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Zhao Y, Zhao X, Ji K, Wang J, Zhao Y, Lin J, Gang Q, Yu M, Yuan Y, Jiang H, Sun C, Fang F, Yan C, Wang Z. The clinical and genetic spectrum of mitochondrial diseases in China: A multicenter retrospective cross-sectional study. Clin Genet 2024. [PMID: 39118480 DOI: 10.1111/cge.14605] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2024] [Revised: 07/16/2024] [Accepted: 07/27/2024] [Indexed: 08/10/2024]
Abstract
Mitochondrial diseases (MtDs) present diverse clinical phenotypes, yet large-scale studies are hindered by their rarity. This retrospective, multicenter study, conducted across five Chinese hospitals' neurology departments from 2009 to 2019, aimed to address this gap. Nationwide, 1351 patients were enrolled, with a median onset age of 14.0 (18.5) years. The predominant phenotype was mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes (MELAS) (45.0%). Mitochondrial DNA (mtDNA) mutations were prevalent (87.4%), with m.3243A>G being the most common locus (48.7%). Meanwhile, POLG mutations in nuclear DNA (nDNA) accounted for 16.5%. Comparative analysis based on age groups (with a cut-off at 14 years) revealed the highest prevalence of MELAS, with Leigh syndrome (LS) and chronic progressive external ophthalmoplegia (CPEO) being the second most common phenotypes in junior and senior groups, respectively. Notably, the most commonly mutated nuclear genes varied across age groups. In conclusion, MELAS predominated in this Chinese MtD cohort, underscored by m.3243A>G and POLG as principal mtDNA mutations and pathogenic nuclear genes. The phenotypic and genotypic disparities observed among different age cohorts highlight the complex nature of MtDs.
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Affiliation(s)
- Yang Zhao
- Department of Neurology, Peking University First Hospital, Beijing, China
| | - Xutong Zhao
- Department of Neurology, Peking University First Hospital, Beijing, China
| | - Kunqian Ji
- Department of Neurology, Qilu Hospital of Shandong University, Jinan, China
| | - Junling Wang
- Department of Neurology, Beijing Children's Hospital, Capital Medical University, National Center for Children's Health, Beijing, China
- Department of Pediatrics, The Third Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Yuying Zhao
- Department of Neurology, Qilu Hospital of Shandong University, Jinan, China
| | - Jie Lin
- Department of Neurology, Huashan Hospital Fudan University, Shanghai, China
| | - Qiang Gang
- Department of Neurology, Peking University First Hospital, Beijing, China
| | - Meng Yu
- Department of Neurology, Peking University First Hospital, Beijing, China
| | - Yun Yuan
- Department of Neurology, Peking University First Hospital, Beijing, China
| | - Haishan Jiang
- Department of Neurology, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Chong Sun
- Department of Neurology, Huashan Hospital Fudan University, Shanghai, China
| | - Fang Fang
- Department of Neurology, Beijing Children's Hospital, Capital Medical University, National Center for Children's Health, Beijing, China
| | - Chuanzhu Yan
- Department of Neurology, Qilu Hospital of Shandong University, Jinan, China
| | - Zhaoxia Wang
- Department of Neurology, Peking University First Hospital, Beijing, China
- Beijing Key Laboratory of Neurovascular Disease Discovery, Peking University First Hospital, Beijing, China
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2
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Borrelli E, Bandello F, Boon CJF, Carelli V, Lenaers G, Reibaldi M, Sadda SR, Sadun AA, Sarraf D, Yu-Wai-Man P, Barboni P. Mitochondrial retinopathies and optic neuropathies: The impact of retinal imaging on modern understanding of pathogenesis, diagnosis, and management. Prog Retin Eye Res 2024; 101:101264. [PMID: 38703886 DOI: 10.1016/j.preteyeres.2024.101264] [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: 01/11/2024] [Revised: 03/18/2024] [Accepted: 04/26/2024] [Indexed: 05/06/2024]
Abstract
Advancements in ocular imaging have significantly broadened our comprehension of mitochondrial retinopathies and optic neuropathies by examining the structural and pathological aspects of the retina and optic nerve in these conditions. This article aims to review the prominent imaging characteristics associated with mitochondrial retinopathies and optic neuropathies, aiming to deepen our insight into their pathogenesis and clinical features. Preceding this exploration, the article provides a detailed overview of the crucial genetic and clinical features, which is essential for the proper interpretation of in vivo imaging. More importantly, we will provide a critical analysis on how these imaging modalities could serve as biomarkers for characterization and monitoring, as well as in guiding treatment decisions. However, these imaging methods have limitations, which will be discussed along with potential strategies to mitigate them. Lastly, the article will emphasize the potential advantages and future integration of imaging techniques in evaluating patients with mitochondrial eye disorders, considering the prospects of emerging gene therapies.
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Affiliation(s)
- Enrico Borrelli
- Department of Surgical Sciences, University of Turin, Turin, Italy; Department of Ophthalmology, "City of Health and Science" Hospital, Turin, Italy.
| | - Francesco Bandello
- Vita-Salute San Raffaele University, Milan, Italy; IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Camiel J F Boon
- Department of Ophthalmology, Amsterdam University Medical Centers, Amsterdam, the Netherlands; Department of Ophthalmology, Leiden University Medical Center, Leiden, the Netherlands
| | - Valerio Carelli
- Dipartimento di Scienze Biomediche e Neuromotorie, Università di Bologna, Bologna, Italy; IRCCS Istituto delle Scienze Neurologiche di Bologna, Programma di Neurogenetica, Bologna, Italy
| | - Guy Lenaers
- Equipe MitoLab, Unité MitoVasc, INSERM U1083, Université d'Angers, 49933, Angers, France; Service de Neurologie, CHU d'Angers, 49100, Angers, France
| | - Michele Reibaldi
- Department of Surgical Sciences, University of Turin, Turin, Italy; Department of Ophthalmology, "City of Health and Science" Hospital, Turin, Italy
| | - Srinivas R Sadda
- Department of Ophthalmology, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA; Doheny Eye Institute, Los Angeles, CA, USA
| | - Alfredo A Sadun
- Department of Ophthalmology, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA; Doheny Eye Institute, Los Angeles, CA, USA
| | - David Sarraf
- Department of Ophthalmology, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA; Retinal Disorders and Ophthalmic Genetics Division, Stein Eye Institute, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| | - Patrick Yu-Wai-Man
- John van Geest Centre for Brain Repair and MRC Mitochondrial Biology Unit, Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK; Cambridge Eye Unit, Addenbrooke's Hospital, Cambridge University Hospitals, Cambridge, UK; Moorfields Eye Hospital NHS Foundation Trust, London, UK; Institute of Ophthalmology, University College London, London, UK
| | - Piero Barboni
- IRCCS San Raffaele Scientific Institute, Milan, Italy; Studio Oculistico d'Azeglio, Bologna, Italy.
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3
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Selvanathan A, Teo J, Parayil Sankaran B. Hematologic Manifestations in Primary Mitochondrial Diseases. J Pediatr Hematol Oncol 2024; 46:e338-e347. [PMID: 38857202 DOI: 10.1097/mph.0000000000002890] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/20/2023] [Accepted: 04/23/2024] [Indexed: 06/12/2024]
Abstract
Primary mitochondrial disorders (PMDs) are known for their pleiotropic manifestations in humans, affecting almost any organ or system at any time. Hematologic manifestations, such as cytopenias and sideroblastic anemia, occur in 10% to 30% of patients with confirmed PMDs. These can be the initial presenting features or complications that develop over time. Surveillance for these manifestations allows for prompt identification and treatment. This article provides an overview of the pathophysiology underpinning the hematologic effects of mitochondrial dysfunction, discussing the 3 key roles of the mitochondria in hematopoiesis: providing energy for cell differentiation and function, synthesizing heme, and generating iron-sulfur clusters. Subsequently, the diagnosis and management of mitochondrial disorders are discussed, focusing on hematologic manifestations and the specific conditions commonly associated with them. Through this, we aimed to provide a concise point of reference for those considering a mitochondrial cause for a patient's hematologic abnormality, or for those considering a hematologic manifestation in a patient with known or suspected mitochondrial disease.
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Affiliation(s)
- Arthavan Selvanathan
- Genetic Metabolic Disorders Service, The Children's Hospital at Westmead, Westmead, NSW, Australia
| | - Juliana Teo
- Haematology Department, The Children's Hospital at Westmead, Westmead, NSW, Australia
| | - Bindu Parayil Sankaran
- Discipline of Child and Adolescent Health, Faculty of Medicine and Health, University of Sydney, NSW, Australia
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4
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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 PMCID: PMC11346376 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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5
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Feng Z, Lai R, Wei J, Liu X, Chen X, Liu Y, Qin W, Qin X, Kong F. Have one's view of the important overshadowed by the trivial: chronic progressive external ophthalmoplegia combined with unilateral facial nerve injury: a case report and literature review. Front Neurol 2024; 14:1268053. [PMID: 38249737 PMCID: PMC10797034 DOI: 10.3389/fneur.2023.1268053] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2023] [Accepted: 12/05/2023] [Indexed: 01/23/2024] Open
Abstract
Chronic progressive external ophthalmoplegia (CPEO) is a mitochondrial encephalomyopathy that is characterized by progressive ptosis and impaired ocular motility. Owing to its nonspecific clinical manifestations, CPEO is often misdiagnosed as other conditions. Herein, we present the case of a 34-year-old woman who primarily presented with incomplete left eyelid closure and limited bilateral eye movements. During the 6-year disease course, she was diagnosed with myasthenia gravis and cranial polyneuritis. Finally, skeletal muscle tissue biopsy confirmed the diagnosis. Biopsy revealed pathological changes in mitochondrial myopathy. Furthermore, mitochondrial gene testing of the skeletal muscle revealed a single chrmM:8469-13447 deletion. In addition, we summarized the findings of 26 patients with CPEO/Kearns-Sayre syndrome who were misdiagnosed with other diseases owing to ocular symptoms. In conclusion, we reported a rare clinical case and emphasized the symptomatic diversity of CPEO. Furthermore, we provided a brief review of the diagnosis and differential diagnosis of the disease.
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Affiliation(s)
- Ziyang Feng
- The Fourth Clinical Medical College, Guangzhou University of Chinese Medicine, Shenzhen, China
| | - Rui Lai
- School of Acupuncture and Tuina, Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Jia Wei
- The Fourth Clinical Medical College, Guangzhou University of Chinese Medicine, Shenzhen, China
- Department of Encephalopathy and Psychology, Shenzhen Traditional Chinese Medicine Hospital, Shenzhen, China
| | - Xuan Liu
- The Fourth Clinical Medical College, Guangzhou University of Chinese Medicine, Shenzhen, China
- Department of Encephalopathy and Psychology, Shenzhen Traditional Chinese Medicine Hospital, Shenzhen, China
| | - Xueqin Chen
- The Fourth Clinical Medical College, Guangzhou University of Chinese Medicine, Shenzhen, China
- Department of Encephalopathy and Psychology, Shenzhen Traditional Chinese Medicine Hospital, Shenzhen, China
| | - Yangsicheng Liu
- The Fourth Clinical Medical College, Guangzhou University of Chinese Medicine, Shenzhen, China
| | - Wenxin Qin
- The Fourth Clinical Medical College, Guangzhou University of Chinese Medicine, Shenzhen, China
| | - Xiude Qin
- The Fourth Clinical Medical College, Guangzhou University of Chinese Medicine, Shenzhen, China
- Department of Encephalopathy and Psychology, Shenzhen Traditional Chinese Medicine Hospital, Shenzhen, China
| | - Fanxin Kong
- The Fourth Clinical Medical College, Guangzhou University of Chinese Medicine, Shenzhen, China
- Department of Encephalopathy and Psychology, Shenzhen Traditional Chinese Medicine Hospital, Shenzhen, China
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6
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Zhao Y, Hou Y, Zhao X, Liufu T, Yu M, Zhang W, Xie Z, Zhang VW, Yuan Y, Wang Z. The clinical, myopathological, and genetic analysis of 155 Chinese mitochondrial ophthalmoplegia patients with mitochondrial DNA single large deletions. Mol Genet Genomic Med 2024; 12:e2328. [PMID: 38018320 PMCID: PMC10767604 DOI: 10.1002/mgg3.2328] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2023] [Revised: 10/20/2023] [Accepted: 11/14/2023] [Indexed: 11/30/2023] Open
Abstract
BACKGROUND Progressive external ophthalmoplegia (PEO) is a common subtype of mitochondrial encephalomyopathy. OBJECTIVE The study aimed to investigate the relationship between mitochondrial DNA (mtDNA) abnormalities, muscle pathology, and clinical manifestations in Chinese patients with single large-scale mtDNA deletion presenting with PEO. METHODS This is a retrospective single-center study. Patients with PEO who had a single large deletion in mitochondrial DNA were included in this study. The associations were analyzed between mtDNA deletion patterns, myopathological changes, and clinical characteristics. RESULTS In total, 155 patients with mitochondrial PEO carrying single large-scale mtDNA mutations were enrolled, including 137 chronic progressive external ophthalmoplegia (CPEO) and 18 Kearns-Sayre syndrome (KSS) patients. The onset ages were 9.61 ± 4.12 in KSS and 20.15 ± 9.06 in CPEO. The mtDNA deletions ranged from 2225 bp to 9131 bp, with m.8470_13446del being the most common. The KSS group showed longer deletions than the CPEO group (p = 0.004). Additionally, a higher number of deleted genes encoding respiratory chain complex subunits (p = 0.001) and tRNA genes (p = 0.009) were also observed in the KSS group. A weak negative correlation between the mtDNA deletion size and ages of onset (p < 0.001, r = -0.369) was observed. The proportion of ragged red fibers, ragged blue fibers, and cytochrome c negative fibers did not correlate significantly with onset ages (p > 0.05). However, a higher percentage of abnormal muscle fibers corresponds to an increased prevalence of exercise intolerance, limb muscle weakness, dysphagia, and cerebellar ataxia. CONCLUSION We reported a large Chinese cohort consisting of mitochondrial PEO patients with single large-scale mtDNA deletions. Our results demonstrated that the length and locations of mtDNA deletions may influence onset ages and clinical phenotypes. The severity of muscle pathology could not only indicate diagnosis but also may be associated with clinical manifestations beyond the extraocular muscles.
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Affiliation(s)
- Yang Zhao
- Department of NeurologyPeking University First HospitalBeijingChina
- Beijing Key Laboratory of Neurovascular Disease DiscoveryBeijingChina
| | - Yue Hou
- Department of GeriatricsPeking University First HospitalBeijingChina
| | - Xutong Zhao
- Department of NeurologyPeking University First HospitalBeijingChina
- Beijing Key Laboratory of Neurovascular Disease DiscoveryBeijingChina
- Department of NeurologyBeijing Jishuitan HospitalBeijingChina
| | - Tongling Liufu
- Department of NeurologyPeking University First HospitalBeijingChina
- Beijing Key Laboratory of Neurovascular Disease DiscoveryBeijingChina
| | - Meng Yu
- Department of NeurologyPeking University First HospitalBeijingChina
- Beijing Key Laboratory of Neurovascular Disease DiscoveryBeijingChina
| | - Wei Zhang
- Department of NeurologyPeking University First HospitalBeijingChina
- Beijing Key Laboratory of Neurovascular Disease DiscoveryBeijingChina
| | - Zhiying Xie
- Department of NeurologyPeking University First HospitalBeijingChina
- Beijing Key Laboratory of Neurovascular Disease DiscoveryBeijingChina
| | | | - Yun Yuan
- Department of NeurologyPeking University First HospitalBeijingChina
- Beijing Key Laboratory of Neurovascular Disease DiscoveryBeijingChina
| | - Zhaoxia Wang
- Department of NeurologyPeking University First HospitalBeijingChina
- Beijing Key Laboratory of Neurovascular Disease DiscoveryBeijingChina
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7
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Alves CAPF, Whitehead MT. Advancing the neuroimaging diagnosis and understanding of mitochondrial disorders. Neurotherapeutics 2024; 21:e00324. [PMID: 38306952 PMCID: PMC10903090 DOI: 10.1016/j.neurot.2024.e00324] [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: 11/03/2023] [Revised: 01/16/2024] [Accepted: 01/16/2024] [Indexed: 02/04/2024] Open
Abstract
Mitochondrial diseases, a diverse and intricate group of disorders, result from both nuclear DNA and mitochondrial DNA malfunctions, leading to a decrease in cellular energy (ATP) production. The increasing understanding of molecular, biochemical, and genetic irregularities associated with mitochondrial dysfunction has led to a wider recognition of varying mitochondrial disease phenotypes. This broadening landscape has led to a diverse array of neuroimaging findings, posing a challenge to radiologists in identifying the extensive range of possible patterns. This review meticulously describes the central imaging features of mitochondrial diseases in children, as revealed by neuroimaging. It spans from traditional imaging findings to more recent and intricate diagnoses, offering insights and highlighting advancements in neuroimaging technology that can potentially guide a more efficient and accurate diagnostic approach.
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Affiliation(s)
- César Augusto P F Alves
- Division of Neuroradiology, Department of Radiology, Boston Children's Hospital - BCH Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, United States.
| | - Matthew T Whitehead
- Division of Neuroradiology, Department of Radiology, The Children's Hospital of Philadelphia, PA, United States; Perelman School of Medicine, University of Pennsylvania Perelman School of Medicine of Philadelphia, United States.
