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Tian Z, Li J, Tang H, Liu W, Hou H, Wang C, Li D, Chen G, Xia T, Wang A. ZLN005 alleviates PBDE-47 induced impairment of mitochondrial translation and neurotoxicity through PGC-1α/ERRα axis. JOURNAL OF HAZARDOUS MATERIALS 2024; 471:134331. [PMID: 38677116 DOI: 10.1016/j.jhazmat.2024.134331] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/25/2023] [Revised: 03/28/2024] [Accepted: 04/15/2024] [Indexed: 04/29/2024]
Abstract
Recent studies are identified the mitochondria as critical targets of 2, 2', 4, 4'-tetrabromodiphenyl ether (PBDE-47) induced neurotoxicity. This study aimed at examining the impact of PBDE-47 exposure on mitochondrial translation, and its subsequent effect on PBDE-47 neurotoxicity. The Sprague-Dawley (SD) rat model and neuroendocrine pheochromocytoma (PC12) cells were adopted for the measurements of mitochondrial ATP levels, mitochondrial translation products, and expressions of important mitochondrial regulators, such as required meiotic nuclear division 1 (RMND1), estrogen-related receptor α (ERRα), and peroxisome proliferator-activated receptor gamma coactivator 1 alpha (PGC-1α). To delve into the role of PGC-1α/ERRα axis in mitochondrial translation, 2-(4-tert-butylphenyl) benzimidazole (ZLN005) was employed. Both cellular and animal model results shown that PBDE-47 impeded PGC-1α/ERRα axis and mitochondrial translation. PBDE-47 suppressed mitochondrial function in rat hippocampus and PC12 cells by decreasing relative mitochondrial DNA (mtDNA) content, mitochondrial translation products, and mitochondrial ATP levels. Particularly, ZLN005 reversed PBDE-47 neurotoxicity by enhancing mitochondrial translation through activation of PGC-1α/ERRα axis, yet suppressing PGC-1α with siRNA attenuates its neuroprotective effect in vitro. In conclusion, this work highlights the importance of mitochondrial translation in PBDE-47 neurotoxicity by presenting results from cellular and animal models and suggests a potential therapeutic approach through activation of PGC-1α/ERRα axis. ENVIRONMENTAL IMPLICATION: PBDEs have attracted extensive attention because of their high lipophilicity, persistence, and detection levels in various environmental media. Increasing evidence has shown that neurodevelopmental disorders in children are associated with PBDE exposure. Several studies have also found that perinatal PBDE exposure can cause long-lasting neurobehavioral abnormalities in experimental animals. Our recent studies have also demonstrated the impact of PBDE-47 exposure on mitochondrial biogenesis and dynamics, leading to memory and neurobehavioral deficits. Therefore, we explore whether the pathological mechanism of PBDE-47-induced neurotoxicity involves the regulation of mitochondrial translation through the PGC-1α/ERRα axis.
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Affiliation(s)
- Zhiyuan Tian
- Department of Occupational and Environmental Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, People's Republic of China; Key Laboratory of Environment and Health, Ministry of Education & Ministry of Environmental Protection, State Key Laboratory of Environmental health (incubating), School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, People's Republic of China
| | - Jing Li
- Department of Occupational and Environmental Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, People's Republic of China; Key Laboratory of Environment and Health, Ministry of Education & Ministry of Environmental Protection, State Key Laboratory of Environmental health (incubating), School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, People's Republic of China
| | - Huayang Tang
- Department of Occupational and Environmental Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, People's Republic of China; Key Laboratory of Environment and Health, Ministry of Education & Ministry of Environmental Protection, State Key Laboratory of Environmental health (incubating), School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, People's Republic of China
| | - Wenhui Liu
- Department of Occupational and Environmental Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, People's Republic of China; Key Laboratory of Environment and Health, Ministry of Education & Ministry of Environmental Protection, State Key Laboratory of Environmental health (incubating), School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, People's Republic of China
| | - Haoqi Hou
- Department of Occupational and Environmental Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, People's Republic of China; Key Laboratory of Environment and Health, Ministry of Education & Ministry of Environmental Protection, State Key Laboratory of Environmental health (incubating), School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, People's Republic of China
| | - Chenxi Wang
- Department of Occupational and Environmental Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, People's Republic of China; Key Laboratory of Environment and Health, Ministry of Education & Ministry of Environmental Protection, State Key Laboratory of Environmental health (incubating), School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, People's Republic of China
| | - Dongjie Li
- Department of Occupational and Environmental Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, People's Republic of China; Key Laboratory of Environment and Health, Ministry of Education & Ministry of Environmental Protection, State Key Laboratory of Environmental health (incubating), School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, People's Republic of China
| | - Gaoshuai Chen
- Department of Occupational and Environmental Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, People's Republic of China; Key Laboratory of Environment and Health, Ministry of Education & Ministry of Environmental Protection, State Key Laboratory of Environmental health (incubating), School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, People's Republic of China
| | - Tao Xia
- Department of Occupational and Environmental Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, People's Republic of China; Key Laboratory of Environment and Health, Ministry of Education & Ministry of Environmental Protection, State Key Laboratory of Environmental health (incubating), School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, People's Republic of China.
| | - Aiguo Wang
- Department of Occupational and Environmental Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, People's Republic of China; Key Laboratory of Environment and Health, Ministry of Education & Ministry of Environmental Protection, State Key Laboratory of Environmental health (incubating), School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, People's Republic of China.
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Conti F, Di Martino S, Drago F, Bucolo C, Micale V, Montano V, Siciliano G, Mancuso M, Lopriore P. Red Flags in Primary Mitochondrial Diseases: What Should We Recognize? Int J Mol Sci 2023; 24:16746. [PMID: 38069070 PMCID: PMC10706469 DOI: 10.3390/ijms242316746] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2023] [Revised: 11/22/2023] [Accepted: 11/23/2023] [Indexed: 12/18/2023] Open
Abstract
Primary mitochondrial diseases (PMDs) are complex group of metabolic disorders caused by genetically determined impairment of the mitochondrial oxidative phosphorylation (OXPHOS). The unique features of mitochondrial genetics and the pivotal role of mitochondria in cell biology explain the phenotypical heterogeneity of primary mitochondrial diseases and the resulting diagnostic challenges that follow. Some peculiar features ("red flags") may indicate a primary mitochondrial disease, helping the physician to orient in this diagnostic maze. In this narrative review, we aimed to outline the features of the most common mitochondrial red flags offering a general overview on the topic that could help physicians to untangle mitochondrial medicine complexity.
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Affiliation(s)
- Federica Conti
- Department of Biomedical and Biotechnological Science, School of Medicine, University of Catania, 95123 Catania, Italy; (F.C.); (S.D.M.); (C.B.); (V.M.)
| | - Serena Di Martino
- Department of Biomedical and Biotechnological Science, School of Medicine, University of Catania, 95123 Catania, Italy; (F.C.); (S.D.M.); (C.B.); (V.M.)
| | - Filippo Drago
- Department of Biomedical and Biotechnological Science, School of Medicine, University of Catania, 95123 Catania, Italy; (F.C.); (S.D.M.); (C.B.); (V.M.)
| | - Claudio Bucolo
- Department of Biomedical and Biotechnological Science, School of Medicine, University of Catania, 95123 Catania, Italy; (F.C.); (S.D.M.); (C.B.); (V.M.)
- Center for Research in Ocular Pharmacology-CERFO, University of Catania, 95213 Catania, Italy
| | - Vincenzo Micale
- Department of Biomedical and Biotechnological Science, School of Medicine, University of Catania, 95123 Catania, Italy; (F.C.); (S.D.M.); (C.B.); (V.M.)
| | - Vincenzo Montano
- Neurological Institute, Department of Clinical and Experimental Medicine, University of Pisa, 56126 Pisa, Italy (P.L.)
| | - Gabriele Siciliano
- Neurological Institute, Department of Clinical and Experimental Medicine, University of Pisa, 56126 Pisa, Italy (P.L.)
| | - Michelangelo Mancuso
- Neurological Institute, Department of Clinical and Experimental Medicine, University of Pisa, 56126 Pisa, Italy (P.L.)
| | - Piervito Lopriore
- Neurological Institute, Department of Clinical and Experimental Medicine, University of Pisa, 56126 Pisa, Italy (P.L.)
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McCormick EM, Keller K, Taylor JP, Coffey AJ, Shen L, Krotoski D, Harding B, Gai X, Falk MJ, Zolkipli-Cunningham Z, Rahman S. Expert Panel Curation of 113 Primary Mitochondrial Disease Genes for the Leigh Syndrome Spectrum. Ann Neurol 2023; 94:696-712. [PMID: 37255483 PMCID: PMC10763625 DOI: 10.1002/ana.26716] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2022] [Revised: 05/22/2023] [Accepted: 05/23/2023] [Indexed: 06/01/2023]
Abstract
OBJECTIVE Primary mitochondrial diseases (PMDs) are heterogeneous disorders caused by inherited mitochondrial dysfunction. Classically defined neuropathologically as subacute necrotizing encephalomyelopathy, Leigh syndrome spectrum (LSS) is the most frequent manifestation of PMD in children, but may also present in adults. A major challenge for accurate diagnosis of LSS in the genomic medicine era is establishing gene-disease relationships (GDRs) for this syndrome with >100 monogenic causes across both nuclear and mitochondrial genomes. METHODS The Clinical Genome Resource (ClinGen) Mitochondrial Disease Gene Curation Expert Panel (GCEP), comprising 40 international PMD experts, met monthly for 4 years to review GDRs for LSS. The GCEP standardized gene curation for LSS by refining the phenotypic definition, modifying the ClinGen Gene-Disease Clinical Validity Curation Framework to improve interpretation for LSS, and establishing a scoring rubric for LSS. RESULTS The GDR with LSS across the nuclear and mitochondrial genomes was classified as definitive for 31 of 114 GDRs curated (27%), moderate for 38 (33%), limited for 43 (38%), and disputed for 2 (2%). Ninety genes were associated with autosomal recessive inheritance, 16 were maternally inherited, 5 were autosomal dominant, and 3 were X-linked. INTERPRETATION GDRs for LSS were established for genes across both nuclear and mitochondrial genomes. Establishing these GDRs will allow accurate variant interpretation, expedite genetic diagnosis of LSS, and facilitate precision medicine, multisystem organ surveillance, recurrence risk counseling, reproductive choice, natural history studies, and determination of eligibility for interventional clinical trials. ANN NEUROL 2023;94:696-712.
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Affiliation(s)
- Elizabeth M. McCormick
- Mitochondrial Medicine Frontier Program, Division of Human Genetics, Department of Pediatrics, Children’s Hospital of Philadelphia (CHOP), Philadelphia, PA, USA
| | - Kierstin Keller
- Center for Mitochondrial and Epigenomic Medicine, Department of Pathology, CHOP, Philadelphia, PA, USA
| | - Julie P. Taylor
- Illumina Clinical Services Laboratory, Illumina Inc., San Diego, CA, USA
| | - Alison J. Coffey
- Illumina Clinical Services Laboratory, Illumina Inc., San Diego, CA, USA
| | - Lishuang Shen
- Center for Personalized Medicine, Department of Pathology & Laboratory Medicine, Children’s Hospital Los Angeles, Los Angeles, CA, USA
| | - Danuta Krotoski
- IDDB/NICHD, National Institutes of Health, Bethesda, MD, USA
| | - Brian Harding
- Departments of Pathology and Lab Medicine (Neuropathology), Children’s Hospital of Philadelphia, Philadelphia, PA, USA
- University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
| | | | - Xiaowu Gai
- Center for Personalized Medicine, Department of Pathology & Laboratory Medicine, Children’s Hospital Los Angeles, Los Angeles, CA, USA
- Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Marni J. Falk
- Mitochondrial Medicine Frontier Program, Division of Human Genetics, Department of Pediatrics, Children’s Hospital of Philadelphia (CHOP), Philadelphia, PA, USA
- University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
| | - Zarazuela Zolkipli-Cunningham
- Mitochondrial Medicine Frontier Program, Division of Human Genetics, Department of Pediatrics, Children’s Hospital of Philadelphia (CHOP), Philadelphia, PA, USA
- University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
| | - Shamima Rahman
- Mitochondrial Research Group, Genetics and Genomic Medicine, UCL Great Ormond Street Institute of Child Health, and Metabolic Unit, Great Ormond Street Hospital for Children NHS Foundation Trust, London, United Kingdom
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Oyefeso FA, Goldberg G, Opoku NYPS, Vazquez M, Bertucci A, Chen Z, Wang C, Muotri AR, Pecaut MJ. Effects of acute low-moderate dose ionizing radiation to human brain organoids. PLoS One 2023; 18:e0282958. [PMID: 37256873 PMCID: PMC10231836 DOI: 10.1371/journal.pone.0282958] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Accepted: 02/27/2023] [Indexed: 06/02/2023] Open
Abstract
Human exposure to low-to-moderate dose ionizing radiation (LMD-IR) is increasing via environmental, medical, occupational sources. Acute exposure to LMD-IR can cause subclinical damage to cells, resulting in altered gene expression and cellular function within the human brain. It has been difficult to identify diagnostic and predictive biomarkers of exposure using traditional research models due to factors including lack of 3D structure in monolayer cell cultures, limited ability of animal models to accurately predict human responses, and technical limitations of studying functional human brain tissue. To address this gap, we generated brain/cerebral organoids from human induced pluripotent stem cells to study the radiosensitivity of human brain cells, including neurons, astrocytes, and oligodendrocytes. While organoids have become popular models for studying brain physiology and pathology, there is little evidence to confirm that exposing brain organoids to LMD-IR will recapitulate previous in vitro and in vivo observations. We hypothesized that exposing brain organoids to proton radiation would (1) cause a time- and dose-dependent increase in DNA damage, (2) induce cell type-specific differences in radiosensitivity, and (3) increase expression of oxidative stress and DNA damage response genes. Organoids were exposed to 0.5 or 2 Gy of 250 MeV protons and samples were collected at 30 minute, 24 hour, and 48 hour timepoints. Using immunofluorescence and RNA sequencing, we found time- and dose-dependent increases in DNA damage in irradiated organoids; no changes in cell populations for neurons, oligodendrocytes, and astrocytes by 24 hours; decreased expression of genes related to oligodendrocyte lineage, astrocyte lineage, mitochondrial function, and cell cycle progression by 48 hours; increased expression of genes related to neuron lineage, oxidative stress, and DNA damage checkpoint regulation by 48 hours. Our findings demonstrate the possibility of using organoids to characterize cell-specific radiosensitivity and early radiation-induced gene expression changes within the human brain, providing new avenues for further study of the mechanisms underlying acute neural cell responses to IR exposure at low-to-moderate doses.
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Affiliation(s)
- Foluwasomi A. Oyefeso
- Department of Biomedical Engineering Sciences, School of Medicine, Loma Linda University, Loma Linda, California, United States of America
| | - Gabriela Goldberg
- Department of Pediatrics, School of Medicine, University of California San Diego, La Jolla, California, United States of America
| | - Nana Yaa P. S. Opoku
- Department of Biomedical Engineering Sciences, School of Medicine, Loma Linda University, Loma Linda, California, United States of America
| | - Marcelo Vazquez
- Departments of Pediatrics and Cellular & Molecular Medicine, School of Medicine, Center for Academic Research and Training in Anthropogeny (CARTA), Kavli Institute for Brain and Mind, Archealization Center (ArchC), University of California San Diego, La Jolla, California, United States of America
- Center for Genomics, School of Medicine, Loma Linda University, Loma Linda, California, United States of America
| | - Antonella Bertucci
- Center for Genomics, School of Medicine, Loma Linda University, Loma Linda, California, United States of America
| | - Zhong Chen
- Department of Basic Sciences, School of Medicine, Loma Linda University, Loma Linda, California, United States of America
| | - Charles Wang
- Departments of Pediatrics and Cellular & Molecular Medicine, School of Medicine, Center for Academic Research and Training in Anthropogeny (CARTA), Kavli Institute for Brain and Mind, Archealization Center (ArchC), University of California San Diego, La Jolla, California, United States of America
- Department of Basic Sciences, School of Medicine, Loma Linda University, Loma Linda, California, United States of America
| | - Alysson R. Muotri
- Department of Radiation Medicine, School of Medicine, Loma Linda University, Loma Linda, California, United States of America
| | - Michael J. Pecaut
- Department of Biomedical Engineering Sciences, School of Medicine, Loma Linda University, Loma Linda, California, United States of America
- Departments of Pediatrics and Cellular & Molecular Medicine, School of Medicine, Center for Academic Research and Training in Anthropogeny (CARTA), Kavli Institute for Brain and Mind, Archealization Center (ArchC), University of California San Diego, La Jolla, California, United States of America
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5
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Ng YS, Gorman GS. Stroke-like episodes in adult mitochondrial disease. HANDBOOK OF CLINICAL NEUROLOGY 2023; 194:65-78. [PMID: 36813321 DOI: 10.1016/b978-0-12-821751-1.00005-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/22/2023]
Abstract
Stroke-like episode is a paroxysmal neurological manifestation which affects a specific group of patients with mitochondrial disease. Focal-onset seizures, encephalopathy, and visual disturbances are prominent findings associated with stroke-like episodes, with a predilection for the posterior cerebral cortex. The most common cause of stroke-like episodes is the m.3243A>G variant in MT-TL1 gene followed by recessive POLG variants. This chapter aims to review the definition of stroke-like episode and delineate the clinical phenomenology, neuroimaging and EEG findings typically seen in patients. In addition, several lines of evidence supporting neuronal hyper-excitability as the key mechanism of stroke-like episodes are discussed. The management of stroke-like episodes should focus on aggressive seizure management and treatment for concomitant complications such as intestinal pseudo-obstruction. There is no robust evidence to prove the efficacy of l-arginine for both acute and prophylactic settings. Progressive brain atrophy and dementia are the sequalae of recurrent stroke-like episode, and the underlying genotype in part predicts prognosis.
