, Faculté de Médecine de Sfax , Sfax , Tunisia
| | - Amel Tej
- b Service de Pédiatrie, C.H.U. Farhat Hached de Sousse , Sousse , Tunisia , and
| | - Imen Chamkha
- a Laboratoire de Génétique Moléculaire Humaine, Faculté de Médecine de Sfax , Sfax , Tunisia
| | - Abdelaziz Tlili
- c Department of Applied Biology , College of Sciences, University of Sharjah , Sharjah , UAE
| | - Jihene Bouguila
- b Service de Pédiatrie, C.H.U. Farhat Hached de Sousse , Sousse , Tunisia , and
| | - Samia Tilouche
- b Service de Pédiatrie, C.H.U. Farhat Hached de Sousse , Sousse , Tunisia , and
| | - Nejla Soyah
- b Service de Pédiatrie, C.H.U. Farhat Hached de Sousse , Sousse , Tunisia , and
| | - Lamia Boughamoura
- b Service de Pédiatrie, C.H.U. Farhat Hached de Sousse , Sousse , Tunisia , and
| | - Faiza Fakhfakh
- a Laboratoire de Génétique Moléculaire Humaine, Faculté de Médecine de Sfax , Sfax , Tunisia
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Finsterer J, Kothari S. Cardiac manifestations of primary mitochondrial disorders. Int J Cardiol 2014; 177:754-63. [PMID: 25465824 DOI: 10.1016/j.ijcard.2014.11.014] [Citation(s) in RCA: 76] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/20/2014] [Revised: 10/23/2014] [Accepted: 11/03/2014] [Indexed: 12/16/2022]
Abstract
OBJECTIVES One of the most frequently affected organs in mitochondrial disorders (MIDs), defined as hereditary diseases due to affection of the mitochondrial energy metabolism, is the heart. Cardiac involvement (CI) in MIDs has therapeutic and prognostic implications. This review aims at summarizing and discussing the various cardiac manifestations in MIDs. METHODS Data for this review were identified by searches of MEDLINE, Current Contents, and PubMed using appropriate search terms. RESULTS CI in MIDs may be classified according to various different criteria. In the present review cardiac abnormalities in MIDs are discussed according to their frequency with which they occur. CI in MIDs includes cardiomyopathy, arrhythmias, heart failure, pulmonary hypertension, dilation of the aortic root, pericardial effusion, coronary heart disease, autonomous nervous system dysfunction, congenital heart defects, or sudden cardiac death. The most frequent among the cardiomyopathies is hypertrophic cardiomyopathy, followed by dilated cardiomyopathy, and noncompaction. CONCLUSIONS CI in MID is more variable and prevalent than previously thought. All tissues of the heart may be variably affected. The most frequently affected tissue is the myocardium. MIDs should be included in the differential diagnoses of cardiac disease.
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DING YU, XIA BOHOU, YU JINFANG, LENG JIANHANG, HUANG JINYU. Mitochondrial DNA mutations and essential hypertension (Review). Int J Mol Med 2013; 32:768-74. [DOI: 10.3892/ijmm.2013.1459] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2013] [Accepted: 07/22/2013] [Indexed: 11/06/2022] Open
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14
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Ikawa M, Arakawa K, Hamano T, Nagata M, Nakamoto Y, Kuriyama M, Koga Y, Yoneda M. Evaluation of systemic redox states in patients carrying the MELAS A3243G mutation in mitochondrial DNA. Eur Neurol 2012; 67:232-7. [PMID: 22517274 DOI: 10.1159/000336568] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2011] [Accepted: 01/14/2012] [Indexed: 11/19/2022]
Abstract
BACKGROUND/AIMS To clarify the change of systemic redox states in patients carrying the A3243G mutation in mitochondrial DNA (A3243G), we evaluated oxidative stress and antioxidant activity in the serum of patients. METHODS Oxidative stress and antioxidant activity in the serum samples obtained from 14 patients carrying A3243G and from 34 healthy controls were analyzed using the diacron-reactive oxygen metabolites (d-ROMs) and biological antioxidant potential (BAP) tests, respectively. RESULTS The mean d-ROMs level of all patients was significantly greater than that of the controls (p < 0.005), and the mean BAP/d-ROMs ratio of all patients was significantly lower than that of the controls (p < 0.02). In the patients with a history of stroke-like episodes (n = 10), both mean d-ROMs and BAP levels were increased compared with those of the controls (both p < 0.01). The mean BAP level of the patients without a history of stroke-like episodes (n = 4) was significantly decreased compared with that of the controls (p < 0.001), but the mean d-ROMs levels were not significantly different. CONCLUSION d-ROMs and BAP tests indicated that patients carrying A3243G are always exposed to underlying oxidative stress, even at a remission state of stroke-like episodes.