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8
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Siri B, D'Alessandro A, Maiorana A, Porzio O, Ravà L, Dionisi-Vici C, Cappa M, Martinelli D. Adrenocortical function in patients with Single Large Scale Mitochondrial DNA Deletions: a retrospective single centre cohort study. Eur J Endocrinol 2023; 189:485-494. [PMID: 37815532 DOI: 10.1093/ejendo/lvad137] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/22/2023] [Revised: 08/11/2023] [Accepted: 08/16/2023] [Indexed: 10/11/2023]
Abstract
OBJECTIVE Single Large Scale Mitochondrial DNA Deletions (SLSMDs), Pearson Syndrome (PS) and Kearns-Sayre Syndrome (KSS), are systemic diseases with multiple endocrine abnormalities. The adrenocortical function has not been systematically investigated with a few anecdotal reports of overt adrenal insufficiency (AI). The study aimed to assess the adrenocortical function in a large cohort of SLSMDs. DESIGN AND METHODS A retrospective monocentric longitudinal study involved a cohort of 18 SLSMDs patients. Adrenocortical function was evaluated by baseline adrenocorticotrophic hormone (ACTH) and cortisol measurements and by high- (HDT) and low-dose (LDT) ACTH stimulation tests and compared with 92 healthy controls (HC). RESULTS Baseline adrenocortical function was impaired in 39% of patients and by the end of the study, 66% of PS and 25% of KSS showed an insufficient increase after ACTH stimulation, with cortisol deficiency due to primary AI in most PS and subclinical AI in KSS. Symptomatic AI was recorded in 44% of patients. Peak cortisol levels after ACTH stimulation tests were significantly lower in patients than in HC (P < .0001), with a more reduced response to LDT vs HDT (P < .05). CONCLUSIONS Our study highlights that cortisol deficiency due to primary AI represents a relevant part of the clinical spectrum in SLSMDs, with more severe impairment in PS than in KSS. Basal and after-stimulus assessment of adrenocortical axis should be early and regularly investigated to identify any degree of adrenocortical dysfunction. The study allowed the elaboration of a diagnostic process designed for the diagnosis, treatment, and follow-up of adrenocortical abnormalities in SLSMDs.
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Affiliation(s)
- Barbara Siri
- Division of Metabolic Diseases and Hepatology, Bambino Gesù Children's Hospital, IRCCS, 00165 Rome, Italy
- Department of Paediatrics, Città della Salute e della Scienza, OIRM, University of Turin, 10126 Turin, Italy
| | - Annamaria D'Alessandro
- Clinical Biochemistry Laboratory, Bambino Gesù Children's Hospital, IRCCS, 00165 Rome, Italy
| | - Arianna Maiorana
- Division of Metabolic Diseases and Hepatology, Bambino Gesù Children's Hospital, IRCCS, 00165 Rome, Italy
| | - Ottavia Porzio
- Clinical Biochemistry Laboratory, Bambino Gesù Children's Hospital, IRCCS, 00165 Rome, Italy
| | - Lucilla Ravà
- Clinical Epidemiology Unit, Bambino Gesù Children's Hospital, IRCCS, 00165 Rome, Italy
| | - Carlo Dionisi-Vici
- Division of Metabolic Diseases and Hepatology, Bambino Gesù Children's Hospital, IRCCS, 00165 Rome, Italy
| | - Marco Cappa
- Research Area of Innovative Therapies in Endocrinopathies, Bambino Gesù Children's Hospital, IRCCS, 00165 Rome, Italy
| | - Diego Martinelli
- Division of Metabolic Diseases and Hepatology, Bambino Gesù Children's Hospital, IRCCS, 00165 Rome, Italy
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9
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Vallbona-Garcia A, Hamers IHJ, van Tienen FHJ, Ochoteco-Asensio J, Berendschot TTJM, de Coo IFM, Benedikter BJ, Webers CAB, Smeets HJM, Gorgels TGMF. Low mitochondrial DNA copy number in buffy coat DNA of primary open-angle glaucoma patients. Exp Eye Res 2023; 232:109500. [PMID: 37178956 DOI: 10.1016/j.exer.2023.109500] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2023] [Revised: 04/22/2023] [Accepted: 05/09/2023] [Indexed: 05/15/2023]
Abstract
Primary open-angle glaucoma (POAG) is characterized by optic nerve degeneration and irreversible loss of retinal ganglion cells (RGCs). The pathophysiology is not fully understood. Since RGCs have a high energy demand, suboptimal mitochondrial function may put the survival of these neurons at risk. In the present study, we explored whether mtDNA copy number or mtDNA deletions could reveal a mitochondrial component in POAG pathophysiology. Buffy coat DNA was isolated from EDTA blood of age- and sex-matched study groups, namely POAG patients with high intraocular pressure (IOP) at diagnosis (high tension glaucoma: HTG; n = 97), normal tension glaucoma patients (NTG, n = 37), ocular hypertensive controls (n = 9), and cataract controls (without glaucoma; n = 32), all without remarkable comorbidities. The number of mtDNA copies was assessed through qPCR quantification of the mitochondrial D-loop and nuclear B2M gene. Presence of the common 4977 base pair mtDNA deletion was assessed by a highly sensitive breakpoint PCR. Analysis showed that HTG patients had a lower number of mtDNA copies per nuclear DNA than NTG patients (p-value <0.01, Dunn test) and controls (p-value <0.001, Dunn test). The common 4977 base pair mtDNA deletion was not detected in any of the participants. A lower mtDNA copy number in blood of HTG patients suggests a role for a genetically defined, deficient mtDNA replication in the pathology of HTG. This may cause a low number of mtDNA copies in RGCs, which together with aging and high IOP, may lead to mitochondrial dysfunction, and contribute to glaucoma pathology.
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Affiliation(s)
- Antoni Vallbona-Garcia
- University Eye Clinic Maastricht, Maastricht University Medical Center+, Maastricht, the Netherlands; Department of Toxicogenomics, Maastricht University, Maastricht, the Netherlands; School for Mental Health and Neuroscience, Maastricht University, Maastricht, the Netherlands.
| | - Ilse H J Hamers
- Department of Toxicogenomics, Maastricht University, Maastricht, the Netherlands
| | - Florence H J van Tienen
- Department of Toxicogenomics, Maastricht University, Maastricht, the Netherlands; School for Mental Health and Neuroscience, Maastricht University, Maastricht, the Netherlands
| | | | - Tos T J M Berendschot
- University Eye Clinic Maastricht, Maastricht University Medical Center+, Maastricht, the Netherlands
| | - Irenaeus F M de Coo
- Department of Toxicogenomics, Maastricht University, Maastricht, the Netherlands
| | - Birke J Benedikter
- University Eye Clinic Maastricht, Maastricht University Medical Center+, Maastricht, the Netherlands; School for Mental Health and Neuroscience, Maastricht University, Maastricht, the Netherlands
| | - Carroll A B Webers
- University Eye Clinic Maastricht, Maastricht University Medical Center+, Maastricht, the Netherlands
| | - Hubert J M Smeets
- Department of Toxicogenomics, Maastricht University, Maastricht, the Netherlands; School for Mental Health and Neuroscience, Maastricht University, Maastricht, the Netherlands
| | - Theo G M F Gorgels
- University Eye Clinic Maastricht, Maastricht University Medical Center+, Maastricht, the Netherlands; School for Mental Health and Neuroscience, Maastricht University, Maastricht, the Netherlands
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10
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Frascarelli C, Zanetti N, Nasca A, Izzo R, Lamperti C, Lamantea E, Legati A, Ghezzi D. Nanopore long-read next-generation sequencing for detection of mitochondrial DNA large-scale deletions. Front Genet 2023; 14:1089956. [PMID: 37456669 PMCID: PMC10344361 DOI: 10.3389/fgene.2023.1089956] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2022] [Accepted: 06/13/2023] [Indexed: 07/18/2023] Open
Abstract
Primary mitochondrial diseases are progressive genetic disorders affecting multiple organs and characterized by mitochondrial dysfunction. These disorders can be caused by mutations in nuclear genes coding proteins with mitochondrial localization or by genetic defects in the mitochondrial genome (mtDNA). The latter include point pathogenic variants and large-scale deletions/rearrangements. MtDNA molecules with the wild type or a variant sequence can exist together in a single cell, a condition known as mtDNA heteroplasmy. MtDNA single point mutations are typically detected by means of Next-Generation Sequencing (NGS) based on short reads which, however, are limited for the identification of structural mtDNA alterations. Recently, new NGS technologies based on long reads have been released, allowing to obtain sequences of several kilobases in length; this approach is suitable for detection of structural alterations affecting the mitochondrial genome. In the present work we illustrate the optimization of two sequencing protocols based on long-read Oxford Nanopore Technology to detect mtDNA structural alterations. This approach presents strong advantages in the analysis of mtDNA compared to both short-read NGS and traditional techniques, potentially becoming the method of choice for genetic studies on mtDNA.
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Affiliation(s)
- Chiara Frascarelli
- Unit of Medical Genetics and Neurogenetics, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Nadia Zanetti
- Unit of Medical Genetics and Neurogenetics, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Alessia Nasca
- Unit of Medical Genetics and Neurogenetics, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Rossella Izzo
- Unit of Medical Genetics and Neurogenetics, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Costanza Lamperti
- Unit of Medical Genetics and Neurogenetics, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Eleonora Lamantea
- Unit of Medical Genetics and Neurogenetics, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Andrea Legati
- Unit of Medical Genetics and Neurogenetics, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Daniele Ghezzi
- Unit of Medical Genetics and Neurogenetics, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
- Department of Pathophysiology and Transplantation (DEPT), University of Milan, Milan, Italy
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11
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Yuzyuk TN, Nelson HA, Johnson LM. Inherited causes of exocrine pancreatic insufficiency in pediatric patients: clinical presentation and laboratory testing. Crit Rev Clin Lab Sci 2023:1-16. [PMID: 36876586 DOI: 10.1080/10408363.2023.2179968] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/07/2023]
Abstract
Pediatric patients with exocrine pancreatic insufficiency (EPI) have symptoms that include abdominal pain, weight loss or poor weight gain, malnutrition, and steatorrhea. This condition can be present at birth or develop during childhood for certain genetic disorders. Cystic fibrosis (CF) is the most prevalent disorder in which patients are screened for EPI; other disorders also are associated with pancreatic dysfunction, such as hereditary pancreatitis, Pearson syndrome, and Shwachman-Diamond syndrome. Understanding the clinical presentation and proposed pathophysiology of the pancreatic dysfunction of these disorders aids in diagnosis and treatment. Testing pancreatic function is challenging. Directly testing aspirates produced from the pancreas after stimulation is considered the gold standard, but the procedures are not standardized or widely available. Instead, indirect tests are often used in diagnosis and monitoring. Although indirect tests are more widely available and easier to perform, they have inherent limitations due to a lack of sensitivity and/or specificity for EPI.
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Affiliation(s)
- Tatiana N Yuzyuk
- Department of Pathology, University of Utah/ARUP Laboratories, Salt Lake City, UT, USA
| | - Heather A Nelson
- Department of Pathology, University of Utah/ARUP Laboratories, Salt Lake City, UT, USA
| | - Lisa M Johnson
- Department of Laboratories, Seattle Children's Hospital, Seattle, WA, USA
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12
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Mavraki E, Labrum R, Sergeant K, Alston CL, Woodward C, Smith C, Knowles CVY, Patel Y, Hodsdon P, Baines JP, Blakely EL, Polke J, Taylor RW, Fratter C. Genetic testing for mitochondrial disease: the United Kingdom best practice guidelines. Eur J Hum Genet 2023; 31:148-163. [PMID: 36513735 PMCID: PMC9905091 DOI: 10.1038/s41431-022-01249-w] [Citation(s) in RCA: 22] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2022] [Revised: 11/12/2022] [Accepted: 11/16/2022] [Indexed: 12/15/2022] Open
Abstract
Primary mitochondrial disease describes a diverse group of neuro-metabolic disorders characterised by impaired oxidative phosphorylation. Diagnosis is challenging; >350 genes, both nuclear and mitochondrial DNA (mtDNA) encoded, are known to cause mitochondrial disease, leading to all possible inheritance patterns and further complicated by heteroplasmy of the multicopy mitochondrial genome. Technological advances, particularly next-generation sequencing, have driven a shift in diagnostic practice from 'biopsy first' to genome-wide analyses of blood and/or urine DNA. This has led to the need for a reference framework for laboratories involved in mitochondrial genetic testing to facilitate a consistent high-quality service. In the United Kingdom, consensus guidelines have been prepared by a working group of Clinical Scientists from the NHS Highly Specialised Service followed by national laboratory consultation. These guidelines summarise current recommended technologies and methodologies for the analysis of mtDNA and nuclear-encoded genes in patients with suspected mitochondrial disease. Genetic testing strategies for diagnosis, family testing and reproductive options including prenatal diagnosis are outlined. Importantly, recommendations for the minimum levels of mtDNA testing for the most common referral reasons are included, as well as guidance on appropriate referrals and information on the minimal appropriate gene content of panels when analysing nuclear mitochondrial genes. Finally, variant interpretation and recommendations for reporting of results are discussed, focussing particularly on the challenges of interpreting and reporting mtDNA variants.
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Affiliation(s)
- Eleni Mavraki
- NHS Highly Specialised Service for Rare Mitochondrial Disorders, Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne, UK
- Wellcome Centre for Mitochondrial Research, Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, UK
| | - Robyn Labrum
- Neurogenetics Unit, National Hospital for Neurology and Neurosurgery, Queen Square, London, UK
| | - Kate Sergeant
- Oxford Genetics Laboratories, Oxford University Hospitals NHS Foundation Trust, Oxford, UK
| | - Charlotte L Alston
- NHS Highly Specialised Service for Rare Mitochondrial Disorders, Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne, UK
- Wellcome Centre for Mitochondrial Research, Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, UK
| | - Cathy Woodward
- Neurogenetics Unit, National Hospital for Neurology and Neurosurgery, Queen Square, London, UK
| | - Conrad Smith
- Oxford Genetics Laboratories, Oxford University Hospitals NHS Foundation Trust, Oxford, UK
| | - Charlotte V Y Knowles
- NHS Highly Specialised Service for Rare Mitochondrial Disorders, Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne, UK
- Wellcome Centre for Mitochondrial Research, Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, UK
| | - Yogen Patel
- Neurogenetics Unit, National Hospital for Neurology and Neurosurgery, Queen Square, London, UK
| | - Philip Hodsdon
- Oxford Genetics Laboratories, Oxford University Hospitals NHS Foundation Trust, Oxford, UK
| | - Jack P Baines
- NHS Highly Specialised Service for Rare Mitochondrial Disorders, Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne, UK
- Wellcome Centre for Mitochondrial Research, Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, UK
| | - Emma L Blakely
- NHS Highly Specialised Service for Rare Mitochondrial Disorders, Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne, UK
- Wellcome Centre for Mitochondrial Research, Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, UK
| | - James Polke
- Neurogenetics Unit, National Hospital for Neurology and Neurosurgery, Queen Square, London, UK
| | - Robert W Taylor
- NHS Highly Specialised Service for Rare Mitochondrial Disorders, Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne, UK
- Wellcome Centre for Mitochondrial Research, Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, UK
| | - Carl Fratter
- Oxford Genetics Laboratories, Oxford University Hospitals NHS Foundation Trust, Oxford, UK.
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13
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Abstract
Progressive external ophthalmoplegia (PEO), characterized by ptosis and impaired eye movements, is a clinical syndrome with an expanding number of etiologically distinct subtypes. Advances in molecular genetics have revealed numerous pathogenic causes of PEO, originally heralded in 1988 by the detection of single large-scale deletions of mitochondrial DNA (mtDNA) in skeletal muscle of people with PEO and Kearns-Sayre syndrome. Since then, multiple point variants of mtDNA and nuclear genes have been identified to cause mitochondrial PEO and PEO-plus syndromes, including mitochondrial neurogastrointestinal encephalomyopathy (MNGIE) and sensory ataxic neuropathy dysarthria ophthalmoplegia (SANDO). Intriguingly, many of those nuclear DNA pathogenic variants impair maintenance of the mitochondrial genome causing downstream mtDNA multiple deletions and depletion. In addition, numerous genetic causes of nonmitochondrial PEO have been identified.
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Affiliation(s)
- Michio Hirano
- H. Houston Merritt Neuromuscular Research Center, Neuromuscular Medicine Division, Department of Neurology, Columbia University Irving Medical Center, New York, NY, United States.
| | - Robert D S Pitceathly
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology, London, United Kingdom; NHS Highly Specialised Service for Rare Mitochondrial Disorders, Queen Square Centre for Neuromuscular Diseases, National Hospital for Neurology and Neurosurgery, London, United Kingdom
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14
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Björkman K, Vissing J, Østergaard E, Bindoff LA, de Coo IFM, Engvall M, Hikmat O, Isohanni P, Kollberg G, Lindberg C, Majamaa K, Naess K, Uusimaa J, Tulinius M, Darin N. Phenotypic spectrum and clinical course of single large-scale mitochondrial DNA deletion disease in the paediatric population: a multicentre study. J Med Genet 2023; 60:65-73. [PMID: 34872991 PMCID: PMC9811091 DOI: 10.1136/jmedgenet-2021-108006] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Accepted: 11/09/2021] [Indexed: 02/04/2023]
Abstract
BACKGROUND Large-scale mitochondrial DNA deletions (LMD) are a common genetic cause of mitochondrial disease and give rise to a wide range of clinical features. Lack of longitudinal data means the natural history remains unclear. This study was undertaken to describe the clinical spectrum in a large cohort of patients with paediatric disease onset. METHODS A retrospective multicentre study was performed in patients with clinical onset <16 years of age, diagnosed and followed in seven European mitochondrial disease centres. RESULTS A total of 80 patients were included. The average age at disease onset and at last examination was 10 and 31 years, respectively. The median time from disease onset to death was 11.5 years. Pearson syndrome was present in 21%, Kearns-Sayre syndrome spectrum disorder in 50% and progressive external ophthalmoplegia in 29% of patients. Haematological abnormalities were the hallmark of the disease in preschool children, while the most common presentations in older patients were ptosis and external ophthalmoplegia. Skeletal muscle involvement was found in 65% and exercise intolerance in 25% of the patients. Central nervous system involvement was frequent, with variable presence of ataxia (40%), cognitive involvement (36%) and stroke-like episodes (9%). Other common features were pigmentary retinopathy (46%), short stature (42%), hearing impairment (39%), cardiac disease (39%), diabetes mellitus (25%) and renal disease (19%). CONCLUSION Our study provides new insights into the phenotypic spectrum of childhood-onset, LMD-associated syndromes. We found a wider spectrum of more prevalent multisystem involvement compared with previous studies, most likely related to a longer time of follow-up.