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Affiliation(s)
- Yi Shiau Ng
- Wellcome Centre for Mitochondrial Research, Translational and Clinical Research Institute, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Gráinne S Gorman
- Wellcome Centre for Mitochondrial Research, Translational and Clinical Research Institute, Newcastle University, Newcastle upon Tyne, United Kingdom.
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Kidere D, Zayakin P, Livcane D, Makrecka-Kuka M, Stavusis J, Lace B, Lin TK, Liou CW, Inashkina I. Impact of the m.13513G>A Variant on the Functions of the OXPHOS System and Cell Retrograde Signaling. Curr Issues Mol Biol 2023; 45:1794-1809. [PMID: 36975485 PMCID: PMC10047405 DOI: 10.3390/cimb45030115] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Revised: 02/08/2023] [Accepted: 02/16/2023] [Indexed: 02/24/2023] Open
Abstract
Mitochondria are involved in many vital functions in living cells, including the synthesis of ATP by oxidative phosphorylation (OXPHOS) and regulation of nuclear gene expression through retrograde signaling. Leigh syndrome is a heterogeneous neurological disorder resulting from an isolated complex I deficiency that causes damage to mitochondrial energy production. The pathogenic mitochondrial DNA (mtDNA) variant m.13513G>A has been associated with Leigh syndrome. The present study investigated the effects of this mtDNA variant on the OXPHOS system and cell retrograde signaling. Transmitochondrial cytoplasmic hybrid (cybrid) cell lines harboring 50% and 70% of the m.13513G>A variant were generated and tested along with wild-type (WT) cells. The functionality of the OXPHOS system was evaluated by spectrophotometric assessment of enzyme activity and high-resolution respirometry. Nuclear gene expression was investigated by RNA sequencing and droplet digital PCR. Increasing levels of heteroplasmy were associated with reduced OXPHOS system complex I, IV, and I + III activities, and high-resolution respirometry also showed a complex I defect. Profound changes in transcription levels of nuclear genes were observed in the cell lines harboring the pathogenic mtDNA variant, indicating the physiological processes associated with defective mitochondria.
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Affiliation(s)
- Dita Kidere
- Latvian Biomedical Research and Study Centre, LV-1067 Riga, Latvia
| | - Pawel Zayakin
- Latvian Biomedical Research and Study Centre, LV-1067 Riga, Latvia
| | - Diana Livcane
- Latvian Biomedical Research and Study Centre, LV-1067 Riga, Latvia
| | | | - Janis Stavusis
- Latvian Biomedical Research and Study Centre, LV-1067 Riga, Latvia
| | - Baiba Lace
- Latvian Biomedical Research and Study Centre, LV-1067 Riga, Latvia
- Children’s Clinical University Hospital, LV-1004 Riga, Latvia
| | - Tsu-Kung Lin
- Department of Neurology, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung 83305, Taiwan
- Center for Mitochondrial Research and Medicine, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung 83301, Taiwan
| | - Chia-Wei Liou
- Department of Neurology, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung 83305, Taiwan
- Center for Mitochondrial Research and Medicine, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung 83301, Taiwan
| | - Inna Inashkina
- Latvian Biomedical Research and Study Centre, LV-1067 Riga, Latvia
- Correspondence:
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Tian Z, Li J, Song L, Xie L, Li D, Xia T, Wang A. PBDE-47 induces impairment of mitochondrial biogenesis and subsequent neurotoxicity through miR-128-3p/PGC-1α axis. Toxicol Sci 2023; 191:123-134. [PMID: 36269211 DOI: 10.1093/toxsci/kfac110] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
The potential adverse effects of 2,2',4,4'-tetrabromodiphenyl ether (PBDE-47) on neurons are extensively studied, and mitochondria are identified as critical targets. This study aimed to investigate whether PBDE-47 impairs mitochondrial biogenesis via the miR-128-3p/PGC-1α axis to trigger mitochondrial dysfunction-related neuronal damage. In vitro neuroendocrine pheochromocytoma (PC12) cells and in vivo Sprague Dawley rat model were adopted. In this study, biochemical methods were used to examine mitochondrial ATP content, cell viability, and expressions of key mitochondrial biogenesis regulators, including peroxisome proliferator-activated receptor gamma coactivator 1 alpha (PGC-1α), nuclear respiratory factor 1 (NRF1), and mitochondrial transcription factor A (TFAM). Mimics and inhibitors of miR-128-3p were employed to explore its role in PBDE-47-induced neurotoxicity. Both in vivo and in vitro evidences suggested that PBDE-47 suppressed PGC-1α/NRF1/TFAM signaling pathways and mitochondrial DNA (mtDNA) encoding proteins synthesis. PBDE-47 also suppressed the relative mtDNA content, mRNA levels of mtDNA-encoded subunits, and mitochondrial ATP levels in vitro. Specifically, 2-(4-tert-butylphenyl) benzimidazole (ZLN005) alleviated PBDE-47-induced neuronal death through the improvement of mitochondrial function by activating PGC-1α/NRF1/TFAM signaling pathways. Mechanistically, PBDE-47 dramatically upregulated miR-128-3p expression. Furthermore, miR-128-3p inhibition enhanced PGC-1α/NRF1/TFAM signaling and abolished PBDE-47-induced impairment of mitochondrial biogenesis. In summary, this study provides in vitro evidence to reveal the role of mitochondrial biogenesis in PBDE-47-induced mitochondrial dysfunction and related neurotoxicity and suggests that miR-128-3p/PGC-1α axis may be a therapeutic target for PBDE-47 neurotoxicity.
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Affiliation(s)
- Zhiyuan Tian
- Department of Occupational and Environmental Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, 430030, People's Republic of China
- Key Laboratory of Environment and Health, Ministry of Education & Ministry of Environmental Protection, State Key Laboratory of Environmental Health (Incubating), School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, 430030, People's Republic of China
| | - Jing Li
- Department of Occupational and Environmental Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, 430030, People's Republic of China
- Key Laboratory of Environment and Health, Ministry of Education & Ministry of Environmental Protection, State Key Laboratory of Environmental Health (Incubating), School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, 430030, People's Republic of China
| | - Li Song
- Department of Occupational and Environmental Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, 430030, People's Republic of China
- Key Laboratory of Environment and Health, Ministry of Education & Ministry of Environmental Protection, State Key Laboratory of Environmental Health (Incubating), School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, 430030, People's Republic of China
| | - Li Xie
- Department of Occupational and Environmental Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, 430030, People's Republic of China
- Key Laboratory of Environment and Health, Ministry of Education & Ministry of Environmental Protection, State Key Laboratory of Environmental Health (Incubating), School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, 430030, People's Republic of China
| | - Dongjie Li
- Department of Occupational and Environmental Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, 430030, People's Republic of China
- Key Laboratory of Environment and Health, Ministry of Education & Ministry of Environmental Protection, State Key Laboratory of Environmental Health (Incubating), School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, 430030, People's Republic of China
| | - Tao Xia
- Department of Occupational and Environmental Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, 430030, People's Republic of China
- Key Laboratory of Environment and Health, Ministry of Education & Ministry of Environmental Protection, State Key Laboratory of Environmental Health (Incubating), School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, 430030, People's Republic of China
| | - Aiguo Wang
- Department of Occupational and Environmental Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, 430030, People's Republic of China
- Key Laboratory of Environment and Health, Ministry of Education & Ministry of Environmental Protection, State Key Laboratory of Environmental Health (Incubating), School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, 430030, People's Republic of China
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Tagliani S, Malaventura C, Ceccato C, Parmeggiani F, Suppiej A. Leber Mitochondrial Optic Neuropathy in Pediatric Females With Focus on Very Early Onset Cases. J Child Neurol 2023; 38:5-15. [PMID: 36659874 DOI: 10.1177/08830738221149962] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
The aim of this study was to describe the phenotype of Leber hereditary optic neuropathy occurring in pediatric females. This disease generally affects young adult males, but it can occur also in females, and research data in this population is lacking. The very early onset can challenge the diagnosis and delay treatment. We searched PubMed through February 2021 and identified 226 pediatric females with genetically confirmed Leber hereditary optic neuropathy and added a new case of a 3-year-old female. The male-female ratio was 1.8:1; the mean onset age in females was 11 years with the onset at 3 years of age occurring in 3 females only. Acute onset with mild visual impairment was the most common presentation, associated with optic disc edema in 16%. Differential diagnoses are pseudotumor cerebri, optic nerve drusen and optic neuritis. The outcome is poor with partial recovery in 50%, despite some receiving Idebenone therapy.
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Affiliation(s)
- Sara Tagliani
- Department of Medical Sciences, Pediatric Section, University Hospital of Ferrara, Ferrara, Italy
| | - Cristina Malaventura
- Department of Medical Sciences, Pediatric Section, University Hospital of Ferrara, Ferrara, Italy
| | | | - Francesco Parmeggiani
- Department of Translational Medicine and for Romagna, 9299University of Ferrara, Ferrara, Italy.,ERN-EYE Network - Center for Retinitis Pigmentosa of Veneto Region, 196013Camposampiero Hospital, Padova, Italy
| | - Agnese Suppiej
- Department of Medical Sciences, Pediatric Section, University Hospital of Ferrara, Ferrara, Italy.,87812Robert Hollman Foundation, Padova, Italy.,ERN-EYE Network - Center for Retinitis Pigmentosa of Veneto Region, 196013Camposampiero Hospital, Padova, Italy
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9
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Abstract
Mitochondrial dysfunction, especially perturbation of oxidative phosphorylation and adenosine triphosphate (ATP) generation, disrupts cellular homeostasis and is a surprisingly frequent cause of central and peripheral nervous system pathology. Mitochondrial disease is an umbrella term that encompasses a host of clinical syndromes and features caused by in excess of 300 different genetic defects affecting the mitochondrial and nuclear genomes. Patients with mitochondrial disease can present at any age, ranging from neonatal onset to late adult life, with variable organ involvement and neurological manifestations including neurodevelopmental delay, seizures, stroke-like episodes, movement disorders, optic neuropathy, myopathy, and neuropathy. Until relatively recently, analysis of skeletal muscle biopsy was the focus of diagnostic algorithms, but step-changes in the scope and availability of next-generation sequencing technology and multiomics analysis have revolutionized mitochondrial disease diagnosis. Currently, there is no specific therapy for most types of mitochondrial disease, although clinical trials research in the field is gathering momentum. In that context, active management of epilepsy, stroke-like episodes, dystonia, brainstem dysfunction, and Parkinsonism are all the more important in improving patient quality of life and reducing mortality.
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Affiliation(s)
- Yi Shiau Ng
- Wellcome Centre for Mitochondrial Research, Translational and Clinical Research Institute, Newcastle University, Newcastle upon Tyne, United Kingdom.
| | - Robert McFarland
- NHS Highly Specialised Service for Rare Mitochondrial Disorders, Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne, United Kingdom
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10
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Na JH, Lee YM. Heteroplasmic Mutant Load Differences in Mitochondrial DNA-Associated Leigh Syndrome. Pediatr Neurol 2023; 138:27-32. [PMID: 36335839 DOI: 10.1016/j.pediatrneurol.2022.09.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Revised: 08/24/2022] [Accepted: 09/28/2022] [Indexed: 11/05/2022]
Abstract
BACKGROUND Mitochondrial DNA (mtDNA)-associated Leigh syndrome is influenced by mutant pathogenicity and corresponding heteroplasmic loads; however, the manner in which heteroplasmic mutant load affects patient phenotypes and the relationship between mutant types and heteroplasmic mutant loads remain unknown. We aimed to investigate the distribution of the mutant load of different mtDNA mutations in a single-center cohort. METHODS We used next-generation sequencing to confirm mtDNA mutations in 31 patients with Leigh syndrome. Subsequently, we counted the number of mtDNA reads to quantitatively analyze the heteroplasmic mutant load and categorize the patients according to the mtDNA mutations they harbored. Confirmed cases of mtDNA-associated Leigh syndrome were classified according to the mutations observed in six genes and 10 nucleotides. RESULTS Of the 31 patients with Leigh syndrome, 27 harbored known pathogenic mutations. We discovered that MT-ATP6 was the most commonly mutated gene (n = 13 patients), followed by MT-ND3 (n = 7) and MT-ND5 (n = 4). MT-ATP6 had a significantly higher mutant load than MT-ND3 and MT-ND5 (P < 0.001, each). By contrast, MT-ND5 had a significantly lower mutant load than MT-ND3 (P = 0.007). Notably, the mutation loads varied significantly among patients carrying the MT-ATP6, MT-ND3, and MT-ND5 mutations. CONCLUSIONS Our study illustrated the heteroplasmic diversity and phenotypic expression threshold of mutated mitochondrial genes in mtDNA-associated Leigh syndrome. The results provide promising insights into the genotype-phenotype correlation in mtDNA-associated Leigh syndrome that are expected to guide the development of tailored treatments for Leigh syndrome.
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Affiliation(s)
- Ji-Hoon Na
- Department of Pediatrics, Yonsei University College of Medicine, Seoul, South Korea
| | - Young-Mock Lee
- Department of Pediatrics, Yonsei University College of Medicine, Seoul, South Korea; Epilepsy Research Institute, Yonsei University College of Medicine, Seoul, South Korea.
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11
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Leber’s hereditary optic neuropathy plus dystonia caused by the mitochondrial ND1 gene m.4160 T > C mutation. Neurol Sci 2022; 43:5581-5592. [DOI: 10.1007/s10072-022-06165-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2022] [Accepted: 05/17/2022] [Indexed: 10/18/2022]
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12
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Xu Q, Sun P, Feng C, Chen Q, Sun X, Chen Y, Tian G. Varying Clinical Phenotypes of Mitochondrial DNA T12811C Mutation: A Case Series Report. Front Med (Lausanne) 2022; 9:912103. [PMID: 35860740 PMCID: PMC9291510 DOI: 10.3389/fmed.2022.912103] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2022] [Accepted: 06/13/2022] [Indexed: 11/18/2022] Open
Abstract
The T12811C mitochondrial DNA (mtDNA) mutation has been reported in Leber hereditary optic neuropathy (LHON) previously, with vision loss as the main manifestation. The involvement of other organ systems, including the central and peripheral nervous system, heart, and extraocular muscles, has not been well described. This case series report investigated four patients with T12811C mtDNA mutation, verified through a next generation sequencing. Two male patients presented with bilateral subacute visual decrease combined with involvement of multiple organ systems: leukoencephalopathy, hypertrophic cardiomyopathy, neurosensory deafness, spinal cord lesion and peripheral neuropathies. Two female patients presented with progressive ptosis and ophthalmoplegia, one of whom also manifested optic atrophy. This study found out that patients harboring T12811C mtDNA mutation manifested not only as vision loss, but also as a multi-system disorder affecting the nervous system, heart, and extraocular muscles.
