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Microhemorrhages in MELAS Lesions: A Case Report. J Belg Soc Radiol 2022; 106:88. [PMID: 36248725 PMCID: PMC9524292 DOI: 10.5334/jbsr.2891] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Accepted: 09/02/2022] [Indexed: 11/20/2022] Open
Abstract
Introduction: Microhemorrhages have not been described in mitochondrial encephalomyopathy with lactic acidosis and stroke-like episodes syndrome (MELAS) on magnetic resonance imaging (MRI). Main symptoms and/or important findings: A MELAS-patient had a rapid succession of 3 stroke-like episodes with dysphasia, visual field deficits and paresis of the right arm. MRI showed a lesion with corticosubcortical vasogenic edema without reduced diffusion, conforming to a stroke-like MELAS-lesion. Microhemorrhages within MELAS-lesions were detected on MRI. The main diagnoses, therapeutic interventions, and outcomes: Microhemorrhages are an atypical imaging finding in MELAS. The patient was treated with L-arginine. Conclusion: Microhemorrhages can present on MRI in (sub)acute MELAS lesions and may reflect mitochondrial microangiopathy.
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Gonçalves FG, Alves CAPF, Heuer B, Peterson J, Viaene AN, Reis Teixeira S, Martín-Saavedra JS, Andronikou S, Goldstein A, Vossough A. Primary Mitochondrial Disorders of the Pediatric Central Nervous System: Neuroimaging Findings. Radiographics 2021; 40:2042-2067. [PMID: 33136487 DOI: 10.1148/rg.2020200052] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Primary mitochondrial disorders (PMDs) constitute the most common cause of inborn errors of metabolism in children, and they frequently affect the central nervous system. Neuroimaging findings of PMDs are variable, ranging from unremarkable and nonspecific to florid and highly suggestive. An overview of PMDs, including a synopsis of the basic genetic concepts, main clinical symptoms, and neuropathologic features, is presented. In addition, eight of the most common PMDs that have a characteristic imaging phenotype in children are reviewed in detail. Online supplemental material is available for this article. ©RSNA, 2020.
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Affiliation(s)
- Fabrício Guimarães Gonçalves
- From the Department of Radiology, Division of Neuroradiology (F.G.G., C.A.P.F.A., S.R.T., J.S.M.S., S.A., A.V.), Department of Pathology (A.N.V.), and Mitochondrial Medicine Frontier Program, Division of Human Genetics, Department of Pediatrics (B.H., J.P., A.G.), Children's Hospital of Philadelphia, 3401 Civic Center Blvd, Philadelphia, PA 19104-4399; and Departments of Pediatrics (A.G.) and Radiology (S.A., A.V.), University of Pennsylvania Perelman School of Medicine (A.N.V.), Philadelphia, Pa
| | - César Augusto Pinheiro Ferreira Alves
- From the Department of Radiology, Division of Neuroradiology (F.G.G., C.A.P.F.A., S.R.T., J.S.M.S., S.A., A.V.), Department of Pathology (A.N.V.), and Mitochondrial Medicine Frontier Program, Division of Human Genetics, Department of Pediatrics (B.H., J.P., A.G.), Children's Hospital of Philadelphia, 3401 Civic Center Blvd, Philadelphia, PA 19104-4399; and Departments of Pediatrics (A.G.) and Radiology (S.A., A.V.), University of Pennsylvania Perelman School of Medicine (A.N.V.), Philadelphia, Pa
| | - Beth Heuer
- From the Department of Radiology, Division of Neuroradiology (F.G.G., C.A.P.F.A., S.R.T., J.S.M.S., S.A., A.V.), Department of Pathology (A.N.V.), and Mitochondrial Medicine Frontier Program, Division of Human Genetics, Department of Pediatrics (B.H., J.P., A.G.), Children's Hospital of Philadelphia, 3401 Civic Center Blvd, Philadelphia, PA 19104-4399; and Departments of Pediatrics (A.G.) and Radiology (S.A., A.V.), University of Pennsylvania Perelman School of Medicine (A.N.V.), Philadelphia, Pa
| | - James Peterson
- From the Department of Radiology, Division of Neuroradiology (F.G.G., C.A.P.F.A., S.R.T., J.S.M.S., S.A., A.V.), Department of Pathology (A.N.V.), and Mitochondrial Medicine Frontier Program, Division of Human Genetics, Department of Pediatrics (B.H., J.P., A.G.), Children's Hospital of Philadelphia, 3401 Civic Center Blvd, Philadelphia, PA 19104-4399; and Departments of Pediatrics (A.G.) and Radiology (S.A., A.V.), University of Pennsylvania Perelman School of Medicine (A.N.V.), Philadelphia, Pa
| | - Angela N Viaene
- From the Department of Radiology, Division of Neuroradiology (F.G.G., C.A.P.F.A., S.R.T., J.S.M.S., S.A., A.V.), Department of Pathology (A.N.V.), and Mitochondrial Medicine Frontier Program, Division of Human Genetics, Department of Pediatrics (B.H., J.P., A.G.), Children's Hospital of Philadelphia, 3401 Civic Center Blvd, Philadelphia, PA 19104-4399; and Departments of Pediatrics (A.G.) and Radiology (S.A., A.V.), University of Pennsylvania Perelman School of Medicine (A.N.V.), Philadelphia, Pa
| | - Sara Reis Teixeira
- From the Department of Radiology, Division of Neuroradiology (F.G.G., C.A.P.F.A., S.R.T., J.S.M.S., S.A., A.V.), Department of Pathology (A.N.V.), and Mitochondrial Medicine Frontier Program, Division of Human Genetics, Department of Pediatrics (B.H., J.P., A.G.), Children's Hospital of Philadelphia, 3401 Civic Center Blvd, Philadelphia, PA 19104-4399; and Departments of Pediatrics (A.G.) and Radiology (S.A., A.V.), University of Pennsylvania Perelman School of Medicine (A.N.V.), Philadelphia, Pa
| | - Juan Sebastián Martín-Saavedra