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Affiliation(s)
- Kristoffer Björkman
- Department of Pediatrics, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden,The Queen Silvia Children's Hospital, Sahlgrenska University Hospital, Gothenburg, Sweden
| | - John Vissing
- Copenhagen Neuromuscular Centre, Rigshospitalet, Kobenhavn, Denmark
| | - Elsebet Østergaard
- Department of Clinical Genetics, Rigshospitalet, Kobenhavn, Denmark,Department of Clinical Medicine, University of Copenhagen, Kobenhavn, Denmark
| | - Laurence A Bindoff
- Department of Clinical Medicine (K1), University of Bergen, Bergen, Norway,Neuro-SysMed, Department of Neurology, Haukeland University Hospital, Bergen, Norway
| | - Irenaeus F M de Coo
- Department of Toxicogenomics, Unit Clinical Genomics, Maastricht University, Maastricht, The Netherlands,Maastricht University School for Mental Health and Neuroscience, Maastricht, The Netherlands
| | - Martin Engvall
- Center for Inherited Metabolic Diseases, Karolinska University Hospital, Stockholm, Sweden,Department of Molecular Medicine and Surgery, Karolinska Institute, Stockholm, Sweden
| | - Omar Hikmat
- Department of Clinical Medicine (K1), University of Bergen, Bergen, Norway,Department of Pediatrics, Haukeland University Hospital, Bergen, Norway
| | - Pirjo Isohanni
- Research Programs Unit, Stem Cells and Metabolism, Faculty of Medicine, University of Helsinki, Helsinki, Finland,University of Helsinki Children's Hospital, Helsinki, Finland
| | - Gittan Kollberg
- Department of Clinical Chemistry, University of Gothenburg, Gothenburg, Sweden
| | - Christopher Lindberg
- Department of Neurology, Neuromuscular Center, Sahlgrenska University Hospital, Gothenburg, Sweden
| | - Kari Majamaa
- Medical Research Center, Oulu University Faculty of Medicine, Oulu, Finland,Medical Research Center, Oulu University Hospital, Oulu, Finland
| | - Karin Naess
- Center for Inherited Metabolic Diseases, Karolinska University Hospital, Stockholm, Sweden,Department of Medical Biochemistry and Biophysics, Karolinska Institute, Stockholm, Sweden
| | - Johanna Uusimaa
- PEDEGO Research Unit, Oulu University Faculty of Medicine, Oulu, Finland,Clinic for Children and Adolescents and Medical Research Center, Oulu University Hospital, Oulu, Finland
| | - Mar Tulinius
- Department of Pediatrics, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden,The Queen Silvia Children's Hospital, Sahlgrenska University Hospital, Gothenburg, Sweden
| | - Niklas Darin
- Department of Pediatrics, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden,The Queen Silvia Children's Hospital, Sahlgrenska University Hospital, Gothenburg, Sweden
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15
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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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16
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Jacoby E, Bar-Yosef O, Gruber N, Lahav E, Varda-Bloom N, Bolkier Y, Bar D, Blumkin MBY, Barak S, Eisenstein E, Ahonniska-Assa J, Silberg T, Krasovsky T, Bar O, Erez N, Bielorai B, Golan H, Dekel B, Besser MJ, Pozner G, Khoury H, Jacobs A, Campbell J, Herskovitz E, Sher N, Yivgi-Ohana N, Anikster Y, Toren A. Mitochondrial augmentation of hematopoietic stem cells in children with single large-scale mitochondrial DNA deletion syndromes. Sci Transl Med 2022; 14:eabo3724. [PMID: 36542693 DOI: 10.1126/scitranslmed.abo3724] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Patients with single large-scale mitochondrial DNA (mtDNA) deletion syndromes (SLSMDs) usually present with multisystemic disease, either as Pearson syndrome in early childhood or as Kearns-Sayre syndrome later in life. No disease-modifying therapies exist for SLSMDs. We have developed a method to enrich hematopoietic cells with exogenous mitochondria, and we treated six patients with SLSMDs through a compassionate use program. Autologous CD34+ hematopoietic cells were augmented with maternally derived healthy mitochondria, a technology termed mitochondrial augmentation therapy (MAT). All patients had substantial multisystemic disease involvement at baseline, including neurologic, endocrine, or renal impairment. We first assessed safety, finding that the procedure was well tolerated and that all study-related severe adverse events were either leukapheresis-related or related to the baseline disorder. After MAT, heteroplasmy decreased in the peripheral blood in four of the six patients. An increase in mtDNA content of peripheral blood cells was measured in all six patients 6 to 12 months after MAT as compared baseline. We noted some clinical improvement in aerobic function, measured in patients 2 and 3 by sit-to-stand or 6-min walk testing, and an increase in the body weight of five of the six patients suffering from very low body weight before treatment. Quality-of-life measurements as per caregiver assessment and physical examination showed improvement in some parameters. Together, this work lays the ground for clinical trials of MAT for the treatment of patients with mtDNA disorders.
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Affiliation(s)
- Elad Jacoby
- Edmond and Lily Safra Children's Hospital, Sheba Medical Center, Tel Hashomer 5262000, Israel.,Sackler School of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Omer Bar-Yosef
- Edmond and Lily Safra Children's Hospital, Sheba Medical Center, Tel Hashomer 5262000, Israel.,Sackler School of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Noah Gruber
- Edmond and Lily Safra Children's Hospital, Sheba Medical Center, Tel Hashomer 5262000, Israel.,Sackler School of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Einat Lahav
- Edmond and Lily Safra Children's Hospital, Sheba Medical Center, Tel Hashomer 5262000, Israel.,Sackler School of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Nira Varda-Bloom
- Stem Cell Processing Laboratory, Sheba Medical Center, Tel Hashomer 5262000, Israel
| | - Yoav Bolkier
- Edmond and Lily Safra Children's Hospital, Sheba Medical Center, Tel Hashomer 5262000, Israel.,Sackler School of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Diana Bar
- Edmond and Lily Safra Children's Hospital, Sheba Medical Center, Tel Hashomer 5262000, Israel
| | | | - Sharon Barak
- Edmond and Lily Safra Children's Hospital, Sheba Medical Center, Tel Hashomer 5262000, Israel.,Department of Nursing, Faculty of Health Sciences, Ariel University, Ariel 40700, Israel
| | - Etzyona Eisenstein
- Edmond and Lily Safra Children's Hospital, Sheba Medical Center, Tel Hashomer 5262000, Israel
| | - Jaana Ahonniska-Assa
- Edmond and Lily Safra Children's Hospital, Sheba Medical Center, Tel Hashomer 5262000, Israel.,School of Behavioral Sciences, Academic College of Tel Aviv Yaffo, Tel Aviv 64044, Israel
| | - Tamar Silberg
- Edmond and Lily Safra Children's Hospital, Sheba Medical Center, Tel Hashomer 5262000, Israel.,Department of Psychology, Bar-Ilan University, Ramat-Gan 52900, Israel
| | - Tal Krasovsky
- Edmond and Lily Safra Children's Hospital, Sheba Medical Center, Tel Hashomer 5262000, Israel.,Department of Physical Therapy, Faculty of Social Welfare and Health Sciences, University of Haifa, Haifa 34988, Israel
| | - Orly Bar
- Edmond and Lily Safra Children's Hospital, Sheba Medical Center, Tel Hashomer 5262000, Israel
| | - Neta Erez
- Edmond and Lily Safra Children's Hospital, Sheba Medical Center, Tel Hashomer 5262000, Israel
| | - Bella Bielorai
- Edmond and Lily Safra Children's Hospital, Sheba Medical Center, Tel Hashomer 5262000, Israel.,Sackler School of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Hana Golan
- Edmond and Lily Safra Children's Hospital, Sheba Medical Center, Tel Hashomer 5262000, Israel.,Sackler School of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Benjamin Dekel
- Edmond and Lily Safra Children's Hospital, Sheba Medical Center, Tel Hashomer 5262000, Israel.,Sackler School of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Michal J Besser
- Sackler School of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel.,Ella Lemelbaum Institute of Immuno-oncology, Sheba Medical Center, Tel Hashomer 5262000, Israel
| | - Gat Pozner
- Minovia Therapeutics, Tirat HaCarmel 3902603, Israel
| | - Hanan Khoury
- Minovia Therapeutics, Tirat HaCarmel 3902603, Israel
| | - Alan Jacobs
- Minovia Therapeutics, Tirat HaCarmel 3902603, Israel
| | - John Campbell
- Minovia Therapeutics, Tirat HaCarmel 3902603, Israel
| | | | - Noa Sher
- Minovia Therapeutics, Tirat HaCarmel 3902603, Israel
| | | | - Yair Anikster
- Edmond and Lily Safra Children's Hospital, Sheba Medical Center, Tel Hashomer 5262000, Israel.,Sackler School of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Amos Toren
- Edmond and Lily Safra Children's Hospital, Sheba Medical Center, Tel Hashomer 5262000, Israel.,Sackler School of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel
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17
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Thomas RH, Hunter A, Butterworth L, Feeney C, Graves TD, Holmes S, Hossain P, Lowndes J, Sharpe J, Upadhyaya S, Varhaug KN, Votruba M, Wheeler R, Staley K, Rahman S. Research priorities for mitochondrial disorders: Current landscape and patient and professional views. J Inherit Metab Dis 2022; 45:796-803. [PMID: 35543492 PMCID: PMC9429991 DOI: 10.1002/jimd.12521] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/19/2022] [Revised: 04/16/2022] [Accepted: 04/27/2022] [Indexed: 11/15/2022]
Abstract
Primary mitochondrial disorders encompass a wide range of clinical presentations and a spectrum of severity. They currently lack effective disease-modifying therapies and have a high mortality and morbidity rate. It is therefore essential to know that competitively funded research designed by academics meets the core needs of people with mitochondrial disorders and their clinicians. Priority setting partnerships are an established collaborative methodology that brings patients, carers and families, charity representatives and clinicians together to try to establish the most pressing and unanswered research priorities for a particular disease. We developed a web-based questionnaire, requesting all patients affected by primary mitochondrial disease, their carers and clinicians to pose their research questions. This yielded 709 questions from 147 participants. These were grouped into overarching themes including basic biology, causation, health services, clinical management, social impacts, prognosis, prevention, symptoms, treatment and psychological impact. Following the removal of "answered questions", the process resulted in a list of 42 discrete, answerable questions. This was further refined by web-based ranking by the community to 24 questions. These were debated at a face-to-face workshop attended by a diverse range of patients, carers, charity representatives and clinicians to create a definitive "Top 10 of unanswered research questions for primary mitochondrial disorders". These Top 10 questions related to understanding biological processes, including triggers of disease onset, mechanisms underlying progression and reasons for differential symptoms between individuals with identical genetic mutations; new treatments; biomarker discovery; psychological support and optimal management of stroke-like episodes and fatigue.
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Affiliation(s)
- Rhys H. Thomas
- Translational and Clinical Research InstituteNewcastle UniversityNewcastleUK
| | | | | | - Catherine Feeney
- NHS Highly Specialised Service for Rare Mitochondrial Diseases, Newcastle Hospitals NHS Foundation TrustNewcastleUK
| | - Tracey D. Graves
- Hinchingbrooke HospitalHuntingdonUK
- The National Hospital for Neurology and NeurosurgeryLondonUK
| | - Sarah Holmes
- The National Hospital for Neurology and NeurosurgeryLondonUK
| | | | - Jo Lowndes
- Oxford University Hospitals NHS Foundation TrustOxfordUK
| | - Jenny Sharpe
- Centre for Innovation in Regulatory ScienceLondonUK
| | | | - Kristin N. Varhaug
- Translational and Clinical Research InstituteNewcastle UniversityNewcastleUK
| | - Marcela Votruba
- University Hospital Wales and School of Vision SciencesCardiff UniversityCardiffUK
| | | | | | - Shamima Rahman
- Mitochondrial Research Group, UCL Great Ormond Street Institute of Child Health and Great Ormond Street Hospital for Children NHS Foundation TrustLondonUK
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18
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Hou Y, Zhao X, Xie Z, Yu M, Lv H, Zhang W, Yuan Y, Wang Z. Novel and recurrent nuclear gene variations in a cohort of Chinese progressive external ophthalmoplegia patients with multiple mtDNA deletions. Mol Genet Genomic Med 2022; 10:e1921. [PMID: 35289132 PMCID: PMC9034679 DOI: 10.1002/mgg3.1921] [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: 10/13/2021] [Revised: 12/30/2021] [Accepted: 02/25/2022] [Indexed: 11/07/2022] Open
Abstract
Objectives This study aimed to investigate the clinical and genetic spectrum in Chinese patients with multiple mtDNA deletions presenting with autosomal‐inherited mitochondrial progressive external ophthalmoplegia (PEO). Methods Long‐range polymerase chain reaction and massively parallel sequencing of the mitochondrial genome were performed to detect deletions in muscle mtDNA of 274 unrelated families. Then, targeted next generation sequencing was used to detect nuclear gene variations in patients with multiple mtDNA deletions. Results A total of 40 Chinese PEO patients (10 males and 30 females) from 20 families were found to have multiple mtDNA deletions in this study, and the median age at onset was 35 (1–70) years. PEO and positive family history were the two prominent features of these patients, and ataxia, neuropathy, and hypogonadism were also present as onset symptoms in some patients. Fifteen of 20 probands with multiple mtDNA deletions were identified to carry nuclear gene variants; eight (40.0%) probands had variants within POLG, two (10.0%) within TWNK, two (10.0%) within RRM2B, two (10.0%) within TK2, and one (5.0%) within POLG2. A total of 24 variants were found in these five nuclear genes, of which 19 were novel. The causal nuclear genetic factors in five pedigrees remain undetermined. Conclusions The POLG gene is the most common disease‐causing gene in this group of PEO patients with multiple mtDNA deletions. While inherited PEO is the most prominent symptoms in these patients, genotypic and phenotypic heterogeneity still exist, for example in onset age, initial symptoms, and accompanying manifestations.
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Affiliation(s)
- Yue Hou
- Department of Neurology, Peking University First Hospital, Beijing, China.,Department of Geriatrics, Peking University First Hospital, Beijing, China
| | - Xutong Zhao
- Department of Neurology, Peking University First Hospital, Beijing, China
| | - Zhiying Xie
- Department of Neurology, Peking University First Hospital, Beijing, China
| | - Meng Yu
- Department of Neurology, Peking University First Hospital, Beijing, China
| | - He Lv
- Department of Neurology, Peking University First Hospital, Beijing, China
| | - Wei Zhang
- Department of Neurology, Peking University First Hospital, Beijing, China
| | - Yun Yuan
- Department of Neurology, Peking University First Hospital, Beijing, China
| | - Zhaoxia Wang
- Department of Neurology, Peking University First Hospital, Beijing, China.,Beijing Key Laboratory of Neurovascular Disease Discovery, Beijing, China
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19
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Hernández-Ainsa C, López-Gallardo E, García-Jiménez MC, Climent-Alcalá FJ, Rodríguez-Vigil C, García Fernández de Villalta M, Artuch R, Montoya J, Ruiz-Pesini E, Emperador S. Development and characterization of cell models harbouring mtDNA deletions for in vitro study of Pearson syndrome. Dis Model Mech 2022; 15:dmm049083. [PMID: 35191981 PMCID: PMC8906170 DOI: 10.1242/dmm.049083] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2021] [Accepted: 12/06/2021] [Indexed: 01/19/2023] Open
Abstract
Pearson syndrome is a rare multisystem disease caused by single large-scale mitochondrial DNA deletions (SLSMDs). The syndrome presents early in infancy and is mainly characterised by refractory sideroblastic anaemia. Prognosis is poor and treatment is supportive, thus the development of new models for the study of Pearson syndrome and new therapy strategies is essential. In this work, we report three different cell models carrying an SLMSD: fibroblasts, transmitochondrial cybrids and induced pluripotent stem cells (iPSCs). All studied models exhibited an aberrant mitochondrial ultrastructure and defective oxidative phosphorylation system function, showing a decrease in different parameters, such as mitochondrial ATP, respiratory complex IV activity and quantity or oxygen consumption. Despite this, iPSCs harbouring 'common deletion' were able to differentiate into three germ layers. Additionally, cybrid clones only showed mitochondrial dysfunction when heteroplasmy level reached 70%. Some differences observed among models may depend on their metabolic profile; therefore, we consider that these three models are useful for the in vitro study of Pearson syndrome, as well as for testing new specific therapies. This article has an associated First Person interview with the first author of the paper.