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Affiliation(s)
- Qingdan Xu
- Department of Ophthalmology, Eye and ENT Hospital, Fudan University, Shanghai, China
| | - Ping Sun
- Department of Ophthalmology, Eye and ENT Hospital, Fudan University, Shanghai, China
| | - Chaoyi Feng
- NHC Key Laboratory of Myopia, Chinese Academy of Medical Sciences, and Shanghai Key Laboratory of Visual Impairment and Restoration, Fudan University, Shanghai, China
| | - Qian Chen
- NHC Key Laboratory of Myopia, Chinese Academy of Medical Sciences, and Shanghai Key Laboratory of Visual Impairment and Restoration, Fudan University, Shanghai, China
| | - Xinghuai Sun
- Department of Ophthalmology, Eye and ENT Hospital, Fudan University, Shanghai, China
- NHC Key Laboratory of Myopia, Chinese Academy of Medical Sciences, and Shanghai Key Laboratory of Visual Impairment and Restoration, Fudan University, Shanghai, China
- State Key Laboratory of Medical Neurobiology, Institute of Brain Science, Fudan University, Shanghai, China
| | - Yuhong Chen
- Department of Ophthalmology, Eye and ENT Hospital, Fudan University, Shanghai, China
- NHC Key Laboratory of Myopia, Chinese Academy of Medical Sciences, and Shanghai Key Laboratory of Visual Impairment and Restoration, Fudan University, Shanghai, China
- *Correspondence: Yuhong Chen,
| | - Guohong Tian
- Department of Ophthalmology, Eye and ENT Hospital, Fudan University, Shanghai, China
- NHC Key Laboratory of Myopia, Chinese Academy of Medical Sciences, and Shanghai Key Laboratory of Visual Impairment and Restoration, Fudan University, Shanghai, China
- Guohong Tian,
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13
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Abstract
Abstract
Mitochondria, the cell powerhouse, are membrane-bound organelles present in the cytoplasm of almost all the eukaryotic cells. Their main function is to generate energy in the form of adenosine triphosphate (ATP). In addition, mitochondria store calcium for the cell signaling activities, generate heat, harbor pathways of intermediate metabolism and mediate cell growth and death. Primary mitochondrial diseases (MDs) form a clinically as well as genetically heterogeneous group of inherited disorders that result from the mitochondrial energetic metabolism malfunctions. The lifetime risk of the MDs development is estimated at 1:1470 of newborns, which makes them one of the most recurrent groups of inherited disorders with an important burden for society.
MDs are progressive with wide range of symptoms of variable severity that can emerge congenitally or anytime during the life. MD can be caused by mutations in the mitochondrial DNA (mtDNA) or nuclear DNA genes. Mutations inducing impairment of mitochondrial function have been found in more than 400 genes. Furthermore, more than 1200 nuclear genes, which could play a role in the MDs’ genetic etiology, are involved in the mitochondrial activities. However, the knowledge regarding the mechanism of the mitochondrial pathogenicity appears to be most essential for the development of effective patient’s treatment suffering from the mitochondrial disease. This is an overview update focused on the mitochondrial biology and the mitochondrial diseases associated genes.
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14
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Barone V, La Morgia C, Caporali L, Fiorini C, Carbonelli M, Gramegna LL, Bartiromo F, Tonon C, Morandi L, Liguori R, Petrini A, Brugnano R, Del Sordo R, Covarelli C, Morroni M, Lodi R, Carelli V. Case Report: Optic Atrophy and Nephropathy With m.13513G>A/MT-ND5 mtDNA Pathogenic Variant. Front Genet 2022; 13:887696. [PMID: 35719398 PMCID: PMC9204033 DOI: 10.3389/fgene.2022.887696] [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: 03/01/2022] [Accepted: 04/21/2022] [Indexed: 11/13/2022] Open
Abstract
Isolated complex I deficiency represents the most common mitochondrial respiratory chain defect involved in mitochondrial disorders. Among these, the mitochondrial DNA (mtDNA) m.13513G>A pathogenic variant in the NADH dehydrogenase 5 subunit gene (MT-ND5) has been associated with heterogenous manifestations, including phenotypic overlaps of mitochondrial encephalomyopathy with lactic acidosis and stroke-like episodes, Leigh syndrome, and Leber’s hereditary optic neuropathy (LHON). Interestingly, this specific mutation has been recently described in patients with adult-onset nephropathy. We, here, report the unique combination of LHON, nephropathy, sensorineural deafness, and subcortical and cerebellar atrophy in association with the m.13513G>A variant.
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Affiliation(s)
- Valentina Barone
- Department of Biomedical and Neuromotor Sciences (DIBINEM), Alma Mater Studiorum-University of Bologna, Bologna, Italy
| | - Chiara La Morgia
- IRCCS Istituto delle Scienze Neurologiche di Bologna, Bologna, Italy
| | - Leonardo Caporali
- IRCCS Istituto delle Scienze Neurologiche di Bologna, Bologna, Italy
| | - Claudio Fiorini
- IRCCS Istituto delle Scienze Neurologiche di Bologna, Bologna, Italy
| | - Michele Carbonelli
- Department of Biomedical and Neuromotor Sciences (DIBINEM), Alma Mater Studiorum-University of Bologna, Bologna, Italy
| | - Laura Ludovica Gramegna
- Department of Biomedical and Neuromotor Sciences (DIBINEM), Alma Mater Studiorum-University of Bologna, Bologna, Italy
- IRCCS Istituto delle Scienze Neurologiche di Bologna, Bologna, Italy
| | - Fiorina Bartiromo
- Department of Biomedical and Neuromotor Sciences (DIBINEM), Alma Mater Studiorum-University of Bologna, Bologna, Italy
- IRCCS Istituto delle Scienze Neurologiche di Bologna, Bologna, Italy
| | - Caterina Tonon
- Department of Biomedical and Neuromotor Sciences (DIBINEM), Alma Mater Studiorum-University of Bologna, Bologna, Italy
- IRCCS Istituto delle Scienze Neurologiche di Bologna, Bologna, Italy
| | - Luca Morandi
- Department of Biomedical and Neuromotor Sciences (DIBINEM), Alma Mater Studiorum-University of Bologna, Bologna, Italy
- IRCCS Istituto delle Scienze Neurologiche di Bologna, Bologna, Italy
| | - Rocco Liguori
- Department of Biomedical and Neuromotor Sciences (DIBINEM), Alma Mater Studiorum-University of Bologna, Bologna, Italy
- IRCCS Istituto delle Scienze Neurologiche di Bologna, Bologna, Italy
| | - Aurelia Petrini
- Nephrology Division, “S. Giovanni Battista Nuovo” Hospital, Foligno, Italy
| | - Rachele Brugnano
- Department of Nephrology and Dialysis, S. Maria della Misericordia Hospital, Perugia, Italy
| | - Rachele Del Sordo
- Department of Medicine and Surgery, Section of Anatomic Pathology and Hystology, Medical School, University of Perugia, Perugia, Italy
| | - Carla Covarelli
- Department of Medicine and Surgery, Section of Anatomic Pathology and Hystology, Medical School, University of Perugia, Perugia, Italy
| | - Manrico Morroni
- Department of Experimental and Clinical Medicine, Section of Neuroscience and Cell Biology, School of Medicine, Università Politecnica delle Marche, Ancona, Italy
| | - Raffaele Lodi
- Department of Biomedical and Neuromotor Sciences (DIBINEM), Alma Mater Studiorum-University of Bologna, Bologna, Italy
- IRCCS Istituto delle Scienze Neurologiche di Bologna, Bologna, Italy
| | - Valerio Carelli
- Department of Biomedical and Neuromotor Sciences (DIBINEM), Alma Mater Studiorum-University of Bologna, Bologna, Italy
- IRCCS Istituto delle Scienze Neurologiche di Bologna, Bologna, Italy
- *Correspondence: Valerio Carelli,
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15
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Ng YS, Lax NZ, Blain AP, Erskine D, Baker MR, Polvikoski T, Thomas RH, Morris CM, Lai M, Whittaker RG, Gebbels A, Winder A, Hall J, Feeney C, Farrugia ME, Hirst C, Roberts M, Lawthom C, Chrysostomou A, Murphy K, Baird T, Maddison P, Duncan C, Poulton J, Nesbitt V, Hanna MG, Pitceathly RDS, Taylor RW, Blakely EL, Schaefer AM, Turnbull DM, McFarland R, Gorman GS. Forecasting stroke-like episodes and outcomes in mitochondrial disease. Brain 2022; 145:542-554. [PMID: 34927673 PMCID: PMC9014738 DOI: 10.1093/brain/awab353] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Revised: 07/16/2021] [Accepted: 08/06/2021] [Indexed: 12/03/2022] Open
Abstract
In this retrospective, multicentre, observational cohort study, we sought to determine the clinical, radiological, EEG, genetics and neuropathological characteristics of mitochondrial stroke-like episodes and to identify associated risk predictors. Between January 1998 and June 2018, we identified 111 patients with genetically determined mitochondrial disease who developed stroke-like episodes. Post-mortem cases of mitochondrial disease (n = 26) were identified from Newcastle Brain Tissue Resource. The primary outcome was to interrogate the clinico-radiopathological correlates and prognostic indicators of stroke-like episode in patients with mitochondrial encephalomyopathy, lactic acidosis and stroke-like episodes syndrome (MELAS). The secondary objective was to develop a multivariable prediction model to forecast stroke-like episode risk. The most common genetic cause of stroke-like episodes was the m.3243A>G variant in MT-TL1 (n = 66), followed by recessive pathogenic POLG variants (n = 22), and 11 other rarer pathogenic mitochondrial DNA variants (n = 23). The age of first stroke-like episode was available for 105 patients [mean (SD) age: 31.8 (16.1)]; a total of 35 patients (32%) presented with their first stroke-like episode ≥40 years of age. The median interval (interquartile range) between first and second stroke-like episodes was 1.33 (2.86) years; 43% of patients developed recurrent stroke-like episodes within 12 months. Clinico-radiological, electrophysiological and neuropathological findings of stroke-like episodes were consistent with the hallmarks of medically refractory epilepsy. Patients with POLG-related stroke-like episodes demonstrated more fulminant disease trajectories than cases of m.3243A>G and other mitochondrial DNA pathogenic variants, in terms of the frequency of refractory status epilepticus, rapidity of progression and overall mortality. In multivariate analysis, baseline factors of body mass index, age-adjusted blood m.3243A>G heteroplasmy, sensorineural hearing loss and serum lactate were significantly associated with risk of stroke-like episodes in patients with the m.3243A>G variant. These factors informed the development of a prediction model to assess the risk of developing stroke-like episodes that demonstrated good overall discrimination (area under the curve = 0.87, 95% CI 0.82-0.93; c-statistic = 0.89). Significant radiological and pathological features of neurodegeneration were more evident in patients harbouring pathogenic mtDNA variants compared with POLG: brain atrophy on cranial MRI (90% versus 44%, P < 0.001) and reduced mean brain weight (SD) [1044 g (148) versus 1304 g (142), P = 0.005]. Our findings highlight the often idiosyncratic clinical, radiological and EEG characteristics of mitochondrial stroke-like episodes. Early recognition of seizures and aggressive instigation of treatment may help circumvent or slow neuronal loss and abate increasing disease burden. The risk-prediction model for the m.3243A>G variant can help inform more tailored genetic counselling and prognostication in routine clinical practice.
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Affiliation(s)
- Yi Shiau Ng
- Wellcome Centre for Mitochondrial Research, Translational and Clinical Research Institute; NIHR Newcastle Biomedical Research Centre and Campus for Ageing and Vitality, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
- Directorate of Neurosciences, Royal Victoria Infirmary, The Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne NE1 4LP, UK
- Department of Neurosciences, NHS Highly Specialised Service for Rare Mitochondrial Disorders, Newcastle upon Tyne NE2 4HH, UK
| | - Nichola Z Lax
- Wellcome Centre for Mitochondrial Research, Translational and Clinical Research Institute; NIHR Newcastle Biomedical Research Centre and Campus for Ageing and Vitality, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
| | - Alasdair P Blain
- Wellcome Centre for Mitochondrial Research, Translational and Clinical Research Institute; NIHR Newcastle Biomedical Research Centre and Campus for Ageing and Vitality, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
| | - Daniel Erskine
- Wellcome Centre for Mitochondrial Research, Translational and Clinical Research Institute; NIHR Newcastle Biomedical Research Centre and Campus for Ageing and Vitality, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
| | - Mark R Baker
- Directorate of Neurosciences, Royal Victoria Infirmary, The Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne NE1 4LP, UK
- Campus for Ageing and Vitality, Newcastle Brain Tissue Resource, Newcastle University, Edwardson Building, Newcastle upon Tyne NE4 5PL, UK
| | - Tuomo Polvikoski
- Campus for Ageing and Vitality, Newcastle Brain Tissue Resource, Newcastle University, Edwardson Building, Newcastle upon Tyne NE4 5PL, UK
| | - Rhys H Thomas
- Wellcome Centre for Mitochondrial Research, Translational and Clinical Research Institute; NIHR Newcastle Biomedical Research Centre and Campus for Ageing and Vitality, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
- Directorate of Neurosciences, Royal Victoria Infirmary, The Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne NE1 4LP, UK
- Department of Neurosciences, NHS Highly Specialised Service for Rare Mitochondrial Disorders, Newcastle upon Tyne NE2 4HH, UK
| | - Christopher M Morris
- Campus for Ageing and Vitality, Newcastle Brain Tissue Resource, Newcastle University, Edwardson Building, Newcastle upon Tyne NE4 5PL, UK
| | - Ming Lai
- Directorate of Neurosciences, Royal Victoria Infirmary, The Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne NE1 4LP, UK
| | - Roger G Whittaker
- Directorate of Neurosciences, Royal Victoria Infirmary, The Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne NE1 4LP, UK
- Translational and Clinical Research Institute, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
| | - Alasdair Gebbels
- Directorate of Neurosciences, Royal Victoria Infirmary, The Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne NE1 4LP, UK
| | - Amy Winder
- Directorate of Neurosciences, Royal Victoria Infirmary, The Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne NE1 4LP, UK
| | - Julie Hall
- Directorate of Neurosciences, Royal Victoria Infirmary, The Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne NE1 4LP, UK
| | - Catherine Feeney
- Wellcome Centre for Mitochondrial Research, Translational and Clinical Research Institute; NIHR Newcastle Biomedical Research Centre and Campus for Ageing and Vitality, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
- Directorate of Neurosciences, Royal Victoria Infirmary, The Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne NE1 4LP, UK
- Department of Neurosciences, NHS Highly Specialised Service for Rare Mitochondrial Disorders, Newcastle upon Tyne NE2 4HH, UK
| | - Maria Elena Farrugia
- Institute of Neurological Sciences, Queen Elizabeth University Hospital, Glasgow G51 4TF, UK
| | - Claire Hirst
- Trust Headquarters, One Talbot Gateway, Baglan Energy Park, Baglan, Port Talbot SA12 7BR, UK
| | - Mark Roberts
- Greater Manchester Neuroscience Centre, Salford Royal NHS Foundation Trust, Manchester Academic Health Science Centre, Salford M6 8HD, UK
| | - Charlotte Lawthom
- Aneurin Bevan Epilepsy Specialist Team, Aneurin Bevan University Health Board, Newport, NP20 2UB, UK
| | - Alexia Chrysostomou
- Wellcome Centre for Mitochondrial Research, Translational and Clinical Research Institute; NIHR Newcastle Biomedical Research Centre and Campus for Ageing and Vitality, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
| | - Kevin Murphy
- Department of Neurology, Sligo University Hospital, Sligo F91 H684, Ireland
| | - Tracey Baird
- Institute of Neurological Sciences, Queen Elizabeth University Hospital, Glasgow G51 4TF, UK
| | - Paul Maddison
- Department of Neurology, Queen’s Medical Centre, Nottingham NG7 2UH, UK
| | - Callum Duncan
- Department of Neurology, Aberdeen Royal Infirmary, NHS Grampian, Aberdeen AB25 2ZN, UK
| | - Joanna Poulton
- Nuffield Department of Women’s and Reproductive Health, University of Oxford, Oxford OX3 9DU, UK
| | - Victoria Nesbitt
- Department of Paediatrics, Medical Sciences Division, Oxford University, Oxford OX3 9DU, UK
- Department of Paediatrics, The Children's Hospital, Oxford, OX3 9DU, UK
| | - Michael G Hanna
- Department of Neuromuscular Diseases, University College London Queen Square Institute of Neurology and The National Hospital for Neurology and Neurosurgery, London WC1N 3BG, UK
| | - Robert D S Pitceathly
- Department of Neuromuscular Diseases, University College London Queen Square Institute of Neurology and The National Hospital for Neurology and Neurosurgery, London WC1N 3BG, UK
| | - Robert W Taylor
- Wellcome Centre for Mitochondrial Research, Translational and Clinical Research Institute; NIHR Newcastle Biomedical Research Centre and Campus for Ageing and Vitality, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
- Department of Neurosciences, NHS Highly Specialised Service for Rare Mitochondrial Disorders, Newcastle upon Tyne NE2 4HH, UK
| | - Emma L Blakely
- Wellcome Centre for Mitochondrial Research, Translational and Clinical Research Institute; NIHR Newcastle Biomedical Research Centre and Campus for Ageing and Vitality, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
- Department of Neurosciences, NHS Highly Specialised Service for Rare Mitochondrial Disorders, Newcastle upon Tyne NE2 4HH, UK
| | - Andrew M Schaefer
- Wellcome Centre for Mitochondrial Research, Translational and Clinical Research Institute; NIHR Newcastle Biomedical Research Centre and Campus for Ageing and Vitality, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
- Directorate of Neurosciences, Royal Victoria Infirmary, The Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne NE1 4LP, UK
- Department of Neurosciences, NHS Highly Specialised Service for Rare Mitochondrial Disorders, Newcastle upon Tyne NE2 4HH, UK
| | - Doug M Turnbull
- Wellcome Centre for Mitochondrial Research, Translational and Clinical Research Institute; NIHR Newcastle Biomedical Research Centre and Campus for Ageing and Vitality, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
- Department of Neurosciences, NHS Highly Specialised Service for Rare Mitochondrial Disorders, Newcastle upon Tyne NE2 4HH, UK
| | - Robert McFarland
- Wellcome Centre for Mitochondrial Research, Translational and Clinical Research Institute; NIHR Newcastle Biomedical Research Centre and Campus for Ageing and Vitality, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
- Department of Neurosciences, NHS Highly Specialised Service for Rare Mitochondrial Disorders, Newcastle upon Tyne NE2 4HH, UK
| | - Gráinne S Gorman
- Wellcome Centre for Mitochondrial Research, Translational and Clinical Research Institute; NIHR Newcastle Biomedical Research Centre and Campus for Ageing and Vitality, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
- Directorate of Neurosciences, Royal Victoria Infirmary, The Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne NE1 4LP, UK
- Department of Neurosciences, NHS Highly Specialised Service for Rare Mitochondrial Disorders, Newcastle upon Tyne NE2 4HH, UK
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16
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Na J, Lee Y. Genotype-phenotype analysis of MT-ATP6-associated Leigh syndrome. Acta Neurol Scand 2022; 145:414-422. [PMID: 34877647 DOI: 10.1111/ane.13566] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2021] [Revised: 11/25/2021] [Accepted: 11/27/2021] [Indexed: 11/29/2022]
Abstract
OBJECTIVES Mitochondrial DNA (mtDNA)-associated Leigh syndrome (LS) is characterized by maternal inheritance, and the heteroplasmic mutant load of mtDNA pathogenic variants is known to affect clinical phenotypes. Among mtDNA pathogenic variants, variants of the MT-ATP6 gene account for most of reported cases. In this report, we aimed to describe the clinical and genetic findings of MT-ATP6-associated LS patients diagnosed at a single tertiary institution in Korea. METHODS Thirteen patients with genetically confirmed MT-ATP6-associated LS were selected. We reviewed each patient's clinical findings, including general characteristics, biochemical parameters, brain MR images, muscle biopsy results, and heteroplasmic mutant load over a long-term follow-up period. RESULTS MT-ATP6-associated LS was of predominantly early onset (age <2 years), although we identified 2 late-onset (>60 months) LS patients. The heteroplasmic mutant load estimated by next-generation sequencing was 96%-100% in all nucleotide change groups. Compared with other forms of MT-ATP6-associated LS, the m.8993T>G point mutation elicited a significantly higher rate of symptom onset before 2 years of age. Brain MRI showed bilateral basal ganglia involvement in all patients, followed by cerebral atrophy, brainstem and thalamus involvement, and cerebellar atrophy. After follow-up (median 7.2 years, range 1.4 to 11.5 years), LS with m.8993T>G point mutations had a slightly more severe clinical progression compared with other forms of MT-ATP6-associated LS. CONCLUSIONS MT-ATP6-associated LS patients presented with a broad spectrum of clinical diagnoses and had a very high heteroplasmic mutant load. This study provides valuable data on MT-ATP6-associated LS that will inform subsequent studies on LS.