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Affiliation(s)
- Masamichi Ikawa
- Second Department of Internal Medicine, Faculty of Medical Sciences, University of Fukui, Fukui, Japan
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15
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BERARDO A, MUSUMECI O, TOSCANO A. Cardiological manifestations of mitochondrial respiratory chain disorders. ACTA MYOLOGICA : MYOPATHIES AND CARDIOMYOPATHIES : OFFICIAL JOURNAL OF THE MEDITERRANEAN SOCIETY OF MYOLOGY 2011; 30:9-15. [PMID: 21842587 PMCID: PMC3185833] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 10/30/2022]
Abstract
Mitochondrial Respiratory Chain Disorders (MRCD) are a heterogeneous group of disorders that share the involvement of the cellular bioenergetic machinery due to molecular defects affecting the mitochondrial oxidative phosphorylation system (OXPHOS). Clinically, they usually involve multiple tissues although they tend to mainly affect nervous system and skeletal muscle. Cardiological manifestations are frequent and include hypertrophic or dilated cardiomyopathies and heart conduction defects, being part of adult or infantile multisystemic mitochondrial disorders or, less frequently, presenting as isolated clinical condition. The aim of this review is to update the cardiological manifestations in both adult and infantile mitochondrial disorders going briefly over mitochondrial genetics. Cardiac involvement is a common feature associated with early and late onset forms of MRCD. In particular cases, these conditions should be considered into the diagnostic algorithm of idiopathic cardiomyopathies. Physicians strictly related with this disorders need to be aware of heart complications and therefore periodical cardiological examinations should be performed in such patients. Finally, therapeutic strategies are suggested to treat cardiac disorders in MRCD
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Affiliation(s)
| | | | - A. TOSCANO
- Address for correspondence: Antonio Toscano, UOC di Neurologia e Malattie Neuromuscolari, AOU Policlinico "G. Martino",
via Consolare Valeria 1, 98125 Messina, Italy.
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16
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Mitochondrial cardiomyopathies: how to identify candidate pathogenic mutations by mitochondrial DNA sequencing, MITOMASTER and phylogeny. Eur J Hum Genet 2010; 19:200-7. [PMID: 20978534 PMCID: PMC3025796 DOI: 10.1038/ejhg.2010.169] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022] Open
Abstract
Pathogenic mitochondrial DNA (mtDNA) mutations leading to mitochondrial dysfunction can cause cardiomyopathy and heart failure. Owing to a high mutation rate, mtDNA defects may occur at any nucleotide in its 16 569 bp sequence. Complete mtDNA sequencing may detect pathogenic mutations, which can be difficult to interpret because of normal ethnic/geographic-associated haplogroup variation. Our goal is to show how to identify candidate mtDNA mutations by sorting out polymorphisms using readily available online tools. The purpose of this approach is to help investigators in prioritizing mtDNA variants for functional analysis to establish pathogenicity. We analyzed complete mtDNA sequences from 29 Italian patients with mitochondrial cardiomyopathy or suspected disease. Using MITOMASTER and PhyloTree, we characterized 593 substitution variants by haplogroup and allele frequencies to identify all novel, non-haplogroup-associated variants. MITOMASTER permitted determination of each variant's location, amino acid change and evolutionary conservation. We found that 98% of variants were common or rare, haplogroup-associated variants, and thus unlikely to be primary cause in 80% of cases. Six variants were novel, non-haplogroup variants and thus possible contributors to disease etiology. Two with the greatest pathogenic potential were heteroplasmic, nonsynonymous variants: m.15132T>C in MT-CYB for a patient with hypertrophic dilated cardiomyopathy and m.6570G>T in MT-CO1 for a patient with myopathy. In summary, we have used our automated information system, MITOMASTER, to make a preliminary distinction between normal mtDNA variation and pathogenic mutations in patient samples; this fast and easy approach allowed us to select the variants for traditional analysis to establish pathogenicity.
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17
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Fayssoil A. Heart diseases in mitochondrial encephalomyopathy, lactic acidosis, and stroke syndrome. ACTA ACUST UNITED AC 2010; 15:284-7. [PMID: 19925507 DOI: 10.1111/j.1751-7133.2009.00108.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Mitochondrial encephalomyopathy, lactic acidosis, and stroke (MELAS) syndrome is a mitochondrial genetic disorder caused by a point mutation, resulting in the substitution of guanine for adenine at nucleotide 3243 (A3243G) of mitochondrial DNA. This disease is characterized by a multisystem disorder with variable manifestations. The authors review heart involvement in this disease.
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Affiliation(s)
- Abdallah Fayssoil
- Critical Care Medicine, Boulevard Raymond-Poincare, Raymond Poincare Hospital, Garches, Ile de France 92380, France.