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Affiliation(s)
- Carmen Hernández-Ainsa
- Departamento de Bioquímica, Biología Molecular y Celular, Universidad de Zaragoza, 50013 Zaragoza, Spain
- Instituto de Investigación Sanitaria de Aragón (IIS-Aragón), 50009 Zaragoza, Spain
- Centro de Investigaciones Biomédicas en Red de Enfermedades Raras (CIBERER), 28029 Madrid, Spain
| | - Ester López-Gallardo
- Departamento de Bioquímica, Biología Molecular y Celular, Universidad de Zaragoza, 50013 Zaragoza, Spain
- Instituto de Investigación Sanitaria de Aragón (IIS-Aragón), 50009 Zaragoza, Spain
- Centro de Investigaciones Biomédicas en Red de Enfermedades Raras (CIBERER), 28029 Madrid, Spain
| | | | | | | | | | - Rafael Artuch
- Centro de Investigaciones Biomédicas en Red de Enfermedades Raras (CIBERER), 28029 Madrid, Spain
- Clinical Biochemistry, Genetics, Pediatric Neurology and Neonatalogy Departments, Institut de Recerca Sant Joan de Déu, 08950 Barcelona, Spain
| | - Julio Montoya
- Departamento de Bioquímica, Biología Molecular y Celular, Universidad de Zaragoza, 50013 Zaragoza, Spain
- Instituto de Investigación Sanitaria de Aragón (IIS-Aragón), 50009 Zaragoza, Spain
- Centro de Investigaciones Biomédicas en Red de Enfermedades Raras (CIBERER), 28029 Madrid, Spain
| | - Eduardo Ruiz-Pesini
- Departamento de Bioquímica, Biología Molecular y Celular, Universidad de Zaragoza, 50013 Zaragoza, Spain
- Instituto de Investigación Sanitaria de Aragón (IIS-Aragón), 50009 Zaragoza, Spain
- Centro de Investigaciones Biomédicas en Red de Enfermedades Raras (CIBERER), 28029 Madrid, Spain
| | - Sonia Emperador
- Departamento de Bioquímica, Biología Molecular y Celular, Universidad de Zaragoza, 50013 Zaragoza, Spain
- Instituto de Investigación Sanitaria de Aragón (IIS-Aragón), 50009 Zaragoza, Spain
- Centro de Investigaciones Biomédicas en Red de Enfermedades Raras (CIBERER), 28029 Madrid, Spain
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20
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Son JS, Seo GH, Kim YM, Kim GH, Jin HK, Bae JS, Im HJ, Yoo HW, Lee BH. Clinical and genetic features of four patients with Pearson syndrome: An observational study. Medicine (Baltimore) 2022; 101:e28793. [PMID: 35119049 PMCID: PMC8812667 DOI: 10.1097/md.0000000000028793] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/27/2021] [Accepted: 01/20/2022] [Indexed: 01/04/2023] Open
Abstract
Pearson syndrome (PS) is a multisystem mitochondrial cytopathy arising from deletions in mitochondrial DNA. Pearson syndrome is a sporadic disease that affects the hematopoietic system, pancreas, eyes, liver, and heart and the prognosis is poor. Causes of morbidity include metabolic crisis, bone marrow dysfunction, sepsis, and liver failure in early infancy or childhood. Early diagnosis may minimize complications, but suspicion of the disease is difficult and only mitochondrial DNA gene testing can identify mutations. There is no specific treatment for PS, which remains supportive care according to symptoms; however, hematopoietic stem cell transplantation may be considered in cases of bone marrow failure.We herein describe the clinical and genetic characteristics of four patients with PS. One patient presented with hypoglycemia, two developed pancytopenia, and the final patient had hypoglycemia and acute hepatitis as the primary manifestation. All patients had lactic acidosis. Additionally, all patients showed a variety of clinical features including coagulation disorder, pancreatic, adrenal, and renal tubular insufficiencies. Two patients with pancytopenia died in their early childhood. Our experience expands the phenotypic spectrum associated with PS and its clinical understanding.
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Affiliation(s)
- Ji Soo Son
- Department of Pediatrics, Asan Medical Center Children's Hospital, University of Ulsan College of Medicine, Seoul, South Korea
| | - Go Hun Seo
- Division of Medical Genetics, 3billion Inc., Seoul, South Korea
| | - Yoon-Myung Kim
- Department of Pediatrics, Gangneung Asan Hospital, University of Ulsan College of Medicine, Gangneung, South Korea
| | - Gu-Hwan Kim
- Medical Genetics Center, Asan Medical Center Children's Hospital, University of Ulsan College of Medicine, Seoul, South Korea
| | - Hee Kyung Jin
- Department of Laboratory Animal Medicine, College of Veterinary Medicine, Kyungpook National University, Daegu, South Korea
| | - Jae-sung Bae
- Department of Physiology, Cell and Matrix Research Institute, School of Medicine, Kyungpook National University, Daegu, South Korea
| | - Ho Joon Im
- Department of Pediatrics, Asan Medical Center Children's Hospital, University of Ulsan College of Medicine, Seoul, South Korea
| | - Han-Wook Yoo
- Department of Pediatrics, Asan Medical Center Children's Hospital, University of Ulsan College of Medicine, Seoul, South Korea
- Medical Genetics Center, Asan Medical Center Children's Hospital, University of Ulsan College of Medicine, Seoul, South Korea
| | - Beom Hee Lee
- Department of Pediatrics, Asan Medical Center Children's Hospital, University of Ulsan College of Medicine, Seoul, South Korea
- Medical Genetics Center, Asan Medical Center Children's Hospital, University of Ulsan College of Medicine, Seoul, South Korea
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21
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Molecular Genetics Overview of Primary Mitochondrial Myopathies. J Clin Med 2022; 11:jcm11030632. [PMID: 35160083 PMCID: PMC8836969 DOI: 10.3390/jcm11030632] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2021] [Revised: 01/13/2022] [Accepted: 01/20/2022] [Indexed: 12/29/2022] Open
Abstract
Mitochondrial disorders are the most common inherited conditions, characterized by defects in oxidative phosphorylation and caused by mutations in nuclear or mitochondrial genes. Due to its high energy request, skeletal muscle is typically involved. According to the International Workshop of Experts in Mitochondrial Diseases held in Rome in 2016, the term Primary Mitochondrial Myopathy (PMM) should refer to those mitochondrial disorders affecting principally, but not exclusively, the skeletal muscle. The clinical presentation may include general isolated myopathy with muscle weakness, exercise intolerance, chronic ophthalmoplegia/ophthalmoparesis (cPEO) and eyelids ptosis, or multisystem conditions where there is a coexistence with extramuscular signs and symptoms. In recent years, new therapeutic targets have been identified leading to the launch of some promising clinical trials that have mainly focused on treating muscle symptoms and that require populations with defined genotype. Advantages in next-generation sequencing techniques have substantially improved diagnosis. So far, an increasing number of mutations have been identified as responsible for mitochondrial disorders. In this review, we focused on the principal molecular genetic alterations in PMM. Accordingly, we carried out a comprehensive review of the literature and briefly discussed the possible approaches which could guide the clinician to a genetic diagnosis.
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22
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Elstner M, Olszewski K, Prokisch H, Klopstock T, Murgia M. Multi-Omics Approach to Mitochondrial DNA Damage in Human Muscle Fibers. Int J Mol Sci 2021; 22:ijms222011080. [PMID: 34681740 PMCID: PMC8537949 DOI: 10.3390/ijms222011080] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2021] [Revised: 10/05/2021] [Accepted: 10/10/2021] [Indexed: 11/16/2022] Open
Abstract
Mitochondrial DNA deletions affect energy metabolism at tissue-specific and cell-specific threshold levels, but the pathophysiological mechanisms determining cell fate remain poorly understood. Chronic progressive external ophthalmoplegia (CPEO) is caused by mtDNA deletions and characterized by a mosaic distribution of muscle fibers with defective cytochrome oxidase (COX) activity, interspersed among fibers with retained functional respiratory chain. We used diagnostic histochemistry to distinguish COX-negative from COX-positive fibers in nine muscle biopsies from CPEO patients and performed laser capture microdissection (LCM) coupled to genome-wide gene expression analysis. To gain molecular insight into the pathogenesis, we applied network and pathway analysis to highlight molecular differences of the COX-positive and COX-negative fiber transcriptome. We then integrated our results with proteomics data that we previously obtained comparing COX-positive and COX-negative fiber sections from three other patients. By virtue of the combination of LCM and a multi-omics approach, we here provide a comprehensive resource to tackle the pathogenic changes leading to progressive respiratory chain deficiency and disease in mitochondrial deletion syndromes. Our data show that COX-negative fibers upregulate transcripts involved in translational elongation and protein synthesis. Furthermore, based on functional annotation analysis, we find that mitochondrial transcripts are the most enriched among those with significantly different expression between COX-positive and COX-negative fibers, indicating that our unbiased large-scale approach resolves the core of the pathogenic changes. Further enrichments include transcripts encoding LIM domain proteins, ubiquitin ligases, proteins involved in RNA turnover, and, interestingly, cell cycle arrest and cell death. These pathways may thus have a functional association to the molecular pathogenesis of the disease. Overall, the transcriptome and proteome show a low degree of correlation in CPEO patients, suggesting a relevant contribution of post-transcriptional mechanisms in shaping this disease phenotype.
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Affiliation(s)
- Matthias Elstner
- Department of Neurology, Technical University Munich, 81675 Munich, Germany;
| | - Konrad Olszewski
- Center for Addictive Disorders, Department of Psychiatry, Psychotherapy and Psychosomatics, Psychiatric Hospital, University of Zurich, 8001 Zurich, Switzerland;
| | - Holger Prokisch
- Institute of Human Genetics, Technical University Munich, 81675 Munich, Germany;
- Institute of Neurogenomics, Helmholtz Zentrum Munich, 85764 Neuherberg, Germany
| | - Thomas Klopstock
- Department of Neurology, Friedrich-Baur-Institute, University of Munich, 80336 Munich, Germany;
- German Center for Neurodegenerative Diseases (DZNE), 81675 Munich, Germany
- Munich Cluster for Systems Neurology (SyNergy), 81675 Munich, Germany
| | - Marta Murgia
- Department of Proteomics a Signal Transduction, Max Planck Institute of Biochemistry, 82352 Martinsried, Germany
- Department of Biomedical Sciences, University of Padova, 35131 Padua, Italy
- Correspondence:
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23
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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: 92] [Impact Index Per Article: 30.7] [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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24
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Bernardino Gomes TM, Ng YS, Pickett SJ, Turnbull DM, Vincent AE. Mitochondrial DNA disorders: From pathogenic variants to preventing transmission. Hum Mol Genet 2021; 30:R245-R253. [PMID: 34169319 PMCID: PMC8490015 DOI: 10.1093/hmg/ddab156] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Revised: 05/28/2021] [Accepted: 06/01/2021] [Indexed: 11/27/2022] Open
Abstract
Mitochondrial DNA (mtDNA) disorders are recognized as one of the most common causes of inherited metabolic disorders. The mitochondrial genome occurs in multiple copies resulting in both homoplasmic and heteroplasmic pathogenic mtDNA variants. A biochemical defect arises when the pathogenic variant level reaches a threshold, which differs between variants. Moreover, variants can segregate, clonally expand, or be lost from cellular populations resulting in a dynamic and tissue-specific mosaic pattern of oxidative deficiency. MtDNA is maternally inherited but transmission patterns of heteroplasmic pathogenic variants are complex. During oogenesis, a mitochondrial bottleneck results in offspring with widely differing variant levels to their mother, whilst highly deleterious variants, such as deletions, are not transmitted. Complemented by a complex interplay between mitochondrial and nuclear genomes, these peculiar genetics produce marked phenotypic variation, posing challenges to the diagnosis and clinical management of patients. Novel therapeutic compounds and several genetic therapies are currently under investigation, but proven disease-modifying therapies remain elusive. Women who carry pathogenic mtDNA variants require bespoke genetic counselling to determine their reproductive options. Recent advances in in vitro fertilization techniques, have greatly improved reproductive choices, but are not without their challenges. Since the first pathogenic mtDNA variants were identified over 30 years ago, there has been remarkable progress in our understanding of these diseases. However, many questions remain unanswered and future studies are required to investigate the mechanisms of disease progression and to identify new disease-specific therapeutic targets.
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Affiliation(s)
- Tiago M Bernardino Gomes
- Wellcome Centre for Mitochondrial Research, Translational and Clinical Research Institute, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK.,NHS Highly Specialised Service for Rare Mitochondrial Disorders, Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne, NE2 4HH, UK
| | - Yi Shiau Ng
- Wellcome Centre for Mitochondrial Research, Translational and Clinical Research Institute, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK.,NHS Highly Specialised Service for Rare Mitochondrial Disorders, Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne, NE2 4HH, UK
| | - Sarah J Pickett
- Wellcome Centre for Mitochondrial Research, Translational and Clinical Research Institute, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK
| | - Doug M Turnbull
- Wellcome Centre for Mitochondrial Research, Translational and Clinical Research Institute, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK
| | - Amy E Vincent
- Wellcome Centre for Mitochondrial Research, Translational and Clinical Research Institute, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK
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25
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Bris C, Goudenège D, Desquiret-Dumas V, Gueguen N, Bannwarth S, Gaignard P, Rucheton B, Trimouille A, Allouche S, Rouzier C, Saadi S, Jardel C, Slama A, Barth M, Verny C, Spinazzi M, Cassereau J, Colin E, Armelle M, Pereon Y, Martin-Negrier ML, Paquis-Flucklinger V, Letournel F, Lenaers G, Bonneau D, Reynier P, Amati-Bonneau P, Procaccio V. Improved detection of mitochondrial DNA instability in mitochondrial genome maintenance disorders. Genet Med 2021; 23:1769-1778. [PMID: 34040194 DOI: 10.1038/s41436-021-01206-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2020] [Revised: 04/27/2021] [Accepted: 04/28/2021] [Indexed: 11/09/2022] Open
Abstract
PURPOSE Diseases caused by defects in mitochondrial DNA (mtDNA) maintenance machinery, leading to mtDNA deletions, form a specific group of disorders. However, mtDNA deletions also appear during aging, interfering with those resulting from mitochondrial disorders. METHODS Here, using next-generation sequencing (NGS) data processed by eKLIPse and data mining, we established criteria distinguishing age-related mtDNA rearrangements from those due to mtDNA maintenance defects. MtDNA deletion profiles from muscle and urine patient samples carrying pathogenic variants in nuclear genes involved in mtDNA maintenance (n = 40) were compared with age-matched controls (n = 90). Seventeen additional patient samples were used to validate the data mining model. RESULTS Overall, deletion number, heteroplasmy level, deletion locations, and the presence of repeats at deletion breakpoints were significantly different between patients and controls, especially in muscle samples. The deletion number was significantly relevant in adults, while breakpoint repeat lengths surrounding deletions were discriminant in young subjects. CONCLUSION Altogether, eKLIPse analysis is a powerful tool for measuring the accumulation of mtDNA deletions between patients of different ages, as well as in prioritizing novel variants in genes involved in mtDNA stability.
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Affiliation(s)
- Celine Bris
- MitoLab, UMR CNRS 6015, INSERM U1083, Institut MitoVasc, Université d'Angers, Angers, France.,Département de Biochimie et Génétique, CHU d'Angers, Angers, France
| | - David Goudenège
- MitoLab, UMR CNRS 6015, INSERM U1083, Institut MitoVasc, Université d'Angers, Angers, France.,Département de Biochimie et Génétique, CHU d'Angers, Angers, France
| | - Valerie Desquiret-Dumas
- MitoLab, UMR CNRS 6015, INSERM U1083, Institut MitoVasc, Université d'Angers, Angers, France.,Département de Biochimie et Génétique, CHU d'Angers, Angers, France
| | - Naig Gueguen
- MitoLab, UMR CNRS 6015, INSERM U1083, Institut MitoVasc, Université d'Angers, Angers, France.,Département de Biochimie et Génétique, CHU d'Angers, Angers, France
| | - Sylvie Bannwarth
- Université Côte d'Azur, CHU de Nice, INSERM, CNRS, IRCAN, Nice, France
| | - Pauline Gaignard
- Service de Biochimie, CHU Bicêtre, APHP Université Paris Saclay, Le Kremlin-Bicêtre, France
| | - Benoit Rucheton
- Département de Biochimie et Génétique, APHP, GHU Pitié-Salpêtrière, Paris, France
| | - Aurelien Trimouille
- Service de Génétique médicale, Centre Hospitalier Universitaire de Bordeaux, Bordeaux, France
| | - Stephane Allouche
- Service de Biochimie, EA4650, Centre Hospitalier Universitaire, Caen, France
| | - Cecile Rouzier
- Université Côte d'Azur, CHU de Nice, INSERM, CNRS, IRCAN, Nice, France
| | - Samira Saadi
- Université Côte d'Azur, CHU de Nice, INSERM, CNRS, IRCAN, Nice, France
| | - Claude Jardel
- Département de Biochimie et Génétique, APHP, GHU Pitié-Salpêtrière, Paris, France
| | - Abdel Slama
- Service de Biochimie, CHU Bicêtre, APHP Université Paris Saclay, Le Kremlin-Bicêtre, France
| | - Magalie Barth
- Département de Biochimie et Génétique, CHU d'Angers, Angers, France
| | - Christophe Verny
- MitoLab, UMR CNRS 6015, INSERM U1083, Institut MitoVasc, Université d'Angers, Angers, France
| | - Marco Spinazzi
- MitoLab, UMR CNRS 6015, INSERM U1083, Institut MitoVasc, Université d'Angers, Angers, France
| | - Julien Cassereau
- MitoLab, UMR CNRS 6015, INSERM U1083, Institut MitoVasc, Université d'Angers, Angers, France
| | - Estelle Colin
- MitoLab, UMR CNRS 6015, INSERM U1083, Institut MitoVasc, Université d'Angers, Angers, France.,Département de Biochimie et Génétique, CHU d'Angers, Angers, France
| | - Magot Armelle
- Centre de Référence Maladies Neuromusculaires, CHU Nantes, Nantes, France
| | - Yann Pereon
- Centre de Référence Maladies Neuromusculaires, CHU Nantes, Nantes, France
| | | | | | - Franck Letournel
- UF de Neurobiologie-Neuropathologie, UMR INSERM 1066 - CNRS 6021, MINT, Angers, France
| | - Guy Lenaers
- MitoLab, UMR CNRS 6015, INSERM U1083, Institut MitoVasc, Université d'Angers, Angers, France
| | - Dominique Bonneau
- MitoLab, UMR CNRS 6015, INSERM U1083, Institut MitoVasc, Université d'Angers, Angers, France.,Département de Biochimie et Génétique, CHU d'Angers, Angers, France
| | - Pascal Reynier
- MitoLab, UMR CNRS 6015, INSERM U1083, Institut MitoVasc, Université d'Angers, Angers, France.,Département de Biochimie et Génétique, CHU d'Angers, Angers, France
| | - Patrizia Amati-Bonneau
- MitoLab, UMR CNRS 6015, INSERM U1083, Institut MitoVasc, Université d'Angers, Angers, France.,Département de Biochimie et Génétique, CHU d'Angers, Angers, France
| | - Vincent Procaccio
- MitoLab, UMR CNRS 6015, INSERM U1083, Institut MitoVasc, Université d'Angers, Angers, France. .,Département de Biochimie et Génétique, CHU d'Angers, Angers, France.
