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Tsai NC, Liou CW, Cheng YH, Lien HT, Lin TL, Lin TK, Lan MY, Hung PL, Wang TJ, Lee CH, Liang YC, Lan KC. The establishment of a molecular diagnostic platform for mitochondrial diseases: from conventional to next-generation sequencing. Biomed J 2024:100770. [PMID: 39048080 DOI: 10.1016/j.bj.2024.100770] [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: 03/12/2024] [Revised: 06/14/2024] [Accepted: 07/18/2024] [Indexed: 07/27/2024] Open
Abstract
BACKGROUND The aim of this study was to create a molecular diagnostic platform and establish a diagnostic pipeline for patients highly suspected of mitochondrial disorders. The effectiveness of three methods, namely, traditional restriction fragment length polymorphism-polymerase chain reaction (RFLP-PCR), Sanger sequencing for hotspot detection and whole mitochondrial DNA (mtDNA), and third-generation (Nanopore) whole mtDNA sequencing, will be compared in diagnosing patients with suspected primary mitochondrial diseases (PMDs). The strengths and limitations of different methods are also discussed. MATERIAL AND METHODS A single-center prospective cohort study was conducted to validate the diagnostic pipeline for suspected mitochondrial diseases. In the first stage, a PCR-based method with five sets of primers was used to screen for eight hotspots (m.3243A>G, m.3460G>A, m.8344A>G, m.8993T>G, m.9185T>C, m.11778G>A, m.13513G>A, and m.4977deletion) using either RFLP or direct Sanger sequencing. Sanger sequencing was also used to confirm the RFLP-positive samples. In the second stage, for samples with negative screening results for the eight hotspots, mitochondrial whole-genome sequencing was performed using Sanger sequencing or third-generation nanopore sequencing. RESULTS Between June 2020 and May 2023, 30 patients from ages 0 to 63 with clinically suspected mitochondrial disease were enrolled. The positive yield for the diagnosis of PMDs was 8/30=26.7%, and the sensitivity of the heteroplasmy level for the RFLP-based method was approximately 5%. The remaining 22 patients who tested negative at the first stage were tested using Sanger sequencing or the third-generation sequencing Nanopore, and all tested negative for pathological mtDNA mutations. Compared to the Sanger sequencing method, the results of RFLP-PCR were compromised by the limitations of incomplete RFLP enzyme digestion. For whole-genome sequencing of mtDNA, Sanger sequencing, instead of nanopore sequencing, is preferred at our institution because of its cost-effectiveness. CONCLUSIONS In our highly selective cohort, most tested positive in the first stage of the 8 hot spots screen. Sanger sequencing is a conventional and accurate method for mitochondrial disease screening, at least for the most common hot spots in the region. The results revealed that Sanger sequencing is an accurate method with the benefit of being more cost-effective. This integral platform of molecular diagnosis bears the advantages of being relatively low cost and having a shorter reporting time, facilitating crucial identification of patients with clinical evidence of such disorders. This diagnostic flowchart has also been translated into routine clinical use in the tertiary hospital.