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18
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Affiliation(s)
- Masamichi Ikawa
- Second Department of Internal Medicine (Neurology), Faculty of Medical Sciences, University of Fukui
| | - Makoto Yoneda
- Second Department of Internal Medicine (Neurology), Faculty of Medical Sciences, University of Fukui
| | - Masashi Tanaka
- Genomics for Longevity and Health, Tokyo Metropolitan Institute of Gerontology
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19
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Sproule DM, Kaufmann P. Mitochondrial encephalopathy, lactic acidosis, and strokelike episodes: basic concepts, clinical phenotype, and therapeutic management of MELAS syndrome. Ann N Y Acad Sci 2008; 1142:133-58. [PMID: 18990125 DOI: 10.1196/annals.1444.011] [Citation(s) in RCA: 214] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Since the initial description almost 25 years ago, the syndrome of mitochondrial encephalopathy, lactic acidosis, and strokelike episodes (MELAS) has been a useful model to study the complex interplay of factors that define mitochondrial disease. This syndrome, most commonly caused by an A-to-G transition mutation at position 3243 of the mitochondrial genome, is typified by characteristic neurological manifestations including seizures, encephalopathy, and strokelike episodes, as well as other frequent secondary manifestations including short stature, cognitive impairment, migraines, depression, cardiomyopathy, cardiac conduction defects, and diabetes mellitus. In this review, we discuss the history, pathogenesis, clinical features, and diagnostic and management strategies of mitochondrial disease in general and of MELAS in particular. We explore features of mitochondrial genetics, including the concepts of heteroplasmy, mitotic segregation, and threshold effect, as a basis for understanding the variability and complicated inheritance patterns seen with this group of diseases. We also describe systemic manifestations of MELAS-associated mutations, including cardiac, renal, endocrine, gastrointestinal, and endothelial abnormalities and pathology, as well as the hypothetical role of derangements to COX enzymatic function in driving the unique pathology and clinical manifestations of MELAS. Although therapeutic options for MELAS and other mitochondrial diseases remain limited, and recent trials have been disappointing, we also consider current and potential therapeutic modalities.
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Affiliation(s)
- Douglas M Sproule
- Columbia University, Pediatric Neurology, 180 Fort Washington Ave., Harkness Pavilion, 5th floor, New York, NY 10032, USA.
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20
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Sproule DM, Dyme J, Coku J, de Vinck D, Rosenzweig E, Chung WK, De Vivo DC. Pulmonary artery hypertension in a child with MELAS due to a point mutation of the mitochondrial tRNA((Leu)) gene (m.3243A>G). J Inherit Metab Dis 2008; 31 Suppl 3:497-503. [PMID: 18181029 DOI: 10.1007/s10545-007-0735-3] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/22/2007] [Revised: 12/02/2007] [Accepted: 12/04/2007] [Indexed: 11/24/2022]
Abstract
Although linked with cardiac dysfunction, the association of MELAS (mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes) and pulmonary artery hypertension (PAH) has not been previously described. PAH and right ventricular heart failure were identified by echocardiography in a 3-year-old boy with a history of hypotonia, microcephaly and developmental delay. He initially presented with a 10-day history of dyspnoea, dependent oedema and reduced oral intake. Lactic acidosis was noted on serial arterial blood sampling and cerebrospinal fluid. Muscle biopsy demonstrated cytochrome-c oxidase-positive 'ragged-red' fibres consistent with MELAS; subsequent analyses revealed the m.3243A>G point mutation most commonly associated with MELAS. The mutation was heteroplasmic, representing 92% of the total mtDNA from a lung sample. Nitric oxide and epoprostenol were administered without significant clinical or echocardiographic improvement of his PAH. A 'mitochondrial cocktail' including biotin, riboflavin, carnitine and coenzyme Q10 also was provided. Five months after presentation, he developed seizures; MRI imaging of his brain demonstrated multiple focal lesions. His clinical status worsened with increasing cardiopulmonary failure. He died two months later. Although therapy for both MELAS and PAH remains limited, recent investigations suggest a beneficial role for l-arginine in both conditions, implying a possible common pathophysiology. Mitochondrial diseases such as MELAS should be considered in cases of idiopathic PAH, particularly when associated with multisystem involvement including short stature, hearing loss, renal dysfunction, retinopathy, diabetes mellitus, migraines, seizures, ophthalmoplegia, fatigability and weakness.
