1
|
Tauchmanová K, Pecinová A, Houštěk J, Mráček T. Variability of Clinical Phenotypes Caused by Isolated Defects of Mitochondrial ATP Synthase. Physiol Res 2024; 73:S243-S278. [PMID: 39016153 DOI: 10.33549/physiolres.935407] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/09/2024] Open
Abstract
Disorders of ATP synthase, the key enzyme in mitochondrial energy supply, belong to the most severe metabolic diseases, manifesting as early-onset mitochondrial encephalo-cardiomyopathies. Since ATP synthase subunits are encoded by both mitochondrial and nuclear DNA, pathogenic variants can be found in either genome. In addition, the biogenesis of ATP synthase requires several assembly factors, some of which are also hotspots for pathogenic variants. While variants of MT-ATP6 and TMEM70 represent the most common cases of mitochondrial and nuclear DNA mutations respectively, the advent of next-generation sequencing has revealed new pathogenic variants in a number of structural genes and TMEM70, sometimes with truly peculiar genetics. Here we present a systematic review of the reported cases and discuss biochemical mechanisms, through which they are affecting ATP synthase. We explore how the knowledge of pathophysiology can improve our understanding of enzyme biogenesis and function. Keywords: Mitochondrial diseases o ATP synthase o Nuclear DNA o Mitochondrial DNA o TMEM70.
Collapse
|
2
|
Gao Y, Guo L, Wang F, Wang Y, Li P, Zhang D. Development of mitochondrial gene-editing strategies and their potential applications in mitochondrial hereditary diseases: a review. Cytotherapy 2024; 26:11-24. [PMID: 37930294 DOI: 10.1016/j.jcyt.2023.10.004] [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: 06/08/2023] [Revised: 10/12/2023] [Accepted: 10/13/2023] [Indexed: 11/07/2023]
Abstract
Mitochondrial DNA (mtDNA) is a critical genome contained within the mitochondria of eukaryotic cells, with many copies present in each mitochondrion. Mutations in mtDNA often are inherited and can lead to severe health problems, including various inherited diseases and premature aging. The lack of efficient repair mechanisms and the susceptibility of mtDNA to damage exacerbate the threat to human health. Heteroplasmy, the presence of different mtDNA genotypes within a single cell, increases the complexity of these diseases and requires an effective editing method for correction. Recently, gene-editing techniques, including programmable nucleases such as restriction endonuclease, zinc finger nuclease, transcription activator-like effector nuclease, clustered regularly interspaced short palindromic repeats/clustered regularly interspaced short palindromic repeats-associated 9 and base editors, have provided new tools for editing mtDNA in mammalian cells. Base editors are particularly promising because of their high efficiency and precision in correcting mtDNA mutations. In this review, we discuss the application of these techniques in mitochondrial gene editing and their limitations. We also explore the potential of base editors for mtDNA modification and discuss the opportunities and challenges associated with their application in mitochondrial gene editing. In conclusion, this review highlights the advancements, limitations and opportunities in current mitochondrial gene-editing technologies and approaches. Our insights aim to stimulate the development of new editing strategies that can ultimately alleviate the adverse effects of mitochondrial hereditary diseases.
Collapse
Affiliation(s)
- Yanyan Gao
- Institute for Translational Medicine, The Affiliated Hospital of Qingdao University, College of Medicine, Qingdao University, Qingdao, China
| | - Linlin Guo
- The Affiliated Cardiovascular Hospital of Qingdao University, Qingdao University, Qingdao, China
| | - Fei Wang
- Institute for Translational Medicine, The Affiliated Hospital of Qingdao University, College of Medicine, Qingdao University, Qingdao, China
| | - Yin Wang
- Institute for Translational Medicine, The Affiliated Hospital of Qingdao University, College of Medicine, Qingdao University, Qingdao, China
| | - Peifeng Li
- Institute for Translational Medicine, The Affiliated Hospital of Qingdao University, College of Medicine, Qingdao University, Qingdao, China
| | - Dejiu Zhang
- Institute for Translational Medicine, The Affiliated Hospital of Qingdao University, College of Medicine, Qingdao University, Qingdao, China.
| |
Collapse
|
3
|
Chen J, Wang J, Gan J, Luo R, Yang Z, Liang M, Chen X. Anti-AQP4-IgG-positive Leigh syndrome: A case report and review of the literature. Front Pediatr 2023; 11:1046731. [PMID: 36814591 PMCID: PMC9939766 DOI: 10.3389/fped.2023.1046731] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/17/2022] [Accepted: 01/09/2023] [Indexed: 02/09/2023] Open
Abstract
BACKGROUND Leigh syndrome (LS; OMIM: 256000) is a progressive neurodegenerative disease caused by genetic mutations resulting in mitochondrial oxidative phosphorylation defects. The prognosis is poor, with most children dying before the age of 2 years. MT-ATP6 variants are the most common mitochondrial DNA mutations in LS. MT-ATP6 variant-induced LS may trigger autoimmunity, and immunotherapy might be effective. Here, we present the first pediatric case of anti-aquaporin 4 (AQP4)-IgG-positive LS caused by an MT-ATP6 variant. CASE A 1-year-old boy was hospitalized due to recurrent fever, cough, and developmental regression. Two months previously, he had developed reduced responses to stimulation and psychomotor retardation. After admission, his condition deteriorated and respiratory failure ensued. Magnetic resonance imaging of the brain showed symmetrical small patchy abnormal signals around the third ventricle, pons, and dorsal periaqueductal gray matter in the dorsal medulla. Laboratory tests revealed anti-AQP4-IgG antibodies. Anti-infection, immunoglobulin, and glucocorticoid therapy were administered for symptomatic treatment. Genetic testing revealed a de novo homogeneous pathogenic variant of MT-ATP6 (m.9176T > C, mutation ratio: 99.97%). The patient was diagnosed with anti-AQP4-IgG-positive LS, treated with "cocktail therapy" (vitamins B1, B2, C, and E, l-carnitine, and coenzyme Q10), and discharged after his condition improved. A literature review revealed that LS-induced mitochondrial defects can impact the immune system; hence, immunotherapy and early mitochondrial cocktail therapy may improve outcomes. CONCLUSION Anti-AQP4-IgG-positive LS is very rare. Patients with LS with the m.9176T > C variant of MT-ATP6 may be susceptible to autoimmune damage of the central nervous system. Early cocktail therapy combined with immunotherapy may improve their prognosis.
Collapse
Affiliation(s)
- Jun Chen
- Department of Pediatrics, West China Second University Hospital, Sichuan University, Chengdu, China.,Department of Pediatrics, Key Laboratory of Obstetric & Gynecologic and Pediatric Diseases and Birth Defects of the Ministry of Education, Sichuan University, Chengdu, China.,Department of Pediatrics, Key Laboratory of Development and Maternal and Child Diseases of Sichuan Province, Sichuan University, Chengdu, China
| | - Jianjun Wang
- Department of Pediatrics, West China Second University Hospital, Sichuan University, Chengdu, China.,Department of Pediatrics, Key Laboratory of Obstetric & Gynecologic and Pediatric Diseases and Birth Defects of the Ministry of Education, Sichuan University, Chengdu, China.,Department of Pediatrics, Key Laboratory of Development and Maternal and Child Diseases of Sichuan Province, Sichuan University, Chengdu, China
| | - Jing Gan
- Department of Pediatrics, West China Second University Hospital, Sichuan University, Chengdu, China.,Department of Pediatrics, Key Laboratory of Obstetric & Gynecologic and Pediatric Diseases and Birth Defects of the Ministry of Education, Sichuan University, Chengdu, China.,Department of Pediatrics, Key Laboratory of Development and Maternal and Child Diseases of Sichuan Province, Sichuan University, Chengdu, China
| | - Rong Luo
- Department of Pediatrics, West China Second University Hospital, Sichuan University, Chengdu, China.,Department of Pediatrics, Key Laboratory of Obstetric & Gynecologic and Pediatric Diseases and Birth Defects of the Ministry of Education, Sichuan University, Chengdu, China.,Department of Pediatrics, Key Laboratory of Development and Maternal and Child Diseases of Sichuan Province, Sichuan University, Chengdu, China
| | - Zuozhen Yang
- Medical Department, Cipher Gene LLC, Beijing, China
| | | | - Xiaolu Chen
- Department of Pediatrics, West China Second University Hospital, Sichuan University, Chengdu, China.,Department of Pediatrics, Key Laboratory of Obstetric & Gynecologic and Pediatric Diseases and Birth Defects of the Ministry of Education, Sichuan University, Chengdu, China.,Department of Pediatrics, Key Laboratory of Development and Maternal and Child Diseases of Sichuan Province, Sichuan University, Chengdu, China
| |
Collapse
|
4
|
Rewiring cell signalling pathways in pathogenic mtDNA mutations. Trends Cell Biol 2021; 32:391-405. [PMID: 34836781 DOI: 10.1016/j.tcb.2021.10.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2021] [Revised: 10/19/2021] [Accepted: 10/22/2021] [Indexed: 12/24/2022]
Abstract
Mitochondria generate the energy to sustain cell viability and serve as a hub for cell signalling. Their own genome (mtDNA) encodes genes critical for oxidative phosphorylation. Mutations of mtDNA cause major disease and disability with a wide range of presentations and severity. We review here an emerging body of data suggesting that changes in cell metabolism and signalling pathways in response to the presence of mtDNA mutations play a key role in shaping disease presentation and progression. Understanding the impact of mtDNA mutations on cellular energy homeostasis and signalling pathways seems fundamental to identify novel therapeutic interventions with the potential to improve the prognosis for patients with primary mitochondrial disease.