- From the Department of Radiology, Division of Neuroradiology (F.G.G., C.A.P.F.A., S.R.T., J.S.M.S., S.A., A.V.), Department of Pathology (A.N.V.), and Mitochondrial Medicine Frontier Program, Division of Human Genetics, Department of Pediatrics (B.H., J.P., A.G.), Children's Hospital of Philadelphia, 3401 Civic Center Blvd, Philadelphia, PA 19104-4399; and Departments of Pediatrics (A.G.) and Radiology (S.A., A.V.), University of Pennsylvania Perelman School of Medicine (A.N.V.), Philadelphia, Pa
| | - Savvas Andronikou
- From the Department of Radiology, Division of Neuroradiology (F.G.G., C.A.P.F.A., S.R.T., J.S.M.S., S.A., A.V.), Department of Pathology (A.N.V.), and Mitochondrial Medicine Frontier Program, Division of Human Genetics, Department of Pediatrics (B.H., J.P., A.G.), Children's Hospital of Philadelphia, 3401 Civic Center Blvd, Philadelphia, PA 19104-4399; and Departments of Pediatrics (A.G.) and Radiology (S.A., A.V.), University of Pennsylvania Perelman School of Medicine (A.N.V.), Philadelphia, Pa
| | - Amy Goldstein
- From the Department of Radiology, Division of Neuroradiology (F.G.G., C.A.P.F.A., S.R.T., J.S.M.S., S.A., A.V.), Department of Pathology (A.N.V.), and Mitochondrial Medicine Frontier Program, Division of Human Genetics, Department of Pediatrics (B.H., J.P., A.G.), Children's Hospital of Philadelphia, 3401 Civic Center Blvd, Philadelphia, PA 19104-4399; and Departments of Pediatrics (A.G.) and Radiology (S.A., A.V.), University of Pennsylvania Perelman School of Medicine (A.N.V.), Philadelphia, Pa
| | - Arastoo Vossough
- From the Department of Radiology, Division of Neuroradiology (F.G.G., C.A.P.F.A., S.R.T., J.S.M.S., S.A., A.V.), Department of Pathology (A.N.V.), and Mitochondrial Medicine Frontier Program, Division of Human Genetics, Department of Pediatrics (B.H., J.P., A.G.), Children's Hospital of Philadelphia, 3401 Civic Center Blvd, Philadelphia, PA 19104-4399; and Departments of Pediatrics (A.G.) and Radiology (S.A., A.V.), University of Pennsylvania Perelman School of Medicine (A.N.V.), Philadelphia, Pa
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Aras S, Purandare N, Gladyck S, Somayajulu-Nitu M, Zhang K, Wallace DC, Grossman LI. Mitochondrial Nuclear Retrograde Regulator 1 (MNRR1) rescues the cellular phenotype of MELAS by inducing homeostatic mechanisms. Proc Natl Acad Sci U S A 2020; 117:32056-32065. [PMID: 33257573 PMCID: PMC7749287 DOI: 10.1073/pnas.2005877117] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
MNRR1 (CHCHD2) is a bi-organellar regulator of mitochondrial function that directly activates cytochrome c oxidase in the mitochondria and functions in the nucleus as a transcriptional activator for hundreds of genes. Since MNRR1 depletion contains features of a mitochondrial disease phenotype, we evaluated the effects of forced expression of MNRR1 on the mitochondrial disease MELAS (mitochondrial encephalomyopathy, lactic acidosis and stroke-like episodes) syndrome. MELAS is a multisystem encephalomyopathy disorder that can result from a heteroplasmic mutation in the mitochondrial DNA (mtDNA; m.3243A > G) at heteroplasmy levels of ∼50 to 90%. Since cybrid cell lines with 73% m.3243A > G heteroplasmy (DW7) display a significant reduction in MNRR1 levels compared to the wild type (0% heteroplasmy) (CL9), we evaluated the effects of MNRR1 levels on mitochondrial functioning. Overexpression of MNRR1 in DW7 cells induces the mitochondrial unfolded protein response (UPRmt), autophagy, and mitochondrial biogenesis, thereby rescuing the mitochondrial phenotype. It does so primarily as a transcription activator, revealing this function to be a potential therapeutic target. The role of MNRR1 in stimulating UPRmt, which is blunted in MELAS cells, was surprising and further investigation uncovered that under conditions of stress the import of MNRR1 into the mitochondria was blocked, allowing the protein to accumulate in the nucleus to enhance its transcription function. In the mammalian system, ATF5, has been identified as a mediator of UPRmt MNRR1 knockout cells display an ∼40% reduction in the protein levels of ATF5, suggesting that MNRR1 plays an important role upstream of this known mediator of UPRmt.
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Affiliation(s)
- Siddhesh Aras
- Center for Molecular Medicine and Genetics, Wayne State University School of Medicine, Detroit, MI 48201
| | - Neeraja Purandare
- Center for Molecular Medicine and Genetics, Wayne State University School of Medicine, Detroit, MI 48201
| | - Stephanie Gladyck
- Center for Molecular Medicine and Genetics, Wayne State University School of Medicine, Detroit, MI 48201
| | - Mallika Somayajulu-Nitu
- Center for Molecular Medicine and Genetics, Wayne State University School of Medicine, Detroit, MI 48201
| | - Kezhong Zhang
- Center for Molecular Medicine and Genetics, Wayne State University School of Medicine, Detroit, MI 48201
| | - Douglas C Wallace
- Center for Mitochondrial and Epigenomic Medicine, Children's Hospital of Philadelphia Research Institute, Philadelphia, PA 19104;
- Department of Pediatrics, Division of Human Genetics, The Children's Hospital of Philadelphia, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104
| | - Lawrence I Grossman
- Center for Molecular Medicine and Genetics, Wayne State University School of Medicine, Detroit, MI 48201;
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Haemorrhagic Transformation of a MELAS Stroke-Like Lesion. Can J Neurol Sci 2020; 47:117-118. [DOI: 10.1017/cjn.2019.317] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Mitochondrial encephalomyopathy, lactic acidosis and stroke-like episodes (MELAS) is a rare progressive maternally inherited mitochondrial disease that clinically harbours various neurological and systemic manifestations.