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26
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Lim AZ, Jones DM, Bates MGD, Schaefer AM, O'Sullivan J, Feeney C, Farrugia ME, Bourke JP, Turnbull DM, Gorman GS, McFarland R, Ng YS. Risk of cardiac manifestations in adult mitochondrial disease caused by nuclear genetic defects. Open Heart 2021. [PMCID: PMC8021886 DOI: 10.1136/openhrt-2020-001510] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Objective Regular cardiac surveillance is advocated for patients with primary mitochondrial DNA disease. However, there is limited information to guide clinical practice in mitochondrial conditions caused by nuclear DNA defects. We sought to determine the frequency and spectrum of cardiac abnormalities identified in adult mitochondrial disease originated from the nuclear genome. Methods Adult patients with a genetically confirmed mitochondrial disease were identified and followed up at the national clinical service for mitochondrial disease in Newcastle upon Tyne, UK (January 2009 to December 2018). Case notes, molecular genetics reports, laboratory data and cardiac investigations, including serial electrocardiograms and echocardiograms, were reviewed. Results In this cohort-based observational study, we included 146 adult patients (92 women) (mean age 53.6±18.7 years, 95% CI 50.6 to 56.7) with a mean follow-up duration of 7.9±5.1 years (95% CI 7.0 to 8.8). Eleven different nuclear genotypes were identified: TWNK, POLG, RRM2B, OPA1, GFER, YARS2, TYMP, ETFDH, SDHA, TRIT1 and AGK. Cardiac abnormalities were detected in 14 patients (9.6%). Seven of these patients (4.8%) had early-onset cardiac manifestations: hypertrophic cardiomyopathy required cardiac transplantation (AGK; n=2/2), left ventricular (LV) hypertrophy and bifascicular heart block (GFER; n=2/3) and mild LV dysfunction (GFER; n=1/3, YARS2; n=1/2, TWNK; n=1/41). The remaining seven patients had acquired heart disease most likely related to conventional cardiovascular risk factors and presented later in life (14.6±12.8 vs 55.1±8.9 years, p<0.0001). Conclusions Our findings demonstrate that the risk of cardiac involvement is genotype specific, suggesting that routine cardiac screening is not indicated for most adult patients with nuclear gene-related mitochondrial disease.
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Affiliation(s)
- Albert Zishen Lim
- Wellcome Centre for Mitochondrial Research, Translational and Clinical Research Institute, 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
| | - Daniel M Jones
- Wellcome Centre for Mitochondrial Research, Translational and Clinical Research Institute, Newcastle University, Newcastle upon Tyne, UK
| | - Matthew G D Bates
- Department of Cardiology, James Cook University Hospital, Middlesbrough, UK
| | - Andrew M Schaefer
- Wellcome Centre for Mitochondrial Research, Translational and Clinical Research Institute, 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
| | - John O'Sullivan
- Cardiology, Freeman Hospital Cardiothoracic Centre, Newcastle upon Tyne, UK
| | - Catherine Feeney
- Wellcome Centre for Mitochondrial Research, Translational and Clinical Research Institute, 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
| | - Maria E Farrugia
- Queen Elizabeth University Hospital, Institute of Neurological Sciences, Glasgow, UK
| | - John P Bourke
- Cardiology, Freeman Hospital Cardiothoracic Centre, Newcastle upon Tyne, UK
| | - Doug M Turnbull
- Wellcome Centre for Mitochondrial Research, Translational and Clinical Research Institute, 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
| | - Gráinne S Gorman
- Wellcome Centre for Mitochondrial Research, Translational and Clinical Research Institute, 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
| | - Robert McFarland
- Wellcome Centre for Mitochondrial Research, Translational and Clinical Research Institute, 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
| | - Yi Shiau Ng
- Wellcome Centre for Mitochondrial Research, Translational and Clinical Research Institute, 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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27
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Loos MA, Gomez G, Mayorga L, Caraballo RH, Eiroa HD, Obregon MG, Rugilo C, Lubieniecki F, Taratuto AL, Saccoliti M, Alonso CN, Aráoz HV. Clinical and molecular characterization of mitochondrial DNA disorders in a group of Argentinian pediatric patients. Mol Genet Metab Rep 2021; 27:100733. [PMID: 33717984 PMCID: PMC7933530 DOI: 10.1016/j.ymgmr.2021.100733] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2020] [Revised: 02/04/2021] [Accepted: 02/05/2021] [Indexed: 11/02/2022] Open
Abstract
Objective To describe the clinical and molecular features of a group of Argentinian pediatric patients with mitochondrial DNA (mtDNA) disorders, and to evaluate the results of the implementation of a classical approach for the molecular diagnosis of mitochondrial diseases. Methods Clinical data from 27 patients with confirmed mtDNA pathogenic variants were obtained from a database of 89 patients with suspected mitochondrial disease, registered from 2014 to 2020. Clinical data, biochemical analysis, neuroimaging findings, muscle biopsy and molecular studies were analyzed. Results Patients were 18 females and 9 males, with ages at onset ranging from 1 week to 14 years (median = 4 years). The clinical phenotypes were: mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS) syndrome (n = 11), Leigh syndrome (n = 5), Kearns-Sayre syndrome (n = 3), Chronic Progressive External Ophthalmoplegia (n = 2), Leber hereditary optic neuropathy (n = 2), myoclonic epilepsy associated with ragged-red fibers (n = 1) and reversible infantile myopathy with cytochrome-C oxidase deficiency (n = 3). Most of the patients harbored pathogenic single nucleotide variants, mainly involving mt-tRNA genes, such as MT-TL1, MT-TE and MT-TK. Other point variants were found in complex I subunits, like MT-ND6, MT-ND4, MT-ND5; or in MT-ATP6. The m.13513G > A variant in MT-ND5 and the m.9185 T > C variant in MT-ATP6 were apparently de novo. The rest of the patients presented large scale-rearrangements, either the "common" deletion or a larger deletion. Conclusions This study highlights the clinical and genetic heterogeneity of pediatric mtDNA disorders. All the cases presented with classical phenotypes, being MELAS the most frequent. Applying classical molecular methods, it was possible to achieve a genetic diagnosis in 30% of the cases, suggesting that this is an effective first approach, especially for those centers from low-middle income countries, leaving NGS studies for those patients with inconclusive results.
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Affiliation(s)
- Mariana Amina Loos
- Department of Neurology, Hospital de Pediatría "Juan P. Garrahan", Combate de los Pozos 1881, Buenos Aires 1245, Argentina
| | - Gimena Gomez
- Genomics Laboratory, Hospital de Pediatría "Juan P. Garrahan", Combate de los Pozos 1881, Buenos Aires 1245, Argentina
| | - Lía Mayorga
- Instituto de Histología y Embriología de Mendoza (IHEM, Universidad Nacional de Cuyo, CONICET), Centro Universitario UNCuyo, 5500 Mendoza, Argentina
| | - Roberto Horacio Caraballo
- Department of Neurology, Hospital de Pediatría "Juan P. Garrahan", Combate de los Pozos 1881, Buenos Aires 1245, Argentina
| | - Hernán Diego Eiroa
- Department of Inborn Errors of Metabolism, Hospital de Pediatría "Juan P. Garrahan", Combate de los Pozos 1881, Buenos Aires, 1245, Argentina
| | - María Gabriela Obregon
- Department of Medical Genetics, Hospital de Pediatría "Juan P. Garrahan", Combate de los Pozos 1881, Buenos Aires 1245, Argentina
| | - Carlos Rugilo
- Department of DiagnosticImaging, Hospital de Pediatría "Juan P. Garrahan", Combate de los Pozos 1881, Buenos Aires 1245, Argentina
| | - Fabiana Lubieniecki
- Department of Pathology, Hospital de Pediatría "Juan P. Garrahan", Combate de los Pozos 1881, Buenos Aires 1245, Argentina
| | - Ana Lía Taratuto
- Neuropathology and Neuromuscular Diseases Laboratory, Buenos Aires, Argentina
| | - María Saccoliti
- Neuropathology and Neuromuscular Diseases Laboratory, Buenos Aires, Argentina
| | - Cristina Noemi Alonso
- Genomics Laboratory, Hospital de Pediatría "Juan P. Garrahan", Combate de los Pozos 1881, Buenos Aires 1245, Argentina
| | - Hilda Verónica Aráoz
- Department of Medical Genetics, Hospital de Pediatría "Juan P. Garrahan", Combate de los Pozos 1881, Buenos Aires 1245, Argentina
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Kierdaszuk B, Kaliszewska M, Rusecka J, Kosińska J, Bartnik E, Tońska K, Kamińska AM, Kostera-Pruszczyk A. Progressive External Ophthalmoplegia in Polish Patients-From Clinical Evaluation to Genetic Confirmation. Genes (Basel) 2020; 12:genes12010054. [PMID: 33396418 PMCID: PMC7824435 DOI: 10.3390/genes12010054] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Revised: 12/27/2020] [Accepted: 12/28/2020] [Indexed: 11/16/2022] Open
Abstract
Mitochondrial encephalomyopathies comprise a group of heterogeneous disorders resulting from impaired oxidative phosphorylation (OxPhos). Among a variety of symptoms progressive external ophthalmoplegia (PEO) seems to be the most common. The aim of this study is to present clinical and genetic characteristics of Polish patients with PEO. Clinical, electrophysiological, neuroradiological, and morphological data of 84 patients were analyzed. Genetic studies of mitochondrial DNA (mtDNA) were performed in all patients. Among nuclear DNA (nDNA) genes POLG was sequenced in 41 patients, TWNK (C10orf2) in 13 patients, and RNASEH1 in 2 patients. Total of 27 patients were included in the chronic progressive external ophthalmoplegia (CPEO) group, 24 in the CPEO+ group. Twenty-six patients had mitochondrial encephalomyopathy (ME), six patients Kearns-Sayre syndrome (KSS), and one patient sensory ataxic neuropathy, dysarthria, ophthalmoparesis (SANDO) syndrome. Genetic analysis of nDNA genes revealed the presence of pathogenic or possibly pathogenic variants in the POLG gene in nine patients, the TWNK gene in five patients and the RNASEH1 gene in two patients. Detailed patients' history and careful assessment of family history are essential in the diagnostic work-up. Genetic studies of both mtDNA and nDNA are necessary for the final diagnosis of progressive external ophthalmoplegia and for genetic counseling.
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MESH Headings
- Adolescent
- Adult
- Aged
- Cerebellum/diagnostic imaging
- Cerebellum/metabolism
- Cerebellum/pathology
- Cerebrum/diagnostic imaging
- Cerebrum/metabolism
- Cerebrum/pathology
- Child
- DNA Helicases/genetics
- DNA Helicases/metabolism
- DNA Polymerase gamma/genetics
- DNA Polymerase gamma/metabolism
- DNA, Mitochondrial/genetics
- DNA, Mitochondrial/metabolism
- Diagnosis, Differential
- Female
- Gene Expression
- Humans
- Kearns-Sayre Syndrome/diagnostic imaging
- Kearns-Sayre Syndrome/genetics
- Kearns-Sayre Syndrome/metabolism
- Kearns-Sayre Syndrome/pathology
- Male
- Middle Aged
- Mitochondria/metabolism
- Mitochondria/pathology
- Mitochondrial Diseases/diagnostic imaging
- Mitochondrial Diseases/genetics
- Mitochondrial Diseases/metabolism
- Mitochondrial Diseases/pathology
- Mitochondrial Encephalomyopathies/diagnostic imaging
- Mitochondrial Encephalomyopathies/genetics
- Mitochondrial Encephalomyopathies/metabolism
- Mitochondrial Encephalomyopathies/pathology
- Mitochondrial Proteins/genetics
- Mitochondrial Proteins/metabolism
- Muscle, Skeletal/metabolism
- Muscle, Skeletal/pathology
- Ophthalmoplegia, Chronic Progressive External/diagnostic imaging
- Ophthalmoplegia, Chronic Progressive External/genetics
- Ophthalmoplegia, Chronic Progressive External/metabolism
- Ophthalmoplegia, Chronic Progressive External/pathology
- Pedigree
- Poland
- Polymorphism, Genetic
- Ribonuclease H/genetics
- Ribonuclease H/metabolism
- Sequence Deletion
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Affiliation(s)
- Biruta Kierdaszuk
- Department of Neurology, Medical University of Warsaw, Banacha 1a, 02-097 Warsaw, Poland; (A.M.K.); (A.K.-P.)
- Correspondence: ; Tel.: +48-22-599-2858; Fax: +48-22-599-1857
| | - Magdalena Kaliszewska
- Institute of Genetics and Biotechnology, Faculty of Biology, University of Warsaw, Pawinskiego 5a, 02-106 Warsaw, Poland; (M.K.); (J.R.); (E.B.); (K.T.)
| | - Joanna Rusecka
- Institute of Genetics and Biotechnology, Faculty of Biology, University of Warsaw, Pawinskiego 5a, 02-106 Warsaw, Poland; (M.K.); (J.R.); (E.B.); (K.T.)
| | - Joanna Kosińska
- Department of Medical Genetics, Medical University of Warsaw, Pawinskiego 3c, 02-106 Warsaw, Poland;
| | - Ewa Bartnik
- Institute of Genetics and Biotechnology, Faculty of Biology, University of Warsaw, Pawinskiego 5a, 02-106 Warsaw, Poland; (M.K.); (J.R.); (E.B.); (K.T.)
| | - Katarzyna Tońska
- Institute of Genetics and Biotechnology, Faculty of Biology, University of Warsaw, Pawinskiego 5a, 02-106 Warsaw, Poland; (M.K.); (J.R.); (E.B.); (K.T.)
| | - Anna M. Kamińska
- Department of Neurology, Medical University of Warsaw, Banacha 1a, 02-097 Warsaw, Poland; (A.M.K.); (A.K.-P.)
| | - Anna Kostera-Pruszczyk
- Department of Neurology, Medical University of Warsaw, Banacha 1a, 02-097 Warsaw, Poland; (A.M.K.); (A.K.-P.)
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29
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Koňaříková E, Marković A, Korandová Z, Houštěk J, Mráček T. Current progress in the therapeutic options for mitochondrial disorders. Physiol Res 2020; 69:967-994. [PMID: 33129249 PMCID: PMC8549882 DOI: 10.33549/physiolres.934529] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2020] [Accepted: 10/02/2020] [Indexed: 12/20/2022] Open
Abstract
Mitochondrial disorders manifest enormous genetic and clinical heterogeneity - they can appear at any age, present with various phenotypes affecting any organ, and display any mode of inheritance. What mitochondrial diseases do have in common, is impairment of respiratory chain activity, which is responsible for more than 90% of energy production within cells. While diagnostics of mitochondrial disorders has been accelerated by introducing Next-Generation Sequencing techniques in recent years, the treatment options are still very limited. For many patients only a supportive or symptomatic therapy is available at the moment. However, decades of basic and preclinical research have uncovered potential target points and numerous compounds or interventions are now subjects of clinical trials. In this review, we focus on current and emerging therapeutic approaches towards the treatment of mitochondrial disorders. We focus on small compounds, metabolic interference, such as endurance training or ketogenic diet and also on genomic approaches.