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Affiliation(s)
- Ji‐Hoon Na
- Department of Pediatrics Yonsei University College of Medicine Seoul Korea
| | - Young‐Mock Lee
- Department of Pediatrics Yonsei University College of Medicine Seoul Korea
- Epilepsy Research Institute Yonsei University College of Medicine Seoul Korea
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17
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Zhang X, Farrell JJ, Tong T, Hu J, Zhu C, Wang L, Mayeux R, Haines JL, Pericak‐Vance MA, Schellenberg GD, Lunetta KL, Farrer LA. Association of mitochondrial variants and haplogroups identified by whole exome sequencing with Alzheimer's disease. Alzheimers Dement 2022; 18:294-306. [PMID: 34152079 PMCID: PMC8764625 DOI: 10.1002/alz.12396] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Revised: 05/03/2021] [Accepted: 05/04/2021] [Indexed: 12/30/2022]
Abstract
INTRODUCTION Findings regarding the association between mitochondrial DNA (mtDNA) variants and Alzheimer's disease (AD) are inconsistent. METHODS We developed a pipeline for accurate assembly and variant calling in mitochondrial genomes embedded within whole exome sequences (WES) from 10,831 participants from the Alzheimer's Disease Sequencing Project (ADSP). Association of AD risk was evaluated with each mtDNA variant and variants located in 1158 nuclear genes related to mitochondrial function using the SCORE test. Gene-based tests were performed using SKAT-O. RESULTS Analysis of 4220 mtDNA variants revealed study-wide significant association of AD with a rare MT-ND4L variant (rs28709356 C>T; minor allele frequency = 0.002; P = 7.3 × 10-5 ) as well as with MT-ND4L in a gene-based test (P = 6.71 × 10-5 ). Significant association was also observed with a MT-related nuclear gene, TAMM41, in a gene-based test (P = 2.7 × 10-5 ). The expression of TAMM41 was lower in AD cases than controls (P = .00046) or mild cognitive impairment cases (P = .03). DISCUSSION Significant findings in MT-ND4L and TAMM41 provide evidence for a role of mitochondria in AD.
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Affiliation(s)
- Xiaoling Zhang
- Department of Medicine (Biomedical Genetics)Boston University School of Medicine72 East Concord StreetBostonMassachusetts02118USA
- Department of BiostatisticsBoston University School of Public Health801 Massachusetts Avenue 3rd FloorBostonMassachusetts02118USA
| | - John J. Farrell
- Department of Medicine (Biomedical Genetics)Boston University School of Medicine72 East Concord StreetBostonMassachusetts02118USA
| | - Tong Tong
- Department of Medicine (Biomedical Genetics)Boston University School of Medicine72 East Concord StreetBostonMassachusetts02118USA
| | - Junming Hu
- Department of Medicine (Biomedical Genetics)Boston University School of Medicine72 East Concord StreetBostonMassachusetts02118USA
| | - Congcong Zhu
- Department of Medicine (Biomedical Genetics)Boston University School of Medicine72 East Concord StreetBostonMassachusetts02118USA
| | | | - Li‐San Wang
- Department of Pathology and Laboratory MedicineUniversity of Pennsylvania Perelman School of MedicinePhiladelphiaPennsylvania19104USA
| | - Richard Mayeux
- Department of NeurologyColumbia UniversityNew YorkNew York10032USA
| | - Jonathan L. Haines
- Department of Population and Quantitative Health Sciences Case Western Reserve UniversityClevelandOhio44106USA
| | | | - Gerard D. Schellenberg
- Department of Pathology and Laboratory MedicineUniversity of Pennsylvania Perelman School of MedicinePhiladelphiaPennsylvania19104USA
| | - Kathryn L. Lunetta
- Department of BiostatisticsBoston University School of Public Health801 Massachusetts Avenue 3rd FloorBostonMassachusetts02118USA
| | - Lindsay A. Farrer
- Department of Medicine (Biomedical Genetics)Boston University School of Medicine72 East Concord StreetBostonMassachusetts02118USA
- Department of BiostatisticsBoston University School of Public Health801 Massachusetts Avenue 3rd FloorBostonMassachusetts02118USA
- Department of NeurologyBoston University School of MedicineBostonMassachusetts02118USA
- Department of OphthalmologyBoston University School of MedicineBostonMassachusetts02118USA
- Department of EpidemiologyBoston University School of Public Health715 Albany StreetBostonMassachusetts02118USA
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18
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Stenton SL, Zou Y, Cheng H, Liu Z, Wang J, Shen D, Jin H, Ding C, Tang X, Sun S, Han H, Ma Y, Zhang W, Jin R, Wang H, Sun D, Lv JL, Prokisch H, Fang F. Leigh syndrome: a study of 209 patients at the Beijing Children's Hospital. Ann Neurol 2022; 91:466-482. [PMID: 35094435 DOI: 10.1002/ana.26313] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2021] [Revised: 01/25/2022] [Accepted: 01/27/2022] [Indexed: 11/12/2022]
Affiliation(s)
- Sarah L. Stenton
- Institute of Human Genetics, School of Medicine Technical University of Munich Munich Germany
- Institute of Neurogenomics Helmholtz Zentrum München Neuherberg Germany
| | - Ying Zou
- Department of Neurology, National Center for Children's Health, Beijing Children's Hospital Capital Medical University Beijing China
| | - Hua Cheng
- Image Center, National Center for Children's Health, Beijing Children's Hospital Capital Medical University Beijing China
| | - Zhimei Liu
- Department of Neurology, National Center for Children's Health, Beijing Children's Hospital Capital Medical University Beijing China
| | - Junling Wang
- Department of Neurology, National Center for Children's Health, Beijing Children's Hospital Capital Medical University Beijing China
| | - Danmin Shen
- Department of Neurology, National Center for Children's Health, Beijing Children's Hospital Capital Medical University Beijing China
| | - Hong Jin
- Department of Neurology, National Center for Children's Health, Beijing Children's Hospital Capital Medical University Beijing China
| | - Changhong Ding
- Department of Neurology, National Center for Children's Health, Beijing Children's Hospital Capital Medical University Beijing China
| | - Xiaolu Tang
- Image Center, National Center for Children's Health, Beijing Children's Hospital Capital Medical University Beijing China
| | - Suzhen Sun
- Department of Neurology Children's Hospital of Hebei Province Shijiazhuang China
| | - Hong Han
- Department of Neurology Children's Hospital of Shanxi Province Taiyuan China
| | - Yanli Ma
- Department of Neurology Children's Hospital Affiliated to Zhengzhou University, Henan Children's Hospital Zhengzhou China
| | - Weihua Zhang
- Department of Neurology, National Center for Children's Health, Beijing Children's Hospital Capital Medical University Beijing China
- Department of Neurology Children's Hospital Affiliated to Zhengzhou University, Henan Children's Hospital Zhengzhou China
| | - Ruifeng Jin
- Department of Neurology Qilu Children's Hospital of Shandong University Jinan China
| | - Hua Wang
- Department of Pediatrics Shengjing Hospital of China Medical University Shenyang China
| | - Dan Sun
- Department of Neurology Wuhan Children's Hospital Wuhan China
| | - Jun Lan Lv
- Department of Neurology, National Center for Children's Health, Beijing Children's Hospital Capital Medical University Beijing China
| | - Holger Prokisch
- Institute of Human Genetics, School of Medicine Technical University of Munich Munich Germany
- Institute of Neurogenomics Helmholtz Zentrum München Neuherberg Germany
| | - Fang Fang
- Department of Neurology, National Center for Children's Health, Beijing Children's Hospital Capital Medical University Beijing China
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19
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Shimura M, Onuki T, Sugiyama Y, Matsuhashi T, Ebihara T, Fushimi T, Tajika M, Ichimoto K, Matsunaga A, Tsuruoka T, Nitta KR, Imai-Okazaki A, Yatsuka Y, Kishita Y, Ohtake A, Okazaki Y, Murayama K. Development of Leigh syndrome with a high probability of cardiac manifestations in infantile-onset patients with m.14453G > A. Mitochondrion 2021; 63:1-8. [PMID: 34933128 DOI: 10.1016/j.mito.2021.12.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2021] [Revised: 11/24/2021] [Accepted: 12/15/2021] [Indexed: 10/19/2022]
Abstract
The m.14453G > A mutation in MT-ND6 has been described in a few patients with mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes or Leigh syndrome.However, the clinical spectrum and molecular characteristics are unclear.Here, we present four infantile-onset patients with m.14453G > A-associated Leigh syndrome. All four patients had brainstem lesions with basal ganglia lesions, and two patients had cardiac manifestations. Decreased ND6 protein expression and immunoreactivity were observed in patient-derived samples. There was no clear correlation between heteroplasmy levels and onset age or between heteroplasmy levels and phenotype; however, infantile onset was associated with Leigh syndrome.
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Affiliation(s)
- Masaru Shimura
- Center for Medical Genetics, Department of Metabolism, Chiba Children's Hospital, 579-1 Heta-cho Midori-ku, Chiba 266-0007, Japan
| | - Takanori Onuki
- Center for Medical Genetics, Department of Metabolism, Chiba Children's Hospital, 579-1 Heta-cho Midori-ku, Chiba 266-0007, Japan
| | - Yohei Sugiyama
- Center for Medical Genetics, Department of Metabolism, Chiba Children's Hospital, 579-1 Heta-cho Midori-ku, Chiba 266-0007, Japan
| | - Tetsuro Matsuhashi
- Center for Medical Genetics, Department of Metabolism, Chiba Children's Hospital, 579-1 Heta-cho Midori-ku, Chiba 266-0007, Japan
| | - Tomohiro Ebihara
- Center for Medical Genetics, Department of Metabolism, Chiba Children's Hospital, 579-1 Heta-cho Midori-ku, Chiba 266-0007, Japan
| | - Takuya Fushimi
- Center for Medical Genetics, Department of Metabolism, Chiba Children's Hospital, 579-1 Heta-cho Midori-ku, Chiba 266-0007, Japan
| | - Makiko Tajika
- Center for Medical Genetics, Department of Metabolism, Chiba Children's Hospital, 579-1 Heta-cho Midori-ku, Chiba 266-0007, Japan
| | - Keiko Ichimoto
- Center for Medical Genetics, Department of Metabolism, Chiba Children's Hospital, 579-1 Heta-cho Midori-ku, Chiba 266-0007, Japan
| | - Ayako Matsunaga
- Center for Medical Genetics, Department of Metabolism, Chiba Children's Hospital, 579-1 Heta-cho Midori-ku, Chiba 266-0007, Japan
| | - Tomoko Tsuruoka
- Center for Medical Genetics, Department of Metabolism, Chiba Children's Hospital, 579-1 Heta-cho Midori-ku, Chiba 266-0007, Japan
| | - Kazuhiro R Nitta
- Diagnostics and Therapeutic of Intractable Diseases, Intractable Disease Research Center, Graduate School of Medicine, Juntendo University, Hongo 2-1-1 Bunkyo-ku, Tokyo 113-8421, Japan
| | - Atsuko Imai-Okazaki
- Diagnostics and Therapeutic of Intractable Diseases, Intractable Disease Research Center, Graduate School of Medicine, Juntendo University, Hongo 2-1-1 Bunkyo-ku, Tokyo 113-8421, Japan
| | - Yukiko Yatsuka
- Diagnostics and Therapeutic of Intractable Diseases, Intractable Disease Research Center, Graduate School of Medicine, Juntendo University, Hongo 2-1-1 Bunkyo-ku, Tokyo 113-8421, Japan
| | - Yoshihito Kishita
- Diagnostics and Therapeutic of Intractable Diseases, Intractable Disease Research Center, Graduate School of Medicine, Juntendo University, Hongo 2-1-1 Bunkyo-ku, Tokyo 113-8421, Japan; Department of Life Science, Faculty of Science and Engineering, Kindai University, 3-4-1 Kowakae, Higashiosaka, Osaka 577-8502, Japan
| | - Akira Ohtake
- Department of Pediatrics & Clinical Genomics, Faculty of Medicine, Saitama Medical University, 38 Morohongo, Moroyama, Saitama 350-0495, Japan
| | - Yasushi Okazaki
- Diagnostics and Therapeutic of Intractable Diseases, Intractable Disease Research Center, Graduate School of Medicine, Juntendo University, Hongo 2-1-1 Bunkyo-ku, Tokyo 113-8421, Japan
| | - Kei Murayama
- Center for Medical Genetics, Department of Metabolism, Chiba Children's Hospital, 579-1 Heta-cho Midori-ku, Chiba 266-0007, Japan; Diagnostics and Therapeutic of Intractable Diseases, Intractable Disease Research Center, Graduate School of Medicine, Juntendo University, Hongo 2-1-1 Bunkyo-ku, Tokyo 113-8421, Japan.
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20
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Ng YS, Bindoff LA, Gorman GS, Klopstock T, Kornblum C, Mancuso M, McFarland R, Sue CM, Suomalainen A, Taylor RW, Thorburn DR, Turnbull DM. Mitochondrial disease in adults: recent advances and future promise. Lancet Neurol 2021; 20:573-584. [PMID: 34146515 DOI: 10.1016/s1474-4422(21)00098-3] [Citation(s) in RCA: 85] [Impact Index Per Article: 28.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Revised: 02/17/2021] [Accepted: 03/17/2021] [Indexed: 02/07/2023]
Abstract
Mitochondrial diseases are some of the most common inherited neurometabolic disorders, and major progress has been made in our understanding, diagnosis, and treatment of these conditions in the past 5 years. Development of national mitochondrial disease cohorts and international collaborations has changed our knowledge of the spectrum of clinical phenotypes and natural history of mitochondrial diseases. Advances in high-throughput sequencing technologies have altered the diagnostic algorithm for mitochondrial diseases by increasingly using a genetics-first approach, with more than 350 disease-causing genes identified to date. While the current management strategy for mitochondrial disease focuses on surveillance for multisystem involvement and effective symptomatic treatment, new endeavours are underway to find better treatments, including repurposing current drugs, use of novel small molecules, and gene therapies. Developments made in reproductive technology offer women the opportunity to prevent transmission of DNA-related mitochondrial disease to their children.