Collapse
|
5
|
Nolte D, Kang JS, Hofmann A, Schwaab E, Krämer HH, Müller U. Mutations in MT-ATP6 are a frequent cause of adult-onset spinocerebellar ataxia. J Neurol 2021; 268:4866-4873. [PMID: 34037856 PMCID: PMC8563540 DOI: 10.1007/s00415-021-10607-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Revised: 05/06/2021] [Accepted: 05/08/2021] [Indexed: 01/30/2023]
Abstract
Adult-onset ataxias are a genetically and clinically heterogeneous group of movement disorders. In addition to nuclear gene mutations, sequence changes have also been described in the mitochondrial genome. Here, we present findings of mutation analysis of the mitochondrial gene MT-ATP6. We analyzed 94 patients with adult-onset spinocerebellar ataxia (SCA), including 34 sporadic cases. In all patients, common sequence changes found in SCAs such as repeat expansions and point mutations had been excluded previously. We found pathogenic MT-ATP variants in five of these patients (5.32%), two of whom were sporadic. Four of the five mutations have not previously been described in ataxias. All but one of these mutations affect transmembrane helices of subunit-α of ATP synthase. Two mutations (p.G16S, and p.P18S) disrupt transmembrane helix 1 (TMH1), one mutation (p.G167D) affects TMH5, and another one (p.L217P) TMH6. The fifth mutation (p.T96A) describes an amino acid change in close proximity to transmembrane helix 3 (TMH3). The level of heteroplasmy was either complete or very high ranging from 87 to 99%. The high prevalence of pathogenic MT-ATP6 variants suggests that analysis of this gene should be included in the routine workup of both hereditary and sporadic ataxias.
Collapse
Affiliation(s)
- Dagmar Nolte
- Institut für Humangenetik , Justus-Liebig-Universität Giessen, Schlangenzahl 14, Giessen, 35392, Germany.
| | - Jun-Suk Kang
- Klinikum der Johann Wolfgang Goethe-Universität, Klinik für Neurologie, Frankfurt, Germany.,Neuropraxis, Frankfurt, Germany
| | - Amrei Hofmann
- Institut für Humangenetik , Justus-Liebig-Universität Giessen, Schlangenzahl 14, Giessen, 35392, Germany.,Klinikum Worms, Klinik für Pädiatrie, Worms, Germany
| | - Eva Schwaab
- Praxis für Humangenetik , Wiesbaden, Germany
| | - Heidrun H Krämer
- Klinik für Neurologie , Justus-Liebig-Universität Giessen, Giessen, Germany
| | - Ulrich Müller
- Institut für Humangenetik , Justus-Liebig-Universität Giessen, Schlangenzahl 14, Giessen, 35392, Germany
| |
Collapse
|
6
|
Homoplasmic deleterious MT-ATP6/8 mutations in adult patients. Mitochondrion 2020; 55:64-77. [PMID: 32858252 DOI: 10.1016/j.mito.2020.08.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Revised: 07/13/2020] [Accepted: 08/14/2020] [Indexed: 01/10/2023]
Abstract
To address the frequency of complex V defects, we systematically sequenced MT-ATP6/8 genes in 512 consecutive patients. We performed functional analysis in muscle or fibroblasts for 12 out of 27 putative homoplasmic mutations and in cybrids for four. Fibroblasts, muscle and cybrids with known deleterious mutations underwent parallel analysis. It included oxidative phosphorylation spectrophotometric assays, western blots, structural analysis, ATP production, glycolysis and cell proliferation evaluation. We demonstrated the deleterious nature of three original mutations. Striking gradation in severity of the mutations consequences and differences between muscle, fibroblasts and cybrids implied a likely under-diagnosis of human complex V defects.
Collapse
|
7
|
Abstract
Mitochondria play various important roles in energy production, metabolism, and apoptosis. Mitochondrial dysfunction caused by alterations in mitochondrial DNA (mtDNA) can lead to the initiation and progression of cancers and other diseases. These alterations include mutations and copy number variations. Especially, the mutations in D-loop, MT-ND1, and MT-ND5 affect mitochondrial functions and are widely detected in various cancers. Meanwhile, several other mutations have been correlated with muscular and neuronal diseases, especially MT-TL1 is deeply related. These pieces of evidence indicated mtDNA alterations in diseases show potential as a novel therapeutic target. mtDNA repair enzymes are the target for delaying or stalling the mtDNA damage-induced cancer progression and metastasis. Moreover, some mutations reveal a prognosis ability of the drug resistance. Current efforts aim to develop mitochondrial transplantation technique as a direct cure for deregulated mitochondria-associated diseases. This review summarizes the implications of mitochondrial dysfunction in cancers and other pathologies; and discusses the relevance of mitochondria-targeted therapies, along with their contribution as potential biomarkers.
Collapse
Affiliation(s)
- Ngoc Ngo Yen Nguyen
- Department of Biomedical Science, Graduate School, Kyung Hee University, Seoul, Republic of Korea.,Biomedical Science Institute, Kyung Hee University, Seoul, Republic of Korea
| | - Sung Soo Kim
- Biomedical Science Institute, Kyung Hee University, Seoul, Republic of Korea.,Department of Biochemistry and Molecular Biology, School of Medicine, Kyung Hee University, Seoul, Republic of Korea
| | - Yong Hwa Jo
- Biomedical Science Institute, Kyung Hee University, Seoul, Republic of Korea.,Department of Biochemistry and Molecular Biology, School of Medicine, Kyung Hee University, Seoul, Republic of Korea
| |
Collapse
|
8
|
Ichikawa K, Tsuyusaki Y, Shimbo H, Goto T. Late-onset Leigh syndrome with m.9176T>C mutation in the mitochondrial ATPase 6 gene. Pediatr Int 2019; 61:1055-1056. [PMID: 31625254 DOI: 10.1111/ped.13991] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/06/2018] [Revised: 02/28/2019] [Accepted: 06/12/2019] [Indexed: 11/29/2022]
Affiliation(s)
- Kazushi Ichikawa
- Division of Neurology, Kanagawa Children's Medical Center, Yokohama, Kanagawa, Japan
| | - Yu Tsuyusaki
- Division of Neurology, Kanagawa Children's Medical Center, Yokohama, Kanagawa, Japan
| | - Hiroko Shimbo
- Division of Neurology, Clinical Research Institute, Kanagawa Children's Medical Center, Yokohama, Kanagawa, Japan
| | - Tomohide Goto
- Division of Neurology, Kanagawa Children's Medical Center, Yokohama, Kanagawa, Japan
| |
Collapse
|
9
|
Ganetzky RD, Stendel C, McCormick EM, Zolkipli-Cunningham Z, Goldstein AC, Klopstock T, Falk MJ. MT-ATP6 mitochondrial disease variants: Phenotypic and biochemical features analysis in 218 published cases and cohort of 14 new cases. Hum Mutat 2019; 40:499-515. [PMID: 30763462 PMCID: PMC6506718 DOI: 10.1002/humu.23723] [Citation(s) in RCA: 59] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2018] [Revised: 01/29/2019] [Accepted: 02/11/2019] [Indexed: 01/30/2023]
Abstract
Mitochondrial complex V (CV) generates cellular energy as adenosine triphosphate (ATP). Mitochondrial disease caused by the m.8993T>G pathogenic variant in the CV subunit gene MT-ATP6 was among the first described human mitochondrial DNA diseases. Due to a lack of clinically available functional assays, validating the definitive pathogenicity of additional MT-ATP6 variants remains challenging. We reviewed all reportedMT-ATP6 disease cases ( n = 218) to date, to assess for MT-ATP6 variants, heteroplasmy levels, and inheritance correlation with clinical presentation and biochemical findings. We further describe the clinical and biochemical features of a new cohort of 14 kindreds with MT-ATP6 variants of uncertain significance. Despite extensive overlap in the heteroplasmy levels of MT-ATP6 variant carriers with and without a wide range of clinical symptoms, previously reported symptomatic subjects had significantly higher heteroplasmy load (p = 2.2 x 10-16 ). Pathogenic MT-ATP6 variants resulted in diverse biochemical features. The most common findings were reduced ATP synthesis rate, preserved ATP hydrolysis capacity, and abnormally increased mitochondrial membrane potential. However, no single biochemical feature was universally observed. Extensive heterogeneity exists among both clinical and biochemical features of distinct MT-ATP6 variants. Improved mechanistic understanding and development of consistent biochemical diagnostic analyses are needed to permit accurate pathogenicity assessment of variants of uncertain significance in MT-ATP6.