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Kalashnikova LA, Dobrynina LA, Dreval MV, Gubanova MV, Krotenkova MV, Konovalov RN, Legenko MS. [Intracerebral hemorrhage in the late period of internal carotid artery dissection]. Zh Nevrol Psikhiatr Im S S Korsakova 2019; 119:28-34. [PMID: 31825359 DOI: 10.17116/jnevro201911908228] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Cervical artery dissection is the common cause of ischemic stroke in young and middle-age patients. According to our previous studies, dissection is related to arterial wall dysplastic changes, which in their turn are due to mitochondrial cytopathy. The authors describe three male patients who at the age of 53, 25 and 35 years underwent internal artery (ICA) dissection with occlusion of its lumen and subsequent recanalization in one of them. In 3.5 months, 13.5 years and 3 years respectively, patients developed intracerebral hemorrhage (IСH), which was not related to arterial hypertension, cerebral arterial aneurysms and anticoagulants. IСH were located on the side of ICA occluded after dissection (2 patients) or bilaterally in the territory of patent ICA (1 patient). Multivoxel 1H-MR spectroscopy performed in one patient on 40 and 48 days after ICH revealed a high lactate peak in the externally unchanged hemispheric white matter. It is assumed that mitochondrial cytopathy in patients with dissection may involve large as well as small intracerebral arteries (mitochondrial microangiopathy), which could be the cause of ICH.
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Affiliation(s)
| | | | - M V Dreval
- Research Center of Nevrology, Moscow, Russia
| | | | | | | | - M S Legenko
- Research Center of Nevrology, Moscow, Russia
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Finsterer J. Cerebral imaging in adult mitochondrial disorders. J Neurol Sci 2019; 404:29-35. [PMID: 31323519 DOI: 10.1016/j.jns.2019.07.013] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2019] [Revised: 06/06/2019] [Accepted: 07/09/2019] [Indexed: 01/15/2023]
Abstract
OBJECTIVES Among the organs/tissues affected in mitochondrial disorders (MIDs), the brain is the second most frequently affected. Cerebral imaging may correlate with clinical findings but not necessarily. This review summarises and discusses current knowledge and recent advances concerning cerebral abnormalities on imaging in adult MIDs (≥18y). METHODS Systematic literature review. RESULTS The most common cerebral abnormalities in imaging in adult MIDs are, as in pediatric MIDs, white matter lesions, grey matter lesions, atrophy, optic atrophy, stroke-like lesions, calcifications, and ischemic stroke. Cerebral lesions may remain stable over years but some may undergo dynamic changes within shorter or longer period of times. Typical dynamic lesions are stroke-like lesions and grey matter lesions in the sense of progression or regression. Since cerebral lesions on imaging may or may not go along with clinical manifestations, it is crucial to screen all MID patients for cerebral involvement, which can be effectively accomplished by application of the MRI. CONCLUSIONS Cerebral imaging is of paramount importance for diagnosing and monitoring cerebral involvement in MIDs. Cerebral imaging in MIDs contributes to the understanding of the pathogenesis of cerebral involvement in MIDs.
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Affiliation(s)
- Josef Finsterer
- Krankenanstalt Rudolfstiftung, Messerli Institute, Postfach 20, 1180 Vienna, Austria.
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Cruz ACP, Ferrasa A, Muotri AR, Herai RH. Frequency and association of mitochondrial genetic variants with neurological disorders. Mitochondrion 2018; 46:345-360. [PMID: 30218715 DOI: 10.1016/j.mito.2018.09.005] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2018] [Revised: 08/24/2018] [Accepted: 09/11/2018] [Indexed: 12/17/2022]
Abstract
Mitochondria are small cytosolic organelles and the main source of energy production for the cells, especially in the brain. This organelle has its own genome, the mitochondrial DNA (mtDNA), and genetic variants in this molecule can alter the normal energy metabolism in the brain, contributing to the development of a wide assortment of Neurological Disorders (ND), including neurodevelopmental syndromes, neurodegenerative diseases and neuropsychiatric disorders. These ND are comprised by a heterogeneous group of syndromes and diseases that encompass different cognitive phenotypes and behavioral disorders, such as autism, Asperger's syndrome, pervasive developmental disorder, attention deficit hyperactivity disorder, Huntington disease, Leigh Syndrome and bipolar disorder. In this work we carried out a Systematic Literature Review (SLR) to identify and describe the mitochondrial genetic variants associated with the occurrence of ND. Most of genetic variants found in mtDNA were associated with Single Nucleotide Polimorphisms (SNPs), ~79%, with ~15% corresponding to deletions, ~3% to Copy Number Variations (CNVs), ~2% to insertions and another 1% included mtDNA replication problems and genetic rearrangements. We also found that most of the variants were associated with coding regions of mitochondrial proteins but were also found in regulatory transcripts (tRNA and rRNA) and in the D-Loop replication region of the mtDNA. After analysis of mtDNA deletions and CNV, none of them occur in the D-Loop region. This SLR shows that all transcribed mtDNA molecules have mutations correlated with ND. Finally, we describe that all mtDNA variants found were associated with deterioration of cognitive (dementia) and intellectual functions, learning disabilities, developmental delays, and personality and behavior problems.
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Affiliation(s)
- Ana Carolina P Cruz
- Experimental Multiuser Laboratory (LEM), Graduate Program in Health Sciences (PPGCS), School of Medicine (PPGCS), Pontifícia Universidade Católica do Paraná (PUCPR), Curitiba, Paraná 80215-901, Brazil
| | - Adriano Ferrasa
- Experimental Multiuser Laboratory (LEM), Graduate Program in Health Sciences (PPGCS), School of Medicine (PPGCS), Pontifícia Universidade Católica do Paraná (PUCPR), Curitiba, Paraná 80215-901, Brazil; Department of Informatics (DEINFO), Universidade Estadual de Ponta Grossa (UEPG), Ponta Grossa, Paraná 84030-900, Brazil
| | - Alysson R Muotri
- University of California San Diego, School of Medicine, Department of Pediatrics/Rady Children's Hospital San Diego, Department of Cellular & Molecular Medicine, Stem Cell Program, La Jolla, CA 92037-0695, USA
| | - Roberto H Herai
- Experimental Multiuser Laboratory (LEM), Graduate Program in Health Sciences (PPGCS), School of Medicine (PPGCS), Pontifícia Universidade Católica do Paraná (PUCPR), Curitiba, Paraná 80215-901, Brazil; Lico Kaesemodel Institute (ILK), Curitiba, Paraná 80240-000, Brazil.