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Affiliation(s)
- Yi Shiau Ng
- Wellcome Centre for Mitochondrial Research, Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, UK; NHS Highly Specialised Service for Rare Mitochondrial Disorders, Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne, UK; Directorate of Neurosciences, Royal Victoria Infirmary, Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne, UK
| | - Laurence A Bindoff
- Department of Clinical Medicine, University of Bergen, Bergen, Norway; Neuro-SysMed, Department of Neurology, Haukeland University Hospital, Bergen, Norway
| | - Gráinne S Gorman
- Wellcome Centre for Mitochondrial Research, Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, UK; NHS Highly Specialised Service for Rare Mitochondrial Disorders, Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne, UK; Directorate of Neurosciences, Royal Victoria Infirmary, Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne, UK
| | - Thomas Klopstock
- Department of Neurology, Friedrich-Baur-Institute, LMU Hospital, Ludwig Maximilians University, Munich, Germany; German Center for Neurodegenerative Diseases, Munich, Germany; Munich Cluster for Systems Neurology, Munich, Germany
| | - Cornelia Kornblum
- Department of Neurology, Neuromuscular Disease Section, University Hospital Bonn, Bonn, Germany; Centre for Rare Diseases, University Hospital Bonn, Bonn, Germany
| | - Michelangelo Mancuso
- Department of Clinical and Experimental Medicine, Neurological Institute, University of Pisa, Italy
| | - Robert McFarland
- Wellcome Centre for Mitochondrial Research, Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, UK; NHS Highly Specialised Service for Rare Mitochondrial Disorders, Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne, UK
| | - Carolyn M Sue
- Department of Neurogenetics, Kolling Institute, Faculty of Medicine and Health, University of Sydney, Sydney, NSW, Australia; Department of Neurology, Royal North Shore Hospital, Northern Sydney Local Health District, St Leonards, NSW, Australia
| | - Anu Suomalainen
- Research Program in Stem Cells and Metabolism, Faculty of Medicine, University of Helsinki, Helsinki, Finland; Neuroscience Centre, HiLife, University of Helsinki, Helsinki, Finland; Helsinki University Hospital, HUSlab, Helsinki, Finland
| | - Robert W Taylor
- Wellcome Centre for Mitochondrial Research, Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, UK; NHS Highly Specialised Service for Rare Mitochondrial Disorders, Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne, UK
| | - David R Thorburn
- Murdoch Children's Research Institute, Royal Children's Hospital, Melbourne, VIC, Australia; Victorian Clinical Genetics Services, Royal Children's Hospital, Melbourne, VIC, Australia; Department of Paediatrics, University of Melbourne, Melbourne, VIC, Australia
| | - Doug M Turnbull
- Wellcome Centre for Mitochondrial Research, Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, UK; NHS Highly Specialised Service for Rare Mitochondrial Disorders, Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne, UK.
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21
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Biochemical consequences of two clinically relevant ND-gene mutations in Escherichia coli respiratory complex I. Sci Rep 2021; 11:12641. [PMID: 34135385 PMCID: PMC8209014 DOI: 10.1038/s41598-021-91631-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Accepted: 05/28/2021] [Indexed: 11/28/2022] Open
Abstract
NADH:ubiquinone oxidoreductase (respiratory complex I) plays a major role in energy metabolism by coupling electron transfer from NADH to quinone with proton translocation across the membrane. Complex I deficiencies were found to be the most common source of human mitochondrial dysfunction that manifest in a wide variety of neurodegenerative diseases. Seven subunits of human complex I are encoded by mitochondrial DNA (mtDNA) that carry an unexpectedly large number of mutations discovered in mitochondria from patients’ tissues. However, whether or how these genetic aberrations affect complex I at a molecular level is unknown. Here, we used Escherichia coli as a model system to biochemically characterize two mutations that were found in mtDNA of patients. The V253AMT-ND5 mutation completely disturbed the assembly of complex I, while the mutation D199GMT-ND1 led to the assembly of a stable complex capable to catalyze redox-driven proton translocation. However, the latter mutation perturbs quinone reduction leading to a diminished activity. D199MT-ND1 is part of a cluster of charged amino acid residues that are suggested to be important for efficient coupling of quinone reduction and proton translocation. A mechanism considering the role of D199MT-ND1 for energy conservation in complex I is discussed.
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22
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Poole OV, Pizzamiglio C, Murphy D, Falabella M, Macken WL, Bugiardini E, Woodward CE, Labrum R, Efthymiou S, Salpietro V, Chelban V, Kaiyrzhanov R, Maroofian R, Amato AA, Gregory A, Hayflick SJ, Jonvik H, Wood N, Houlden H, Vandrovcova J, Hanna MG, Pittman A, Pitceathly RD. Mitochondrial DNA Analysis from Exome Sequencing Data Improves Diagnostic Yield in Neurological Diseases. Ann Neurol 2021; 89:1240-1247. [PMID: 33704825 PMCID: PMC8494076 DOI: 10.1002/ana.26063] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2020] [Revised: 03/05/2021] [Accepted: 03/08/2021] [Indexed: 12/18/2022]
Abstract
A rapidly expanding catalog of neurogenetic disorders has encouraged a diagnostic shift towards early clinical whole exome sequencing (WES). Adult primary mitochondrial diseases (PMDs) frequently exhibit neurological manifestations that overlap with other nervous system disorders. However, mitochondrial DNA (mtDNA) is not routinely analyzed in standard clinical WES bioinformatic pipelines. We reanalyzed 11,424 exomes, enriched with neurological diseases, for pathogenic mtDNA variants. Twenty-four different mtDNA mutations were detected in 64 exomes, 11 of which were considered disease causing based on the associated clinical phenotypes. These findings highlight the diagnostic uplifts gained by analyzing mtDNA from WES data in neurological diseases. ANN NEUROL 2021;89:1240-1247.
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Affiliation(s)
- Olivia V. Poole
- Department of Neuromuscular DiseasesUCL Queen Square Institute of Neurology and The National Hospital for Neurology and NeurosurgeryLondonUK
| | - Chiara Pizzamiglio
- Department of Neuromuscular DiseasesUCL Queen Square Institute of Neurology and The National Hospital for Neurology and NeurosurgeryLondonUK
| | - David Murphy
- Department of Clinical and Movement NeurosciencesUCL Queen Square Institute of Neurology and The National Hospital for Neurology and NeurosurgeryLondonUK
| | - Micol Falabella
- Department of Neuromuscular DiseasesUCL Queen Square Institute of NeurologyLondonUK
| | - William L. Macken
- Department of Neuromuscular DiseasesUCL Queen Square Institute of Neurology and The National Hospital for Neurology and NeurosurgeryLondonUK
| | - Enrico Bugiardini
- Department of Neuromuscular DiseasesUCL Queen Square Institute of Neurology and The National Hospital for Neurology and NeurosurgeryLondonUK
| | - Cathy E. Woodward
- Neurogenetics UnitThe National Hospital for Neurology and NeurosurgeryLondonUK
| | - Robyn Labrum
- Neurogenetics UnitThe National Hospital for Neurology and NeurosurgeryLondonUK
| | - Stephanie Efthymiou
- Department of Neuromuscular DiseasesUCL Queen Square Institute of Neurology and The National Hospital for Neurology and NeurosurgeryLondonUK
| | - Vincenzo Salpietro
- Department of Neuromuscular DiseasesUCL Queen Square Institute of Neurology and The National Hospital for Neurology and NeurosurgeryLondonUK
| | - Viorica Chelban
- Department of Neuromuscular DiseasesUCL Queen Square Institute of Neurology and The National Hospital for Neurology and NeurosurgeryLondonUK
| | - Rauan Kaiyrzhanov
- Department of Neuromuscular DiseasesUCL Queen Square Institute of Neurology and The National Hospital for Neurology and NeurosurgeryLondonUK
| | - Reza Maroofian
- Department of Neuromuscular DiseasesUCL Queen Square Institute of Neurology and The National Hospital for Neurology and NeurosurgeryLondonUK
| | | | - Anthony A. Amato
- Department of NeurologyBrigham and Women's Hospital and Harvard Medical SchoolBostonMA
| | - Allison Gregory
- Departments of Molecular and Medical Genetics, Pediatrics, and NeurologyOregon Health and Science UniversityPortlandOR
| | - Susan J. Hayflick
- Departments of Molecular and Medical Genetics, Pediatrics, and NeurologyOregon Health and Science UniversityPortlandOR
| | | | - Hallgeir Jonvik
- Department of Clinical and Movement NeurosciencesUCL Queen Square Institute of Neurology and The National Hospital for Neurology and NeurosurgeryLondonUK
| | - Nicholas Wood
- Department of Clinical and Movement NeurosciencesUCL Queen Square Institute of Neurology and The National Hospital for Neurology and NeurosurgeryLondonUK
| | - Henry Houlden
- Department of Neuromuscular DiseasesUCL Queen Square Institute of Neurology and The National Hospital for Neurology and NeurosurgeryLondonUK
| | - Jana Vandrovcova
- Department of Neuromuscular DiseasesUCL Queen Square Institute of Neurology and The National Hospital for Neurology and NeurosurgeryLondonUK
| | - Michael G. Hanna
- Department of Neuromuscular DiseasesUCL Queen Square Institute of Neurology and The National Hospital for Neurology and NeurosurgeryLondonUK
| | - Alan Pittman
- Genetics Research CentreSt. George's, University of LondonLondonUK
| | - Robert D.S. Pitceathly
- Department of Neuromuscular DiseasesUCL Queen Square Institute of Neurology and The National Hospital for Neurology and NeurosurgeryLondonUK
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23
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Engvall M, Kawasaki A, Carelli V, Wibom R, Bruhn H, Lesko N, Schober FA, Wredenberg A, Wedell A, Träisk F. Case Report: A Novel Mutation in the Mitochondrial MT-ND5 Gene Is Associated With Leber Hereditary Optic Neuropathy (LHON). Front Neurol 2021; 12:652590. [PMID: 33841319 PMCID: PMC8027302 DOI: 10.3389/fneur.2021.652590] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Accepted: 03/02/2021] [Indexed: 11/13/2022] Open
Abstract
Leber hereditary optic neuropathy (LHON) is a mitochondrial disease causing severe bilateral visual loss, typically in young adults. The disorder is commonly caused by one of three primary point mutations in mitochondrial DNA, but a number of other rare mutations causing or associated with the clinical syndrome of LHON have been reported. The mutations in LHON are almost exclusively located in genes encoding subunits of complex I in the mitochondrial respiratory chain. Here we report two patients, a mother and her son, with the typical LHON phenotype. Genetic investigations for the three common mutations were negative, instead we found a new and previously unreported mutation in mitochondrial DNA. This homoplasmic mutation, m.13345G>A, is located in the MT-ND5 gene, encoding a core subunit in complex I in the mitochondrial respiratory chain. Investigation of the patients mitochondrial respiratory chain in muscle found a mild defect in the combined activity of complex I+III. In the literature six other mutations in the MT-ND5 gene have been associated with LHON and by this report a new putative mutation in the MT-ND5 can be added.
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Affiliation(s)
- Martin Engvall
- Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden.,Centre for Inherited Metabolic Diseases, Karolinska University Hospital, Stockholm, Sweden
| | - Aki Kawasaki
- Hopital Ophtalmique Jules Gonin, Fondation Asile des Aveugles, University of Lausanne, Lausanne, Switzerland
| | - Valerio Carelli
- Programma di Neurogenetica, IRCCS Istituto delle Scienze Neurologiche di Bologna, Bologna, Italy.,Department of Biomedical and Neuromotor Sciences (DIBINEM), University of Bologna, Bologna, Italy
| | - Rolf Wibom
- Centre for Inherited Metabolic Diseases, Karolinska University Hospital, Stockholm, Sweden.,Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
| | - Helene Bruhn
- Centre for Inherited Metabolic Diseases, Karolinska University Hospital, Stockholm, Sweden.,Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
| | - Nicole Lesko
- Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden.,Centre for Inherited Metabolic Diseases, Karolinska University Hospital, Stockholm, Sweden
| | - Florian A Schober
- Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden
| | - Anna Wredenberg
- Centre for Inherited Metabolic Diseases, Karolinska University Hospital, Stockholm, Sweden.,Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
| | - Anna Wedell
- Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden.,Centre for Inherited Metabolic Diseases, Karolinska University Hospital, Stockholm, Sweden
| | - Frank Träisk
- Department of Clinical Neuroscience, Division of Eye and Vision, St. Erik Eye Hospital, Karolinska Institutet, Solna, Sweden.,Department of Neuro-Ophthalmology, St.Erik Eye Hospital, Solna, Sweden
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24
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Pozzi A, Dowling DK. Small mitochondrial RNAs as mediators of nuclear gene regulation, and potential implications for human health. Bioessays 2021; 43:e2000265. [PMID: 33763872 DOI: 10.1002/bies.202000265] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Revised: 03/03/2021] [Accepted: 03/05/2021] [Indexed: 02/06/2023]
Abstract
Much research has focused on the effects of pathogenic mitochondrial mutations on health. Notwithstanding, the mechanisms regulating the link between these mutations and their effects remain elusive in several cases. Here, we propose that certain mitochondrial mutations may disrupt function of a set of mitochondrial-transcribed small RNAs, perturbing communication between mitochondria and nucleus, leading to disease. Our hypothesis synthesises two lines of supporting evidence. First, several mitochondrial mutations cannot be directly linked to effects on energy production or protein synthesis. Second, emerging studies have described the existence of small RNAs encoded by the mitochondria and proposed their involvement in RNA interference. We present a roadmap to testing this hypothesis.
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Affiliation(s)
- Andrea Pozzi
- School of Biological Sciences, Monash University, Melbourne, Victoria, Australia
| | - Damian K Dowling
- School of Biological Sciences, Monash University, Melbourne, Victoria, Australia
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25
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Gusic M, Prokisch H. Genetic basis of mitochondrial diseases. FEBS Lett 2021; 595:1132-1158. [PMID: 33655490 DOI: 10.1002/1873-3468.14068] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Revised: 02/17/2021] [Accepted: 02/18/2021] [Indexed: 12/13/2022]
Abstract
Mitochondrial disorders are monogenic disorders characterized by a defect in oxidative phosphorylation and caused by pathogenic variants in one of over 340 different genes. The implementation of whole-exome sequencing has led to a revolution in their diagnosis, duplicated the number of associated disease genes, and significantly increased the diagnosed fraction. However, the genetic etiology of a substantial fraction of patients exhibiting mitochondrial disorders remains unknown, highlighting limitations in variant detection and interpretation, which calls for improved computational and DNA sequencing methods, as well as the addition of OMICS tools. More intriguingly, this also suggests that some pathogenic variants lie outside of the protein-coding genes and that the mechanisms beyond the Mendelian inheritance and the mtDNA are of relevance. This review covers the current status of the genetic basis of mitochondrial diseases, discusses current challenges and perspectives, and explores the contribution of factors beyond the protein-coding regions and monogenic inheritance in the expansion of the genetic spectrum of disease.
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Affiliation(s)
- Mirjana Gusic
- Institute of Neurogenomics, Helmholtz Zentrum München, Neuherberg, Germany.,Institute of Human Genetics, Technical University of Munich, Germany.,DZHK (German Centre for Cardiovascular Research), Partner Site Munich Heart Alliance, Germany
| | - Holger Prokisch
- Institute of Neurogenomics, Helmholtz Zentrum München, Neuherberg, Germany.,Institute of Human Genetics, Technical University of Munich, Germany
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26
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Blackout in the powerhouse: clinical phenotypes associated with defects in the assembly of OXPHOS complexes and the mitoribosome. Biochem J 2021; 477:4085-4132. [PMID: 33151299 PMCID: PMC7657662 DOI: 10.1042/bcj20190767] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2020] [Revised: 09/29/2020] [Accepted: 10/05/2020] [Indexed: 12/26/2022]
Abstract
Mitochondria produce the bulk of the energy used by almost all eukaryotic cells through oxidative phosphorylation (OXPHOS) which occurs on the four complexes of the respiratory chain and the F1–F0 ATPase. Mitochondrial diseases are a heterogenous group of conditions affecting OXPHOS, either directly through mutation of genes encoding subunits of OXPHOS complexes, or indirectly through mutations in genes encoding proteins supporting this process. These include proteins that promote assembly of the OXPHOS complexes, the post-translational modification of subunits, insertion of cofactors or indeed subunit synthesis. The latter is important for all 13 of the proteins encoded by human mitochondrial DNA, which are synthesised on mitochondrial ribosomes. Together the five OXPHOS complexes and the mitochondrial ribosome are comprised of more than 160 subunits and many more proteins support their biogenesis. Mutations in both nuclear and mitochondrial genes encoding these proteins have been reported to cause mitochondrial disease, many leading to defective complex assembly with the severity of the assembly defect reflecting the severity of the disease. This review aims to act as an interface between the clinical and basic research underpinning our knowledge of OXPHOS complex and ribosome assembly, and the dysfunction of this process in mitochondrial disease.