Collapse
Affiliation(s)
- Rebecca D. Ganetzky
- Department of Pediatrics, Mitochondrial Medicine Frontier Program, Division of Human Genetics
Children’s Hospital of Philadelphia, Philadelphia, PA 19104 USA
- Department of Pediatrics, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104
USA
| | - Claudia Stendel
- Department of Psychiatry, Ludwig Maximilians University of Munich, Munich, Germany
| | - Elizabeth M. McCormick
- Department of Pediatrics, Mitochondrial Medicine Frontier Program, Division of Human Genetics
Children’s Hospital of Philadelphia, Philadelphia, PA 19104 USA
| | - Zarazuela Zolkipli-Cunningham
- Department of Pediatrics, Mitochondrial Medicine Frontier Program, Division of Human Genetics
Children’s Hospital of Philadelphia, Philadelphia, PA 19104 USA
- Department of Pediatrics, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104
USA
| | - Amy C. Goldstein
- Department of Pediatrics, Mitochondrial Medicine Frontier Program, Division of Human Genetics
Children’s Hospital of Philadelphia, Philadelphia, PA 19104 USA
- Department of Pediatrics, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104
USA
| | - Thomas Klopstock
- Department of Neurology, Ludwig Maximilians University of Munich, Munich, Germany
| | - Marni J. Falk
- Department of Pediatrics, Mitochondrial Medicine Frontier Program, Division of Human Genetics
Children’s Hospital of Philadelphia, Philadelphia, PA 19104 USA
- Department of Pediatrics, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104
USA
| |
Collapse
|
10
|
Chen Z, Zhang F, Xu H. Human mitochondrial DNA diseases and Drosophila models. J Genet Genomics 2019; 46:201-212. [DOI: 10.1016/j.jgg.2019.03.009] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2018] [Revised: 03/05/2019] [Accepted: 03/25/2019] [Indexed: 01/06/2023]
|
11
|
Oh EH, Chae SH, Cho JW, Baik SK, Choi SY, Choi KD, Choi JH. Fatigable ptosis as an initial presentation of adult-onset Leigh syndrome. Neurology 2018; 89:1754. [PMID: 29038134 DOI: 10.1212/wnl.0000000000004528] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Affiliation(s)
- Eun Hye Oh
- From the Departments of Neurology (E.H.O., S.-H.C., J.-W.C., J.-H.C.) and Radiology (S.K.B.), Research Institute for Convergence of Biomedical Science and Technology, Pusan National University School of Medicine, Pusan National University Yangsan Hospital; and Department of Neurology (S.-Y.C., K.-D.C.), Pusan National University School of Medicine and Biomedical Research Institute, Pusan National University Hospital, Busan, South Korea
| | - Song-Hwa Chae
- From the Departments of Neurology (E.H.O., S.-H.C., J.-W.C., J.-H.C.) and Radiology (S.K.B.), Research Institute for Convergence of Biomedical Science and Technology, Pusan National University School of Medicine, Pusan National University Yangsan Hospital; and Department of Neurology (S.-Y.C., K.-D.C.), Pusan National University School of Medicine and Biomedical Research Institute, Pusan National University Hospital, Busan, South Korea
| | - Jae-Wook Cho
- From the Departments of Neurology (E.H.O., S.-H.C., J.-W.C., J.-H.C.) and Radiology (S.K.B.), Research Institute for Convergence of Biomedical Science and Technology, Pusan National University School of Medicine, Pusan National University Yangsan Hospital; and Department of Neurology (S.-Y.C., K.-D.C.), Pusan National University School of Medicine and Biomedical Research Institute, Pusan National University Hospital, Busan, South Korea
| | - Seung Kug Baik
- From the Departments of Neurology (E.H.O., S.-H.C., J.-W.C., J.-H.C.) and Radiology (S.K.B.), Research Institute for Convergence of Biomedical Science and Technology, Pusan National University School of Medicine, Pusan National University Yangsan Hospital; and Department of Neurology (S.-Y.C., K.-D.C.), Pusan National University School of Medicine and Biomedical Research Institute, Pusan National University Hospital, Busan, South Korea
| | - Seo-Young Choi
- From the Departments of Neurology (E.H.O., S.-H.C., J.-W.C., J.-H.C.) and Radiology (S.K.B.), Research Institute for Convergence of Biomedical Science and Technology, Pusan National University School of Medicine, Pusan National University Yangsan Hospital; and Department of Neurology (S.-Y.C., K.-D.C.), Pusan National University School of Medicine and Biomedical Research Institute, Pusan National University Hospital, Busan, South Korea
| | - Kwang-Dong Choi
- From the Departments of Neurology (E.H.O., S.-H.C., J.-W.C., J.-H.C.) and Radiology (S.K.B.), Research Institute for Convergence of Biomedical Science and Technology, Pusan National University School of Medicine, Pusan National University Yangsan Hospital; and Department of Neurology (S.-Y.C., K.-D.C.), Pusan National University School of Medicine and Biomedical Research Institute, Pusan National University Hospital, Busan, South Korea
| | - Jae-Hwan Choi
- From the Departments of Neurology (E.H.O., S.-H.C., J.-W.C., J.-H.C.) and Radiology (S.K.B.), Research Institute for Convergence of Biomedical Science and Technology, Pusan National University School of Medicine, Pusan National University Yangsan Hospital; and Department of Neurology (S.-Y.C., K.-D.C.), Pusan National University School of Medicine and Biomedical Research Institute, Pusan National University Hospital, Busan, South Korea.
| |
Collapse
|
12
|
Wei Y, Wang L. Adult-onset Leigh syndrome with central fever and peripheral neuropathy due to mitochondrial 9176T>C mutation. Neurol Sci 2018; 39:2225-2228. [DOI: 10.1007/s10072-018-3541-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2018] [Accepted: 08/17/2018] [Indexed: 11/29/2022]
|
13
|
Chourasia N, Adejumo R, Patel R, Koenig MK. Reply to the Letter to the Editor by Josef Finsterer and Sinda Zarrouk-Mahjoub. Pediatr Neurol 2018; 78:e11. [PMID: 29169869 DOI: 10.1016/j.pediatrneurol.2017.09.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Affiliation(s)
- Nitish Chourasia
- University of Texas Health Science Center at Houston, Mitochondrial Center of Excellence, Division of Child and Adolescent Neurology, Houston, Texas.
| | - Rahmat Adejumo
- University of Texas Health Science Center at Houston, Mitochondrial Center of Excellence, Division of Child and Adolescent Neurology, Houston, Texas
| | - Rajan Patel
- Department of Diagnostic & Interventional Imaging, Division of Neuroradiology, University of Texas Health Science Center at Houston, Houston, Texas
| | - Mary Kay Koenig
- University of Texas Health Science Center at Houston, Mitochondrial Center of Excellence, Division of Child and Adolescent Neurology, Houston, Texas
| |
Collapse
|
14
|
Panosyan FB, Tawil R, Herrmann DN. Episodic weakness and Charcot-marie-tooth disease due to a mitochondrial MT-ATP6 mutation. Muscle Nerve 2017; 55:922-927. [PMID: 27783406 DOI: 10.1002/mus.25453] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/24/2016] [Indexed: 01/08/2023]
Abstract
INTRODUCTION Episodic muscle weakness is the hallmark of a heterogeneous group of disorders known as periodic paralysis. A majority are due to single nucleotide mutations causing membrane depolarization. METHODS We report 2 family members with chronic, slowly progressive, distal axonal neuropathy, or Charcot-Marie-Tooth disease type 2 (CMT2) and episodic weakness resembling periodic paralysis. RESULTS Next generation sequencing (NGS) identified a mitochondrial MT-ATP6 mutation m.9185T>C (p.Leu220Pro) in both patients, consistent with a previous report of an association with this phenotype. The episodic weakness has been responsive to acetazolamide therapy for a few decades. By contrast, the underlying axonal neuropathy is quite progressive despite treatment with acetazolamide. CONCLUSIONS Mitochondrial DNA mutations should be considered in patients with a history of episodic weakness and axonal inherited neuropathy (CMT2). The episodic weakness is responsive to acetazolamide therapy, and electrophysiological testing for periodic paralysis with a long exercise protocol is negative in these cases. Muscle Nerve 55: 922-927, 2017.