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Affiliation(s)
- Ni-Chin Tsai
- Graduate Institute of Clinical Medicine, College of Medicine, Kaohsiung Medical University, 100, Shih-Chuan 1st Road, Kaohsiung, 80708, Taiwan; Center for Mitochondrial Research and Medicine, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung 833, Taiwan; Department of Obstetrics and Gynecology, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung, Taiwan; Center for Menopause and Reproductive Medicine Research, Kaohsiung Chang Gung Memorial Hospital
| | - Chai-Wai Liou
- Center for Mitochondrial Research and Medicine, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung 833, Taiwan; Department of Neurology, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung, Taiwan
| | - Yin-Hua Cheng
- Center for Mitochondrial Research and Medicine, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung 833, Taiwan; Department of Obstetrics and Gynecology, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung, Taiwan; Center for Menopause and Reproductive Medicine Research, Kaohsiung Chang Gung Memorial Hospital
| | - Hao-Ting Lien
- Center for Mitochondrial Research and Medicine, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung 833, Taiwan; Department of Obstetrics and Gynecology, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung, Taiwan
| | - Tzu-Ling Lin
- Center for Mitochondrial Research and Medicine, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung 833, Taiwan; Center for Menopause and Reproductive Medicine Research, Kaohsiung Chang Gung Memorial Hospital
| | - Tsu-Kung Lin
- Center for Mitochondrial Research and Medicine, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung 833, Taiwan; Department of Neurology, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung, Taiwan
| | - Min-Yu Lan
- Center for Mitochondrial Research and Medicine, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung 833, Taiwan; Department of Neurology, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung, Taiwan
| | - Pi-Lien Hung
- Center for Mitochondrial Research and Medicine, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung 833, Taiwan; Department of Pediatrics, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung, Taiwan
| | - Tzu-Jou Wang
- Center for Mitochondrial Research and Medicine, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung 833, Taiwan; Department of Pediatrics, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung, Taiwan
| | - Chen-Hao Lee
- Department of Pediatrics, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung, Taiwan
| | - Yi-Chih Liang
- Department of Pediatrics, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung, Taiwan
| | - Kuo-Chung Lan
- Graduate Institute of Clinical Medicine, College of Medicine, Kaohsiung Medical University, 100, Shih-Chuan 1st Road, Kaohsiung, 80708, Taiwan; Center for Mitochondrial Research and Medicine, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung 833, Taiwan; Department of Obstetrics and Gynecology, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung, Taiwan; Center for Menopause and Reproductive Medicine Research, Kaohsiung Chang Gung Memorial Hospital; Department of Obstetrics and Gynecology, Jen-Ai Hospital, Taichung 412, Taiwan.
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Dobner J, Nguyen T, Pavez-Giani MG, Cyganek L, Distelmaier F, Krutmann J, Prigione A, Rossi A. mtDNA analysis using Mitopore. Mol Ther Methods Clin Dev 2024; 32:101231. [PMID: 38572068 PMCID: PMC10988129 DOI: 10.1016/j.omtm.2024.101231] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2023] [Accepted: 03/08/2024] [Indexed: 04/05/2024]
Abstract
Mitochondrial DNA (mtDNA) analysis is crucial for the diagnosis of mitochondrial disorders, forensic investigations, and basic research. Existing pipelines are complex, expensive, and require specialized personnel. In many cases, including the diagnosis of detrimental single nucleotide variants (SNVs), mtDNA analysis is still carried out using Sanger sequencing. Here, we developed a simple workflow and a publicly available webserver named Mitopore that allows the detection of mtDNA SNVs, indels, and haplogroups. To simplify mtDNA analysis, we tailored our workflow to process noisy long-read sequencing data for mtDNA analysis, focusing on sequence alignment and parameter optimization. We implemented Mitopore with eliBQ (eliminate bad quality reads), an innovative quality enhancement that permits the increase of per-base quality of over 20% for low-quality data. The whole Mitopore workflow and webserver were validated using patient-derived and induced pluripotent stem cells harboring mtDNA mutations. Mitopore streamlines mtDNA analysis as an easy-to-use fast, reliable, and cost-effective analysis method for both long- and short-read sequencing data. This significantly enhances the accessibility of mtDNA analysis and reduces the cost per sample, contributing to the progress of mtDNA-related research and diagnosis.