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Selim L, Mehaney D. Mitochondrial encephalopathy with lactic acidosis and stroke-like episodes in a Japanese child: Clinical, radiological and molecular genetic analysis. EGYPTIAN JOURNAL OF MEDICAL HUMAN GENETICS 2013. [DOI: 10.1016/j.ejmhg.2013.03.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
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Sofou K, Steneryd K, Wiklund LM, Tulinius M, Darin N. MRI of the brain in childhood-onset mitochondrial disorders with central nervous system involvement. Mitochondrion 2013; 13:364-71. [DOI: 10.1016/j.mito.2013.04.008] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2012] [Revised: 04/10/2013] [Accepted: 04/18/2013] [Indexed: 11/28/2022]
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Iommarini L, Calvaruso MA, Kurelac I, Gasparre G, Porcelli AM. Complex I impairment in mitochondrial diseases and cancer: Parallel roads leading to different outcomes. Int J Biochem Cell Biol 2013; 45:47-63. [DOI: 10.1016/j.biocel.2012.05.016] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2012] [Revised: 05/03/2012] [Accepted: 05/24/2012] [Indexed: 02/06/2023]
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Mutations in mitochondrially encoded complex I enzyme as the second common cause in a cohort of Chinese patients with mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes. J Hum Genet 2011; 56:759-64. [DOI: 10.1038/jhg.2011.96] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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12
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Chi CS, Lee HF, Tsai CR, Chen CCC, Tung JN. Cranial magnetic resonance imaging findings in children with nonsyndromic mitochondrial diseases. Pediatr Neurol 2011; 44:171-6. [PMID: 21310331 DOI: 10.1016/j.pediatrneurol.2010.09.009] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/29/2010] [Revised: 08/18/2010] [Accepted: 09/22/2010] [Indexed: 11/29/2022]
Abstract
Cranial magnetic resonance imaging findings suggestive of specific mitochondrial syndromes are reported. However, cranial magnetic resonance imaging features in children with nonsyndromic mitochondrial diseases are rarely described. From January 1992-September 2009, data from 33 patients with nonsyndromic mitochondrial diseases were collected. We investigated cranial magnetic resonance imaging features in children with nonsyndromic mitochondrial diseases, and identified potential diagnostic characteristics. Eleven of 33 patients (33.3%) demonstrated normal findings, and 22 (66.7%) demonstrated abnormal findings. The most common abnormal finding was cerebral atrophy, with or without other lesion sites (15/33; 45.5%). The second most common was bilateral basal ganglia involvement (6/33; 18.2%). Follow-up imaging was performed in 20 patients. Ten of these 20 (50.0%) demonstrated evolutionary changes, in which progressive global brain atrophy was evident. Three patients with normal results and one patient with cerebral atrophy on initial imaging demonstrated prominent signal changes over the basal ganglia, brainstem, gray matter, white matter, and bilateral cerebellar hemispheres on follow-up imaging. Imaging in children with nonsyndromic mitochondrial diseases may produce variable findings. Normal results and cerebral atrophy on the initial cranial magnetic resonance imaging are commonly evident in this patient group.
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Affiliation(s)
- Ching-Shiang Chi
- Department of Pediatrics, Tungs' Taichung Metroharbor Hospital, Taichung, Taiwan
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Saracchi E, Tremolizzo L, DiFrancesco JC, Brighina L, Costantino G, Frigeni B, Brioschi M, Piatti ML, Fumagalli L, Marzorati L, Curtò NA, Ferrarese C. Cerebellar hematoma in a carrier of the A3243G MELAS mutation. Neurol Sci 2011; 32:365-6. [PMID: 21327397 DOI: 10.1007/s10072-011-0493-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2010] [Accepted: 02/03/2011] [Indexed: 11/29/2022]
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14
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Hsieh YT, Yang MT, Peng YJ, Hsu WC. Central retinal vein occlusion as the initial manifestation of LHON / MELAS overlap syndrome with mitochondrial DNA G13513A mutation—Case report and literature review. Ophthalmic Genet 2010; 32:31-8. [DOI: 10.3109/13816810.2010.531880] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Wang Z, Qi XK, Yao S, Chen B, Luan X, Zhang W, Han M, Yuan Y. Phenotypic patterns of MELAS/LS overlap syndrome associated with m.13513G>A mutation, and neuropathological findings in one autopsy case. Neuropathology 2010; 30:606-14. [DOI: 10.1111/j.1440-1789.2010.01115.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Abstract
More than 200 disease-related mitochondrial DNA (mtDNA) point mutations have been reported in the Mitomap (http://www.mitomap.org) database. These mutations can be divided into two groups: mutations affecting mitochondrial protein synthesis, including mutations in tRNA and rRNA genes; and mutations in protein-encoding genes (mRNAs). This review focuses on mutations in mitochondrial genes that encode proteins. These mutations are involved in a broad spectrum of human diseases, including a variety of multisystem disorders as well as more tissue-specific diseases such as isolated myopathy and Leber hereditary optic neuropathy (LHON). Because the mitochondrial genome contains a large number of apparently neutral polymorphisms that have little pathogenic significance, along with secondary homoplasmic mutations that do not have primary disease-causing effect, the pathogenic role of all newly discovered mutations must be rigorously established. A scoring system has been applied to evaluate the pathogenicity of the mutations in mtDNA protein-encoding genes and to review the predominant clinical features and the molecular characteristics of mutations in each mtDNA-encoded respiratory chain complex.
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Affiliation(s)
- Lee-Jun C Wong
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, NAB2015, Houston, Texas 77030, USA.