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Affiliation(s)
- D M Sproule
- Division of Pediatric Neurology, Departments of Neurology and Pediatrics, Columbia University Medical Center, Harkness Pavilion, HP-544, 180 Fort Washington Avenue, New York, NY, 10032-3791, USA,
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21
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Wang W, Seak CJ, Liao SC, Chiu TF, Chen JC. Cardiac tamponade: a new complication in a patient with mitochondrial myopathy, encephalopathy, lactic acidosis, and strokelike episodes. Am J Emerg Med 2008; 26:382.e1-2. [DOI: 10.1016/j.ajem.2007.05.027] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2007] [Accepted: 05/19/2007] [Indexed: 10/22/2022] Open
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22
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Rajasimha HK, Chinnery PF, Samuels DC. Selection against pathogenic mtDNA mutations in a stem cell population leads to the loss of the 3243A-->G mutation in blood. Am J Hum Genet 2008; 82:333-43. [PMID: 18252214 PMCID: PMC2427290 DOI: 10.1016/j.ajhg.2007.10.007] [Citation(s) in RCA: 85] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2007] [Revised: 09/18/2007] [Accepted: 10/03/2007] [Indexed: 12/30/2022] Open
Abstract
The mutation 3243A-->G is the most common heteroplasmic pathogenic mitochondrial DNA (mtDNA) mutation in humans, but it is not understood why the proportion of this mutation decreases in blood during life. Changing levels of mtDNA heteroplasmy are fundamentally related to the pathophysiology of the mitochondrial disease and correlate with clinical progression. To understand this process, we simulated the segregation of mtDNA in hematopoietic stem cells and leukocyte precursors. Our observations show that the percentage of mutant mtDNA in blood decreases exponentially over time. This is consistent with the existence of a selective process acting at the stem cell level and explains why the level of mutant mtDNA in blood is almost invariably lower than in nondividing (postmitotic) tissues such as skeletal muscle. By using this approach, we derived a formula from human data to correct for the change in heteroplasmy over time. A comparison of age-corrected blood heteroplasmy levels with skeletal muscle, an embryologically distinct postmitotic tissue, provides independent confirmation of the model. These findings indicate that selection against pathogenic mtDNA mutations occurs in a stem cell population.
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Affiliation(s)
- Harsha Karur Rajasimha
- Virginia Bioinformatics Institute, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061 USA
| | - Patrick F. Chinnery
- Mitochondrial Research Group and Institute of Human Genetics, Newcastle University, The Medical School, Newcastle-upon-Tyne NE2 4HH, UK
| | - David C. Samuels
- Virginia Bioinformatics Institute, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061 USA
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A novel mitochondrial DNA tRNAIle (m.4322dupC) mutation associated with idiopathic dilated cardiomyopathy. ACTA ACUST UNITED AC 2008; 16:238-42. [PMID: 18043288 DOI: 10.1097/pdm.0b013e3180cc313b] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
We identified a novel heteroplasmic mitochondrial DNA (mtDNA) (m.4322dupC) mutation in tRNA gene associated with isolated dilated cardiomyopathy (DCM) as maternal trait. Mutation screening techniques and automated DNA sequencing were performed to identify mtDNA mutations and to assess heteroplasmy in family's proband and healthy control subjects. All family members tested had heteroplasmic mtDNA m.4322dupC mutation. We also screened 350 normal controls for this mutation and found no evidence of heteroplasmy. The m.4322dupC mutation was found in the skeletal tissue from the proband that exhibited slightly reduced deficiency of mitochondrial respiratory chain enzymes (complex III). The present study reports the novel m.4322dupC mutation in tRNA gene, which is possibly associated to the disease, to isolated DCM. It was localized in a hot-spot region for mutations and is possibly pathogenic because of a cosegregation with the matrilineal transmission of DCM.
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24
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Mkaouar-Rebai E, Tlili A, Masmoudi S, Belguith N, Charfeddine I, Mnif M, Triki C, Fakhfakh F. Mutational analysis of the mitochondrial tRNALeu(UUR) gene in Tunisian patients with mitochondrial diseases. Biochem Biophys Res Commun 2007; 355:1031-7. [PMID: 17336924 DOI: 10.1016/j.bbrc.2007.02.083] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2007] [Accepted: 02/14/2007] [Indexed: 11/29/2022]
Abstract
The mitochondrial tRNA(Leu(UUR)) gene (MTTL) is a hot spot for pathogenic mutations that are associated with mitochondrial diseases with various clinical features. Among these mutations, the A3243G mutation was associated with various types of mitochondrial multisystem disorders, such as MIDD, MELAS, MERRF, PEO, hypertrophic cardiomyopathy, and a subtype of Leigh syndrome. We screened 128 Tunisian patients for the A3243G mutation in the mitochondrial tRNA(Leu(UUR)) gene. This screening was carried out using PCR-RFLP with the restriction endonuclease ApaI. None of the 128 patients or the 100 controls tested were found to carry the mitochondrial A3243G mutation in the tRNA(Leu(UUR)) gene in homoplasmic or heteroplasmic form. After direct sequencing of the entire mitochondrial tRNA(Leu(UUR)) gene and a part of the mitochondrial NADH dehydrogenase 1, we found neither mutations nor polymorphisms in the MTTL1 gene in the tested patients and controls, and we confirmed the absence of the A3243G mutation in this gene. We also found a T3396C transition in the ND1 gene in one family with NSHL which was absent in the other patients and in 100 controls. Neither polymorphisms nor other mutations were found in the mitochondrial tRNA(Leu(UUR)) gene in the tested patients.
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Affiliation(s)
- Emna Mkaouar-Rebai
- Laboratoire de Génétique Moléculaire Humaine, Faculté de Médecine, 3029 Sfax, Tunisia.