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Affiliation(s)
- Jochen Dobner
- Institut für Umweltmedizinische Forschung (IUF)-Leibniz Research Institute for Environmental Medicine, 40225 Düsseldorf, Germany
| | - Thach Nguyen
- Institut für Umweltmedizinische Forschung (IUF)-Leibniz Research Institute for Environmental Medicine, 40225 Düsseldorf, Germany
| | - Mario Gustavo Pavez-Giani
- Clinic for Cardiology and Pneumology, University Medical Center Göttingen, 37075 Göttingen, Germany
- DZHK (German Center for Cardiovascular Research), Partner Site Göttingen, 37075 Göttingen, Germany
| | - Lukas Cyganek
- Clinic for Cardiology and Pneumology, University Medical Center Göttingen, 37075 Göttingen, Germany
- DZHK (German Center for Cardiovascular Research), Partner Site Göttingen, 37075 Göttingen, Germany
- Cluster of Excellence “Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells” (MBExC), University of Göttingen, 37075 Göttingen, Germany
| | - Felix Distelmaier
- Department of General Pediatrics, Neonatology and Pediatric Cardiology, Medical Faculty, Heinrich Heine University, 40225 Düsseldorf, Germany
| | - Jean Krutmann
- Institut für Umweltmedizinische Forschung (IUF)-Leibniz Research Institute for Environmental Medicine, 40225 Düsseldorf, Germany
- Medical Faculty, Heinrich Heine University, 40225 Düsseldorf, Germany
| | - Alessandro Prigione
- Department of General Pediatrics, Neonatology and Pediatric Cardiology, Medical Faculty, Heinrich Heine University, 40225 Düsseldorf, Germany
| | - Andrea Rossi
- Institut für Umweltmedizinische Forschung (IUF)-Leibniz Research Institute for Environmental Medicine, 40225 Düsseldorf, Germany
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Bernardino Gomes TM, Vincent AE, Menger KE, Stewart JB, Nicholls TJ. Mechanisms and pathologies of human mitochondrial DNA replication and deletion formation. Biochem J 2024; 481:683-715. [PMID: 38804971 DOI: 10.1042/bcj20230262] [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] [Received: 03/22/2024] [Revised: 05/13/2024] [Accepted: 05/14/2024] [Indexed: 05/29/2024]
Abstract
Human mitochondria possess a multi-copy circular genome, mitochondrial DNA (mtDNA), that is essential for cellular energy metabolism. The number of copies of mtDNA per cell, and their integrity, are maintained by nuclear-encoded mtDNA replication and repair machineries. Aberrant mtDNA replication and mtDNA breakage are believed to cause deletions within mtDNA. The genomic location and breakpoint sequences of these deletions show similar patterns across various inherited and acquired diseases, and are also observed during normal ageing, suggesting a common mechanism of deletion formation. However, an ongoing debate over the mechanism by which mtDNA replicates has made it difficult to develop clear and testable models for how mtDNA rearrangements arise and propagate at a molecular and cellular level. These deletions may impair energy metabolism if present in a high proportion of the mtDNA copies within the cell, and can be seen in primary mitochondrial diseases, either in sporadic cases or caused by autosomal variants in nuclear-encoded mtDNA maintenance genes. These mitochondrial diseases have diverse genetic causes and multiple modes of inheritance, and show notoriously broad clinical heterogeneity with complex tissue specificities, which further makes establishing genotype-phenotype relationships challenging. In this review, we aim to cover our current understanding of how the human mitochondrial genome is replicated, the mechanisms by which mtDNA replication and repair can lead to mtDNA instability in the form of large-scale rearrangements, how rearranged mtDNAs subsequently accumulate within cells, and the pathological consequences when this occurs.
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Affiliation(s)
- Tiago M Bernardino Gomes
- Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne NE2 4HH, U.K
- Wellcome Centre for Mitochondrial Research, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne NE2 4HH, U.K
- NHS England Highly Specialised Service for Rare Mitochondrial Disorders, Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne NE2 4HH, U.K
| | - Amy E Vincent
- Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne NE2 4HH, U.K
- Wellcome Centre for Mitochondrial Research, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne NE2 4HH, U.K
| | - Katja E Menger
- Wellcome Centre for Mitochondrial Research, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne NE2 4HH, U.K
- Biosciences Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne NE2 4HH, U.K
| | - James B Stewart