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Blok MJ, Spruijt L, de Coo IFM, Schoonderwoerd K, Hendrickx A, Smeets HJ. Mutations in the ND5 subunit of complex I of the mitochondrial DNA are a frequent cause of oxidative phosphorylation disease. J Med Genet 2007; 44:e74. [PMID: 17400793 PMCID: PMC2598042 DOI: 10.1136/jmg.2006.045716] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
BACKGROUND Detection of mutations in the mitochondrial DNA (mtDNA) is usually limited to common mutations and the transfer RNA genes. However, mutations in other mtDNA regions can be an important cause of oxidative phosphorylation (OXPHOS) disease as well. OBJECTIVE To investigate whether regions in the mtDNA are preferentially mutated in patients with OXPHOS disease. METHODS Screening of the mtDNA for heteroplasmic mutations was performed by denaturing high-performance liquid chromatography analysis of 116 patients with OXPHOS disease but without the common mtDNA mutations. RESULTS An mtDNA sequence variant was detected in 15 patients, 5 of which were present in the ND5 gene. One sequence variant was new and three were known, one of which was found twice. The novel sequence variant m.13511A-->T occurred in a patient with a Leigh-like syndrome. The known mutation m.13513G-->A, associated with mitochondrial encephalomyopathy lactic acidosis and stroke-like syndrome (MELAS) and MELAS/Leigh/Leber hereditary optic neuropathy overlap syndrome, was found in a relatively low percentage in two patients from two different families, one with a MELAS/Leigh phenotype and one with a MELAS/chronic progressive external ophthalmoplegia phenotype. The known mutation m.13042G-->A, detected previously in a patient with a MELAS/myoclonic epilepsy, ragged red fibres phenotype and in a family with a prevalent ocular phenotype, was now found in a patient with a Leigh-like phenotype. The sequence variant m.12622G-->A was reported once in a control database as a polymorphism, but is reported in this paper as heteroplasmic in three brothers, all with infantile encephalopathy (Leigh syndrome) fatal within the first 15 days of life. Therefore, a causal relationship between the presence of this sequence variant and the onset of mitochondrial disease cannot be entirely excluded at this moment. CONCLUSIONS Mutation screening of the ND5 gene is advised for routine diagnostics of patients with OXPHOS disease, especially for those with MELAS- and Leigh-like syndrome with a complex I deficiency.
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Affiliation(s)
- M J Blok
- Department of Clinical Genetics, University Hospital, Maastricht, The Netherlands.
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Ruiter EM, Siers MH, van den Elzen C, van Engelen BG, Smeitink JAM, Rodenburg RJ, Hol FA. The mitochondrial 13513G > A mutation is most frequent in Leigh syndrome combined with reduced complex I activity, optic atrophy and/or Wolff-Parkinson-White. Eur J Hum Genet 2006; 15:155-61. [PMID: 17106447 DOI: 10.1038/sj.ejhg.5201735] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
The m.13513G > A transition in the mitochondrial gene encoding the ND5 subunit of respiratory chain complex I, can cause mitochondrial encephalomyopathy with lactic acidosis and stroke-like episodes (MELAS) and has been reported to be a frequent cause of Leigh syndrome (LS). We determined the frequency of the mutation in a cohort of 123 patients with reduced complex I activity in muscle (n = 113) or fibroblast (n = 10) tissue. We describe a Pyrosequencing assay for rapid detection and quantification of the m.13513G > A mutation. Two patients with the mutation were identified; both had LS, optical atrophy and a Wolff-Parkinson-White Syndrome (WPWS)-like cardiac conduction defect. The clinical presentation of the m.13513G > A mutation is discussed. We conclude that the m.13513G > A mutation seems not as frequent as previously suggested and is most likely to be present in patients with Leigh (-like) syndrome combined with a complex I deficiency, optic atrophy and/ or WPWS. In addition, we confirmed that the adjacent m.13514A > G mutation is a rare cause of LS or MELAS since no cases with this transition were found.
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Affiliation(s)
- E Mariken Ruiter
- Radboud University Nijmegen Medical Centre, Department of Human Genetics, Nijmegen, The Netherlands.
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19
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Abstract
The central nervous system (CNS) is, after the peripheral nervous system, the second most frequently affected organ in mitochondrial disorders (MCDs). CNS involvement in MCDs is clinically heterogeneous, manifesting as epilepsy, stroke-like episodes, migraine, ataxia, spasticity, extrapyramidal abnormalities, bulbar dysfunction, psychiatric abnormalities, neuropsychological deficits, or hypophysial abnormalities. CNS involvement is found in syndromic and non-syndromic MCDs. Syndromic MCDs with CNS involvement include mitochondrial encephalomyopathy, lactacidosis, stroke-like episodes syndrome, myoclonic epilepsy and ragged red fibers syndrome, mitochondrial neuro-gastrointestinal encephalomyopathy syndrome, neurogenic muscle weakness, ataxia, and retinitis pigmentosa syndrome, mitochondrial depletion syndrome, Kearns-Sayre syndrome, and Leigh syndrome, Leber's hereditary optic neuropathy, Friedreich's ataxia, and multiple systemic lipomatosis. As CNS involvement is often subclinical, the CNS including the spinal cord should be investigated even in the absence of overt clinical CNS manifestations. CNS investigations comprise the history, clinical neurological examination, neuropsychological tests, electroencephalogram, cerebral computed tomography scan, and magnetic resonance imaging. A spinal tap is indicated if there is episodic or permanent impaired consciousness or in case of cognitive decline. More sophisticated methods are required if the CNS is solely affected. Treatment of CNS manifestations in MCDs is symptomatic and focused on epilepsy, headache, lactacidosis, impaired consciousness, confusion, spasticity, extrapyramidal abnormalities, or depression. Valproate, carbamazepine, corticosteroids, acetyl salicylic acid, local and volatile anesthetics should be applied with caution. Avoiding certain drugs is often more beneficial than application of established, apparently indicated drugs.
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Affiliation(s)
- J Finsterer
- Krankenanstalt Rudolfstiftung, Vienna, Austria.
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20
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van Eijsden RGE, Gerards M, Eijssen LMT, Hendrickx ATM, Jongbloed RJE, Wokke JHJ, Hintzen RQ, Rubio-Gozalbo ME, De Coo IFM, Briem E, Tiranti V, Smeets HJM. Chip-based mtDNA mutation screening enables fast and reliable genetic diagnosis of OXPHOS patients. Genet Med 2006; 8:620-7. [PMID: 17079878 DOI: 10.1097/01.gim.0000237782.94878.05] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
PURPOSE Oxidative phosphorylation is under dual genetic control of the nuclear and the mitochondrial DNA (mtDNA). Oxidative phosphorylation disorders are clinically and genetically heterogeneous, which makes it difficult to determine the genetic defect, and symptom-based protocols which link clinical symptoms directly to a specific gene or mtDNA mutation are falling short. Moreover, approximately 25% of the pediatric patients with oxidative phosphorylation disorders is estimated to have mutations in the mtDNA and a standard screening approach for common mutations and deletions will only explain part of these cases. Therefore, we tested a new CHIP-based screening method for the mtDNA. METHODS MitoChip (Affymetrix) resequencing was performed on three test samples and on 28 patient samples. RESULTS Call rates were 94% on average and heteroplasmy detection levels varied from 5-50%. A genetic diagnosis can be made in almost one-quarter of the patients at a potential output of 8 complete mtDNA sequences every 4 days. Moreover, a number of potentially pathogenic unclassified variants (UV) were detected. CONCLUSIONS The availability of long-range PCR protocols and the predominance of single nucleotide substitutions in the mtDNA make the resequencing CHIP a very fast and reliable method to screen the complete mtDNA for mutations.