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Affiliation(s)
- E Koňaříková
- Laboratory of Bioenergetics, Institute of Physiology Czech Acad. Sci., Prague, Czech Republic. ,
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30
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Montano V, Gruosso F, Simoncini C, Siciliano G, Mancuso M. Clinical features of mtDNA-related syndromes in adulthood. Arch Biochem Biophys 2020; 697:108689. [PMID: 33227288 DOI: 10.1016/j.abb.2020.108689] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Revised: 11/06/2020] [Accepted: 11/15/2020] [Indexed: 01/26/2023]
Abstract
Mitochondrial diseases are the most common inheritable metabolic diseases, due to defects in oxidative phosphorylation. They are caused by mutations of nuclear or mitochondrial DNA in genes involved in mitochondrial function. The peculiarity of "mitochondrial DNA genetics rules" in part explains the marked phenotypic variability, the complexity of genotype-phenotype correlations and the challenge of genetic counseling. The new massive genetic sequencing technologies have changed the diagnostic approach, enhancing mitochondrial DNA-related syndromes diagnosis and often avoiding the need of a tissue biopsy. Here we present the most common phenotypes associated with a mitochondrial DNA mutation with the recent advances in diagnosis and in therapeutic perspectives.
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Affiliation(s)
- V Montano
- Department of Clinical and Experimental Medicine, Neurological Clinic, University of Pisa, Italy
| | - F Gruosso
- Department of Clinical and Experimental Medicine, Neurological Clinic, University of Pisa, Italy
| | - C Simoncini
- Department of Clinical and Experimental Medicine, Neurological Clinic, University of Pisa, Italy
| | - G Siciliano
- Department of Clinical and Experimental Medicine, Neurological Clinic, University of Pisa, Italy
| | - M Mancuso
- Department of Clinical and Experimental Medicine, Neurological Clinic, University of Pisa, Italy.
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31
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Pasquini L, Guarnera A, Rossi-Espagnet MC, Napolitano A, Diodato D, Martinelli D, Longo D. Reply to: "Is the spinal cord truly affected in half of the patients with Kearns-Sayre syndrome?" and "Spinal cord and heart involvement in Kearns Sayre Syndrome: which link?". Neuroradiology 2020; 63:9-10. [PMID: 33145628 DOI: 10.1007/s00234-020-02593-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Accepted: 10/21/2020] [Indexed: 11/30/2022]
Affiliation(s)
- Luca Pasquini
- Neuroradiology Unit, Imaging Department, Bambino Gesù Children's Hospital, Piazza Sant'Onofrio 4, 00165, Rome, Italy.
- Neuroradiology Unit, NESMOS Department, Sant'Andrea Hospital, La Sapienza University, Via Grottarossa 1035, Rome, 00189, Italy.
| | - Alessia Guarnera
- Neuroradiology Unit, Imaging Department, Bambino Gesù Children's Hospital, Piazza Sant'Onofrio 4, 00165, Rome, Italy
- Neuroradiology Unit, NESMOS Department, Sant'Andrea Hospital, La Sapienza University, Via Grottarossa 1035, Rome, 00189, Italy
| | - Maria Camilla Rossi-Espagnet
- Neuroradiology Unit, Imaging Department, Bambino Gesù Children's Hospital, Piazza Sant'Onofrio 4, 00165, Rome, Italy
- Neuroradiology Unit, NESMOS Department, Sant'Andrea Hospital, La Sapienza University, Via Grottarossa 1035, Rome, 00189, Italy
| | - Antonio Napolitano
- Medical Physics Department, Bambino Gesù Children's Hospital, IRCCS, P.zza Sant'Onofrio 4, Rome, 00165, Italy
| | - Daria Diodato
- Division of Metabolism, Ospedale Pediatrico Bambino Gesù, IRCCS, P.zza Sant'Onofrio 4, Rome, 00165, Italy
| | - Diego Martinelli
- Division of Metabolism, Ospedale Pediatrico Bambino Gesù, IRCCS, P.zza Sant'Onofrio 4, Rome, 00165, Italy
| | - Daniela Longo
- Neuroradiology Unit, Imaging Department, Bambino Gesù Children's Hospital, Piazza Sant'Onofrio 4, 00165, Rome, Italy
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32
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Jeppesen TD, Duno M, Vissing J. Mutation Load of Single, Large-Scale Deletions of mtDNA in Mitotic and Postmitotic Tissues. Front Genet 2020; 11:547638. [PMID: 33133144 PMCID: PMC7566915 DOI: 10.3389/fgene.2020.547638] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Accepted: 08/26/2020] [Indexed: 11/22/2022] Open
Abstract
It is generally accepted that patients with chronic progressive ophthalmoplegia caused by single large-scale deletion (SLD) of mitochondrial DNA (mtDNA) only harbor mutation in skeletal and eye muscles. The aim of this study was to investigate the presence and the level of heteroplasmy of mtDNA deletions in mitotic tissues of patients displaying mtDNA deletion of mitotic tissues in patients with SLDs and pure muscle phenotype. MtDNA mutation load was studied in three mitotic (urine epithelial cells, buccal mucosa, and blood) and one postmitotic (skeletal muscle) tissues in 17 patients with SLDs of mtDNA and pure muscle involvement. All patients had mtDNA deletion in skeletal muscle, and 78% of the patients also displayed the mtDNA deletion in mitotic tissues. The mtDNA mutation load was higher in skeletal muscle versus mitotic tissues. The mtDNA mutation load did not correlate with age of sampling of tissues, but there was a correlation between the mtDNA mutations load in skeletal muscle and (1) the site of 5′ end breaking point of the SLD, (2) the size of SLD, (3) the number of affected tRNAs, and (4) age at onset (r > 0.58, P < 0.05). The findings indicate that mtDNA mutation in mitotic tissue is common in patients with SLDs of mtDNA. The lack of correlation between age of tissue sampling, age at onset, and mtDNA mutation load in mitotic tissues indicates that there is no extensive post-natal modification of mtDNA mutation load in mitotic tissues of patients with pure muscle phenotype.
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Affiliation(s)
- Tina D Jeppesen
- Copenhagen Neuromuscular Center, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - Morten Duno
- Department of Clinical Genetics, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - John Vissing
- Copenhagen Neuromuscular Center, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
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33
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Saneto RP. Mitochondrial diseases: expanding the diagnosis in the era of genetic testing. JOURNAL OF TRANSLATIONAL GENETICS AND GENOMICS 2020; 4:384-428. [PMID: 33426505 PMCID: PMC7791531 DOI: 10.20517/jtgg.2020.40] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Mitochondrial diseases are clinically and genetically heterogeneous. These diseases were initially described a little over three decades ago. Limited diagnostic tools created disease descriptions based on clinical, biochemical analytes, neuroimaging, and muscle biopsy findings. This diagnostic mechanism continued to evolve detection of inherited oxidative phosphorylation disorders and expanded discovery of mitochondrial physiology over the next two decades. Limited genetic testing hampered the definitive diagnostic identification and breadth of diseases. Over the last decade, the development and incorporation of massive parallel sequencing has identified approximately 300 genes involved in mitochondrial disease. Gene testing has enlarged our understanding of how genetic defects lead to cellular dysfunction and disease. These findings have expanded the understanding of how mechanisms of mitochondrial physiology can induce dysfunction and disease, but the complete collection of disease-causing gene variants remains incomplete. This article reviews the developments in disease gene discovery and the incorporation of gene findings with mitochondrial physiology. This understanding is critical to the development of targeted therapies.
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Affiliation(s)
- Russell P. Saneto
- Center for Integrative Brain Research, Neuroscience Institute, Seattle, WA 98101, USA
- Department of Neurology/Division of Pediatric Neurology, Seattle Children’s Hospital/University of Washington, Seattle, WA 98105, USA
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34
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Varhaug KN, Nido GS, de Coo I, Isohanni P, Suomalainen A, Tzoulis C, Knappskog P, Bindoff LA. Using urine to diagnose large-scale mtDNA deletions in adult patients. Ann Clin Transl Neurol 2020; 7:1318-1326. [PMID: 32634300 PMCID: PMC7448145 DOI: 10.1002/acn3.51119] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Revised: 06/04/2020] [Accepted: 06/08/2020] [Indexed: 12/30/2022] Open
Abstract
OBJECTIVE The aim of this study was to evaluate if urinary sediment cells offered a robust alternative to muscle biopsy for the diagnosis of single mtDNA deletions. METHODS Eleven adult patients with progressive external ophthalmoplegia and a known single mtDNA deletion were investigated. Urinary sediment cells were used to isolate DNA, which was then subjected to long-range polymerase chain reaction. Where available, the patient`s muscle DNA was studied in parallel. Breakpoint and thus deletion size were identified using both Sanger sequencing and next generation sequencing. The level of heteroplasmy was determined using quantitative polymerase chain reaction. RESULTS We identified the deletion in urine in 9 of 11 cases giving a sensitivity of 80%. Breakpoints and deletion size were readily detectable in DNA extracted from urine. Mean heteroplasmy level in urine was 38% ± 26 (range 8 - 84%), and 57% ± 28 (range 12 - 94%) in muscle. While the heteroplasmy level in urinary sediment cells differed from that in muscle, we did find a statistically significant correlation between these two levels (R = 0.714, P = 0.031(Pearson correlation)). INTERPRETATION Our findings suggest that urine can be used to screen patients suspected clinically of having a single mtDNA deletion. Based on our data, the use of urine could considerably reduce the need for muscle biopsy in this patient group.
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Affiliation(s)
- Kristin N Varhaug
- Department of Neurology, Haukeland University Hospital, Bergen, Norway.,Department of Clinical Medicine (K1), University of Bergen, Bergen, Norway
| | - Gonzalo S Nido
- Department of Clinical Medicine (K1), University of Bergen, Bergen, Norway.,Neuro-SysMed, Department of Neurology, Haukeland University Hospital, Bergen, Norway
| | - Irenaeus de Coo
- Department of Neurology, Medical Spectrum Twente, Enschede, The Netherlands.,Department of Genetics and Cell Biology, University of Maastricht, Maastricht, The Netherlands
| | - Pirjo Isohanni
- Research Programs Unit, Stem Cells and Metabolism, Faculty of Medicine, University of Helsinki, Helsinki, Finland.,Children´s Hospital, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
| | - Anu Suomalainen
- Research Programs Unit, Stem Cells and Metabolism, Faculty of Medicine, University of Helsinki, Helsinki, Finland.,HUSlab, Helsinki University Hospital Helsinki, Helsinki, Finland.,Neuroscience Center, University of Helsinki, Hilife, Helsinki, Finland
| | - Charalampos Tzoulis
- Department of Clinical Medicine (K1), University of Bergen, Bergen, Norway.,Neuro-SysMed, Department of Neurology, Haukeland University Hospital, Bergen, Norway
| | - Per Knappskog
- Center for Medical Genetics and Molecular Medicine, Haukeland University Hospital, Bergen, Norway.,Department of Clinical Science, University of Bergen, Bergen, Norway
| | - Laurence A Bindoff
- Department of Clinical Medicine (K1), University of Bergen, Bergen, Norway.,Neuro-SysMed, Department of Neurology, Haukeland University Hospital, Bergen, Norway
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35
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La Morgia C, Maresca A, Caporali L, Valentino ML, Carelli V. Mitochondrial diseases in adults. J Intern Med 2020; 287:592-608. [PMID: 32463135 DOI: 10.1111/joim.13064] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/17/2020] [Revised: 02/07/2020] [Accepted: 02/21/2020] [Indexed: 02/07/2023]
Abstract
Mitochondrial medicine is a field that expanded exponentially in the last 30 years. Individually rare, mitochondrial diseases as a whole are probably the most frequent genetic disorder in adults. The complexity of their genotype-phenotype correlation, in terms of penetrance and clinical expressivity, natural history and diagnostic algorithm derives from the dual genetic determination. In fact, in addition to the about 1.500 genes encoding mitochondrial proteins that reside in the nuclear genome (nDNA), we have the 13 proteins encoded by the mitochondrial genome (mtDNA), for which 22 specific tRNAs and 2 rRNAs are also needed. Thus, besides Mendelian genetics, we need to consider all peculiarities of how mtDNA is inherited, maintained and expressed to fully understand the pathogenic mechanisms of these disorders. Yet, from the initial restriction to the narrow field of oxidative phosphorylation dysfunction, the landscape of mitochondrial functions impinging on cellular homeostasis, driving life and death, is impressively enlarged. Finally, from the clinical standpoint, starting from the neuromuscular field, where brain and skeletal muscle were the primary targets of mitochondrial dysfunction as energy-dependent tissues, after three decades virtually any subspecialty of medicine is now involved. We will summarize the key clinical pictures and pathogenic mechanisms of mitochondrial diseases in adults.
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Affiliation(s)
- C La Morgia
- From the, Dipartimento di Scienze Biomediche e Neuromotorie, Università di Bologna, Bologna, Italy.,IRCCS Istituto delle Scienze Neurologiche di Bologna, UOC Clinica Neurologica, Bologna, Italy
| | - A Maresca
- IRCCS Istituto delle Scienze Neurologiche di Bologna, UOC Clinica Neurologica, Bologna, Italy
| | - L Caporali
- IRCCS Istituto delle Scienze Neurologiche di Bologna, UOC Clinica Neurologica, Bologna, Italy
| | - M L Valentino
- From the, Dipartimento di Scienze Biomediche e Neuromotorie, Università di Bologna, Bologna, Italy.,IRCCS Istituto delle Scienze Neurologiche di Bologna, UOC Clinica Neurologica, Bologna, Italy
| | - V Carelli
- From the, Dipartimento di Scienze Biomediche e Neuromotorie, Università di Bologna, Bologna, Italy.,IRCCS Istituto delle Scienze Neurologiche di Bologna, UOC Clinica Neurologica, Bologna, Italy
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36
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Oliveira MT, Pontes CDB, Ciesielski GL. Roles of the mitochondrial replisome in mitochondrial DNA deletion formation. Genet Mol Biol 2020; 43:e20190069. [PMID: 32141473 PMCID: PMC7197994 DOI: 10.1590/1678-4685-gmb-2019-0069] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2019] [Accepted: 08/12/2019] [Indexed: 01/07/2023] Open
Abstract
Mitochondrial DNA (mtDNA) deletions are a common cause of human mitochondrial
diseases. Mutations in the genes encoding components of the mitochondrial
replisome, such as DNA polymerase gamma (Pol γ) and the mtDNA helicase Twinkle,
have been associated with the accumulation of such deletions and the development
of pathological conditions in humans. Recently, we demonstrated that changes in
the level of wild-type Twinkle promote mtDNA deletions, which implies that not
only mutations in, but also dysregulation of the stoichiometry between the
replisome components is potentially pathogenic. The mechanism(s) by which
alterations to the replisome function generate mtDNA deletions is(are) currently
under debate. It is commonly accepted that stalling of the replication fork at
sites likely to form secondary structures precedes the deletion formation. The
secondary structural elements can be bypassed by the replication-slippage
mechanism. Otherwise, stalling of the replication fork can generate single- and
double-strand breaks, which can be repaired through recombination leading to the
elimination of segments between the recombination sites. Here, we discuss
aberrances of the replisome in the context of the two debated outcomes, and
suggest new mechanistic explanations based on replication restart and template
switching that could account for all the deletion types reported for
patients.
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Affiliation(s)
- Marcos T Oliveira
- Universidade Estadual Paulista Júlio de Mesquita Filho, Faculdade de Ciências Agrárias e Veterinárias, Departamento de Tecnologia, Jaboticabal, SP, Brazil
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37
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Dard L, Blanchard W, Hubert C, Lacombe D, Rossignol R. Mitochondrial functions and rare diseases. Mol Aspects Med 2020; 71:100842. [PMID: 32029308 DOI: 10.1016/j.mam.2019.100842] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2019] [Revised: 12/26/2019] [Accepted: 12/27/2019] [Indexed: 12/19/2022]
Abstract
Mitochondria are dynamic cellular organelles responsible for a large variety of biochemical processes as energy transduction, REDOX signaling, the biosynthesis of hormones and vitamins, inflammation or cell death execution. Cell biology studies established that 1158 human genes encode proteins localized to mitochondria, as registered in MITOCARTA. Clinical studies showed that a large number of these mitochondrial proteins can be altered in expression and function through genetic, epigenetic or biochemical mechanisms including the interaction with environmental toxics or iatrogenic medicine. As a result, pathogenic mitochondrial genetic and functional defects participate to the onset and the progression of a growing number of rare diseases. In this review we provide an exhaustive survey of the biochemical, genetic and clinical studies that demonstrated the implication of mitochondrial dysfunction in human rare diseases. We discuss the striking diversity of the symptoms caused by mitochondrial dysfunction and the strategies proposed for mitochondrial therapy, including a survey of ongoing clinical trials.
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Affiliation(s)
- L Dard
- Bordeaux University, 33000, Bordeaux, France; INSERM U1211, 33000, Bordeaux, France; CELLOMET, CGFB-146 Rue Léo Saignat, Bordeaux, France
| | - W Blanchard
- Bordeaux University, 33000, Bordeaux, France; INSERM U1211, 33000, Bordeaux, France; CELLOMET, CGFB-146 Rue Léo Saignat, Bordeaux, France
| | - C Hubert
- Bordeaux University, 33000, Bordeaux, France; INSERM U1211, 33000, Bordeaux, France
| | - D Lacombe
- Bordeaux University, 33000, Bordeaux, France; INSERM U1211, 33000, Bordeaux, France; CHU de Bordeaux, Service de Génétique Médicale, F-33076, Bordeaux, France
| | - R Rossignol
- Bordeaux University, 33000, Bordeaux, France; INSERM U1211, 33000, Bordeaux, France; CELLOMET, CGFB-146 Rue Léo Saignat, Bordeaux, France.