- Wellcome Centre for Mitochondrial Research, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne NE2 4HH, U.K
- Biosciences Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne NE2 4HH, U.K
| | - Thomas J Nicholls
- Wellcome Centre for Mitochondrial Research, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne NE2 4HH, U.K
- Biosciences Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne NE2 4HH, U.K
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Lin Y, Wang J, Xu R, Xu Z, Wang Y, Pan S, Zhang Y, Tao Q, Zhao Y, Yan C, Cao Z, Ji K. HiFi long-read amplicon sequencing for full-spectrum variants of human mtDNA. BMC Genomics 2024; 25:538. [PMID: 38822239 PMCID: PMC11141058 DOI: 10.1186/s12864-024-10433-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2024] [Accepted: 05/20/2024] [Indexed: 06/02/2024] Open
Abstract
BACKGROUND Mitochondrial diseases (MDs) can be caused by single nucleotide variants (SNVs) and structural variants (SVs) in the mitochondrial genome (mtDNA). Presently, identifying deletions in small to medium-sized fragments and accurately detecting low-percentage variants remains challenging due to the limitations of next-generation sequencing (NGS). METHODS In this study, we integrated targeted long-range polymerase chain reaction (LR-PCR) and PacBio HiFi sequencing to analyze 34 participants, including 28 patients and 6 controls. Of these, 17 samples were subjected to both targeted LR-PCR and to compare the mtDNA variant detection efficacy. RESULTS Among the 28 patients tested by long-read sequencing (LRS), 2 patients were found positive for the m.3243 A > G hotspot variant, and 20 patients exhibited single or multiple deletion variants with a proportion exceeding 4%. Comparison between the results of LRS and NGS revealed that both methods exhibited similar efficacy in detecting SNVs exceeding 5%. However, LRS outperformed NGS in detecting SNVs with a ratio below 5%. As for SVs, LRS identified single or multiple deletions in 13 out of 17 cases, whereas NGS only detected single deletions in 8 cases. Furthermore, deletions identified by LRS were validated by Sanger sequencing and quantified in single muscle fibers using real-time PCR. Notably, LRS also effectively and accurately identified secondary mtDNA deletions in idiopathic inflammatory myopathies (IIMs). CONCLUSIONS LRS outperforms NGS in detecting various types of SNVs and SVs in mtDNA, including those with low frequencies. Our research is a significant advancement in medical comprehension and will provide profound insights into genetics.
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Affiliation(s)
- Yan Lin
- Research Institute of Neuromuscular and Neurodegenerative Diseases and Department of Neurology, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan, Shandong, 250012, China
| | - Jiayin Wang
- Research Institute of Neuromuscular and Neurodegenerative Diseases and Department of Neurology, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan, Shandong, 250012, China
| | - Ran Xu
- GrandOmics Biosciences, No.56 Zhichun Road, Haidian District, Beijing, 100098, China
| | - Zhe Xu
- School of Life Sciences, Westlake University, Hangzhou, Zhejiang, China
| | - Yifan Wang
- GrandOmics Biosciences, No.56 Zhichun Road, Haidian District, Beijing, 100098, China
| | - Shirang Pan
- GrandOmics Biosciences, No.56 Zhichun Road, Haidian District, Beijing, 100098, China
| | - Yan Zhang
- GrandOmics Biosciences, No.56 Zhichun Road, Haidian District, Beijing, 100098, China
| | - Qing Tao
- GrandOmics Biosciences, No.56 Zhichun Road, Haidian District, Beijing, 100098, China
| | - Yuying Zhao
- Research Institute of Neuromuscular and Neurodegenerative Diseases and Department of Neurology, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan, Shandong, 250012, China
| | - Chuanzhu Yan
- Research Institute of Neuromuscular and Neurodegenerative Diseases and Department of Neurology, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan, Shandong, 250012, China
- Mitochondrial Medicine Laboratory, Qilu Hospital (Qingdao), Shandong University, Qingdao, Shandong, 266035, China
- Brain Science Research Institute, Shandong University, Jinan, Shandong, 250012, China
| | - Zhenhua Cao
- GrandOmics Biosciences, No.56 Zhichun Road, Haidian District, Beijing, 100098, China.
| | - Kunqian Ji
- Research Institute of Neuromuscular and Neurodegenerative Diseases and Department of Neurology, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan, Shandong, 250012, China.
- Research Institute of Neuromuscular and Neurodegenerative Diseases, Department of Neurology, Qilu Hospital, Shandong University, No. 107 West Wenhua Road, Jinan, Shandong, 250012, China.