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Affiliation(s)
- Rudy G E van Eijsden
- Department of Clinical Genetics, Maastricht University, Maastricht, The Netherlands
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21
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Valentino ML, Barboni P, Rengo C, Achilli A, Torroni A, Lodi R, Tonon C, Barbiroli B, Fortuna F, Montagna P, Baruzzi A, Carelli V. The 13042G --> A/ND5 mutation in mtDNA is pathogenic and can be associated also with a prevalent ocular phenotype. J Med Genet 2006; 43:e38. [PMID: 16816025 PMCID: PMC2564567 DOI: 10.1136/jmg.2005.037507] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2005] [Revised: 12/12/2005] [Accepted: 12/13/2005] [Indexed: 01/08/2023]
Abstract
BACKGROUND Overlapping phenotypes including LHON, MELAS, and Leigh syndrome have recently been associated with numerous mtDNA point mutations in the ND5 gene of complex I, now considered a mutational hot spot. OBJECTIVE To identify the mtDNA defect in a family with a prevalent ocular phenotype, including LHON-like optic neuropathy, retinopathy, and cataract, but characterised also by strokes, early deaths, and miscarriages on the maternal line. RESULTS Sequencing of the entire mitochondrial genome from the proband's muscle DNA identified the heteroplasmic 13042G-->A transition, which was previously described only once in a patient with a different mitochondrial disease. This mutation fulfils the major pathogenic criteria, inducing an amino acid change (A236T) at an invariant position in a highly conserved domain of the ND5 gene. Phosphorus magnetic resonance spectroscopy in the proband disclosed an in vivo brain and skeletal muscle energy metabolism deficit. CONCLUSIONS These findings conclusively establish the pathogenic role of the 13042G-->A mutation and underscore its variable clinical expression.
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Affiliation(s)
- M L Valentino
- Dipartimento di Scienze Neurologiche, Università di Bologna, Via Ugo Foscolo 7, 40123, Bologna, Italy
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22
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Bai Y, Park JS, Deng JH, Li Y, Hu P. Restoration of Mitochondrial Function in Cells with Complex I Deficiency. Ann N Y Acad Sci 2006; 1042:25-35. [PMID: 15965042 DOI: 10.1196/annals.1338.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The mammalian mitochondrial NADH dehydrogenase (complex I) is the major entry point for the electron transport chain. It is the largest and most complicated respiratory complex consisting of at least 46 subunits, 7 of which are encoded by mitochondrial DNA (mtDNA). Deficiency in complex I function has been associated with various human diseases including neurodegenerative diseases and the aging process. To explore ways to restore mitochondrial function in complex I-deficient cells, various cell models with mutations in genes encoding subunits for complex I have been established. In this paper, we discuss various approaches to recover mitochondrial activity, the complex I activity in particular, in cultured cells.
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Affiliation(s)
- Yidong Bai
- Department of Cellular and Structural Biology, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA.
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23
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Dickerson BC, Holtzman D, Grant PE, Tian D. Case records of the Massachusetts General Hospital. Case 36-2005. A 61-year-old woman with seizure, disturbed gait, and altered mental status. N Engl J Med 2005; 353:2271-80. [PMID: 16306525 DOI: 10.1056/nejmcpc059032] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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24
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Kato H, Uchigata M, Iijima M, Shimizu S, Nonaka I, Goto Y. Fatal cerebral hemorrhage in mitochondrial encephalomyopathy. J Neurol 2005; 253:529-30. [PMID: 16283102 DOI: 10.1007/s00415-005-0010-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2005] [Revised: 07/14/2005] [Accepted: 08/03/2005] [Indexed: 10/25/2022]
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25
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Auré K, Jardel C, Lombès A. Les maladies mitochondriales : mécanismes moléculaires, principaux cadres cliniques et approches diagnostiques. Ann Pathol 2005; 25:270-81. [PMID: 16327653 DOI: 10.1016/s0242-6498(05)80131-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Mitochondrial diseases are relatively common inherited metabolic diseases due to mitochondrial respiratory chain dysfunction. Their clinical presentation is extremely diverse, multisystemic or confined to a single tissue, sporadic or transmitted, by maternal or mendelian inheritance. The diagnosis of mitochondrial disorders is difficult. It is based upon several types of clues both clinical (family history, type of symptoms but also their association in syndromic presentation,...) and biological (alteration of the lactate metabolism, brain imaging, morphological alterations especially of muscle tissue). The diagnosis relies upon the demonstration of a defect of the respiratory chain activities and/or upon the identification of the underlying genetic alteration. Molecular diagnosis remains quite difficult and up to-date concerns essentially mitochondrial DNA mutations. On one hand, clinical and biological presentations as well as enzymatic defects lack specificity. On the other hand, candidate genes are very numerous and part of them are probably still unknown.