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Meldau S, Owen EP, Khan K, Riordan GT. Mitochondrial molecular genetic results in a South African cohort: divergent mitochondrial and nuclear DNA findings. J Clin Pathol 2020; 75:34-38. [PMID: 33115810 DOI: 10.1136/jclinpath-2020-207026] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2020] [Revised: 10/09/2020] [Accepted: 10/11/2020] [Indexed: 12/22/2022]
Abstract
AIMS Mitochondrial diseases form one of the largest groups of inborn errors of metabolism. The birth prevalence is approximately 1/5000 in well-studied populations, but little has been reported from Sub-Saharan Africa. The aim of this study was to describe the genetics underlying mitochondrial disease in South Africa. METHODS An audit was performed on all mitochondrial disease genetic testing performed in Cape Town, South Africa. RESULTS Of 1614 samples tested for mitochondrial DNA (mtDNA) or nuclear DNA (nDNA) variants in South Africa between 1994 and 2019, there were 155 (9.6 %) positive results. Pathogenic mtDNA variants accounted for 113 (73%)/155, from 96 families. Mitochondrial encephalopathy with lactic acidosis and stroke-like episodes, 37 (33%)/113, Leber's hereditary optic neuropathy, 26 (23%)/113, and single large mtDNA deletions, 22 (20%)/113, accounted for 76%. Thirty eight of 42 nDNA-positive results were homozygous for the MPV17 pathogenic variant c.106C>T (p.[Gln36Ter, Ser25Profs*49]) causing infantile neurohepatopathy, one of the largest homozygous groups reported in the literature. The other nDNA variants were in TAZ1, CPT2, BOLA3 and SERAC1. None were identified in SURF1, POLG or PDHA1. CONCLUSIONS Finding a large group with a homozygous nuclear pathogenic variant emphasises the importance of looking for possible founder effects. The absence of other widely described pathogenic nDNA variants in this cohort may be due to reduced prevalence or insufficient testing. As advances in therapeutics develop, it is critical to develop diagnostic platforms on the African subcontinent so that population-specific genetic variations can be identified.
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Affiliation(s)
- Surita Meldau
- Division of Chemical Pathology, Department of Pathology, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa .,Chemical Pathology, National Health Laboratory Services, Groote Schuur Hospital, Cape Town, South Africa
| | - Elizabeth Patricia Owen
- Division of Chemical Pathology, Department of Pathology, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa.,Chemical Pathology, National Health Laboratory Services, Groote Schuur Hospital, Cape Town, South Africa
| | - Kashief Khan
- Chemical Pathology, National Health Laboratory Services, Groote Schuur Hospital, Cape Town, South Africa
| | - Gillian Tracy Riordan
- Division of Paediatric Neurology, Department of Paediatrics and Child Health, University of Cape Town, Cape Town, Western Cape, South Africa.,Red Cross War Memorial Children's Hospital, Cape Town, South Africa
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Brusa R, Mauri E, Dell'Arti L, Magri F, Ronchi D, Minorini V, Mainetti C, Gagliardi D, Faravelli I, Meneri M, Bresolin N, Viola F, Corti S, Comi GP. Expanding the clinical spectrum of the mitochondrial mutation A13084T in the ND5 gene. NEUROLOGY-GENETICS 2020; 6:e511. [PMID: 33062892 PMCID: PMC7524578 DOI: 10.1212/nxg.0000000000000511] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/01/2020] [Accepted: 06/11/2020] [Indexed: 11/24/2022]
Affiliation(s)
- Roberta Brusa
- Neurology Unit (R.B., E.M., F,M., D.R., M.M., N.B., S.C.); Ophthalmological Unit (L.D.A., V.M., C.M., F.V.), IRCCS Foundation Ca' Granda Ospedale Maggiore Policlinico; Department of Pathophysiology and Transplantation (D.R., D.G., I.F., N.B., S.C., G.P.C.), Dino Ferrari Center, University of Milan; and Neuromuscular and Rare Diseases Unit (G.P.C.), IRCCS Foundation Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy
| | - Eleonora Mauri
- Neurology Unit (R.B., E.M., F,M., D.R., M.M., N.B., S.C.); Ophthalmological Unit (L.D.A., V.M., C.M., F.V.), IRCCS Foundation Ca' Granda Ospedale Maggiore Policlinico; Department of Pathophysiology and Transplantation (D.R., D.G., I.F., N.B., S.C., G.P.C.), Dino Ferrari Center, University of Milan; and Neuromuscular and Rare Diseases Unit (G.P.C.), IRCCS Foundation Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy
| | - Laura Dell'Arti
- Neurology Unit (R.B., E.M., F,M., D.R., M.M., N.B., S.C.); Ophthalmological Unit (L.D.A., V.M., C.M., F.V.), IRCCS Foundation Ca' Granda Ospedale Maggiore Policlinico; Department of Pathophysiology and Transplantation (D.R., D.G., I.F., N.B., S.C., G.P.C.), Dino Ferrari Center, University of Milan; and Neuromuscular and Rare Diseases Unit (G.P.C.), IRCCS Foundation Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy
| | - Francesca Magri
- Neurology Unit (R.B., E.M., F,M., D.R., M.M., N.B., S.C.); Ophthalmological Unit (L.D.A., V.M., C.M., F.V.), IRCCS Foundation Ca' Granda Ospedale Maggiore Policlinico; Department of Pathophysiology and Transplantation (D.R., D.G., I.F., N.B., S.C., G.P.C.), Dino Ferrari Center, University of Milan; and Neuromuscular and Rare Diseases Unit (G.P.C.), IRCCS Foundation Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy
| | - Dario Ronchi
- Neurology Unit (R.B., E.M., F,M., D.R., M.M., N.B., S.C.); Ophthalmological Unit (L.D.A., V.M., C.M., F.V.), IRCCS Foundation Ca' Granda Ospedale Maggiore Policlinico; Department of Pathophysiology and Transplantation (D.R., D.G., I.F., N.B., S.C., G.P.C.), Dino Ferrari Center, University of Milan; and Neuromuscular and Rare Diseases Unit (G.P.C.), IRCCS Foundation Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy
| | - Valeria Minorini
- Neurology Unit (R.B., E.M., F,M., D.R., M.M., N.B., S.C.); Ophthalmological Unit (L.D.A., V.M., C.M., F.V.), IRCCS Foundation Ca' Granda Ospedale Maggiore Policlinico; Department of Pathophysiology and Transplantation (D.R., D.G., I.F., N.B., S.C., G.P.C.), Dino Ferrari Center, University of Milan; and Neuromuscular and Rare Diseases Unit (G.P.C.), IRCCS Foundation Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy
| | - Claudia Mainetti
- Neurology Unit (R.B., E.M., F,M., D.R., M.M., N.B., S.C.); Ophthalmological Unit (L.D.A., V.M., C.M., F.V.), IRCCS Foundation Ca' Granda Ospedale Maggiore Policlinico; Department of Pathophysiology and Transplantation (D.R., D.G., I.F., N.B., S.C., G.P.C.), Dino Ferrari Center, University of Milan; and Neuromuscular and Rare Diseases Unit (G.P.C.), IRCCS Foundation Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy
| | - Delia Gagliardi
- Neurology Unit (R.B., E.M., F,M., D.R., M.M., N.B., S.C.); Ophthalmological Unit (L.D.A., V.M., C.M., F.V.), IRCCS Foundation Ca' Granda Ospedale Maggiore Policlinico; Department of Pathophysiology and Transplantation (D.R., D.G., I.F., N.B., S.C., G.P.C.), Dino Ferrari Center, University of Milan; and Neuromuscular and Rare Diseases Unit (G.P.C.), IRCCS Foundation Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy
| | - Irene Faravelli
- Neurology Unit (R.B., E.M., F,M., D.R., M.M., N.B., S.C.); Ophthalmological Unit (L.D.A., V.M., C.M., F.V.), IRCCS Foundation Ca' Granda Ospedale Maggiore Policlinico; Department of Pathophysiology and Transplantation (D.R., D.G., I.F., N.B., S.C., G.P.C.), Dino Ferrari Center, University of Milan; and Neuromuscular and Rare Diseases Unit (G.P.C.), IRCCS Foundation Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy
| | - Megi Meneri
- Neurology Unit (R.B., E.M., F,M., D.R., M.M., N.B., S.C.); Ophthalmological Unit (L.D.A., V.M., C.M., F.V.), IRCCS Foundation Ca' Granda Ospedale Maggiore Policlinico; Department of Pathophysiology and Transplantation (D.R., D.G., I.F., N.B., S.C., G.P.C.), Dino Ferrari Center, University of Milan; and Neuromuscular and Rare Diseases Unit (G.P.C.), IRCCS Foundation Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy
| | - Nereo Bresolin
- Neurology Unit (R.B., E.M., F,M., D.R., M.M., N.B., S.C.); Ophthalmological Unit (L.D.A., V.M., C.M., F.V.), IRCCS Foundation Ca' Granda Ospedale Maggiore Policlinico; Department of Pathophysiology and Transplantation (D.R., D.G., I.F., N.B., S.C., G.P.C.), Dino Ferrari Center, University of Milan; and Neuromuscular and Rare Diseases Unit (G.P.C.), IRCCS Foundation Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy
| | - Francesco Viola
- Neurology Unit (R.B., E.M., F,M., D.R., M.M., N.B., S.C.); Ophthalmological Unit (L.D.A., V.M., C.M., F.V.), IRCCS Foundation Ca' Granda Ospedale Maggiore Policlinico; Department of Pathophysiology and Transplantation (D.R., D.G., I.F., N.B., S.C., G.P.C.), Dino Ferrari Center, University of Milan; and Neuromuscular and Rare Diseases Unit (G.P.C.), IRCCS Foundation Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy
| | - Stefania Corti
- Neurology Unit (R.B., E.M., F,M., D.R., M.M., N.B., S.C.); Ophthalmological Unit (L.D.A., V.M., C.M., F.V.), IRCCS Foundation Ca' Granda Ospedale Maggiore Policlinico; Department of Pathophysiology and Transplantation (D.R., D.G., I.F., N.B., S.C., G.P.C.), Dino Ferrari Center, University of Milan; and Neuromuscular and Rare Diseases Unit (G.P.C.), IRCCS Foundation Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy
| | - Giacomo Pietro Comi
- Neurology Unit (R.B., E.M., F,M., D.R., M.M., N.B., S.C.); Ophthalmological Unit (L.D.A., V.M., C.M., F.V.), IRCCS Foundation Ca' Granda Ospedale Maggiore Policlinico; Department of Pathophysiology and Transplantation (D.R., D.G., I.F., N.B., S.C., G.P.C.), Dino Ferrari Center, University of Milan; and Neuromuscular and Rare Diseases Unit (G.P.C.), IRCCS Foundation Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy
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Affiliation(s)
- Yi Shiau Ng
- NHS Highly Specialised Service for Rare Mitochondrial Disorders, Royal Victoria Infirmary, Newcastle upon Tyne, UK
| | - Doug M Turnbull
- NHS Highly Specialised Service for Rare Mitochondrial Disorders, Royal Victoria Infirmary, Newcastle upon Tyne, UK .,NHS Highly Specialised Service for Rare Mitochondrial Disorders, Royal Victoria Infirmary, Newcastle upon Tyne, UK
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30
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Wong LJC, Chen T, Schmitt ES, Wang J, Tang S, Landsverk M, Li F, Zhang S, Wang Y, Zhang VW, Craigen WJ. Clinical and laboratory interpretation of mitochondrial mRNA variants. Hum Mutat 2020; 41:1783-1796. [PMID: 32652755 DOI: 10.1002/humu.24082] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Revised: 06/29/2020] [Accepted: 07/09/2020] [Indexed: 12/26/2022]
Abstract
Interpretation of mitochondrial protein-encoding (mt-mRNA) variants has been challenging due to mitochondrial characteristics that have not been addressed by American College of Medical Genetics and Genomics guidelines. We developed criteria for the interpretation of mt-mRNA variants via literature review of reported variants, tested and refined these criteria by using our new cases, followed by interpreting 421 novel variants in our clinical database using these verified criteria. A total of 32 of 56 previously reported pathogenic (P) variants had convincing evidence for pathogenicity. These variants are either null variants, well-known disease-causing variants, or have robust functional data or strong phenotypic correlation with heteroplasmy levels. Based on our criteria, 65.7% (730/1,111) of variants of unknown significance (VUS) were reclassified as benign (B) or likely benign (LB), and one variant was scored as likely pathogenic (LP). Furthermore, using our criteria we classified 2, 12, and 23 as P, LP, and LB, respectively, among 421 novel variants. The remaining stayed as VUS (91.2%). Appropriate interpretation of mt-mRNA variants is the basis for clinical diagnosis and genetic counseling. Mutation type, heteroplasmy levels in different tissues of the probands and matrilineal relatives, in silico predictions, population data, as well as functional studies are key points for pathogenicity assessments.
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Affiliation(s)
- Lee-Jun C Wong
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas.,Baylor Genetics Laboratory, Houston, Texas
| | - Ting Chen
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas
| | - Eric S Schmitt
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas.,Baylor Genetics Laboratory, Houston, Texas
| | - Jing Wang
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas
| | - Sha Tang
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas
| | - Megan Landsverk
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas
| | - Fangyuan Li
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas
| | - Shulin Zhang
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas
| | - Yue Wang
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas.,Baylor Genetics Laboratory, Houston, Texas
| | - Victor W Zhang
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas
| | - William J Craigen
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas.,Baylor Genetics Laboratory, Houston, Texas
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31
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Yokota Y, Hara M, Akimoto T, Mizoguchi T, Goto YI, Nishino I, Kamei S, Nakajima H. Late-onset MELAS syndrome with mtDNA 14453G→A mutation masquerading as an acute encephalitis: a case report. BMC Neurol 2020; 20:247. [PMID: 32552696 PMCID: PMC7298965 DOI: 10.1186/s12883-020-01818-w] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2020] [Accepted: 06/03/2020] [Indexed: 02/06/2023] Open
Abstract
Background A unique patient with MELAS syndrome, who initially masqueraded as having acute encephalitis and was eventually diagnosed with MELAS syndrome harboring a mtDNA 14453G → A mutation, is described. Case presentation A 74-year-old Japanese man was admitted to another hospital due to acute onset of cognitive impairment and psychosis. After 7 days he was transferred to our hospital with seizures and deteriorating psychosis. The results of primary ancillary tests that included EEG, CSF findings, and brain MRI supported the diagnosis of an acute encephalitis. HSV-DNA and antibodies against neuronal surface antigens in the CSF were all negative. With the assistance of the lactate peak on the brain lesions in the magnetic resonance spectroscopy image and genetic analysis of the biopsied muscle, he was eventually diagnosed with MELAS syndrome harboring mtDNA 14453G → A mutation in the ND6 gene. Conclusions This case provides a caveat that MELAS syndrome can manifest in the symptoms and ancillary tests masquerading as an acute encephalitis caused by infection or autoimmunity. This is the first adult patient seen to harbor the mtDNA14453G → A with a unique onset, which broadens the phenotypic spectrum of MELAS syndrome associated with ND6 gene mutation.