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Li F, Xiang R, Liu Y, Hu G, Jiang Q, Jia T. Approaches and challenges in identifying, quantifying, and manipulating dynamic mitochondrial genome variations. Cell Signal 2024; 117:111123. [PMID: 38417637 DOI: 10.1016/j.cellsig.2024.111123] [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] [Received: 12/07/2023] [Revised: 02/14/2024] [Accepted: 02/25/2024] [Indexed: 03/01/2024]
Abstract
Mitochondria, the cellular powerhouses, possess their own unique genetic system, including replication, transcription, and translation. Studying these processes is crucial for comprehending mitochondrial disorders, energy production, and their related diseases. Over the past decades, various approaches have been applied in detecting and quantifying mitochondrial genome variations with also the purpose of manipulation of mitochondria or mitochondrial genome for therapeutics. Understanding the scope and limitations of above strategies is not only fundamental to the understanding of basic biology but also critical for exploring disease-related novel target(s), as well to develop innovative therapies. Here, this review provides an overview of different tools and techniques for accurate mitochondrial genome variations identification, quantification, and discuss novel strategies for the manipulation of mitochondria to develop innovative therapeutic interventions, through combining the insights gained from the study of mitochondrial genetics with ongoing single cell omics combined with advanced single molecular tools.
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Affiliation(s)
- Fei Li
- Key Laboratory of Drug-Targeting and Drug Delivery System of the Education Ministry and Sichuan Province, Sichuan Engineering Laboratory for Plant-Sourced Drug and Sichuan Research Center for Drug Precision Industrial Technology, West China School of Pharmacy, Sichuan University, Chengdu 610041, China
| | - Run Xiang
- Key Laboratory of Drug-Targeting and Drug Delivery System of the Education Ministry and Sichuan Province, Sichuan Engineering Laboratory for Plant-Sourced Drug and Sichuan Research Center for Drug Precision Industrial Technology, West China School of Pharmacy, Sichuan University, Chengdu 610041, China; Department of Thoracic Surgery, Sichuan Clinical Research Center for Cancer, Sichuan Cancer Hospital & Institute, Sichuan Cancer Center, Affiliated Cancer Hospital of University of Electronic Science and Technology of China, Chengdu, China
| | - Yue Liu
- Key Laboratory of Drug-Targeting and Drug Delivery System of the Education Ministry and Sichuan Province, Sichuan Engineering Laboratory for Plant-Sourced Drug and Sichuan Research Center for Drug Precision Industrial Technology, West China School of Pharmacy, Sichuan University, Chengdu 610041, China
| | - Guoliang Hu
- Key Laboratory of Drug-Targeting and Drug Delivery System of the Education Ministry and Sichuan Province, Sichuan Engineering Laboratory for Plant-Sourced Drug and Sichuan Research Center for Drug Precision Industrial Technology, West China School of Pharmacy, Sichuan University, Chengdu 610041, China; Department of Thoracic Surgery, Sichuan Clinical Research Center for Cancer, Sichuan Cancer Hospital & Institute, Sichuan Cancer Center, Affiliated Cancer Hospital of University of Electronic Science and Technology of China, Chengdu, China
| | - Quanbo Jiang
- Light, Nanomaterials, Nanotechnologies (L2n) Laboratory, CNRS EMR 7004, University of Technology of Troyes, 12 rue Marie Curie, 10004 Troyes, France
| | - Tao Jia
- Key Laboratory of Drug-Targeting and Drug Delivery System of the Education Ministry and Sichuan Province, Sichuan Engineering Laboratory for Plant-Sourced Drug and Sichuan Research Center for Drug Precision Industrial Technology, West China School of Pharmacy, Sichuan University, Chengdu 610041, China; CNRS-UMR9187, INSERM U1196, PSL-Research University, 91405 Orsay, France; CNRS-UMR9187, INSERM U1196, Université Paris Saclay, 91405 Orsay, France.
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Chin HL, Lai PS, Tay SKH. A clinical approach to diagnosis and management of mitochondrial myopathies. Neurotherapeutics 2024; 21:e00304. [PMID: 38241155 PMCID: PMC10903095 DOI: 10.1016/j.neurot.2023.11.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2023] [Accepted: 11/11/2023] [Indexed: 01/21/2024] Open
Abstract
This paper provides an overview of the different types of mitochondrial myopathies (MM), associated phenotypes, genotypes as well as a practical clinical approach towards disease diagnosis, surveillance, and management. nDNA-related MM are more common in pediatric-onset disease whilst mtDNA-related MMs are more frequent in adults. Genotype-phenotype correlation in MM is challenging due to clinical and genetic heterogeneity. The multisystemic nature of many MMs adds to the diagnostic challenge. Diagnostic approaches utilizing genetic sequencing with next generation sequencing approaches such as gene panel, exome and genome sequencing are available. This aids molecular diagnosis, heteroplasmy detection in MM patients and furthers knowledge of known mitochondrial genes. Precise disease diagnosis can end the diagnostic odyssey for patients, avoid unnecessary testing, provide prognosis, facilitate anticipatory management, and enable access to available therapies or clinical trials. Adjunctive tests such as functional and exercise testing could aid surveillance of MM patients. Management requires a multi-disciplinary approach, systemic screening for comorbidities, cofactor supplementation, avoidance of substances that inhibit the respiratory chain and exercise training. This update of the current understanding on MMs provides practical perspectives on current diagnostic and management approaches for this complex group of disorders.