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Affiliation(s)
- Karine Auré
- Unité INSERM 582, Institut de Myologie, Laboratoire de Biochimie, Hôpital Pitié Salpêtrière, Paris
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26
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DiMauro S, Hirano M. Mitochondrial encephalomyopathies: an update. Neuromuscul Disord 2005; 15:276-86. [PMID: 15792866 DOI: 10.1016/j.nmd.2004.12.008] [Citation(s) in RCA: 115] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2004] [Revised: 12/10/2004] [Accepted: 12/10/2004] [Indexed: 01/10/2023]
Abstract
A genetic classification of the mitochondrial encephalomyopathies includes disorders due to defects of mitochondrial DNA (mtDNA) and disorders due to defects of nuclear DNA (nDNA). Recent progress in mtDNA-related diseases includes: (i) new pathogenic mutations in protein-coding genes, especially those encoding subunits of complex I (ND genes); (ii) the pathogenic nature of homoplasmic mutations, whose expression is regulated by environmental and genetic factors; (iii) increasing interest in the functional and pathophysiological role of haplotypes. Advances in mendelian mitochondrial diseases include: (i) new mutations in genes for complex I subunits; (ii) identification of new mutant ancillary proteins associated with complex IV and complex V deficiencies; (iii) better molecular understanding of disorders due to faulty intergenomic communication, which are associated with multiple mtDNA deletions, mtDNA depletion, or defects of mtDNA translation; (iv) the pathogenic role of alterations of the inner mitochondrial membrane phospholipid components, especially cardiolipin; (v) the emerging importance of defects in mitochondrial motility, fission, or fusion.
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Affiliation(s)
- Salvatore DiMauro
- Department of Neurology, Columbia University Medical Center, College of Physicians and Surgeons, Room 4-420, 630 West 168th Street, New York, NY 10032, USA.
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27
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Thorburn DR, Sugiana C, Salemi R, Kirby DM, Worgan L, Ohtake A, Ryan MT. Biochemical and molecular diagnosis of mitochondrial respiratory chain disorders. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2005; 1659:121-8. [PMID: 15576043 DOI: 10.1016/j.bbabio.2004.08.006] [Citation(s) in RCA: 84] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/2004] [Revised: 08/16/2004] [Accepted: 08/16/2004] [Indexed: 12/25/2022]
Abstract
Biochemical diagnosis of mitochondrial respiratory chain disorders requires caution to avoid misdiagnosis of secondary enzyme defects, and can be improved by the use of conservative diagnostic criteria. Pathogenic mutations causing mitochondrial disorders have now been identified in more than 30 mitochondrial DNA (mtDNA) genes encoding respiratory chain subunits, ribosomal- and t-RNAs. mtDNA mutations appear to be responsible for most adult patients with mitochondrial disease and approximately a quarter of paediatric patients. A family history suggesting maternal inheritance is the exception rather than the norm for children with mtDNA mutations, many of whom have de novo mutations. Prenatal diagnosis and pre-implantation genetic diagnosis can be offered to some women at risk of transmitting a mtDNA mutation, particularly those at lower recurrence risk. Mutations in more than 30 nuclear genes, including those encoding for respiratory chain subunits and assembly factors, have now been shown to cause mitochondrial disorders, creating difficulties in prioritising which genes should be studied by mutation analysis in individual patients. A number of approaches offer promise to guide the choice of candidate genes, including Blue Native-PAGE immunoblotting and microarray expression analysis.
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Affiliation(s)
- David R Thorburn
- Murdoch Children's Research Institute, Royal Children's Hospital, Melbourne, Victoria 3052 Australia.
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28
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Bugiani M, Invernizzi F, Alberio S, Briem E, Lamantea E, Carrara F, Moroni I, Farina L, Spada M, Donati MA, Uziel G, Zeviani M. Clinical and molecular findings in children with complex I deficiency. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2005; 1659:136-47. [PMID: 15576045 DOI: 10.1016/j.bbabio.2004.09.006] [Citation(s) in RCA: 207] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2004] [Revised: 09/11/2004] [Accepted: 09/13/2004] [Indexed: 12/22/2022]
Abstract
Isolated complex I deficiency, the most frequent OXPHOS disorder in infants and children, is genetically heterogeneous. Mutations have been found in seven mitochondrial DNA (mtDNA) and eight nuclear DNA encoded subunits, respectively, but in most of the cases the genetic basis of the biochemical defect is unknown. We analyzed the entire mtDNA and 11 nuclear encoded complex I subunits in 23 isolated complex I-deficient children, classified into five clinical groups: Leigh syndrome, progressive leukoencephalopathy, neonatal cardiomyopathy, severe infantile lactic acidosis, and a miscellaneous group of unspecified encephalomyopathies. A genetic definition was reached in eight patients (35%). Mutations in mtDNA were found in six out of eight children with Leigh syndrome, indicating a prevalent association between this phenotype and abnormalities in ND genes. In two patients with leukoencephalopathy, homozygous mutations were detected in two different nuclear-encoded complex I genes, including a novel transition in NDUFS1 subunit. In addition to these, a child affected by mitochondrial encephalomyopathy had heterozygous mutations in NDUFA8 and NDUFS2 genes, while another child with neonatal cardiomyopathy had a complex rearrangement in a single NDUFS7 allele. The latter cases suggest the possibility of unconventional patterns of inheritance in complex I defects.
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Affiliation(s)
- M Bugiani
- Department of Child Neurology, National Institute of Neurology C. Besta, Milano, Italy
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29
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Dimauro S. Mitochondrial medicine. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2004; 1659:107-14. [PMID: 15576041 DOI: 10.1016/j.bbabio.2004.08.003] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2004] [Revised: 08/02/2004] [Accepted: 08/09/2004] [Indexed: 11/28/2022]
Abstract
After reviewing the history of mitochondrial diseases, I follow a genetic classification to discuss new developments and old conundrums. In the field of mitochondrial DNA (mtDNA) mutations, I argue that we are not yet scraping the bottom of the barrel because: (i) new mtDNA mutations are still being discovered, especially in protein-coding genes; (ii) the pathogenicity of homoplasmic mutations is being revisited; (iii) some genetic dogmas are chipped but not broken; (iv) mtDNA haplotypes are gaining interest in human pathology; (v) pathogenesis is still largely enigmatic. In the field of nuclear DNA (nDNA) mutations, there has been good progress in our understanding of disorders due to faulty intergenomic communication. Of the genes responsible for multiple deletions and depletion of mtDNA, mutations in POLG have been associated with a great variety of clinical phenotypes in humans and to precocious aging in mice. Novel pathogenetic mechanisms include alterations in the lipid milieu of the inner mitochondrial membrane and mutations in genes controlling mitochondrial motility, fission, and fusion.
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Affiliation(s)
- Salvatore Dimauro
- Department of Neurology, Columbia University, 4-420 College of Physicians & Surgeons, 630 West 168th Street, New York, NY 10032, USA.