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38
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Hjelm BE, Rollins B, Morgan L, Sequeira A, Mamdani F, Pereira F, Damas J, Webb MG, Weber MD, Schatzberg AF, Barchas JD, Lee FS, Akil H, Watson SJ, Myers RM, Chao EC, Kimonis V, Thompson PM, Bunney WE, Vawter MP. Splice-Break: exploiting an RNA-seq splice junction algorithm to discover mitochondrial DNA deletion breakpoints and analyses of psychiatric disorders. Nucleic Acids Res 2019; 47:e59. [PMID: 30869147 PMCID: PMC6547454 DOI: 10.1093/nar/gkz164] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2019] [Accepted: 02/28/2019] [Indexed: 12/20/2022] Open
Abstract
Deletions in the 16.6 kb mitochondrial genome have been implicated in numerous disorders that often display muscular and/or neurological symptoms due to the high-energy demands of these tissues. We describe a catalogue of 4489 putative mitochondrial DNA (mtDNA) deletions, including their frequency and relative read rate, using a combinatorial approach of mitochondria-targeted PCR, next-generation sequencing, bioinformatics, post-hoc filtering, annotation, and validation steps. Our bioinformatics pipeline uses MapSplice, an RNA-seq splice junction detection algorithm, to detect and quantify mtDNA deletion breakpoints rather than mRNA splices. Analyses of 93 samples from postmortem brain and blood found (i) the 4977 bp ‘common deletion’ was neither the most frequent deletion nor the most abundant; (ii) brain contained significantly more deletions than blood; (iii) many high frequency deletions were previously reported in MitoBreak, suggesting they are present at low levels in metabolically active tissues and are not exclusive to individuals with diagnosed mitochondrial pathologies; (iv) many individual deletions (and cumulative metrics) had significant and positive correlations with age and (v) the highest deletion burdens were observed in major depressive disorder brain, at levels greater than Kearns–Sayre Syndrome muscle. Collectively, these data suggest the Splice-Break pipeline can detect and quantify mtDNA deletions at a high level of resolution.
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Affiliation(s)
- Brooke E Hjelm
- Department of Psychiatry and Human Behavior, University of California-Irvine (UCI), Irvine, CA 92697, USA.,Department of Translational Genomics, Keck School of Medicine of USC, University of Southern California (USC), Los Angeles, CA 90033, USA
| | - Brandi Rollins
- Department of Psychiatry and Human Behavior, University of California-Irvine (UCI), Irvine, CA 92697, USA
| | - Ling Morgan
- Department of Psychiatry and Human Behavior, University of California-Irvine (UCI), Irvine, CA 92697, USA
| | - Adolfo Sequeira
- Department of Psychiatry and Human Behavior, University of California-Irvine (UCI), Irvine, CA 92697, USA
| | - Firoza Mamdani
- Department of Psychiatry and Human Behavior, University of California-Irvine (UCI), Irvine, CA 92697, USA
| | - Filipe Pereira
- Interdisciplinary Centre of Marine and Environmental Research (CIIMAR), University of Porto, Matosinhos 4050-123, Portugal
| | - Joana Damas
- The Genome Center, University of California-Davis, Davis, CA 95616, USA
| | - Michelle G Webb
- Department of Translational Genomics, Keck School of Medicine of USC, University of Southern California (USC), Los Angeles, CA 90033, USA
| | - Matthieu D Weber
- Department of Psychiatry and Human Behavior, University of California-Irvine (UCI), Irvine, CA 92697, USA
| | - Alan F Schatzberg
- Department of Psychiatry and Behavioral Sciences, Stanford University, Stanford, CA 94305, USA
| | - Jack D Barchas
- Department of Psychiatry, Weill Cornell Medical College at Cornell University, New York, NY 10065, USA
| | - Francis S Lee
- Department of Psychiatry, Weill Cornell Medical College at Cornell University, New York, NY 10065, USA
| | - Huda Akil
- The Molecular and Behavioral Neuroscience Institute, University of Michigan, Ann Arbor, MI 48109, USA
| | - Stanley J Watson
- The Molecular and Behavioral Neuroscience Institute, University of Michigan, Ann Arbor, MI 48109, USA
| | - Richard M Myers
- HudsonAlpha Institute for Biotechnology, Huntsville, AL 35806, USA
| | - Elizabeth C Chao
- Division of Genetics and Genomic Medicine, Department of Pediatrics, UCI, Irvine, CA, USA
| | - Virginia Kimonis
- Division of Genetics and Genomic Medicine, Department of Pediatrics, UCI, Irvine, CA, USA
| | - Peter M Thompson
- Southwest Brain Bank, Department of Psychiatry, Texas Tech University Health Sciences Center (TTUHSC), El Paso, TX 79905, USA
| | - William E Bunney
- Department of Psychiatry and Human Behavior, University of California-Irvine (UCI), Irvine, CA 92697, USA
| | - Marquis P Vawter
- Department of Psychiatry and Human Behavior, University of California-Irvine (UCI), Irvine, CA 92697, USA
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39
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Heighton JN, Brady LI, Sadikovic B, Bulman DE, Tarnopolsky MA. Genotypes of chronic progressive external ophthalmoplegia in a large adult-onset cohort. Mitochondrion 2019; 49:227-231. [PMID: 31521625 DOI: 10.1016/j.mito.2019.09.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2018] [Revised: 03/28/2019] [Accepted: 09/11/2019] [Indexed: 12/11/2022]
Abstract
Chronic progressive external ophthalmoplegia (CPEO) is a common presentation of mitochondrial disease. We performed a retrospective evaluation of the molecular genetic testing and genotype-phenotype correlations in a large cohort of adult-onset CPEO patients (N = 111). One hundred percent of patients tested had at least one mitochondrial DNA (mtDNA) deletion. Genetic testing of nuclear genes encoding mitochondrial proteins identified pathogenic/likely pathogenic variants likely to be associated with CPEO in 7.6% of patients. As expected, the nuclear gene most associated with DNA variation was POLG. A single likely pathogenic mitochondrial DNA variant (m.12278T>C) was identified in two unrelated patients. No significant differences were noted in the clinical phenotypes of patients with pathogenic or likely pathogenic nuclear variants in comparison to those with negative nuclear gene testing. Analysis of deletion size and heteroplasmy in muscle-derived mtDNA showed significant correlations with age of symptom onset but not disease severity (number of canonical CPEO features). Results suggest that smaller mtDNA deletions (p = 0.0127, r2 = 0.1201) and higher heteroplasmy of single mtDNA deletions (p = 0.0112, r2 = 0.2483) are associated with an earlier age of onset in CPEO patients.
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Affiliation(s)
- Julia N Heighton
- Department of Pediatrics, McMaster University, Hamilton, ON, Canada
| | - Lauren I Brady
- Department of Pediatrics, McMaster University, Hamilton, ON, Canada
| | - Bekim Sadikovic
- Department of Pathology and Laboratory Medicine, Western University, London, ON, Canada; Molecular Genetics Laboratory, Molecular Diagnostics Division, London Health Sciences Centre, London, ON, Canada
| | - Dennis E Bulman
- Newborn Screening Ontario and CHEO Research Institute, Children's Hospital of Eastern Ontario, Ottawa, ON, Canada
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40
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He J, Huang Y, Du G, Wang Z, Xiang Y, Wang Q. Lasting spatial learning and memory deficits following chronic cerebral hypoperfusion are associated with hippocampal mitochondrial aging in rats. Neuroscience 2019; 415:215-229. [DOI: 10.1016/j.neuroscience.2019.04.044] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2018] [Revised: 04/18/2019] [Accepted: 04/23/2019] [Indexed: 12/16/2022]
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41
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Jennifer MS, Cortez D. Pearson marrow-pancreas syndrome with cardiac conduction abnormality necessitating prophylactic pacemaker implantation. Ann Noninvasive Electrocardiol 2019; 25:e12681. [PMID: 31475425 DOI: 10.1111/anec.12681] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/27/2019] [Revised: 05/07/2019] [Accepted: 07/01/2019] [Indexed: 11/29/2022] Open
Abstract
Pearson marrow-pancreas syndrome (PS), an exceedingly rare mitochondrial disorder, involves multiple systems including hematologic system and pancreas. Other mitochondrial disorders have been associated with progressive infrahisian block but this has not yet been described as a major feature of PS. We report a 7-year-old girl with classical features of PS and cardiac conduction defect. Her electrocardiogram revealed QRS prolongation with right bundle and left anterior fascicular blocks. Follow-up Holter revealed bifascicular block, alternating left and right bundle branch blocks, supraventricular tachycardia (with alternating bundles), and suspicion for nonsustained ventricular tachycardia. She underwent successful transvenous single-chamber ventricular pacemaker.
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Affiliation(s)
- Mats Steffi Jennifer
- Division of Pediatric Cardiology, University of Minnesota Masonic Children's Hospital, Minneapolis, Minnesota
| | - Daniel Cortez
- Division of Pediatric Cardiology, University of Minnesota Masonic Children's Hospital, Minneapolis, Minnesota
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42
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Appendicular skeletal muscle mass: A more sensitive biomarker of disease severity than BMI in adults with mitochondrial diseases. PLoS One 2019; 14:e0219628. [PMID: 31344055 PMCID: PMC6657836 DOI: 10.1371/journal.pone.0219628] [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: 03/24/2019] [Accepted: 06/27/2019] [Indexed: 02/06/2023] Open
Abstract
The study aimed to evaluate the body composition of patients with mitochondrial diseases (MD) and correlate it with disease severity. Overall, 89 patients (age ≥ 18 years) with MD were recruited, including 49 with chronic progressive external ophthalmoplegia (CPEO) and 40 with mitochondrial encephalomyopathy with lactate acidosis and stroke-like episodes (MELAS). Body composition, including fat mass index (FMI), fat-free mass index (FFMI), skeletal muscle mass index (SMI), and appendicular skeletal muscle mass index (ASMI), were examined using multifrequency bioelectric impedance analysis. Clinical assessments, including muscle strength, usual gait speed, and disease severity determined by the Newcastle Mitochondrial Disease Adult Scale score (NMDAS), were performed. The comparisons between patients group and age- and gender-matched healthy controls, as well as the correlations between anthropometric measurements, body composition, and disease severity were analyzed. Height, weight, body mass index (BMI), FFMI, SMI, and ASMI were significantly lower in patients with MD than in healthy controls. Notably, low muscle mass was noted in 69.7% (62/89) of MD patients, with 22 patients also presenting with compromised physical performance as indicated by decreased gait speed, resulting in 24.7% satisfied the sarcopenia diagnostic criteria. Disease severity was more negatively correlated with ASMI than it was with height, weight, and BMI. Subgroup analysis showed that in the MELAS subgroup, disease severity was negatively correlated with height, weight, and ASMI; whereas in the CPEO subgroup, it was only negatively correlated with ASMI and SMI. Additionally, ASMI was positively associated with muscle strength. Altogether, compared with BMI, ASMI is a more sensitive biomarker predicting disease severity of MD, both in MELAS and CPEO patients.
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43
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Grady JP, Pickett SJ, Ng YS, Alston CL, Blakely EL, Hardy SA, Feeney CL, Bright AA, Schaefer AM, Gorman GS, McNally RJ, Taylor RW, Turnbull DM, McFarland R. mtDNA heteroplasmy level and copy number indicate disease burden in m.3243A>G mitochondrial disease. EMBO Mol Med 2019; 10:emmm.201708262. [PMID: 29735722 PMCID: PMC5991564 DOI: 10.15252/emmm.201708262] [Citation(s) in RCA: 182] [Impact Index Per Article: 36.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Mitochondrial disease associated with the pathogenic m.3243A>G variant is a common, clinically heterogeneous, neurogenetic disorder. Using multiple linear regression and linear mixed modelling, we evaluated which commonly assayed tissue (blood N = 231, urine N = 235, skeletal muscle N = 77) represents the m.3243A>G mutation load and mitochondrial DNA (mtDNA) copy number most strongly associated with disease burden and progression. m.3243A>G levels are correlated in blood, muscle and urine (R2 = 0.61–0.73). Blood heteroplasmy declines by ~2.3%/year; we have extended previously published methodology to adjust for age. In urine, males have higher mtDNA copy number and ~20% higher m.3243A>G mutation load; we present formulas to adjust for this. Blood is the most highly correlated mutation measure for disease burden and progression in m.3243A>G‐harbouring individuals; increasing age and heteroplasmy contribute (R2 = 0.27, P < 0.001). In muscle, heteroplasmy, age and mtDNA copy number explain a higher proportion of variability in disease burden (R2 = 0.40, P < 0.001), although activity level and disease severity are likely to affect copy number. Whilst our data indicate that age‐corrected blood m.3243A>G heteroplasmy is the most convenient and reliable measure for routine clinical assessment, additional factors such as mtDNA copy number may also influence disease severity.
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Affiliation(s)
- John P Grady
- Wellcome Centre for Mitochondrial Research, Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, UK
| | - Sarah J Pickett
- Wellcome Centre for Mitochondrial Research, Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, UK
| | - Yi Shiau Ng
- Wellcome Centre for Mitochondrial Research, Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, UK
| | - Charlotte L Alston
- Wellcome Centre for Mitochondrial Research, Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, UK.,NHS Highly Specialised Mitochondrial Diagnostic Laboratory, Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne, UK
| | - Emma L Blakely
- Wellcome Centre for Mitochondrial Research, Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, UK.,NHS Highly Specialised Mitochondrial Diagnostic Laboratory, Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne, UK
| | - Steven A Hardy
- Wellcome Centre for Mitochondrial Research, Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, UK.,NHS Highly Specialised Mitochondrial Diagnostic Laboratory, Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne, UK
| | - Catherine L Feeney
- Wellcome Centre for Mitochondrial Research, Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, UK
| | - Alexandra A Bright
- Wellcome Centre for Mitochondrial Research, Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, UK
| | - Andrew M Schaefer
- Wellcome Centre for Mitochondrial Research, Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, UK
| | - Gráinne S Gorman
- Wellcome Centre for Mitochondrial Research, Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, UK
| | - Richard Jq McNally
- Institute of Health and Society, Newcastle University, Newcastle upon Tyne, UK
| | - Robert W Taylor
- Wellcome Centre for Mitochondrial Research, Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, UK.,NHS Highly Specialised Mitochondrial Diagnostic Laboratory, Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne, UK
| | - Doug M Turnbull
- Wellcome Centre for Mitochondrial Research, Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, UK
| | - Robert McFarland
- Wellcome Centre for Mitochondrial Research, Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, UK
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44
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Reichart G, Mayer J, Zehm C, Kirschstein T, Tokay T, Lange F, Baltrusch S, Tiedge M, Fuellen G, Ibrahim S, Köhling R. Mitochondrial complex IV mutation increases reactive oxygen species production and reduces lifespan in aged mice. Acta Physiol (Oxf) 2019; 225:e13214. [PMID: 30376218 DOI: 10.1111/apha.13214] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2018] [Revised: 10/18/2018] [Accepted: 10/24/2018] [Indexed: 12/17/2022]
Abstract
AIM Mitochondrial DNA (mtDNA) mutations can negatively influence lifespan and organ function. More than 250 pathogenic mtDNA mutations are known, often involving neurological symptoms. Major neurodegenerative diseases share key etiopathogenetic components ie mtDNA mutations, mitochondrial dysfunction and oxidative stress. METHODS Here, we characterized a conplastic mouse strain (C57BL/6 J-mtNOD) carrying an electron transport chain complex IV mutation that leads to an altered cytochrome c oxidase subunit III. Since this mouse also harbours adenine insertions in the mitochondrial tRNA for arginine, we chose the C57BL/6 J-mtMRL as control strain which also carries a heteroplasmic stretch of adenine repetitions in this tRNA isoform. RESULTS Using MitoSOX fluorescence, we observed an elevated mitochondrial superoxide production and a reduced gene expression of superoxide dismutase 2 in the 24-month-old mtNOD mouse as compared to control. Together with the decreased expression of the fission-relevant gene Fis1, these data confirmed that the ageing mtNOD mouse had a mitochondrial dysfunctional phenotype. On the functional level, we could not detect significant differences in synaptic long-term potentiation, but found a markedly poor physical constitution to perform the Morris water maze task at the age of 24 months. Moreover, the median lifespan of mtNOD mice was significantly shorter than of control animals. CONCLUSION Our findings demonstrate that a complex IV mutation leads to mitochondrial dysfunction that translates into survival.