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Affiliation(s)
- Hui-Lin Chin
- Division of Genetics and Metabolism, Department of Paediatrics, Khoo Teck Puat-National University Children's Medical Institute, National University Hospital, Singapore; Department of Paediatrics, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Poh San Lai
- Department of Paediatrics, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Stacey Kiat Hong Tay
- Division of Genetics and Metabolism, Department of Paediatrics, Khoo Teck Puat-National University Children's Medical Institute, National University Hospital, Singapore; Department of Paediatrics, Yong Loo Lin School of Medicine, National University of Singapore, Singapore; Division of Neurology, Department of Paediatrics, Khoo Teck Puat-National University Children's Medical Institute, National University Hospital, Singapore.
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Owusu R, Savarese M. Long-read sequencing improves diagnostic rate in neuromuscular disorders. ACTA MYOLOGICA : MYOPATHIES AND CARDIOMYOPATHIES : OFFICIAL JOURNAL OF THE MEDITERRANEAN SOCIETY OF MYOLOGY 2023; 42:123-128. [PMID: 38406378 PMCID: PMC10883326 DOI: 10.36185/2532-1900-394] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Accepted: 12/05/2023] [Indexed: 02/27/2024]
Abstract
Massive parallel sequencing methods, such as exome, genome, and targeted DNA sequencing, have aided molecular diagnosis of genetic diseases in the last 20 years. However, short-read sequencing methods still have several limitations, such inaccurate genome assembly, the inability to detect large structural variants, and variants located in hard-to-sequence regions like highly repetitive areas. The recently emerged PacBio single-molecule real-time (SMRT) and Oxford nanopore technology (ONT) long-read sequencing (LRS) methods have been shown to overcome most of these technical issues, leading to an increase in diagnostic rate. LRS methods are contributing to the detection of repeat expansions in novel disease-causing genes (e.g., ABCD3, NOTCH2NLC and RILPL1 causing an Oculopharyngodistal myopathy or PLIN4 causing a Myopathy with rimmed ubiquitin-positive autophagic vacuolation), of structural variants (e.g., in DMD), and of single nucleotide variants in repetitive regions (TTN and NEB). Moreover, these methods have simplified the characterization of the D4Z4 repeats in DUX4, facilitating the diagnosis of Facioscapulohumeral muscular dystrophy (FSHD). We review recent studies that have used either ONT or PacBio SMRT sequencing methods and discuss different types of variants that have been detected using these approaches in individuals with neuromuscular disorders.