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25
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Ikawa M, Kawai Y, Arakawa K, Tsuchida T, Miyamori I, Kuriyama M, Tanaka M, Yoneda M. Evaluation of respiratory chain failure in mitochondrial cardiomyopathy by assessments of 99mTc-MIBI washout and 123I-BMIPP/99mTc-MIBI mismatch. Mitochondrion 2007; 7:164-70. [PMID: 17280875 DOI: 10.1016/j.mito.2006.11.008] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2006] [Accepted: 11/09/2006] [Indexed: 01/01/2023]
Abstract
Cardiomyopathy is one of the main features that determines prognosis in patients with mitochondrial encephalomyopathy. We investigated respiratory chain failure using 99mTc-MIBI- and 123I-BMIPP-SPECT in vivo in five patients with mitochondrial cardiomyopathty. With the lowering of cardiac function, the 99mTc-MIBI-washout rate (WOR) increased, and the 99mTc-MIBI-uptake decreased, conversely. In patients who showed severe cardiac involvement, 99mTc-MIBI-uptake was markedly reduced, and by contrast, 123I-BMIPP-uptake increased (123I-BMIPP/99mTc-MIBI mismatch). There were significant correlations between the WOR on 99mTc-MIBI-SPECT and interventricular septal thickness (IVST) on echocardiography and between WOR and left ventricular ejection fraction (LVEF) on 99mTc-MIBI-SPECT. The increased WOR and decreased uptake of 99mTc-MIBI were reflected by the lowered mitochondrial membrane potential created by mitochondrial respiratory chain whereas 123I-BMIPP/99mTc-MIBI mismatch may be created by the enhanced triglyceride-pool. These nuclear medicine techniques are the potential tools to evaluate the energy state in mitochondrial cardiomyopathy.
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Affiliation(s)
- Masamichi Ikawa
- Second Department of Internal Medicine, Faculty of Medical Sciences, University of Fukui, 23-3 Shimoaiduki, Matsuoka, Fukui 910-1193, Japan
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26
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Singh R, Ellard S, Hattersley A, Harries LW. Rapid and sensitive real-time polymerase chain reaction method for detection and quantification of 3243A>G mitochondrial point mutation. J Mol Diagn 2006; 8:225-30. [PMID: 16645209 PMCID: PMC1867583 DOI: 10.2353/jmoldx.2006.050067] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Maternally inherited diabetes and deafness and mitochondrial encephalomyopathy, lactic acidosis with stroke-like episodes result from the 3243A>G mitochondrial point mutation. Current methods to detect the presence of the mutation have limited sensitivity and may lead to potential misclassification of patients with low levels of heteroplasmy. Here, we describe development and validation of a rapid real-time polymerase chain reaction (PCR) method for detection and quantification of levels of heteroplasmy in a single assay. Standard curve analysis indicated that the sensitivity of detection was less than 0.1%. Time from sample loading to data analysis was 110 minutes. We tested 293 samples including 23 known positives, 40 known negatives, and 230 samples from patients clinically classified as having type 2 diabetes. All positive samples were correctly detected, and of those samples previously quantified, heteroplasmy levels determined using the real-time assay correlated well (r(2) = 0.88 and 0.93) with results from fluorescently labeled PCR-restriction fragment length polymorphism and pyrosequencing methods. Screening of 230 patients classified as having type 2 diabetes revealed one patient with 0.6% heteroplasmy who had previously tested negative by PCR-restriction fragment length polymorphism. Real-time PCR provides rapid simultaneous detection and quantification of the 3243A>G mutation to a detection limit of less than 0.1%, without post-PCR manipulation.
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Affiliation(s)
- Rinki Singh
- Institute of Biomedical Sciences, Peninsula Medical School, Exeter, EX2 5DW UK
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27
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Majamaa-Voltti K, Peuhkurinen K, Kortelainen ML, Hassinen IE, Majamaa K. Cardiac abnormalities in patients with mitochondrial DNA mutation 3243A>G. BMC Cardiovasc Disord 2002; 2:12. [PMID: 12150714 PMCID: PMC119851 DOI: 10.1186/1471-2261-2-12] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2002] [Accepted: 08/01/2002] [Indexed: 01/19/2023] Open
Abstract
BACKGROUND Tissues that depend on aerobic energy metabolism suffer most in diseases caused by mutations in mitochondrial DNA (mtDNA). Cardiac abnormalities have been described in many cases, but their frequency and clinical spectrum among patients with mtDNA mutations is unknown. METHODS Thirty-nine patients with the 3243A>G mtDNA mutation were examined, methods used included clinical evaluation, electrocardiogram, Holter recording and echocardiography. Autopsy reports on 17 deceased subjects were also reviewed. The degree of 3243A>G mutation heteroplasmy was determined using an Apa I restriction fragment analysis. Better hearing level (BEHL0.5-4 kHz) was used as a measure of the clinical severity of disease. RESULTS Left ventricular hypertrophy (LVH) was diagnosed in 19 patients (56%) by echocardiography and in six controls (15%) giving an odds ratio of 7.5 (95% confidence interval; 1.74-67). The dimensions of the left ventricle suggested a concentric hypertrophy. Left ventricular systolic or diastolic dysfunction was observed in 11 patients. Holter recording revealed frequent ventricular extrasystoles (>10/h) in five patients. Patients with LVH differed significantly from those without LVH in BEHL0.5-4 kHz, whereas the contribution of age or the degree of the mutant heteroplasmy in skeletal muscle to the risk of LVH was less remarkable. CONCLUSIONS Structural and functional abnormalities of the heart were common in patients with 3243A>G. The risk of LVH was related to the clinical severity of the phenotype, and to a lesser degree to age, suggesting that patients presenting with any symptoms from the mutation should also be evaluated for cardiac abnormalities.