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Affiliation(s)
- Gesine Reichart
- Oscar Langendorff Institute of Physiology Rostock University Medical Center Rostock Germany
| | - Johannes Mayer
- Oscar Langendorff Institute of Physiology Rostock University Medical Center Rostock Germany
| | - Cindy Zehm
- Institute of Medical Biochemistry and Molecular Biology Rostock University Medical Center Rostock Germany
| | - Timo Kirschstein
- Oscar Langendorff Institute of Physiology Rostock University Medical Center Rostock Germany
| | - Tursonjan Tokay
- Oscar Langendorff Institute of Physiology Rostock University Medical Center Rostock Germany
- Center for Life Sciences Nazarbayev University Astana Kazakhstan
| | - Falko Lange
- Oscar Langendorff Institute of Physiology Rostock University Medical Center Rostock Germany
| | - Simone Baltrusch
- Institute of Medical Biochemistry and Molecular Biology Rostock University Medical Center Rostock Germany
| | - Markus Tiedge
- Institute of Medical Biochemistry and Molecular Biology Rostock University Medical Center Rostock Germany
| | - Georg Fuellen
- Institute for Biostatistics and Informatics in Medicine and Ageing Research Rostock Germany
- Interdisciplinary Faculty University of Rostock Rostock Germany
| | - Saleh Ibrahim
- Department of Dermatology Lübeck University Medical Center Lübeck Germany
| | - Rüdiger Köhling
- Oscar Langendorff Institute of Physiology Rostock University Medical Center Rostock Germany
- Interdisciplinary Faculty University of Rostock Rostock Germany
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45
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Tesarova M, Vondrackova A, Stufkova H, Veprekova L, Stranecky V, Berankova K, Hansikova H, Magner M, Galoova N, Honzik T, Vodickova E, Stary J, Zeman J. Sideroblastic anemia associated with multisystem mitochondrial disorders. Pediatr Blood Cancer 2019; 66:e27591. [PMID: 30588737 DOI: 10.1002/pbc.27591] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/10/2018] [Revised: 11/18/2018] [Accepted: 11/29/2018] [Indexed: 01/19/2023]
Abstract
BACKGROUND Sideroblastic anemia represents a heterogeneous group of inherited or acquired diseases with disrupted erythroblast iron utilization, ineffective erythropoiesis, and variable systemic iron overload. In a cohort of 421 patients with multisystem mitochondrial diseases, refractory anemia was found in 8 children. RESULTS Five children had sideroblastic anemia with increased numbers of ring sideroblasts >15%. Two of the children had a fatal course of MLASA1 syndrome (mitochondrial myopathy, lactic acidosis, and sideroblastic anemia [SA]) due to a homozygous, 6-kb deletion in the PUS1 gene, part of the six-member family of pseudouridine synthases (pseudouridylases). Large homozygous deletions represent a novel cause of presumed PUS1-loss-of-function phenotype. The other three children with SA had Pearson syndrome (PS) due to mtDNA deletions of 4 to 8 kb; two of these children showed early onset of PS and died due to repeated sepsis; the other child had later onset of PS and survived as the hematological parameters normalized and the disease transitioned to Kearns-Sayre syndrome. In addition, anemia without ring sideroblasts was found in three other patients with mitochondrial disorders, including two children with later onset of PS and one child with failure to thrive, microcephaly, developmental delay, hypertrophic cardiomyopathy, and renal tubular acidosis due to the heterozygous mutations c.610A>G (p.Asn204Asp) and c.674C>T (p.Pro225Leu) in the COX10 gene encoding the cytochrome c oxidase assembly factor. CONCLUSIONS Sideroblastic anemia was found in fewer than 1.2% of patients with multisystem mitochondrial disease, and it was usually associated with an unfavorable prognosis.
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Affiliation(s)
- Marketa Tesarova
- Department of Paediatrics and Adolescent Medicine, First Faculty of Medicine, Charles University and General University Hospital, Prague, Czech Republic
| | - Alzbeta Vondrackova
- Department of Paediatrics and Adolescent Medicine, First Faculty of Medicine, Charles University and General University Hospital, Prague, Czech Republic
| | - Hana Stufkova
- Department of Paediatrics and Adolescent Medicine, First Faculty of Medicine, Charles University and General University Hospital, Prague, Czech Republic
| | - Lenka Veprekova
- Department of Paediatrics and Adolescent Medicine, First Faculty of Medicine, Charles University and General University Hospital, Prague, Czech Republic
| | - Viktor Stranecky
- Department of Paediatrics and Adolescent Medicine, First Faculty of Medicine, Charles University and General University Hospital, Prague, Czech Republic
| | - Kamila Berankova
- Department of Paediatrics and Adolescent Medicine, First Faculty of Medicine, Charles University and General University Hospital, Prague, Czech Republic
| | - Hana Hansikova
- Department of Paediatrics and Adolescent Medicine, First Faculty of Medicine, Charles University and General University Hospital, Prague, Czech Republic
| | - Martin Magner
- Department of Paediatrics and Adolescent Medicine, First Faculty of Medicine, Charles University and General University Hospital, Prague, Czech Republic
| | - Natalia Galoova
- Department of Paediatric Oncology and Haematology, Children's University Hospital, Kosice, Slovakia
| | - Tomas Honzik
- Department of Paediatrics and Adolescent Medicine, First Faculty of Medicine, Charles University and General University Hospital, Prague, Czech Republic
| | - Elena Vodickova
- Department of Haematology, Motol University Hospital, Prague, Czech Republic
| | - Jan Stary
- Department of Paediatric Haematology and Oncology, Second Faculty of Medicine, Charles University and Motol University Hospital, Prague, Czech Republic
| | - Jiri Zeman
- Department of Paediatrics and Adolescent Medicine, First Faculty of Medicine, Charles University and General University Hospital, Prague, Czech Republic
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46
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Rocha MC, Rosa HS, Grady JP, Blakely EL, He L, Romain N, Haller RG, Newman J, McFarland R, Ng YS, Gorman GS, Schaefer AM, Tuppen HA, Taylor RW, Turnbull DM. Pathological mechanisms underlying single large-scale mitochondrial DNA deletions. Ann Neurol 2019; 83:115-130. [PMID: 29283441 PMCID: PMC5893934 DOI: 10.1002/ana.25127] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2017] [Revised: 12/01/2017] [Accepted: 12/21/2017] [Indexed: 12/17/2022]
Abstract
OBJECTIVE Single, large-scale deletions in mitochondrial DNA (mtDNA) are a common cause of mitochondrial disease. This study aimed to investigate the relationship between the genetic defect and molecular phenotype to improve understanding of pathogenic mechanisms associated with single, large-scale mtDNA deletions in skeletal muscle. METHODS We investigated 23 muscle biopsies taken from adult patients (6 males/17 females with a mean age of 43 years) with characterized single, large-scale mtDNA deletions. Mitochondrial respiratory chain deficiency in skeletal muscle biopsies was quantified by immunoreactivity levels for complex I and complex IV proteins. Single muscle fibers with varying degrees of deficiency were selected from 6 patient biopsies for determination of mtDNA deletion level and copy number by quantitative polymerase chain reaction. RESULTS We have defined 3 "classes" of single, large-scale deletion with distinct patterns of mitochondrial deficiency, determined by the size and location of the deletion. Single fiber analyses showed that fibers with greater respiratory chain deficiency harbored higher levels of mtDNA deletion with an increase in total mtDNA copy number. For the first time, we have demonstrated that threshold levels for complex I and complex IV deficiency differ based on deletion class. INTERPRETATION Combining genetic and immunofluorescent assays, we conclude that thresholds for complex I and complex IV deficiency are modulated by the deletion of complex-specific protein-encoding genes. Furthermore, removal of mt-tRNA genes impacts specific complexes only at high deletion levels, when complex-specific protein-encoding genes remain. These novel findings provide valuable insight into the pathogenic mechanisms associated with these mutations. Ann Neurol 2018;83:115-130.
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Affiliation(s)
- Mariana C Rocha
- Wellcome Centre for Mitochondrial Research, Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Hannah S Rosa
- Wellcome Centre for Mitochondrial Research, Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - John P Grady
- Wellcome Centre for Mitochondrial Research, Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Emma L Blakely
- Wellcome Centre for Mitochondrial Research, Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, United Kingdom.,National Health Service Highly Specialised Mitochondrial Diagnostic Laboratory, Newcastle upon Tyne Hospitals, National Health Service Foundation Trust, Newcastle upon Tyne, United Kingdom
| | - Langping He
- Wellcome Centre for Mitochondrial Research, Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, United Kingdom.,National Health Service Highly Specialised Mitochondrial Diagnostic Laboratory, Newcastle upon Tyne Hospitals, National Health Service Foundation Trust, Newcastle upon Tyne, United Kingdom
| | - Nadine Romain
- Department of Neurology and Neurotherapeutics, University of Texas Southwestern Medical Center, Dallas, TX.,Institute for Exercise and Environmental Medicine of Texas Health Presbyterian Hospital, Dallas, TX
| | - Ronald G Haller
- Department of Neurology and Neurotherapeutics, University of Texas Southwestern Medical Center, Dallas, TX.,Institute for Exercise and Environmental Medicine of Texas Health Presbyterian Hospital, Dallas, TX
| | - Jane Newman
- 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
| | - Yi Shiau Ng
- Wellcome Centre for Mitochondrial Research, Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Grainne S Gorman
- Wellcome Centre for Mitochondrial Research, Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Andrew M Schaefer
- Wellcome Centre for Mitochondrial Research, Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Helen A Tuppen
- 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.,National Health Service Highly Specialised Mitochondrial Diagnostic Laboratory, Newcastle upon Tyne Hospitals, National Health Service Foundation Trust, Newcastle upon Tyne, United Kingdom
| | - Doug M Turnbull
- Wellcome Centre for Mitochondrial Research, Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, United Kingdom
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47
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Paiva Coelho M, Martins E, Vilarinho L. Diagnosis, management, and follow-up of mitochondrial disorders in childhood: a personalized medicine in the new era of genome sequence. Eur J Pediatr 2019; 178:21-32. [PMID: 30535772 DOI: 10.1007/s00431-018-3292-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/26/2018] [Revised: 11/05/2018] [Accepted: 11/08/2018] [Indexed: 12/11/2022]
Abstract
Primary mitochondrial disorders are highly variable in clinical presentation, biochemistry, and molecular etiology. Mitochondrial disorders can be caused by genetic defects in the mitochondrial, in nuclear genome, or in the interplay between the two genomes. Biochemical screening tests may be inconclusive or misleading since patients, with confirmed mitochondrial disorders specially in pediatric age, may exhibit normal routine biochemistry, muscle histology, or enzymatic analysis of the mitochondrial respiratory chain. Diagnosis is often challenging even with combination of multiple criteria (clinical, biochemical, histological, and functional), as innumerous conditions cause secondary mitochondrial dysfunction. Nowadays, a definite diagnosis is only possible by genetic confirmation since no single score system is satisfactorily accurate, being sensitive but not specific.Conclusion: Awareness between physicians is of major importance considering that clinical suspicion may not be obvious regarding the heterogenicity in presentation and biochemical features of mitochondrial disorders. In this review, we provide information on diagnosis approach to patients suspected for mitochondrial disorders as well as management on chronic and acute settings. Follow-up should provide comprehensive information on patient's status, since intervention on these diseases is mostly supportive and prognosis is variable and sometimes unpredictable. What is Known: • Mitochondrial disorders are heterogenous and may present at any age, with any symptoms and any type of inheritance. • Mitochondrial disorders may be due to pathogenic variants in mitochondrial DNA (mtDNA) or nuclear genes (nDNA). What is New: • Since no single score system is satisfactorily accurate, a definite diagnosis is only possible with genetic studies with gene panels proving to be a cost-effective approach. • Clinical and biochemical features of patients without a confirmed diagnosis must be reviewed and other diagnosis must be considered. A wider genetic approach may be applied (WES or WGS).
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Affiliation(s)
- Margarida Paiva Coelho
- Pediatrics Department, Centro Materno Infantil do Norte, Centro Hospitalar do Porto, Largo da Maternidade, S/N, 4450, Porto, Portugal.
| | - Esmeralda Martins
- Reference Center for Inherited Metabolic Disorders, Centro Hospitalar do Porto, Porto, Portugal
| | - Laura Vilarinho
- Newborn Screening, Metabolism and Genetics Unit, Human Genetics Department, National Institute of Health Dr. Ricardo Jorge, Porto, Portugal
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Whole sequence of the mitochondrial DNA genome of Kearns Sayre Syndrome patients: Identification of deletions and variants. Gene 2018; 688:171-181. [PMID: 30528267 DOI: 10.1016/j.gene.2018.11.085] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2018] [Revised: 09/04/2018] [Accepted: 11/28/2018] [Indexed: 02/07/2023]
Abstract
Mitochondria both produce the energy of the cell as ATP via respiration and regulate cellular metabolism. Accordingly, any deletion or mutation in the mitochondrial DNA (mtDNA) may result in a disease. One of these diseases is Kearns Sayre syndrome (KSS), described for the first time in 1958, where different large-scale deletions of different sizes and at different positions have been reported in the mitochondrial genome of patients with similar clinical symptoms. In this study, sequences of the mitochondrial genome of three patients with clinic features of KSS were analyzed. Our results revealed the position, heteroplasmy percentage, size of deletions, and their haplogroups. Two patients contained deletions reported previously and one patient showed a new deletion not reported previously. These results display for the first time a systematic analysis of mtDNA variants in the whole mtDNA genome of patients with KSS to help to understand their association with the disease.
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Abstract
Mitochondrial myopathies are progressive muscle conditions caused primarily by the impairment of oxidative phosphorylation (OXPHOS) in the mitochondria. This causes a deficit in energy production in the form of adenosine triphosphate (ATP), particularly in skeletal muscle. The diagnosis of mitochondrial myopathy is reliant on the combination of numerous techniques including traditional histochemical, immunohistochemical, and biochemical testing combined with the fast-emerging molecular genetic techniques, namely next-generation sequencing (NGS). This has allowed for the diagnosis to become more effective in terms of determining causative or novel genes. However, there are currently no effective or disease-modifying treatments available for the vast majority of patients with mitochondrial myopathies. Existing therapeutic options focus on the symptomatic management of disease manifestations. An increasing number of clinical trials have investigated the therapeutic effects of various vitamins, cofactors, and small molecules, though these trials have failed to show definitive outcome measures for clinical practice thus far. In addition, new molecular strategies, specifically mtZFNs and mtTALENs, that cause beneficial heteroplasmic shifts in cell lines harboring varying pathogenic mtDNA mutations offer hope for the future. Moreover, recent developments in the reproductive options for patients with mitochondrial myopathies mean that for some families, the possibility of preventing transmission of the mutation to the next generation is now possible.
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Affiliation(s)
- Syeda T Ahmed
- Wellcome Centre for Mitochondrial Research, Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, UK
| | - Lyndsey Craven
- Wellcome Centre for Mitochondrial Research, Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, UK
| | - Oliver M Russell
- Wellcome Centre for Mitochondrial Research, Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, UK
| | - Doug M Turnbull
- Wellcome Centre for Mitochondrial Research, Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, UK
- MRC Centre for Ageing and Vitality, Newcastle University, Newcastle upon Tyne, UK
| | - Amy E Vincent
- Wellcome Centre for Mitochondrial Research, Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, UK.
- MRC Centre for Ageing and Vitality, Newcastle University, Newcastle upon Tyne, UK.
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50
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Kozak I, Oystreck DT, Abu-Amero KK, Nowilaty SR, Alkhalidi H, Elkhamary SM, Mohamed S, Hamad MHA, Salih MA, Blakely EL, Taylor RW, Bosley TM. NEW OBSERVATIONS REGARDING THE RETINOPATHY OF GENETICALLY CONFIRMED KEARNS-SAYRE SYNDROME. Retin Cases Brief Rep 2018; 12:349-358. [PMID: 28296806 DOI: 10.1097/icb.0000000000000503] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
PURPOSE To report novel retinal findings in Kearns-Sayre syndrome and correlate degree of retinopathy with other clinical findings. METHODS Observational case series of patients from Saudi Arabia with retinal and neuroophthalmologic examinations, medical chart review, and mitochondrial genetic evaluation. RESULTS The three unrelated patients had progressive external ophthalmoplegia and pigmentary retinopathy bilaterally. Muscle biopsy in two of the cases revealed mitochondrial myopathy. All three had abnormal findings on neuroimaging and modestly reduced visual acuity in both eyes with a variable pigmentary retinopathy. One of the patients had bilateral subretinal fibrosis with a full-thickness macular hole in the right eye. All three patients had single, large-scale mitochondrial DNA (mtDNA) deletions (5.0-7.6 kb in size) with blood mtDNA heteroplasmy levels ranging from below 20% to 57%. Severity of pigmentary retinopathy did not correlate with severity of progressive external ophthalmoplegia, but did correspond grossly with electroretinographic abnormalities, just as the degree of ocular motility restriction and ptosis in each patient correlated with the size of their extraocular muscles on neuroimaging. In addition, the size of the single, large-scale mtDNA deletion and level of mtDNA heteroplasmy corresponded with degree of ocular motility restriction but not with severity of retinopathy. CONCLUSION Subretinal fibrosis and macular hole are novel retinal observations which expand clinical profile in Kearns-Sayre syndrome. Genetic testing for mtDNA deletions and heteroplasmy in blood, muscle biopsy, careful ocular and retinal examination including electroretinography, and imaging are indispensable tests for this condition.
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Affiliation(s)
- Igor Kozak
- King Khaled Eye Specialist Hospital, Riyadh, Saudi Arabia
| | - Darren T Oystreck
- Department of Ophthalmology, College of Medicine, King Saud University, Riyadh, Saudi Arabia
- The Division of Ophthalmology, Faculty of Health Sciences, University of Stellenbosch, Tygerberg, South Africa
| | - Khaled K Abu-Amero
- Department of Ophthalmology, College of Medicine, King Saud University, Riyadh, Saudi Arabia
- Department of Ophthalmology, College of Medicine, University of Florida, Jacksonville, Florida
| | | | | | | | - Sarar Mohamed
- Pediatrics, College of Medicine, King Saud University Riyadh, Saudi Arabia
| | | | - Mustafa A Salih
- Pediatrics, College of Medicine, King Saud University Riyadh, Saudi Arabia
| | - Emma L Blakely
- The Wellcome Trust Centre for Mitochondrial Research, Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Robert W Taylor
- The Wellcome Trust Centre for Mitochondrial Research, Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Thomas M Bosley
- Department of Ophthalmology, College of Medicine, King Saud University, Riyadh, Saudi Arabia
- The Wilmer Eye Institute, Johns Hopkins University, Baltimore, Maryland
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