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Affiliation(s)
| | - Marco Savarese
- Folkhälsan Research Center, Helsinki, Finland
- University of Helsinki, Faculty of Medicine, Helsinki, Finland
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8
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Serag M, Plutino M, Charles P, Azulay JP, Chaussenot A, Paquis-Flucklinger V, Ait-El-Mkadem Saadi S, Rouzier C. A Case Report of SYNE1 Deficiency-Mimicking Mitochondrial Disease and the Value of Pangenomic Investigations. Genes (Basel) 2023; 14:2154. [PMID: 38136976 PMCID: PMC10743207 DOI: 10.3390/genes14122154] [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] [Received: 11/08/2023] [Revised: 11/24/2023] [Accepted: 11/27/2023] [Indexed: 12/24/2023] Open
Abstract
Mitochondrial disorders are characterized by a huge clinical, biochemical, and genetic heterogeneity, which poses significant diagnostic challenges. Several studies report that more than 50% of patients with suspected mitochondrial disease could have a non-mitochondrial disorder. Thus, only the identification of the causative pathogenic variant can confirm the diagnosis. Herein, we describe the diagnostic journey of a family suspected of having a mitochondrial disorder who were referred to our Genetics Department. The proband presented with the association of cerebellar ataxia, COX-negative fibers on muscle histology, and mtDNA deletions. Whole exome sequencing (WES), supplemented by a high-resolution array, comparative genomic hybridization (array-CGH), allowed us to identify two pathogenic variants in the non-mitochondrial SYNE1 gene. The proband and her affected sister were found to be compound heterozygous for a known nonsense variant (c.13258C>T, p.(Arg4420Ter)), and a large intragenic deletion that was predicted to result in a loss of function. To our knowledge, this is the first report of a large intragenic deletion of SYNE1 in patients with cerebellar ataxia (ARCA1). This report highlights the interest in a pangenomic approach to identify the genetic basis in heterogeneous neuromuscular patients with the possible cause of mitochondrial disease. Moreover, even rare copy number variations should be considered in patients with a phenotype suggestive of SYNE1 deficiency.
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Affiliation(s)
- Mounir Serag
- Service de Génétique Médicale, Hôpital l’Archet 2, CHU de Nice, 151 Route Saint-Antoine de Ginestière, 06202 Nice, France; (M.S.); (M.P.); (A.C.); (V.P.-F.); (S.A.-E.-M.S.)
- CNRS UMR7284/ INSERM U1081, Faculté de Médecine, Université Côte d’Azur, 06107 Nice, France
| | - Morgane Plutino
- Service de Génétique Médicale, Hôpital l’Archet 2, CHU de Nice, 151 Route Saint-Antoine de Ginestière, 06202 Nice, France; (M.S.); (M.P.); (A.C.); (V.P.-F.); (S.A.-E.-M.S.)
- CNRS UMR7284/ INSERM U1081, Faculté de Médecine, Université Côte d’Azur, 06107 Nice, France
| | - Perrine Charles
- Service de Génétique, La Pitié-Salpêtrière, AP-HP, 75610 Paris, France;
| | | | - Annabelle Chaussenot
- Service de Génétique Médicale, Hôpital l’Archet 2, CHU de Nice, 151 Route Saint-Antoine de Ginestière, 06202 Nice, France; (M.S.); (M.P.); (A.C.); (V.P.-F.); (S.A.-E.-M.S.)
- CNRS UMR7284/ INSERM U1081, Faculté de Médecine, Université Côte d’Azur, 06107 Nice, France
| | - Véronique Paquis-Flucklinger
- Service de Génétique Médicale, Hôpital l’Archet 2, CHU de Nice, 151 Route Saint-Antoine de Ginestière, 06202 Nice, France; (M.S.); (M.P.); (A.C.); (V.P.-F.); (S.A.-E.-M.S.)
- CNRS UMR7284/ INSERM U1081, Faculté de Médecine, Université Côte d’Azur, 06107 Nice, France
| | - Samira Ait-El-Mkadem Saadi
- Service de Génétique Médicale, Hôpital l’Archet 2, CHU de Nice, 151 Route Saint-Antoine de Ginestière, 06202 Nice, France; (M.S.); (M.P.); (A.C.); (V.P.-F.); (S.A.-E.-M.S.)
- CNRS UMR7284/ INSERM U1081, Faculté de Médecine, Université Côte d’Azur, 06107 Nice, France
| | - Cécile Rouzier
- Service de Génétique Médicale, Hôpital l’Archet 2, CHU de Nice, 151 Route Saint-Antoine de Ginestière, 06202 Nice, France; (M.S.); (M.P.); (A.C.); (V.P.-F.); (S.A.-E.-M.S.)