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Affiliation(s)
| | - Keijo Peuhkurinen
- Department of Internal Medicine, University of Kuopio, Kuopio, Finland
| | | | - Ilmo E Hassinen
- Department of Medical Biochemistry and Molecular Biology, University of Oulu, Oulu, Finland
| | - Kari Majamaa
- Department of Medical Biochemistry and Molecular Biology, University of Oulu, Oulu, Finland
- Department of Neurology, University of Oulu, Oulu, Finland
- Biocenter, University of Oulu, Oulu, Finland
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28
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Karadimas C, Tanji K, Geremek M, Chronopoulou P, Vu T, Krishna S, Sue CM, Shanske S, Bonilla E, DiMauro S, Lipson M, Bachman R. A5814G mutation in mitochondrial DNA can cause mitochondrial myopathy and cardiomyopathy. J Child Neurol 2001; 16:531-3. [PMID: 11453453 DOI: 10.1177/088307380101600715] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
We describe a 5-year-old child with hypertrophic cardiomyopathy, mitochondrial myopathy, and lactic acidosis. Mitochondrial DNA analysis showed a heteroplasmic A5814G point mutation in the tRNA(Cys) gene. The mutational load was extremely high (>95%) in muscle, fibroblasts, and blood. This report expands the clinical heterogeneity of the A5814G mutation, which should be considered in the differential diagnosis of hypertrophic cardiomyopathy in childhood.
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Affiliation(s)
- C Karadimas
- Department of Neurology, Columbia University College of Physicians and Surgeons, New York, New York, USA
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Abstract
Since the identification of the first pathogenic mutations of mitochondrial DNA in 1988, a plethora of information about human mitochondrial diseases has been brought to light. Not surprisingly, many of these disorders affect the myocardium, because this tissue relies heavily upon oxidative metabolism. This review focuses on disorders of the respiratory chain, the only area of mammalian cellular metabolism under the control of two genomes, nuclear and mitochondrial. Consequently, defects of aerobic synthesis of adenosine triphosphate (ATP) can be due to mutations of either genome. We describe genetic mitochondrial cardiomyopathies and briefly review mouse models and the mitochondrial theory of presbycardia.
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Affiliation(s)
- M Hirano
- Department of Neurology, Columbia University College of Physicians & Surgeons, New York, New York, USA.
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30
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Abstract
OBJECTIVE Our purpose was to present an updated review on the spectrum of mitochondrial DNA-related syndromes relevant to cardiac disturbances. BACKGROUND The advent of molecular genetics has provided important insight into the mechanisms underlying a variety of inherited heart disorders, including cardiac arrhythmias and cardiomyopathies. These studies pointed to defects in ion channels, contractile proteins, structural proteins, and signaling molecules as key players in disease pathogenesis, and they have opened up new mechanism-based approaches to therapy. RESULTS AND CONCLUSIONS Mitochondrial DNA defects and faulty oxidative phosphorylation are infrequently considered as causes of cardiomyopathies. This is surprising given the heavy dependence of the heart on oxidative metabolism and the recent advances in understanding the molecular features of mitochondrial disorders. This remarkable progress and the implications it may have for more common forms of cardiovascular disease are reviewed.
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Affiliation(s)
- F M Santorelli
- Molecular Medicine, Children's Hospital "Bambino Gesù," the Department of Experimental Medicine and Pathology, and the Istituto di Clinica delle Malattie Nervose e Mentali, La Sapienza University, Rome, Italy
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31
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Brega A, Narula J, Arbustini E. Functional, structural, and genetic mitochondrial abnormalities in myocardial diseases. J Nucl Cardiol 2001; 8:89-97. [PMID: 11182713 DOI: 10.1067/mnc.2001.112755] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Myocardial tissue is highly dependent on energy supplied by normal mitochondrial function. Therefore defects of energy production or utilization affect the heart in both syndromic and isolated disorders. Knowledge of the peculiar structural, functional, and genetic characteristics of mitochondria provides the basis for identification and classification of mitochondrial defects as well as for establishment of a diagnostic workup useful for related cardiac disorders. This review is therefore dedicated to the characteristics of normal mitochondria and the pathologic alterations of these organelles in various cardiovascular diseases.