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Affiliation(s)
- Yuki Yokota
- Division of Neurology, Department of Medicine, Nihon University School of Medicine, 30-1, Oyaguchi-Kamicyo, Itabashi-ku, Tokyo, 173-8610, Japan
| | - Makoto Hara
- Division of Neurology, Department of Medicine, Nihon University School of Medicine, 30-1, Oyaguchi-Kamicyo, Itabashi-ku, Tokyo, 173-8610, Japan.
| | - Takayoshi Akimoto
- Division of Neurology, Department of Medicine, Nihon University School of Medicine, 30-1, Oyaguchi-Kamicyo, Itabashi-ku, Tokyo, 173-8610, Japan
| | - Tomotaka Mizoguchi
- Division of Neurology, Department of Medicine, Nihon University School of Medicine, 30-1, Oyaguchi-Kamicyo, Itabashi-ku, Tokyo, 173-8610, Japan
| | - Yu-Ichi Goto
- Medical Genome Center, National Center of Neurology and Psychiatry, Tokyo, Japan.,Department of Mental Retardation and Birth Defect Research, National Institute of Neuroscience, National Center of Neurology and Psychiatry, Tokyo, Japan
| | - Ichizo Nishino
- Department of Neuromuscular Research, National Institute of Neuroscience, National Center of Neurology and Psychiatry, Tokyo, Japan
| | - Satoshi Kamei
- Division of Neurology, Department of Medicine, Nihon University School of Medicine, 30-1, Oyaguchi-Kamicyo, Itabashi-ku, Tokyo, 173-8610, Japan.,Center for Neuro-infection, Department of Neurology, Ageo Central General Hospital, Saitama, Japan
| | - Hideto Nakajima
- Division of Neurology, Department of Medicine, Nihon University School of Medicine, 30-1, Oyaguchi-Kamicyo, Itabashi-ku, Tokyo, 173-8610, Japan
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32
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Cappa R, de Campos C, Maxwell AP, McKnight AJ. "Mitochondrial Toolbox" - A Review of Online Resources to Explore Mitochondrial Genomics. Front Genet 2020; 11:439. [PMID: 32457801 PMCID: PMC7225359 DOI: 10.3389/fgene.2020.00439] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2019] [Accepted: 04/09/2020] [Indexed: 12/30/2022] Open
Abstract
Mitochondria play a significant role in many biological systems. There is emerging evidence that differences in the mitochondrial genome may contribute to multiple common diseases, leading to an increasing number of studies exploring mitochondrial genomics. There is often a large amount of complex data generated (for example via next generation sequencing), which requires optimised bioinformatics tools to efficiently and effectively generate robust outcomes from these large datasets. Twenty-four online resources dedicated to mitochondrial genomics were reviewed. This 'mitochondrial toolbox' summary resource will enable researchers to rapidly identify the resource(s) most suitable for their needs. These resources fulfil a variety of functions, with some being highly specialised. No single tool will provide all users with the resources they require; therefore, the most suitable tool will vary between users depending on the nature of the work they aim to carry out. Genetics resources are well established for phylogeny and DNA sequence changes, but further epigenetic and gene expression resources need to be developed for mitochondrial genomics.
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Affiliation(s)
- Ruaidhri Cappa
- Centre for Public Health, Institute of Clinical Sciences B, Queen's University Belfast, Royal Victoria Hospital, Belfast, United Kingdom
| | - Cassio de Campos
- School of Electronics, Electrical Engineering and Computer Science, Queen's University Belfast, Belfast, United Kingdom
| | - Alexander P Maxwell
- Centre for Public Health, Institute of Clinical Sciences B, Queen's University Belfast, Royal Victoria Hospital, Belfast, United Kingdom
| | - Amy J McKnight
- Centre for Public Health, Institute of Clinical Sciences B, Queen's University Belfast, Royal Victoria Hospital, Belfast, United Kingdom
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Ng YS, Thompson K, Loher D, Hopton S, Falkous G, Hardy SA, Schaefer AM, Shaunak S, Roberts ME, Lilleker JB, Taylor RW. Novel MT-ND Gene Variants Causing Adult-Onset Mitochondrial Disease and Isolated Complex I Deficiency. Front Genet 2020; 11:24. [PMID: 32158465 PMCID: PMC7052259 DOI: 10.3389/fgene.2020.00024] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2019] [Accepted: 01/08/2020] [Indexed: 11/13/2022] Open
Abstract
Mitochondrial complex I deficiency is associated with a diverse range of clinical phenotypes and can arise due to either mitochondrial DNA (mtDNA) or nuclear gene defects. We investigated two adult patients who exhibited non-syndromic neurological features and evidence of isolated mitochondrial complex I deficiency in skeletal muscle biopsies. The first presented with indolent myopathy, progressive since age 17, while the second developed deafness around age 20 and other relapsing-remitting neurological symptoms since. A novel, likely de novo, frameshift variant in MT-ND6 (m.14512_14513del) and a novel maternally-inherited transversion mutation in MT-ND1 were identified, respectively. Skewed tissue segregation of mutant heteroplasmy level was observed; the mutant heteroplasmy levels of both variants were greater than 70% in muscle homogenate, however, in blood the MT-ND6 variant was undetectable while the mutant heteroplasmy level of the MT-ND1 variant was low (12%). Assessment of complex I assembly by Blue-Native PAGE demonstrated a decrease in fully assembled complex I in the muscle of both cases. SDS-PAGE and immunoblotting showed decreased levels of mtDNA-encoded ND1 and several nuclear encoded complex I subunits in both cases, consistent with functional pathogenic consequences of the identified variants. Pathogenicity of the m.14512_14513del was further corroborated by single-fiber segregation studies.
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Affiliation(s)
- Yi Shiau Ng
- Wellcome Centre for Mitochondrial Research, Faculty of Medical Sciences, Translational and Clinical Research Institute, Newcastle University, Newcastle upon Tyne, United Kingdom
- Directorate of Neurosciences, Royal Victoria Infirmary, The Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne, United Kingdom
| | - Kyle Thompson
- Wellcome Centre for Mitochondrial Research, Faculty of Medical Sciences, Translational and Clinical Research Institute, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Daniela Loher
- Wellcome Centre for Mitochondrial Research, Faculty of Medical Sciences, Translational and Clinical Research Institute, Newcastle University, Newcastle upon Tyne, United Kingdom
- Faculty of Medicine, Institute of Biochemistry and Molecular Biology, ZBMZ, University of Freiburg, Freiburg, Germany
| | - Sila Hopton
- Wellcome Centre for Mitochondrial Research, Faculty of Medical Sciences, Translational and Clinical Research Institute, Newcastle University, Newcastle upon Tyne, United Kingdom
- Newcastle upon Tyne Hospitals NHS Foundation Trust, NHS Highly Specialised Service for Rare Mitochondrial Disorders, Newcastle upon Tyne, United Kingdom
| | - Gavin Falkous
- Wellcome Centre for Mitochondrial Research, Faculty of Medical Sciences, Translational and Clinical Research Institute, Newcastle University, Newcastle upon Tyne, United Kingdom
- Newcastle upon Tyne Hospitals NHS Foundation Trust, NHS Highly Specialised Service for Rare Mitochondrial Disorders, Newcastle upon Tyne, United Kingdom
| | - Steven A. Hardy
- Wellcome Centre for Mitochondrial Research, Faculty of Medical Sciences, Translational and Clinical Research Institute, Newcastle University, Newcastle upon Tyne, United Kingdom
- Newcastle upon Tyne Hospitals NHS Foundation Trust, NHS Highly Specialised Service for Rare Mitochondrial Disorders, Newcastle upon Tyne, United Kingdom
| | - Andrew M. Schaefer
- Wellcome Centre for Mitochondrial Research, Faculty of Medical Sciences, Translational and Clinical Research Institute, Newcastle University, Newcastle upon Tyne, United Kingdom
- Directorate of Neurosciences, Royal Victoria Infirmary, The Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne, United Kingdom
| | - Sandip Shaunak
- Department of Neurology, Royal Preston Hospital, Preston, United Kingdom
| | - Mark E. Roberts
- Manchester Centre for Clinical Neuroscience, Salford Royal NHS Foundation Trust, Manchester Academic Health Science Centre, Salford, United Kingdom
| | - James B. Lilleker
- Manchester Centre for Clinical Neuroscience, Salford Royal NHS Foundation Trust, Manchester Academic Health Science Centre, Salford, United Kingdom
- Centre for Musculoskeletal Research, Division of Musculoskeletal and Dermatological Sciences, School of Biological Sciences, The University of Manchester, Manchester, United Kingdom
| | - Robert W. Taylor
- Wellcome Centre for Mitochondrial Research, Faculty of Medical Sciences, Translational and Clinical Research Institute, Newcastle University, Newcastle upon Tyne, United Kingdom
- Newcastle upon Tyne Hospitals NHS Foundation Trust, NHS Highly Specialised Service for Rare Mitochondrial Disorders, Newcastle upon Tyne, United Kingdom
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Multisystem mitochondrial diseases due to mutations in mtDNA-encoded subunits of complex I. BMC Pediatr 2020; 20:41. [PMID: 31996177 PMCID: PMC6988306 DOI: 10.1186/s12887-020-1912-x] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/27/2019] [Accepted: 01/07/2020] [Indexed: 12/18/2022] Open
Abstract
Background Maternally inherited complex I deficiencies due to mutations in MT-ND genes represent a heterogeneous group of multisystem mitochondrial disorders (MD) with a unfavourable prognosis. The aim of the study was to characterize the impact of the mutations in MT-ND genes, including the novel m.13091 T > C variant, on the course of the disease, and to analyse the activities of respiratory chain complexes, the amount of protein subunits, and the mitochondrial energy-generating system (MEGS) in available muscle biopsies and cultivated fibroblasts. Methods The respiratory chain complex activities were measured by spectrophotometry, MEGS were analysed using radiolabelled substrates, and protein amount by SDS-PAGE or BN-PAGE in muscle or fibroblasts. Results In our cohort of 106 unrelated families carrying different mtDNA mutations, we found heteroplasmic mutations in the genes MT-ND1, MT-ND3, and MT-ND5, including the novel variant m.13091 T > C, in 13 patients with MD from 12 families. First symptoms developed between early childhood and adolescence and progressed to multisystem disease with a phenotype of Leigh or MELAS syndromes. MRI revealed bilateral symmetrical involvement of deep grey matter typical of Leigh syndrome in 6 children, cortical/white matter stroke-like lesions suggesting MELAS syndrome in 3 patients, and a combination of cortico-subcortical lesions and grey matter involvement in 4 patients. MEGS indicated mitochondrial disturbances in all available muscle samples, as well as a significantly decreased oxidation of [1-14C] pyruvate in fibroblasts. Spectrophotometric analyses revealed a low activity of complex I and/or complex I + III in all muscle samples except one, but the activities in fibroblasts were mostly normal. No correlation was found between complex I activities and mtDNA mutation load, but higher levels of heteroplasmy were generally found in more severely affected patients. Conclusions Maternally inherited complex I deficiencies were found in 11% of families with mitochondrial diseases in our region. Six patients manifested with Leigh, three with MELAS. The remaining four patients presented with an overlap between these two syndromes. MEGS, especially the oxidation of [1-14C] pyruvate in fibroblasts might serve as a sensitive indicator of functional impairment due to MT-ND mutations. Early onset of the disease and higher level of mtDNA heteroplasmy were associated with a worse prognosis.
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35
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A novel mutation in the mitochondrial MT-ND5 gene in a family with MELAS. The relevance of genetic analysis on targeted tissues. Mitochondrion 2019; 50:14-18. [PMID: 31639449 DOI: 10.1016/j.mito.2019.10.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2019] [Revised: 09/07/2019] [Accepted: 10/04/2019] [Indexed: 11/23/2022]
Abstract
We report the case of two members of the same family with a novel mitochondrial DNA (mtDNA) gene variant in the MT-ND5 gene associated with MELAS syndrome and discuss limitations of genetics studies. The m.13045A > G mutation was detected at very low load in the daughter's urine cells (5%) and at different levels in the skeletal muscle of both mother (50%) and daughter (84%), being absent in blood, hair and saliva. Our findings suggest that non-invasive genetic assessment in urine cells may not be a sensitive diagnostic method neither a good predictor of disease development in relatives of some families with mtDNA-associated MELAS, particularly if involving MT-ND5 gene.
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36
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Ng YS, Martikainen MH, Gorman GS, Blain A, Bugiardini E, Bunting A, Schaefer AM, Alston CL, Blakely EL, Sharma S, Hughes I, Lim A, de Goede C, McEntagart M, Spinty S, Horrocks I, Roberts M, Woodward CE, Chinnery PF, Horvath R, Nesbitt V, Fratter C, Poulton J, Hanna MG, Pitceathly RDS, Taylor RW, Turnbull DM, McFarland R. Pathogenic variants in MT-ATP6: A United Kingdom-based mitochondrial disease cohort study. Ann Neurol 2019; 86:310-315. [PMID: 31187502 PMCID: PMC6771528 DOI: 10.1002/ana.25525] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2019] [Revised: 06/06/2019] [Accepted: 06/07/2019] [Indexed: 12/20/2022]
Abstract
Distinct clinical syndromes have been associated with pathogenic MT-ATP6 variants. In this cohort study, we identified 125 individuals (60 families) including 88 clinically affected individuals and 37 asymptomatic carriers. Thirty-one individuals presented with Leigh syndrome and 7 with neuropathy ataxia retinitis pigmentosa. The remaining 50 patients presented with variable nonsyndromic features including ataxia, neuropathy, and learning disability. We confirmed maternal inheritance in 39 families and demonstrated that tissue segregation patterns and phenotypic threshold are variant dependent. Our findings suggest that MT-ATP6-related mitochondrial DNA disease is best conceptualized as a mitochondrial disease spectrum disorder and should be routinely included in genetic ataxia and neuropathy gene panels. ANN NEUROL 2019;86:310-315.
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Affiliation(s)
- Yi Shiau Ng
- Wellcome Centre for Mitochondrial ResearchNewcastle UniversityNewcastle upon TyneUnited Kingdom
| | - Mika H. Martikainen
- Wellcome Centre for Mitochondrial ResearchNewcastle UniversityNewcastle upon TyneUnited Kingdom
- Faculty of MedicineUniversity of Turku, and Division of Clinical Neurosciences, Turku University HospitalTurkuFinland
| | - Gráinne S. Gorman
- Wellcome Centre for Mitochondrial ResearchNewcastle UniversityNewcastle upon TyneUnited Kingdom
| | - Alasdair Blain
- Wellcome Centre for Mitochondrial ResearchNewcastle UniversityNewcastle upon TyneUnited Kingdom
| | - Enrico Bugiardini
- Medical Research Council Centre for Neuromuscular DiseasesUniversity College London Queen Square Institute of Neurology and National Hospital for Neurology and NeurosurgeryLondonUnited Kingdom
- Department of Neuromuscular DiseasesUniversity College London Queen Square Institute of NeurologyLondonUnited Kingdom
| | - Apphia Bunting
- Nuffield Department of Obstetrics and GynaecologyUniversity of OxfordOxfordUnited Kingdom
| | - Andrew M. Schaefer
- Wellcome Centre for Mitochondrial ResearchNewcastle UniversityNewcastle upon TyneUnited Kingdom
| | - Charlotte L. Alston
- Wellcome Centre for Mitochondrial ResearchNewcastle UniversityNewcastle upon TyneUnited Kingdom
| | - Emma L. Blakely
- Wellcome Centre for Mitochondrial ResearchNewcastle UniversityNewcastle upon TyneUnited Kingdom
| | - Sunil Sharma
- Wellcome Centre for Mitochondrial ResearchNewcastle UniversityNewcastle upon TyneUnited Kingdom
| | - Imelda Hughes
- Royal Manchester Children's HospitalCentral Manchester University Hospitals National Health Service Foundation TrustManchesterUnited Kingdom
| | - Albert Lim
- Wellcome Centre for Mitochondrial ResearchNewcastle UniversityNewcastle upon TyneUnited Kingdom
| | - Christian de Goede
- Department of Paediatric NeurologyRoyal Preston HospitalPrestonUnited Kingdom
| | - Meriel McEntagart
- South West Thames Regional Genetics ServiceSt. George's HospitalLondonUnited Kingdom
| | - Stefan Spinty
- Alder Hey Children's National Health Service Foundation TrustLiverpoolUnited Kingdom
| | - Iain Horrocks
- Greater Glasgow and Clyde National Health Service Yorkhill HospitalGlasgowUnited Kingdom
| | - Mark Roberts
- Greater Manchester Neuroscience CentreSalford Royal National Health Service Foundation Trust, Manchester Academic Health Science CentreSalfordUnited Kingdom
| | - Cathy E. Woodward
- Neurogenetics UnitNational Hospital for Neurology and NeurosurgeryLondonUnited Kingdom
| | - Patrick F. Chinnery
- Department of Clinical NeurosciencesUniversity of Cambridge, Cambridge Biomedical CampusCambridgeUnited Kingdom
- MRC Mitochondrial Biology UnitUniversity of CambridgeCambridgeUnited Kingdom
| | - Rita Horvath
- Wellcome Centre for Mitochondrial ResearchNewcastle UniversityNewcastle upon TyneUnited Kingdom
- Department of Clinical NeurosciencesUniversity of Cambridge, Cambridge Biomedical CampusCambridgeUnited Kingdom
| | - Victoria Nesbitt
- Department of PaediatricsThe Children's HospitalOxfordUnited Kingdom
| | - Carl Fratter
- Oxford Medical Genetics LaboratoriesOxford University Hospitals National Health Service Foundation TrustOxfordUnited Kingdom
| | - Joanna Poulton
- Nuffield Department of Obstetrics and GynaecologyUniversity of OxfordOxfordUnited Kingdom
| | - Michael G. Hanna
- Medical Research Council Centre for Neuromuscular DiseasesUniversity College London Queen Square Institute of Neurology and National Hospital for Neurology and NeurosurgeryLondonUnited Kingdom
- Department of Neuromuscular DiseasesUniversity College London Queen Square Institute of NeurologyLondonUnited Kingdom
| | - Robert D. S. Pitceathly
- Medical Research Council Centre for Neuromuscular DiseasesUniversity College London Queen Square Institute of Neurology and National Hospital for Neurology and NeurosurgeryLondonUnited Kingdom
- Department of Neuromuscular DiseasesUniversity College London Queen Square Institute of NeurologyLondonUnited Kingdom
| | - Robert W. Taylor
- Wellcome Centre for Mitochondrial ResearchNewcastle UniversityNewcastle upon TyneUnited Kingdom
| | - Doug M. Turnbull
- Wellcome Centre for Mitochondrial ResearchNewcastle UniversityNewcastle upon TyneUnited Kingdom
| | - Robert McFarland
- Wellcome Centre for Mitochondrial ResearchNewcastle UniversityNewcastle upon TyneUnited Kingdom
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37
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Ko A, Lee SJ, Lee YM. Focal cerebellar infarction as an initial sign of mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes. J Inherit Metab Dis 2019; 42:575-576. [PMID: 30693531 DOI: 10.1002/jimd.12020] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/25/2018] [Revised: 11/10/2018] [Accepted: 11/20/2018] [Indexed: 01/06/2023]
Abstract
Mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS) is a type of mitochondrial disorder and stroke-like lesions are observed prominently in the brain magnetic resonance imaging. Those stroke-like lesions of MELAS patients are usually located in the posterior quadrants and do not correspond to typical vascular territories. This case illustrates that focal cerebellar infarction can be the sole initial sign of MELAS.