Collapse
Affiliation(s)
- Francis B Panosyan
- Department of Neurology, University of Rochester Medical Center, Box 673, 601 Elmwood Avenue, Rochester, New York, 14642, USA
| | - Rabi Tawil
- Department of Neurology, University of Rochester Medical Center, Box 673, 601 Elmwood Avenue, Rochester, New York, 14642, USA
| | - David N Herrmann
- Department of Neurology, University of Rochester Medical Center, Box 673, 601 Elmwood Avenue, Rochester, New York, 14642, USA
| |
Collapse
|
15
|
Chuquilin M, Govindarajan R, Peck D, Font Montgomery E. Response to letter to the editor: Why does Leigh syndrome responds to immunotherapy? Mol Genet Metab Rep 2016; 8:85-6. [PMID: 27547733 PMCID: PMC4982918 DOI: 10.1016/j.ymgmr.2016.08.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2016] [Revised: 08/02/2016] [Accepted: 08/02/2016] [Indexed: 11/28/2022] Open
Affiliation(s)
- Miguel Chuquilin
- Department of Neurology, University of Florida, HSC Box 100236, Gainesville, FL 32610
| | - Raghav Govindarajan
- Department of Neurology, University of Missouri in Columbia, Five Hospital Drive CE 514, Columbia, MO 65212, USA
| | - Dawn Peck
- Department of Genetics, University of Missouri in Columbia, 404 N Keene St, Suite 101, Columbia, MO 65201, USA
| | - Esperanza Font Montgomery
- Department of Genetics, University of Missouri in Columbia, 404 N Keene St, Suite 101, Columbia, MO 65201, USA
| |
Collapse
|
16
|
Chuquilin M, Govindarajan R, Peck D, Font-Montgomery E. Response to immunotherapy in a patient with adult onset Leigh syndrome and T9176C mtDNA mutation. Mol Genet Metab Rep 2016; 8:28-32. [PMID: 27408822 PMCID: PMC4932611 DOI: 10.1016/j.ymgmr.2016.06.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2016] [Accepted: 06/23/2016] [Indexed: 01/06/2023] Open
Abstract
Leigh syndrome is a mitochondrial disease caused by mutations in different genes, including ATP6A for which no known therapy is available. We report a case of adult-onset Leigh syndrome with response to immunotherapy. A twenty year-old woman with baseline learning difficulties was admitted with progressive behavioral changes, diplopia, headaches, bladder incontinence, and incoordination. Brain MRI and PET scan showed T2 hyperintensity and increased uptake in bilateral basal ganglia, respectively. Autoimmune encephalitis was suspected and she received plasmapheresis with clinical improvement. She was readmitted 4 weeks later with dysphagia and aspiration pneumonia. Plasmapheresis was repeated with resolution of her symptoms. Given the multisystem involvement and suggestive MRI changes, genetic testing was done, revealing a homoplasmic T9176C ATPase 6 gene mtDNA mutation. Monthly IVIG provided clinical improvement with worsening when infusions were delayed. Leigh syndrome secondary to mtDNA T9176C mutations could have an autoimmune mechanism that responds to immunotherapy.
Collapse
Affiliation(s)
- Miguel Chuquilin
- Department of Neurology, University of Missouri in Columbia, Five Hospital Drive CE 537 DC 047.00, Columbia, MO 65212, USA
| | - Raghav Govindarajan
- Department of Neurology, University of Missouri in Columbia, Five Hospital Drive CE 537, Columbia, MO 65212, USA
| | - Dawn Peck
- Department of Genetics, University of Missouri in Columbia, 404 N Keene St, Suite 101, Columbia, MO 65201, USA
| | - Esperanza Font-Montgomery
- Department of Genetics, University of Missouri in Columbia, 404 N Keene St, Suite 101, Columbia, MO 65201, USA
| |
Collapse
|
17
|
Xu T, Pagadala V, Mueller DM. Understanding structure, function, and mutations in the mitochondrial ATP synthase. MICROBIAL CELL 2015; 2:105-125. [PMID: 25938092 PMCID: PMC4415626 DOI: 10.15698/mic2015.04.197] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The mitochondrial ATP synthase is a multimeric enzyme complex with an overall molecular weight of about 600,000 Da. The ATP synthase is a molecular motor composed of two separable parts: F1 and Fo. The F1 portion contains the catalytic sites for ATP synthesis and protrudes into the mitochondrial matrix. Fo forms a proton turbine that is embedded in the inner membrane and connected to the rotor of F1. The flux of protons flowing down a potential gradient powers the rotation of the rotor driving the synthesis of ATP. Thus, the flow of protons though Fo is coupled to the synthesis of ATP. This review will discuss the structure/function relationship in the ATP synthase as determined by biochemical, crystallographic, and genetic studies. An emphasis will be placed on linking the structure/function relationship with understanding how disease causing mutations or putative single nucleotide polymorphisms (SNPs) in genes encoding the subunits of the ATP synthase, will affect the function of the enzyme and the health of the individual. The review will start by summarizing the current understanding of the subunit composition of the enzyme and the role of the subunits followed by a discussion on known mutations and their effect on the activity of the ATP synthase. The review will conclude with a summary of mutations in genes encoding subunits of the ATP synthase that are known to be responsible for human disease, and a brief discussion on SNPs.
Collapse
Affiliation(s)
- Ting Xu
- Department of Biochemistry and Molecular Biology, The Chicago Medical School, Rosalind Franklin University of Medicine and Science, 3333 Green Bay Road, North Chicago, IL 60064
| | - Vijayakanth Pagadala
- Department of Chemical Biology and Medicinal Chemistry, Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, NC
| | - David M Mueller
- Department of Biochemistry and Molecular Biology, The Chicago Medical School, Rosalind Franklin University of Medicine and Science, 3333 Green Bay Road, North Chicago, IL 60064
| |
Collapse
|
18
|
O'Callaghan MM, Emperador S, Pineda M, López-Gallardo E, Montero R, Yubero D, Jou C, Jimenez-Mallebrera C, Nascimento A, Ferrer I, García-Cazorla A, Ruiz-Pesini E, Montoya J, Artuch R. Mutation loads in different tissues from six pathogenic mtDNA point mutations. Mitochondrion 2015; 22:17-22. [PMID: 25765153 DOI: 10.1016/j.mito.2015.03.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2014] [Revised: 01/30/2015] [Accepted: 03/03/2015] [Indexed: 01/30/2023]
Abstract
In this work, we studied the mtDNA mutations m.3243A>G, m.3252A>G, m.15923A>G, m.13513G>A, m.8993T>G and m.9176T>C in the blood, urine and buccal mucosa of a cohort of 27 subjects. Urine cells had the highest mutation load for all of the mtDNA mutations studied. The mutation loads in the blood, urine and the buccal mucosa were significantly higher in the mitochondrial disorder group that manifested clinical signs than in the asymptomatic subjects. In conclusion, urine is a suitable biological sample for molecular diagnosis of mtDNA mutations and for the study of the attendant risk of recurrence in the offspring of asymptomatic mothers identified as non-carriers after mutation analysis in blood.