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Affiliation(s)
- A Brega
- Department of Biology and Genetics for Medical Sciences, University of Milan, Italy
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Deschauer M, Neudecker S, Müller T, Gellerich FN, Zierz S. Higher proportion of mitochondrial A3243G mutation in blood than in skeletal muscle in a patient with cardiomyopathy and hearing loss. Mol Genet Metab 2000; 70:235-7. [PMID: 10924279 DOI: 10.1006/mgme.2000.3002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Phenotypes of individuals with the mitochondrial A3243G mutation and amount of mutant DNA in different tissues can be very variable, but the proportion of mutant DNA was consistantly lower in blood than muscle in previously studied patients. We detected the A3243G mutation in a 54-year-old patient with cardiomyopathy and hearing loss, where the amount of mutant DNA was higher in blood (19%) than in muscle (6%). This shows that the level of A3243G mutation is not always lower in rapidly dividing tissues such as blood than in muscle, as has been presumed until now.
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Affiliation(s)
- M Deschauer
- Department of Neurology, Martin-Luther-Universität Halle-Wittenberg, Ernst-Grube-Str. 40, Halle, D-06097, Germany
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Abstract
The ubiquitous nature of mitochondria, the dual genetic control of the respiratory chain, and the peculiar rules of mitochondrial genetics contribute to explain the extraordinary clinical heterogeneity of disorders associated with defects of oxidative phosphorylation (mitochondrial encephalomyopathies). To provide a practical approach to the diagnostic challenge posed by these conditions, we critically review the following criteria: (1) clinical presentation; (2) family history; (3) laboratory data; (4) neuroradiologic patterns; (5) standardized exercise testing; (6) muscle morphology; (7) muscle biochemistry; and (8) molecular genetic screening. Judicious sequential application of these tools should provide help in recognizing patients with mitochondrial disease and define the biochemical and molecular basis of the disorder for each patient. This knowledge is indispensable for accurate genetic counseling and prenatal diagnosis and is a prerequisite for the development of rational therapies, which are still woefully inadequate.
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Affiliation(s)
- S DiMauro
- Department of Neurology, Columbia University College of Physicians and Surgeons, New York, NY 10032, USA.
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Bauer MF, Gempel K, Hofmann S, Jaksch M, Philbrook C, Gerbitz KD. Mitochondrial disorders. A diagnostic challenge in clinical chemistry. Clin Chem Lab Med 1999; 37:855-76. [PMID: 10596952 DOI: 10.1515/cclm.1999.129] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Mitochondria play a pivotal role in cellular metabolism and in energy production in particular. Defects in structure or function of mitochondria, mainly involving the oxidative phosphorylation (OXPHOS), mitochondrial biogenesis and other metabolic pathways, have been shown to be associated with a wide spectrum of clinical phenotypes. The ubiquitous nature of mitochondria and their unique genetic features contribute to the clinical, biochemical and genetic heterogeneity of mitochondrial diseases. We will focus on the recent advances in the field of mitochondrial disorders and their consequences for an advanced clinical and genetic diagnostics. In addition, an overview on recently identified genetic defects and their pathogenic molecular mechanisms will be given.
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Affiliation(s)
- M F Bauer
- Institute of Clinical Chemistry, Molecular Diagnostics and Mitochondrial Genetics, Diabetes Research Group, Academic Hospital Munich-Schwabing, Germany.
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Bruno C, Kirby DM, Koga Y, Garavaglia B, Duran G, Santorelli FM, Shield LK, Xia W, Shanske S, Goldstein JD, Iwanaga R, Akita Y, Carrara F, Davis A, Zeviani M, Thorburn DR, DiMauro S. The mitochondrial DNA C3303T mutation can cause cardiomyopathy and/or skeletal myopathy. J Pediatr 1999; 135:197-202. [PMID: 10431114 DOI: 10.1016/s0022-3476(99)70022-3] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
OBJECTIVE Several mutations in mitochondrial DNA have been associated with infantile cardiomyopathy, including a C3303T mutation in the mitochondrial transfer RNA(Leu(UUR)) gene. Although this mutation satisfied generally accepted criteria for pathogenicity, its causative role remained to be confirmed in more families. Our objective was to establish the frequency of the C3303T mutation and to define its clinical presentation. STUDY DESIGN Families with cardiomyopathy and maternal inheritance were studied by polymerase chain reaction/restriction fragment length polymorphism analysis looking for the C3303T mutation. RESULTS We found the C3303T mutation in 8 patients from 4 unrelated families. In one, the clinical presentation was infantile cardiomyopathy; in the second family, proximal limb and neck weakness dominated the clinical picture for the first 10 years of life, when cardiac dysfunction became apparent; in the third family, 2 individuals presented with isolated skeletal myopathy and 2 others with skeletal myopathy and cardiomyopathy; in the fourth family, one patient had fatal infantile cardiomyopathy and the other had a combination of skeletal myopathy and cardiomyopathy. CONCLUSIONS Our findings confirm the pathogenicity of the C3303T mutation and suggest that this mutation may not be rare. The C3303T mutation should be considered in the differential diagnosis of skeletal myopathies and cardiomyopathy, especially when onset is in infancy.