- CNRS UMR7284/ INSERM U1081, Faculté de Médecine, Université Côte d’Azur, 06107 Nice, France
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Macken WL, Falabella M, Pizzamiglio C, Woodward CE, Scotchman E, Chitty LS, Polke JM, Bugiardini E, Hanna MG, Vandrovcova J, Chandler N, Labrum R, Pitceathly RDS. Enhanced mitochondrial genome analysis: bioinformatic and long-read sequencing advances and their diagnostic implications. Expert Rev Mol Diagn 2023; 23:797-814. [PMID: 37642407 DOI: 10.1080/14737159.2023.2241365] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2023] [Accepted: 07/24/2023] [Indexed: 08/31/2023]
Abstract
INTRODUCTION Primary mitochondrial diseases (PMDs) comprise a large and heterogeneous group of genetic diseases that result from pathogenic variants in either nuclear DNA (nDNA) or mitochondrial DNA (mtDNA). Widespread adoption of next-generation sequencing (NGS) has improved the efficiency and accuracy of mtDNA diagnoses; however, several challenges remain. AREAS COVERED In this review, we briefly summarize the current state of the art in molecular diagnostics for mtDNA and consider the implications of improved whole genome sequencing (WGS), bioinformatic techniques, and the adoption of long-read sequencing, for PMD diagnostics. EXPERT OPINION We anticipate that the application of PCR-free WGS from blood DNA will increase in diagnostic laboratories, while for adults with myopathic presentations, WGS from muscle DNA may become more widespread. Improved bioinformatic strategies will enhance WGS data interrogation, with more accurate delineation of mtDNA and NUMTs (nuclear mitochondrial DNA segments) in WGS data, superior coverage uniformity, indirect measurement of mtDNA copy number, and more accurate interpretation of heteroplasmic large-scale rearrangements (LSRs). Separately, the adoption of diagnostic long-read sequencing could offer greater resolution of complex LSRs and the opportunity to phase heteroplasmic variants.
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Affiliation(s)
- William L Macken
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology, London, UK
- NHS Highly Specialised Service for Rare Mitochondrial Disorders, Queen Square Centre for Neuromuscular Diseases, The National Hospital for Neurology and Neurosurgery, London, UK
| | - Micol Falabella
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology, London, UK
| | - Chiara Pizzamiglio
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology, London, UK
- NHS Highly Specialised Service for Rare Mitochondrial Disorders, Queen Square Centre for Neuromuscular Diseases, The National Hospital for Neurology and Neurosurgery, London, UK
| | - Cathy E Woodward
- NHS Highly Specialised Service for Rare Mitochondrial Disorders, Queen Square Centre for Neuromuscular Diseases, The National Hospital for Neurology and Neurosurgery, London, UK
- Rare and Inherited Disease Laboratory, North Thames Genomic Laboratory Hub, Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK
| | - Elizabeth Scotchman
- Rare and Inherited Disease Laboratory, North Thames Genomic Laboratory Hub, Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK
| | - Lyn S Chitty
- Rare and Inherited Disease Laboratory, North Thames Genomic Laboratory Hub, Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK
| | - James M Polke
- NHS Highly Specialised Service for Rare Mitochondrial Disorders, Queen Square Centre for Neuromuscular Diseases, The National Hospital for Neurology and Neurosurgery, London, UK
- Rare and Inherited Disease Laboratory, North Thames Genomic Laboratory Hub, Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK
| | - Enrico Bugiardini
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology, London, UK
- NHS Highly Specialised Service for Rare Mitochondrial Disorders, Queen Square Centre for Neuromuscular Diseases, The National Hospital for Neurology and Neurosurgery, London, UK
| | - Michael G Hanna
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology, London, UK
- NHS Highly Specialised Service for Rare Mitochondrial Disorders, Queen Square Centre for Neuromuscular Diseases, The National Hospital for Neurology and Neurosurgery, London, UK
| | - Jana Vandrovcova
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology, London, UK
| | - Natalie Chandler
- Rare and Inherited Disease Laboratory, North Thames Genomic Laboratory Hub, Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK
| | - Robyn Labrum
- NHS Highly Specialised Service for Rare Mitochondrial Disorders, Queen Square Centre for Neuromuscular Diseases, The National Hospital for Neurology and Neurosurgery, London, UK
- Rare and Inherited Disease Laboratory, North Thames Genomic Laboratory Hub, Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK
| | - Robert D S Pitceathly
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology, London, UK
- NHS Highly Specialised Service for Rare Mitochondrial Disorders, Queen Square Centre for Neuromuscular Diseases, The National Hospital for Neurology and Neurosurgery, London, UK
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