Collapse
Affiliation(s)
- María M O'Callaghan
- Departamentos de Neurología, Bioquímica Clínica y de Patología, Hospital Sant Joan de Déu, Barcelona, Spain; Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Instituto de Salud Carlos III, Spain
| | - Sonia Emperador
- Departamento de Bioquímica, Biología Molecular y Celular, Universidad de Zaragoza, Instituto Aragonés de Ciencias de la Salud, Spain; Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Instituto de Salud Carlos III, Spain
| | - Mercè Pineda
- Departamentos de Neurología, Bioquímica Clínica y de Patología, Hospital Sant Joan de Déu, Barcelona, Spain; Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Instituto de Salud Carlos III, Spain
| | - Ester López-Gallardo
- Departamento de Bioquímica, Biología Molecular y Celular, Universidad de Zaragoza, Instituto Aragonés de Ciencias de la Salud, Spain; Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Instituto de Salud Carlos III, Spain
| | - Raquel Montero
- Departamentos de Neurología, Bioquímica Clínica y de Patología, Hospital Sant Joan de Déu, Barcelona, Spain; Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Instituto de Salud Carlos III, Spain
| | - Delia Yubero
- Departamentos de Neurología, Bioquímica Clínica y de Patología, Hospital Sant Joan de Déu, Barcelona, Spain
| | - Cristina Jou
- Departamentos de Neurología, Bioquímica Clínica y de Patología, Hospital Sant Joan de Déu, Barcelona, Spain
| | - Cecilia Jimenez-Mallebrera
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Instituto de Salud Carlos III, Spain; Unidad de Patologia Neuromuscular, Hospital Sant Joan de Deu, Barcelona, Spain
| | - Andrés Nascimento
- Departamentos de Neurología, Bioquímica Clínica y de Patología, Hospital Sant Joan de Déu, Barcelona, Spain; Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Instituto de Salud Carlos III, Spain
| | - Isidre Ferrer
- Instituto de Neuropatología, Hospital Universitario de Bellvitge, Hospitalet de Llobregat, Centro de Investigación Biomédica de Enfermedades Neurodegenerativas (CIBERNED), Spain
| | - Angels García-Cazorla
- Departamentos de Neurología, Bioquímica Clínica y de Patología, Hospital Sant Joan de Déu, Barcelona, Spain; Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Instituto de Salud Carlos III, Spain
| | - Eduardo Ruiz-Pesini
- Departamento de Bioquímica, Biología Molecular y Celular, Universidad de Zaragoza, Instituto Aragonés de Ciencias de la Salud, Spain; Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Instituto de Salud Carlos III, Spain
| | - Julio Montoya
- Departamento de Bioquímica, Biología Molecular y Celular, Universidad de Zaragoza, Instituto Aragonés de Ciencias de la Salud, Spain; Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Instituto de Salud Carlos III, Spain
| | - Rafael Artuch
- Departamentos de Neurología, Bioquímica Clínica y de Patología, Hospital Sant Joan de Déu, Barcelona, Spain; Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Instituto de Salud Carlos III, Spain.
| |
Collapse
|
19
|
Nesbitt V, Alston CL, Blakely EL, Fratter C, Feeney CL, Poulton J, Brown GK, Turnbull DM, Taylor RW, McFarland R. A national perspective on prenatal testing for mitochondrial disease. Eur J Hum Genet 2014; 22:1255-9. [PMID: 24642831 PMCID: PMC4200441 DOI: 10.1038/ejhg.2014.35] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2013] [Revised: 12/17/2013] [Accepted: 01/16/2014] [Indexed: 01/30/2023] Open
Abstract
Mitochondrial diseases affect >1 in 7500 live births and may be due to mutations in either mitochondrial DNA (mtDNA) or nuclear DNA (nDNA). Genetic counselling for families with mitochondrial diseases, especially those due to mtDNA mutations, provides unique and difficult challenges particularly in relation to disease transmission and prevention. We have experienced an increasing demand for prenatal diagnostic testing from families affected by mitochondrial disease since we first offered this service in 2007. We review the diagnostic records of the 62 prenatal samples (17 mtDNA and 45 nDNA) analysed since 2007, the reasons for testing, mutation investigated and the clinical outcome. Our findings indicate that prenatal testing for mitochondrial disease is reliable and informative for the nuclear and selected mtDNA mutations we have tested. Where available, the results of mtDNA heteroplasmy analyses from other family members are helpful in interpreting the prenatal mtDNA test result. This is particularly important when the mutation is rare or the mtDNA heteroplasmy is observed at intermediate levels. At least 11 cases of mitochondrial disease were prevented following prenatal testing, 3 of which were mtDNA disease. On the basis of our results, we believe that prenatal testing for mitochondrial disease is an important option for couples where appropriate genetic analyses and pre/post-test counselling can be provided.
Collapse
Affiliation(s)
- Victoria Nesbitt
- Wellcome Trust Centre for Mitochondrial Research, The Medical School, Institute for Ageing and Health, Newcastle University, Newcastle-upon-Tyne, UK
| | - Charlotte L Alston
- NHS Specialised Services for Rare Mitochondrial Disorders of Adults and Children UK, Oxford, UK
| | - Emma L Blakely
- NHS Specialised Services for Rare Mitochondrial Disorders of Adults and Children UK, Oxford, UK
| | - Carl Fratter
- NHS Specialised Services for Rare Mitochondrial Disorders of Adults and Children UK, Oxford, UK
- Oxford Medical Genetics Laboratories, Oxford University Hospitals NHS Trust, Oxford, UK
| | - Catherine L Feeney
- NHS Specialised Services for Rare Mitochondrial Disorders of Adults and Children UK, Oxford, UK
| | - Joanna Poulton
- NHS Specialised Services for Rare Mitochondrial Disorders of Adults and Children UK, Oxford, UK
- Nuffield Department of Obstetrics and Gynaecology, University of Oxford, John Radcliffe Hospital, Oxford, UK
| | - Garry K Brown
- NHS Specialised Services for Rare Mitochondrial Disorders of Adults and Children UK, Oxford, UK
- Department of Biochemistry, University of Oxford, Oxford, UK
| | - Doug M Turnbull
- Wellcome Trust Centre for Mitochondrial Research, The Medical School, Institute for Ageing and Health, Newcastle University, Newcastle-upon-Tyne, UK
- NHS Specialised Services for Rare Mitochondrial Disorders of Adults and Children UK, Oxford, UK
| | - Robert W Taylor
- Wellcome Trust Centre for Mitochondrial Research, The Medical School, Institute for Ageing and Health, Newcastle University, Newcastle-upon-Tyne, UK
- NHS Specialised Services for Rare Mitochondrial Disorders of Adults and Children UK, Oxford, UK
| | - Robert McFarland
- Wellcome Trust Centre for Mitochondrial Research, The Medical School, Institute for Ageing and Health, Newcastle University, Newcastle-upon-Tyne, UK
- NHS Specialised Services for Rare Mitochondrial Disorders of Adults and Children UK, Oxford, UK
| |
Collapse
|
20
|
Tang S, Wang J, Zhang VW, Li FY, Landsverk M, Cui H, Truong CK, Wang G, Chen LC, Graham B, Scaglia F, Schmitt ES, Craigen WJ, Wong LJC. Transition to next generation analysis of the whole mitochondrial genome: a summary of molecular defects. Hum Mutat 2013; 34:882-93. [PMID: 23463613 DOI: 10.1002/humu.22307] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2012] [Accepted: 02/15/2013] [Indexed: 01/06/2023]
Abstract
The diagnosis of mitochondrial disorders is challenging because of the clinical variability and genetic heterogeneity. Conventional analysis of the mitochondrial genome often starts with a screening panel for common mitochondrial DNA (mtDNA) point mutations and large deletions (mtScreen). If negative, it has been traditionally followed by Sanger sequencing of the entire mitochondrial genome (mtWGS). The recently developed "Next-Generation Sequencing" (NGS) technology offers a robust high-throughput platform for comprehensive mtDNA analysis. Here, we summarize the results of the past 6 years of clinical practice using the mtScreen and mtWGS tests on 9,261 and 2,851 unrelated patients, respectively. A total of 344 patients (3.7%) had mutations identified by mtScreen and 99 (3.5%) had mtDNA mutations identified by mtWGS. The combinatorial analyses of mtDNA and POLG revealed a diagnostic yield of 6.7% in patients with suspected mitochondrial disorders but no recognizable syndromes. From the initial mtWGS-NGS cohort of 391 patients, 21 mutation-positive cases (5.4%) have been identified. The mtWGS-NGS provides a one-step approach to detect common and uncommon point mutations, as well as deletions. Additionally, NGS provides accurate, sensitive heteroplasmy measurement, and the ability to map deletion breakpoints. A new era of more efficient molecular diagnosis of mtDNA mutations has arrived.