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Affiliation(s)
- C Bruno
- The H. Houston Merritt Clinical Research Center for Muscular Dystrophy and Related Diseases, Department of Neurology, Columbia Presbyterian Medical Center, New York, New York, USA
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Chinnery PF, Howell N, Andrews RM, Turnbull DM. Mitochondrial DNA analysis: polymorphisms and pathogenicity. J Med Genet 1999; 36:505-10. [PMID: 10424809 PMCID: PMC1734403] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/13/2023]
Abstract
The investigation of mtDNA disease can be relatively straightforward if a person has a recognisable phenotype and if it is possible to identify a known pathogenic mtDNA mutation. The difficulties arise when no known mtDNA defect can be found, or when the clinical abnormalities are complex and not easily matched to those of the more common mitochondrial disorders. We will describe here the difficulties that can be encountered during the identification of pathogenic mtDNA mutations and the approaches that can be used to confirm, or eliminate, a likely pathogenic role, in either single gene diseases or in multifactorial disorders.
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Affiliation(s)
- P F Chinnery
- Department of Neurology, The University of Newcastle upon Tyne, UK
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Chinnery PF, Howell N, Andrews RM, Turnbull DM. Clinical mitochondrial genetics. J Med Genet 1999; 36:425-36. [PMID: 10874629 PMCID: PMC1734386] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
Abstract
The last decade has been an age of enlightenment as far as mitochondrial pathology is concerned. Well established nuclear genetic diseases, such as Friedreich's ataxia,12 Wilson disease,3 and autosomal recessive hereditary spastic paraplegia,4 have been shown to have a mitochondrial basis, and we are just starting to unravel the complex nuclear genetic disorders which directly cause mitochondrial dysfunction (table 1). However, in addition to the 3 billion base pair nuclear genome, each human cell typically contains thousands of copies of a small, 16.5 kb circular molecule of double stranded DNA (fig 1). Mitochondrial DNA (mtDNA) accounts for only 1% of the total cellular nucleic acid content. It encodes for 13 polypeptides which are essential for aerobic metabolism and defects of the mitochondrial genome are an important cause of human disease.9293 Since the characterisation of the first pathogenic mtDNA defects in 1988,513 over 50 point mutations and well over 100 rearrangements of the mitochondrial genome have been associated with human disease9495 (http://www.gen.emory.edu/mitomap.html). These disorders form the focus of this article.
Keywords: mitochondrial DNA; mitochondrial disease; heteroplasmy; genetic counselling
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Affiliation(s)
- P F Chinnery
- Department of Neurology, University of Newcastle upon Tyne, UK
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Vilarinho L, Santorelli FM, Coelho I, Rodrigues L, Maia M, Barata I, Cabral P, Dionísio A, Costa A, Guimarães A, DiMauro S. The mitochondrial DNA A3243G mutation in Portugal: clinical and molecular studies in 5 families. J Neurol Sci 1999; 163:168-74. [PMID: 10371079 DOI: 10.1016/s0022-510x(99)00030-1] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Out of 90 Portuguese patients with mitochondrial cytopathy, six harbored the A3243G mutation in the mtDNA tRNA(Leu(UUR)) gene ('MELAS mutation'). They had heterogeneous clinical features, including myopathy with stroke-like episodes, progressive external ophthalmoparesis, diabetes mellitus, and subacute encephalopathy. Histochemical and biochemical analyses of muscle biopsies showed abundant ragged-red fibers reacting positively with the cytochrome oxidase stain, and decreased respiratory chain enzyme activities. On average, the proportion of mutated mtDNA was 67% (20-88%) in tissues from patients and 21% (0-49%) in blood from 20 maternal relatives. The proportion of mutated mitochondrial genomes in muscle did not correlate with clinical presentation or duration of disease. This study, the first in Portuguese patients, confirms the frequent occurrence of the A3243G mutation in patients with mitochondrial diseases, and emphasises the usefulness of genetic testing in reaching a correct diagnosis.
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Affiliation(s)
- L Vilarinho
- Department of Clinical Biology, Pr. Pedro Nunes, Instituto de Genética Médica, Porto, Portugal.
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Syndrome MELAS chez un enfant de 5 ans: caractéristiques cliniques, biologiques et génétiques. Arch Pediatr 1998. [DOI: 10.1016/s0929-693x(98)80011-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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