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Affiliation(s)
- Ara Ko
- Department of Pediatrics, Pusan National University Children's Hospital, Pusan National University School of Medicine, Yangsan, Republic of Korea
- Research Institute for Convergence of Biomedical Science and Technology, Pusan National University Yangsan Hospital, Yangsan, Republic of Korea
| | - Sang-Jun Lee
- Department of Pediatrics, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Young-Mock Lee
- Department of Pediatrics, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Republic of Korea
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38
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Tolomeo D, Rubegni A, Severino M, Pochiero F, Bruno C, Cassandrini D, Madeo A, Doccini S, Pedemonte M, Rossi A, D'Amore F, Donati M, Di Rocco M, Santorelli F, Nesti C. Clinical and neuroimaging features of the m.10197G>A mtDNA mutation: New case reports and expansion of the phenotype variability. J Neurol Sci 2019; 399:69-75. [DOI: 10.1016/j.jns.2019.02.010] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2018] [Revised: 02/01/2019] [Accepted: 02/05/2019] [Indexed: 12/20/2022]
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39
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Finsterer J. Mitochondrial metabolic stroke: Phenotype and genetics of stroke-like episodes. J Neurol Sci 2019; 400:135-141. [PMID: 30946993 DOI: 10.1016/j.jns.2019.03.021] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2019] [Revised: 03/21/2019] [Accepted: 03/22/2019] [Indexed: 02/07/2023]
Abstract
Stroke-like episodes (SLEs) are the hallmark of mitochondrial encephalopathy with lactic acidosis and stroke-like episode (MELAS) syndrome but rarely occur also in other specific or nonspecific mitochondrial disorders. Pathophysiologically, SLLs are most likely due to a regional disruption of the blood-brain barrier triggered by the underlying metabolic defect, epileptic activity, drugs, or other factors. SLEs manifest clinically with a plethora of cerebral manifestations, which not only include features typically seen in ischemic stroke, but also headache, epilepsy, ataxia, visual impairment, vomiting, and psychiatric abnormalities. The morphological correlate of a SLE is the stroke-like lesion (SLL), best visualised on multimodal MRI. In the acute stages, a SLL presents as vasogenic edema but may be mixed up with cytotoxic components. Additionally, SLLs are characterized by hyperperfusion on perfusion studies. In the chronic stage, SLLs present with a colorful picture before they completely disappear, or end up as white matter lesion, cyst, laminar cortical necrosis, focal atrophy, or as toenail sign. Treatment of SLLs is symptomatic and relies on recommendations by experts. Beneficial effects have been reported with nitric-oxide precursors, antiepileptic drugs, antioxidants, the ketogenic diet, and steroids. Lot of research is still needed to uncover the enigma SLE/SLL.
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Affiliation(s)
- Josef Finsterer
- Krankenanstalt Rudolfstiftung, Messerli Institute, Vienna, Austria.
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40
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Hayhurst H, de Coo IFM, Piekutowska-Abramczuk D, Alston CL, Sharma S, Thompson K, Rius R, He L, Hopton S, Ploski R, Ciara E, Lake NJ, Compton AG, Delatycki MB, Verrips A, Bonnen PE, Jones SA, Morris AA, Shakespeare D, Christodoulou J, Wesol-Kucharska D, Rokicki D, Smeets HJM, Pronicka E, Thorburn DR, Gorman GS, McFarland R, Taylor RW, Ng YS. Leigh syndrome caused by mutations in MTFMT is associated with a better prognosis. Ann Clin Transl Neurol 2019; 6:515-524. [PMID: 30911575 PMCID: PMC6414492 DOI: 10.1002/acn3.725] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2018] [Revised: 12/21/2018] [Accepted: 12/26/2018] [Indexed: 12/18/2022] Open
Abstract
Objectives Mitochondrial methionyl‐tRNA formyltransferase (MTFMT) is required for the initiation of translation and elongation of mitochondrial protein synthesis. Pathogenic variants in MTFMT have been associated with Leigh syndrome (LS) and mitochondrial multiple respiratory chain deficiencies. We sought to elucidate the spectrum of clinical, neuroradiological and molecular genetic findings of patients with bi‐allelic pathogenic variants in MTFMT. Methods Retrospective cohort study combining new cases and previously published cases. Results Thirty‐eight patients with pathogenic variants in MTFMT were identified, including eight new cases. The median age of presentation was 14 months (range: birth to 17 years, interquartile range [IQR] 4.5 years), with developmental delay and motor symptoms being the most frequent initial manifestation. Twenty‐nine percent of the patients survived into adulthood. MRI headings in MTFMT pathogenic variants included symmetrical basal ganglia changes (62%), periventricular and subcortical white matter abnormalities (55%), and brainstem lesions (48%). Isolated complex I and combined respiratory chain deficiencies were identified in 31% and 59% of the cases, respectively. Reduction of the mitochondrial complex I and complex IV subunits was identified in the fibroblasts (13/13). Sixteen pathogenic variants were identified, of which c.626C>T was the most common. Seventy‐four percent of the patients were alive at their last clinical review (median 6.8 years, range: 14 months to 31 years, IQR 14.5 years). Interpretation Patients that harbour pathogenic variants in MTFMT have a milder clinical phenotype and disease progression compared to LS caused by other nuclear defects. Fibroblasts may preclude the need for muscle biopsy, to prove causality of any novel variant.
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Affiliation(s)
- Hannah Hayhurst
- Wellcome Centre for Mitochondrial Research Institute of Neuroscience Newcastle University Newcastle upon Tyne United Kingdom
| | - Irenaeus F M de Coo
- Department of Neurology Erasmus Medical Centre Rotterdam Netherlands.,Department of Paediatrics, Nutrition and Metabolic Diseases The Children's Memorial Health Institute Warsaw Poland
| | | | - Charlotte L Alston
- Wellcome Centre for Mitochondrial Research Institute of Neuroscience Newcastle University Newcastle upon Tyne United Kingdom
| | - Sunil Sharma
- Wellcome Centre for Mitochondrial Research Institute of Neuroscience Newcastle University Newcastle upon Tyne United Kingdom
| | - Kyle Thompson
- Wellcome Centre for Mitochondrial Research Institute of Neuroscience Newcastle University Newcastle upon Tyne United Kingdom
| | - Rocio Rius
- Victorian Clinical Genetics Service and Murdoch Children's Research Institute Parkville Victoria 3052 Australia.,Department of Paediatrics University of Melbourne Melbourne Victoria 3052 Australia
| | - Langping He
- Wellcome Centre for Mitochondrial Research Institute of Neuroscience Newcastle University Newcastle upon Tyne United Kingdom
| | - Sila Hopton
- Wellcome Centre for Mitochondrial Research Institute of Neuroscience Newcastle University Newcastle upon Tyne United Kingdom
| | - Rafal Ploski
- Department of Medical Genetics The Children's Memorial Health Institute Warsaw 04-730 Poland
| | - Elzbieta Ciara
- Department of Medical Genetics The Children's Memorial Health Institute Warsaw 04-730 Poland
| | - Nicole J Lake
- Victorian Clinical Genetics Service and Murdoch Children's Research Institute Parkville Victoria 3052 Australia.,Department of Paediatrics University of Melbourne Melbourne Victoria 3052 Australia
| | - Alison G Compton
- Victorian Clinical Genetics Service and Murdoch Children's Research Institute Parkville Victoria 3052 Australia.,Department of Paediatrics University of Melbourne Melbourne Victoria 3052 Australia
| | - Martin B Delatycki
- Victorian Clinical Genetics Service and Murdoch Children's Research Institute Parkville Victoria 3052 Australia.,Department of Paediatrics University of Melbourne Melbourne Victoria 3052 Australia
| | - Aad Verrips
- Department of Neurology Canisius Wilhelmina Hospital Nijmegen The Netherlands
| | - Penelope E Bonnen
- Department of Molecular and Human Genetics Baylor College of Medicine Houston Texas
| | - Simon A Jones
- Manchester Centre for Genomic Medicine Manchester University NHS Foundation Trust Manchester Academic Health Sciences Centre Manchester UK
| | - Andrew A Morris
- Manchester Centre for Genomic Medicine Manchester University NHS Foundation Trust Manchester Academic Health Sciences Centre Manchester UK
| | - David Shakespeare
- Neuro-Rehabilitation Unit Royal Preston Hospital Preston United Kingdom
| | - John Christodoulou
- Victorian Clinical Genetics Service and Murdoch Children's Research Institute Parkville Victoria 3052 Australia.,Department of Paediatrics University of Melbourne Melbourne Victoria 3052 Australia
| | - Dorota Wesol-Kucharska
- Department of Clinical Genomics Research Schools GROW and MHeNS Maastricht University Maastricht The Netherlands
| | - Dariusz Rokicki
- Department of Clinical Genomics Research Schools GROW and MHeNS Maastricht University Maastricht The Netherlands
| | - Hubert J M Smeets
- Department of Paediatrics, Nutrition and Metabolic Diseases The Children's Memorial Health Institute Warsaw Poland
| | - Ewa Pronicka
- Department of Medical Genetics The Children's Memorial Health Institute Warsaw 04-730 Poland.,Neuro-Rehabilitation Unit Royal Preston Hospital Preston United Kingdom
| | - David R Thorburn
- Victorian Clinical Genetics Service and Murdoch Children's Research Institute Parkville Victoria 3052 Australia.,Department of Paediatrics University of Melbourne Melbourne Victoria 3052 Australia
| | - Grainne S Gorman
- Wellcome Centre for Mitochondrial Research Institute of Neuroscience Newcastle University Newcastle upon Tyne United Kingdom
| | - Robert McFarland
- Wellcome Centre for Mitochondrial Research Institute of Neuroscience Newcastle University Newcastle upon Tyne United Kingdom
| | - Robert W Taylor
- Wellcome Centre for Mitochondrial Research Institute of Neuroscience Newcastle University Newcastle upon Tyne United Kingdom
| | - Yi Shiau Ng
- Wellcome Centre for Mitochondrial Research Institute of Neuroscience Newcastle University Newcastle upon Tyne United Kingdom
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41
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Bris C, Goudenege D, Desquiret-Dumas V, Charif M, Colin E, Bonneau D, Amati-Bonneau P, Lenaers G, Reynier P, Procaccio V. Bioinformatics Tools and Databases to Assess the Pathogenicity of Mitochondrial DNA Variants in the Field of Next Generation Sequencing. Front Genet 2018; 9:632. [PMID: 30619459 PMCID: PMC6297213 DOI: 10.3389/fgene.2018.00632] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2018] [Accepted: 11/27/2018] [Indexed: 11/13/2022] Open
Abstract
The development of next generation sequencing (NGS) has greatly enhanced the diagnosis of mitochondrial disorders, with a systematic analysis of the whole mitochondrial DNA (mtDNA) sequence and better detection sensitivity. However, the exponential growth of sequencing data renders complex the interpretation of the identified variants, thereby posing new challenges for the molecular diagnosis of mitochondrial diseases. Indeed, mtDNA sequencing by NGS requires specific bioinformatics tools and the adaptation of those developed for nuclear DNA, for the detection and quantification of mtDNA variants from sequence alignment to the calling steps, in order to manage the specific features of the mitochondrial genome including heteroplasmy, i.e., coexistence of mutant and wildtype mtDNA copies. The prioritization of mtDNA variants remains difficult, relying on a limited number of specific resources: population and clinical databases, and in silico tools providing a prediction of the variant pathogenicity. An evaluation of the most prominent bioinformatics tools showed that their ability to predict the pathogenicity was highly variable indicating that special efforts should be directed at developing new bioinformatics tools dedicated to the mitochondrial genome. In addition, massive parallel sequencing raised several issues related to the interpretation of very low mtDNA mutational loads, discovery of variants of unknown significance, and mutations unrelated to patient phenotype or the co-occurrence of mtDNA variants. This review provides an overview of the current strategies and bioinformatics tools for accurate annotation, prioritization and reporting of mtDNA variations from NGS data, in order to carry out accurate genetic counseling in individuals with primary mitochondrial diseases.
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Affiliation(s)
- Céline Bris
- UMR CNRS 6015-INSERM U1083, MitoVasc Institute, Angers University, Angers, France.,Biochemistry and Genetics Department, Angers Hospital, Angers, France
| | - David Goudenege
- UMR CNRS 6015-INSERM U1083, MitoVasc Institute, Angers University, Angers, France.,Biochemistry and Genetics Department, Angers Hospital, Angers, France
| | - Valérie Desquiret-Dumas
- UMR CNRS 6015-INSERM U1083, MitoVasc Institute, Angers University, Angers, France.,Biochemistry and Genetics Department, Angers Hospital, Angers, France
| | - Majida Charif
- UMR CNRS 6015-INSERM U1083, MitoVasc Institute, Angers University, Angers, France
| | - Estelle Colin
- UMR CNRS 6015-INSERM U1083, MitoVasc Institute, Angers University, Angers, France.,Biochemistry and Genetics Department, Angers Hospital, Angers, France
| | - Dominique Bonneau
- UMR CNRS 6015-INSERM U1083, MitoVasc Institute, Angers University, Angers, France.,Biochemistry and Genetics Department, Angers Hospital, Angers, France
| | - Patrizia Amati-Bonneau
- UMR CNRS 6015-INSERM U1083, MitoVasc Institute, Angers University, Angers, France.,Biochemistry and Genetics Department, Angers Hospital, Angers, France
| | - Guy Lenaers
- UMR CNRS 6015-INSERM U1083, MitoVasc Institute, Angers University, Angers, France
| | - Pascal Reynier
- UMR CNRS 6015-INSERM U1083, MitoVasc Institute, Angers University, Angers, France.,Biochemistry and Genetics Department, Angers Hospital, Angers, France
| | - Vincent Procaccio
- UMR CNRS 6015-INSERM U1083, MitoVasc Institute, Angers University, Angers, France.,Biochemistry and Genetics Department, Angers Hospital, Angers, France
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42
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Mitochondrial disease genetics update: recent insights into the molecular diagnosis and expanding phenotype of primary mitochondrial disease. Curr Opin Pediatr 2018; 30:714-724. [PMID: 30199403 PMCID: PMC6467265 DOI: 10.1097/mop.0000000000000686] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
PURPOSE OF REVIEW Primary mitochondrial disease (PMD) is a genetically and phenotypically diverse group of inherited energy deficiency disorders caused by impaired mitochondrial oxidative phosphorylation (OXPHOS) capacity. Mutations in more than 350 genes in both mitochondrial and nuclear genomes are now recognized to cause primary mitochondrial disease following every inheritance pattern. Next-generation sequencing technologies have dramatically accelerated mitochondrial disease gene discovery and diagnostic yield. Here, we provide an up-to-date review of recently identified, novel mitochondrial disease genes and/or pathogenic variants that directly impair mitochondrial structure, dynamics, and/or function. RECENT FINDINGS A review of PubMed publications was performed from the past 12 months that identified 16 new PMD genes and/or pathogenic variants, and recognition of expanded phenotypes for a wide variety of mitochondrial disease genes. SUMMARY Broad-based exome sequencing has become the standard first-line diagnostic approach for PMD. This has facilitated more rapid and accurate disease identification, and greatly expanded understanding of the wide spectrum of potential clinical phenotypes. A comprehensive dual-genome sequencing approach to PMD diagnosis continues to improve diagnostic yield, advance understanding of mitochondrial physiology, and provide strong potential to develop precision therapeutics targeted to diverse aspects of mitochondrial disease pathophysiology.
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43
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Revealing the Complexity of Mitochondrial DNA-Related Disorders. EBioMedicine 2018; 30:3-4. [PMID: 29550239 PMCID: PMC5952338 DOI: 10.1016/j.ebiom.2018.03.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2018] [Accepted: 03/08/2018] [Indexed: 01/30/2023] Open
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