Collapse
Affiliation(s)
- Sha Tang
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas 77030, USA
| | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
21
|
Unusual adult-onset Leigh syndrome presentation due to the mitochondrial m.9176T>C mutation. Biochem Biophys Res Commun 2011; 412:245-8. [DOI: 10.1016/j.bbrc.2011.07.076] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2011] [Accepted: 07/19/2011] [Indexed: 11/18/2022]
|
22
|
Verny C, Guegen N, Desquiret V, Chevrollier A, Prundean A, Dubas F, Cassereau J, Ferre M, Amati-Bonneau P, Bonneau D, Reynier P, Procaccio V. Hereditary spastic paraplegia-like disorder due to a mitochondrial ATP6 gene point mutation. Mitochondrion 2010; 11:70-5. [PMID: 20656066 DOI: 10.1016/j.mito.2010.07.006] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2010] [Revised: 07/11/2010] [Accepted: 07/14/2010] [Indexed: 01/22/2023]
Abstract
Hereditary spastic paraplegia refers to a genetically heterogeneous syndrome. We identified five members of a family suffering from a late-onset spastic paraplegia-like disorder, carrying the homoplasmic m.9176 T>C mutation in the mitochondrial ATP6 gene. The clinical severity of the disease observed in the family was correlated with the biochemical and assembly defects of the ATP synthase. The m.9176 T>C mutation has been previously associated to Leigh syndrome or familial bilateral striatal necrosis. Other factors such as modifying genes may be involved in the phenotypic expression of the disease. The family belongs to the mitochondrial haplogroup J, previously shown to play a role in modulating the phenotype of mitochondrial diseases and be associated with longevity. Moreover other nuclear modifying genes or environmental factors may contribute to the disease phenotype. This finding extends the genetic heterogeneity of the hereditary spastic paraplegia together with the clinical spectrum of mutations of the ATP6 gene.
Collapse
Affiliation(s)
- Christophe Verny
- Department of Neurology, Angers University Hospital, School of Medicine, Angers F-49000, France
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
23
|
Modeling mitochondrial encephalomyopathy in Drosophila. Neurobiol Dis 2010; 40:40-5. [PMID: 20472065 DOI: 10.1016/j.nbd.2010.05.009] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2010] [Revised: 05/04/2010] [Accepted: 05/06/2010] [Indexed: 11/21/2022] Open
Abstract
Mitochondrial encephalomyopathies are disturbingly complex and devastating diseases, reflecting the underlying importance of the affected organelle. Therapeutic approaches for these diseases remain limited due to a poor understanding of disease pathogenesis resulting largely from a lack of tractable model systems in which to study these diseases. This is especially so for disease conditions resulting from mutations directly affecting the mitochondrial genome. Recent studies using Drosophila to develop genetic models with endogenous mitochondrial mutations suggest the fruit fly will contribute significantly to our understanding of mitochondrial disease pathogenesis and the development of novel therapeutic avenues.
Collapse
|
24
|
Abstract
Mitochondrial disorders (MIDs) are an increasingly recognized condition. The second most frequently affected organ in MIDs is the central nervous system. One of the most prevalent clinical CNS manifestations of MIDs is ataxia. Ataxia may be even the dominant manifestation of a MID. This is why certain MIDs should be included in the classification of heredoataxias or at least considered as differentials of classical heredoataxias. MIDs due to mutations of the mitochondrial DNA, which develop ataxia include the MERRF, NARP, MILS, or KSS syndrome. More rarely, ataxia may be a feature of MELAS, LHON, PS, MIDD, or MSL. MIDs due to mutations of the nuclear DNA, which develop ataxia include LS, SANDO, SCAE, AHS, XSLA/A, IOSCA, MIRAS, MEMSA, or LBSL syndrome. More rarely ataxia can be found in AD-CPEO, AR-CPEO, MNGIE, DIDMOAD, CoQ-deficiency, ADOAD, DCMA, or PDC-deficiency. MIDs most frequently associated with ataxia are the non-syndromic MIDs. Syndromic and non-syndromic MIDs with ataxia should be delineated from classical heredoataxias to initiate appropriate symptomatic or supportive treatment.
Collapse
|
25
|
Vazquez-Memije ME, Rizza T, Meschini MC, Nesti C, Santorelli FM, Carrozzo R. Cellular and functional analysis of four mutations located in the mitochondrial ATPase6 gene. J Cell Biochem 2009; 106:878-86. [PMID: 19160410 DOI: 10.1002/jcb.22055] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The smallest rotary motor of living cells, F0F1-ATP synthase, couples proton flow-generated by the OXPHOS system-from the intermembrane space back to the matrix with the conversion of ADP to ATP. While all mutations affecting the multisubunit complexes of the OXPHOS system probably impact on the cell's output of ATP, only mutations in complex V can be considered to affect this output directly. So far, most of the F0F1-ATP synthase variations have been detected in the mitochondrial ATPase6 gene. In this study, the four most frequent mutations in the ATPase6 gene, namely L156R, L217R, L156P, and L217P, are studied for the first time together, both in primary cells and in cybrid clones. Arginine ("R") mutations were associated with a much more severe phenotype than Proline ("P") mutations, in terms of both biochemical activity and growth capacity. Also, a threshold effect in both "R" mutations appeared at 50% mutation load. Different mechanisms seemed to emerge for the two "R" mutations: the F1 seemed loosely bound to the membrane in the L156R mutant, whereas the L217R mutant induced low activity of complex V, possibly the result of a reduced rate of proton flow through the A6 channel.
Collapse
Affiliation(s)
- Martha Elisa Vazquez-Memije
- Unidad de Investigacion Medica en Genetica, Centro Medico Nacional, Instituto Mexicano del Seguro Social, Mexico City, Mexico
| | | | | | | | | | | |
Collapse
|
26
|
Abstract
Leigh syndrome (also termed subacute, necrotizing encephalopathy) is a devastating neurodegenerative disorder, characterized by almost identical brain changes, e.g., focal, bilaterally symmetric lesions, particularly in the basal ganglia, thalamus, and brainstem, but with considerable clinical and genetic heterogeneity. Clinically, Leigh syndrome is characterized by a wide variety of abnormalities, from severe neurologic problems to a near absence of abnormalities. Most frequently the central nervous system is affected, with psychomotor retardation, seizures, nystagmus, ophthalmoparesis, optic atrophy, ataxia, dystonia, or respiratory failure. Some patients also present with peripheral nervous system involvement, including polyneuropathy or myopathy, or non-neurologic abnormalities, e.g., diabetes, short stature, hypertrichosis, cardiomyopathy, anemia, renal failure, vomiting, or diarrhea (Leigh-like syndrome). In the majority of cases, onset is in early childhood, but in a small number of cases, adults are affected. In the majority of cases, dysfunction of the respiratory chain (particularly complexes I, II, IV, or V), of coenzyme Q, or of the pyruvate dehydrogenase complex are responsible for the disease. Associated mutations affect genes of the mitochondrial or nuclear genome. Leigh syndrome and Leigh-like syndrome are the mitochondrial disorders with the largest genetic heterogeneity.
Collapse
|
27
|
Finsterer J. Cognitive decline as a manifestation of mitochondrial disorders (mitochondrial dementia). J Neurol Sci 2008; 272:20-33. [DOI: 10.1016/j.jns.2008.05.011] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2007] [Revised: 05/18/2008] [Accepted: 05/20/2008] [Indexed: 11/28/2022]
|
28
|
Kucharczyk R, Zick M, Bietenhader M, Rak M, Couplan E, Blondel M, Caubet SD, di Rago JP. Mitochondrial ATP synthase disorders: molecular mechanisms and the quest for curative therapeutic approaches. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2008; 1793:186-99. [PMID: 18620007 DOI: 10.1016/j.bbamcr.2008.06.012] [Citation(s) in RCA: 89] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2008] [Revised: 06/06/2008] [Accepted: 06/11/2008] [Indexed: 01/09/2023]
Abstract
In mammals, the majority of cellular ATP is produced by the mitochondrial F1F(O)-ATP synthase through an elaborate catalytic mechanism. While most subunits of this enzymatic complex are encoded by the nuclear genome, a few essential components are encoded in the mitochondrial genome. The biogenesis of this multi-subunit enzyme is a sophisticated multi-step process that is regulated on levels of transcription, translation and assembly. Defects that result in diminished abundance or functional impairment of the F1F(O)-ATP synthase can cause a variety of severe neuromuscular disorders. Underlying mutations have been identified in both the nuclear and the mitochondrial DNA. The pathogenic mechanisms are only partially understood. Currently, the therapeutic options are extremely limited. Alternative methods of treatment have however been proposed, but still encounter several technical difficulties. The application of novel scientific approaches promises to deepen our understanding of the molecular mechanisms of the ATP synthase, unravel novel therapeutic pathways and improve the unfortunate situation of the patients suffering from such diseases.