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30
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Sudo A, Honzawa S, Nonaka I, Goto YI. Leigh syndrome caused by mitochondrial DNA G13513A mutation: frequency and clinical features in Japan. J Hum Genet 2004; 49:92-96. [PMID: 14730434 DOI: 10.1007/s10038-003-0116-1] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2003] [Accepted: 11/18/2003] [Indexed: 10/26/2022]
Abstract
The mitochondrial DNA (mtDNA) G13513A mutation in the ND5 subunit gene has been recently reported as a common cause of some phenotypes of mitochondrial myopathy. Until now, the prevalence and characteristics of this mutation in Leigh syndrome (LS) has not been determined. We screened 84 patients with Leigh syndrome (LS) and found the mutation in six (7%) of them. The proportions of mutant mtDNA in muscles were relatively low (42-70%). The onset of symptoms for patients with this mutation was from 9 months to 5 years. It should be noted that five patients had cardiac conduction abnormalities, particularly Wolff-Parkinson-White (WPW) syndrome (three patients). This study suggests that G13513A mutation is a frequent cause of LS and that patients with this mutation may have a characteristic clinical course.
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Affiliation(s)
- Akira Sudo
- Department of Mental Retardation and Birth Defect Research, National Institute of Neuroscience, NCNP, 4-1-1 Ogawahigashi, Kodaira, Tokyo 187-8502, Japan
- Department of Child Neurology, National Center Hospital for Mental, Nervous, and Muscular Disorders, National Center of Neurology and Psychiatry, Tokyo, Japan
| | - Shiho Honzawa
- Department of Mental Retardation and Birth Defect Research, National Institute of Neuroscience, NCNP, 4-1-1 Ogawahigashi, Kodaira, Tokyo 187-8502, Japan
- Department of Pediatrics, Koshigaya Hospital, Dokkyo University School of Medicine, Saitama, Japan
| | - Ikuya Nonaka
- Department of Child Neurology, National Center Hospital for Mental, Nervous, and Muscular Disorders, National Center of Neurology and Psychiatry, Tokyo, Japan
| | - Yu-Ichi Goto
- Department of Mental Retardation and Birth Defect Research, National Institute of Neuroscience, NCNP, 4-1-1 Ogawahigashi, Kodaira, Tokyo 187-8502, Japan.
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31
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Parry A, Matthews PM. Roles for Imaging in Understanding the Pathophysiology, Clinical Evaluation, and Management of Patients with Mitochondrial Disease. J Neuroimaging 2003. [DOI: 10.1111/j.1552-6569.2003.tb00195.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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32
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Kirby DM, Boneh A, Chow CW, Ohtake A, Ryan MT, Thyagarajan D, Thorburn DR. Low mutant load of mitochondrial DNA G13513A mutation can cause Leigh's disease. Ann Neurol 2003; 54:473-8. [PMID: 14520659 DOI: 10.1002/ana.10687] [Citation(s) in RCA: 85] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Respiratory chain complex I deficiency is a common cause of Leigh's disease (LD) and can be caused by mutations in genes encoded by either nuclear or mitochondrial DNA (mtDNA). Most pathogenic mtDNA mutations act recessively and only cause disease when present at high mutant loads (typically >90%) in tissues such as muscle and brain. Two mitochondrial DNA mutations in complex I subunit genes, G14459A in ND6, and T12706C in ND5, have been associated with complex I deficiency and LD. We report another ND5 mutation, G13513A, in three unrelated patients with complex I deficiency and LD. The G13513A mutation was present at mutant loads of approximately 50% or less in all tissues tested, including multiple brain regions. The threshold mutant load for causing a complex I defect in cultured cells was approximately 30%. Blue Native polyacrylamide gel electrophoresis showed that fibroblasts with 45% G13513A mutant load had approximately 50% of the normal amount of fully assembled complex I. Fibroblasts with greater than 97% of the ND6 G14459A mutation had only 20% fully assembled complex I, suggesting that both mutations disrupt complex I assembly or turnover. We conclude that the G13513A mutation causes a complex I defect when present at unusually low mutant load and may act dominantly.
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Affiliation(s)
- Denise M Kirby
- Murdoch Children's Research Institute, University of Melbourne, Victoria, Australia
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33
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Liolitsa D, Rahman S, Benton S, Carr LJ, Hanna MG. Is the mitochondrial complex I ND5 gene a hot-spot for MELAS causing mutations? Ann Neurol 2003; 53:128-32. [PMID: 12509858 DOI: 10.1002/ana.10435] [Citation(s) in RCA: 95] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
We identified two novel heteroplasmic mitochondrial DNA point mutations in the gene encoding the ND5 subunit of complex I: a 12770A-->G transition identified in a patient with MELAS (mitochondrial encephalomyopathy with lactic acidosis and stroke-like episodes) and a 13045A-->C transversion in a patient with a MELAS/Leber's hereditary optic neuropathy/Leigh's overlap syndrome. Biochemical analysis of muscle homogenates showed normal or very mildly reduced complex I activity. Histochemistry was normal. Our observations add to the evidence that mitochondrial ND5 protein coding gene mutations frequently associate with the MELAS phenotype, and it highlights the role of complex I dysfunction in MELAS.
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Affiliation(s)
- Danae Liolitsa
- Neuromuscular Unit, Institute of Neurology, University College London, United Kingdom
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34
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Abstract
The mitochondrial encephalomyopathies are a genetically heterogeneous group of disorders associated with impaired oxidative phosphorylation. Patients may exhibit a wide range of clinical symptoms and experience significant morbidity and mortality. There is currently no curative treatment. At present the majority of genetically defined mitochondrial encephalomyopathies are caused by mutations in mitochondrial DNA. The underlying molecular mechanisms and the complex relationship between genotype and phenotype in these mitochondrial DNA diseases remain only partially understood. We describe the key features of mitochondrial DNA genetics and outline some of the common disease phenotypes associated with mtDNA defects. A classification of pathogenic mitochondrial DNA point mutations which may have therapeutic implications is outlined.
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Affiliation(s)
- T Pulkes
- Muscle and Neurogenetics Sections, University Department of Clinical Neurology, Institute of Neurology, University College London, Queen Square, WC1N 3BG, London, UK
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