Collapse
Affiliation(s)
- Roza Kucharczyk
- Institut de Biochimie et Génétique Cellulaires, CNRS-Université Bordeaux2, Bordeaux 33077, France
| | | | | | | | | | | | | | | |
Collapse
|
29
|
Lee HF, Lee HJ, Chi CS, Tsai CR, Chang TK, Wang CJ. The neurological evolution of Pearson syndrome: case report and literature review. Eur J Paediatr Neurol 2007; 11:208-14. [PMID: 17434771 DOI: 10.1016/j.ejpn.2006.12.008] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/04/2006] [Revised: 12/03/2006] [Accepted: 12/11/2006] [Indexed: 11/30/2022]
Abstract
BACKGROUND Pearson syndrome (PS) is an uncommon specific syndrome among mitochondrial diseases. It has unique clinical presentations. AIMS The purpose of this article is to clarify the neurological evolution, neuroimage findings, molecular genetic analysis and outcomes in PS cases with neurologic manifestations. METHODS We described the clinical progress of a female patient who was diagnosed as PS with a novel 6.0 kbp mitochondrial DNA deletion. She had typical clinical features of PS in early infancy followed by multiple organs involvement after the age of 1 year. At age 3, Kearns-Sayre syndrome (KSS) and Leigh syndrome (LS) developed. We also reviewed PS cases reported in the literature and analyzed the neurological evolution. RESULTS Total 55 PS cases, including our index case, had been reported. Among them, 11 cases had detailed clinical descriptions in terms of hypotonia, developmental delay, ataxia or tremor. In whom, PS might evolve into KSS and/or LS: three cases evolving into KSS; one case on the transition of KSS; three cases evolve into LS; our index case has both presentations. The neuroimage findings of PS were quite different which might be from normal to specific abnormal findings over the cerebral white matter, cerebellum, basal ganglion and brainstem. Among those cases, the molecular analysis revealed large-scale mitochondrial deletion around 3.1-6.0kbp. The outcome of PS was opposite: either early death before age 4 or survived beyond age 7. CONCLUSIONS The neurological features of PS have potential evolution changes that are from normal, mild neurological deficits to special mitochondrial syndromes: KSS and LS. Closely monitoring neurological symptoms, arranging eye fundus examinations and neuroimaging studies in cases with changes of neurological signs are crucial.
Collapse
Affiliation(s)
- Hsiu-Fen Lee
- Department of Pediatrics, Taichung Veterans General Hospital, No. 160, Sec. 3 Taichung-Kang Road, Taichung 407, Taiwan, ROC
| | | | | | | | | | | |
Collapse
|
30
|
Castagna AE, Addis J, McInnes RR, Clarke JTR, Ashby P, Blaser S, Robinson BH. Late onset Leigh syndrome and ataxia due to a T to C mutation at bp 9,185 of mitochondrial DNA. Am J Med Genet A 2007; 143A:808-16. [PMID: 17352390 DOI: 10.1002/ajmg.a.31637] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
A T-to-C missense mutation at nucleotide position 9,185 in the protein-coding ATP6 gene of the mitochondrial genome was present at high heteroplasmy in members of a Canadian family with Leigh syndrome with predominant ataxia and peripheral neuropathy. This mutation results in the substitution of a proline residue for an evolutionary-conserved leucine at position of amino acid 220 near the carboxyl terminus of the mitochondrial protein. The index patient and brother, who had an identical clinical presentation, had >90% mutant mtDNA in cultured skin fibroblasts, lymphocytes, and whole blood. Their mother and a maternal uncle, symptomatic with a peripheral neuropathy alone, had 86% and 85% heteroplasmy, respectively. Symptomatic maternal cousins with early onset revealed 90% and 91% mutant mtDNA in all tissues analyzed. Studies of lymphoblasts from the asymptomatic maternal grandmother and eldest brother of the proband were heteroplasmic for mutant mtDNA with 56% and 17%, respectively. Biochemical analysis demonstrated normal respiratory chain enzyme activity in muscle and fibroblasts, normal ATP synthesis, but reduced oligomycin-sensitive H(+)ATPase in cultured lymphoblast mitochondria. We propose that the 9,185T > C mtDNA mutation is pathogenic even though the initial phenotype is mild and the biochemical phenotype not easily detectable.
Collapse
Affiliation(s)
- Avril E Castagna
- Scarborough General Hospital, Hospital for Sick Children, Toronto, Ontario
| | | | | | | | | | | | | |
Collapse
|
31
|
Abstract
The central nervous system (CNS) is, after the peripheral nervous system, the second most frequently affected organ in mitochondrial disorders (MCDs). CNS involvement in MCDs is clinically heterogeneous, manifesting as epilepsy, stroke-like episodes, migraine, ataxia, spasticity, extrapyramidal abnormalities, bulbar dysfunction, psychiatric abnormalities, neuropsychological deficits, or hypophysial abnormalities. CNS involvement is found in syndromic and non-syndromic MCDs. Syndromic MCDs with CNS involvement include mitochondrial encephalomyopathy, lactacidosis, stroke-like episodes syndrome, myoclonic epilepsy and ragged red fibers syndrome, mitochondrial neuro-gastrointestinal encephalomyopathy syndrome, neurogenic muscle weakness, ataxia, and retinitis pigmentosa syndrome, mitochondrial depletion syndrome, Kearns-Sayre syndrome, and Leigh syndrome, Leber's hereditary optic neuropathy, Friedreich's ataxia, and multiple systemic lipomatosis. As CNS involvement is often subclinical, the CNS including the spinal cord should be investigated even in the absence of overt clinical CNS manifestations. CNS investigations comprise the history, clinical neurological examination, neuropsychological tests, electroencephalogram, cerebral computed tomography scan, and magnetic resonance imaging. A spinal tap is indicated if there is episodic or permanent impaired consciousness or in case of cognitive decline. More sophisticated methods are required if the CNS is solely affected. Treatment of CNS manifestations in MCDs is symptomatic and focused on epilepsy, headache, lactacidosis, impaired consciousness, confusion, spasticity, extrapyramidal abnormalities, or depression. Valproate, carbamazepine, corticosteroids, acetyl salicylic acid, local and volatile anesthetics should be applied with caution. Avoiding certain drugs is often more beneficial than application of established, apparently indicated drugs.
Collapse
Affiliation(s)
- J Finsterer
- Krankenanstalt Rudolfstiftung, Vienna, Austria.
| |
Collapse
|
32
|
Abstract
A growing body of evidence indicates that mitochondrial dysfunction may play an important role in the pathogenesis of many neurodegenerative disorders. Because mitochondrial metabolism is not only the principal source of high energy intermediates, but also of free radicals, it has been suggested that inherited or acquired mitochondrial defects could be the cause of neuronal degeneration as a consequence of energy defects and oxidative damage. Mitochondrial respiratory chain dysfunction has been reported in association with primary mitochondrial DNA abnormalities, and also as a consequence of mutations in nuclear genes directly involved in mitochondrial functions, such as SURF1, frataxin, and paraplegin. Defects of oxidative phosphorylation and increased free radical production have also been observed in diseases that are not due to primary mitochondrial abnormalities. In these cases, the mitochondrial dysfunction is likely to be an epiphenomenon, which, nevertheless, could be of importance in precipitating a cascade of events leading to cell death. In either case, understanding the role of mitochondria in the pathogenesis of neurodegenerative diseases could be important for the development of therapeutic strategies in these disorders.
Collapse
Affiliation(s)
- G Manfredi
- Department of Neurology and Neuroscience, Weill Medical College of Cornell University and the New York Hospital, Cornell Medical Center, New York 10021, USA.
| | | |
Collapse
|
33
|
Celotto AM, Frank AC, McGrath SW, Fergestad T, Van Voorhies WA, Buttle KF, Mannella CA, Palladino MJ. Mitochondrial encephalomyopathy in Drosophila. J Neurosci 2006; 26:810-20. [PMID: 16421301 PMCID: PMC6675365 DOI: 10.1523/jneurosci.4162-05.2006] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Mitochondrial encephalomyopathies are common and devastating multisystem genetic disorders characterized by neuromuscular dysfunction and tissue degeneration. Point mutations in the human mitochondrial ATP6 gene are known to cause several related mitochondrial disorders: NARP (neuropathy, ataxia, and retinitis pigmentosa), MILS (maternally inherited Leigh's syndrome), and FBSN (familial bilateral striatal necrosis). We identified a pathogenic mutation in the Drosophila mitochondrial ATP6 gene that causes progressive, adult-onset neuromuscular dysfunction and myodegeneration. Our results demonstrate ultrastructural defects in the mitochondrial innermembrane, neural dysfunction, and a marked reduction in mitochondrial ATP synthase activity associated with this mutation. This Drosophila mutant recapitulates key features of the human neuromuscular disorders enabling detailed in vivo studies of these enigmatic diseases.
Collapse
Affiliation(s)
- Alicia M Celotto
- Department of Pharmacology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15261, USA
| | | | | | | | | | | | | | | |
Collapse
|
34
|
Tzen CY, Wu TY. Evolutional Analysis in Determining Pathogenic versus Nonpathogenic Mutations of ATPase 6 in Human Mitochondriopathy. Ann N Y Acad Sci 2006; 1042:19-24. [PMID: 15965041 DOI: 10.1196/annals.1338.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Because mitochondrial ATPase 6 plays an important role in ATP synthesis, mutations affecting ATPase 6 can undoubtedly cause human diseases. In contrast, the ATPase 6 gene is known to be a fast-evolving gene and has generated enough polymorphisms to allow identity investigation for forensic casework. To investigate these seemingly opposite views, we analyzed amino acid sequences of ATPase 6 in at least 1,266 humans, 102 mammals, and 213 vertebrates. The result showed that the amino acids of human ATPase 6 could be divided into the following four groups. Amino acid residue 192 (affected by alteration at nt 9101) and 79 other residues were variable, and therefore substitutions of these residues would not be pathogenic. Amino acid residue 156 (affected by alteration at nt 8993) and 93 other residues were conserved in Homo sapiens, but not in Mammalia. Therefore, they were potentially pathogenic if altered. Function studies would be necessary to confirm their role in pathogenesis. Amino acid residue 217 (affected by alteration at nt 9176) and 9 other residues were conserved across all species, including S. cerevisiae and E. coli. Mutations involving these residues would be pathogenic, some of which might even be life threatening. The remainder (42 residues) were conserved in Mammalia, but not in yeast and E. coli. They were probably pathogenic if mutated. The classification proposed in this study may, therefore, provide an algorithm for a diagnostic approach when a newly identified change of ATPase 6 is suspected for human mitochondriopathy.
Collapse
Affiliation(s)
- Chin-Yuan Tzen
- Department of Pathology, Mackay Memorial Hospital, 45, Minsheng Road, Tamshui, Taipei 251, Taiwan.
| | | |
Collapse
|
35
|
Bhat VB, Choi MH, Wishnok JS, Tannenbaum SR. Comparative plasma proteome analysis of lymphoma-bearing SJL mice. J Proteome Res 2006; 4:1814-25. [PMID: 16212437 DOI: 10.1021/pr0501463] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
In SJL mice, growth of RcsX lymphoma cells induces an inflammatory response by stimulating V(beta)16+ T cells. During inflammation, various serum protein levels can increase (e.g., acute phase reactants) or decrease (e.g., albumin), and most of these altered proteins are thus potential biomarkers. Although blood plasma is a valuable and promising sample for biomarker discovery for diseases or for novel drug targets, its proteome is complex. To address this, we have focused on a comprehensive comparison of the plasma proteomes from normal and RcsX-tumor-bearing SJL mice using the 1D-Gel-LC-MS/MS method after removing albumin and immunoglobulins. This analysis resulted in the identification of a total of 1079 nonredundant mouse plasma proteins; more than 480 in normal and 790 in RcsX-tumor-bearing SJL mouse plasma. Of these, only 191 proteins were found in common. The molecular weights ranged from 2 to 876 kDa, covering the pI values between 4.22 and 12.09, and included proteins with predicted transmembrane domains. By comparing the plasma proteomic profile of normal and RcsX-tumor-bearing SJL mice, we found significant changes in the levels of many proteins in RcsX-tumor-bearing mouse plasma. Most of the up-regulated proteins were identified as acute-phase proteins (APPs). Also, several unique proteins i.e., haptoglobin, proteosome subunits, fetuin-B, 14-3-3 zeta, MAGE-B4 antigen, etc, were found only in the tumor-bearing mouse plasma; either secreted, shed by membrane vesicles, or externalized due to cell death. These results affirm the effectiveness of this approach for protein identification from small samples, and for comparative proteomics in potential animal models of human disorders.
Collapse
Affiliation(s)
- Vadiraja B Bhat
- Biological Engineering Division and Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, 56-731A, Cambridge, MA 02139, USA
| | | | | | | |
Collapse
|
36
|
Leshinsky-Silver E, Lev D, Tzofi-Berman Z, Cohen S, Saada A, Yanoov-Sharav M, Gilad E, Lerman-Sagie T. Fulminant neurological deterioration in a neonate with Leigh syndrome due to a maternally transmitted missense mutation in the mitochondrial ND3 gene. Biochem Biophys Res Commun 2005; 334:582-7. [PMID: 16023078 DOI: 10.1016/j.bbrc.2005.06.134] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2005] [Accepted: 06/20/2005] [Indexed: 10/25/2022]
Abstract
Leigh syndrome can result from both nuclear and mitochondrial DNA defects. Mutations in complex V genes of the respiratory chain were considered until recently as the most frequent cause for mitochondrial inherited Leigh syndrome, while gene defects in complex I were related to recessive Leigh syndrome. Recently few reports of mutations in the mitochondrial-encoded complex I subunit genes causing Leigh syndrome have been reported. We describe a 1-month-old baby who acutely deteriorated, with abrupt onset of brainstem dysfunction, due to basal ganglia lesions extending to the brainstem. A muscle biopsy demonstrated complex I deficiency. Subsequent analysis of the mitochondrial genome revealed a homoplastic T10191C mutation in the ND3 gene (in blood and muscle), resulting in a substitution of serine to proline. Hair root analysis revealed a 50% mutant load, reflecting heteroplasmy in early embryonic stages. The mutation was also detected in his mother (5%). Western blot analysis revealed a decrease of the 20 kDa subunit (likely ND6) and of the 30 kDa subunit (NDUFA9), which is probably due to instability attributed to the inability to form subcomplexes with ND3. This is the first description of infantile Leigh syndrome due to a maternally transmitted T10191C substitution in ND3 and not due to a de novo mutation. This mutation is age and tissue dependent and therefore may not be amenable to prenatal testing.
Collapse
|
37
|
Jacobs LJAM, de Coo IFM, Nijland JG, Galjaard RJH, Los FJ, Schoonderwoerd K, Niermeijer MF, Geraedts JPM, Scholte HR, Smeets HJM. Transmission and prenatal diagnosis of the T9176C mitochondrial DNA mutation. Mol Hum Reprod 2005; 11:223-8. [PMID: 15709156 DOI: 10.1093/molehr/gah152] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
A family presented with three affected children with Leigh syndrome, a progressive neurodegenerative disorder. Analysis of the OXPHOS complexes in muscle of two affected patients showed an increase in activity of pyruvate dehydrogenase and a decrease of complex V activity. Mutation analysis revealed the T9176C mutation in the mtATPase 6 gene (OMIM 516060) and the mutation load was above 90% in the patients. Unaffected maternal relatives were tested for carrier-ship and one of them, with a mutation load of 55% in blood, was pregnant with her first child. The possibility of prenatal diagnosis was evaluated. The main problem was the lack of data on genotype-phenotype associations for the T9176C mutation and on variation of the mutation percentage in tissues and in time. Therefore, multiple tissues of affected and unaffected carriers were analysed. Eventually, prenatal diagnosis was offered with understanding by the couple that there could be considerable uncertainty in the interpretation of the results. Prenatal diagnosis was carried out twice on cultured and uncultured chorion villi and amniotic fluid cells. The result was a mutation percentage just below the assumed threshold of expression (90%). The couple decided to continue the pregnancy and an apparently healthy child was born with an as yet unclear prognosis. This is the first prenatal diagnosis for a carrier of the T9176C mutation. Prenatal diagnosis for this mutation is technically reliable, but the prognostic predictions are not straightforward.
Collapse
Affiliation(s)
- L J A M Jacobs
- Department of Genetics and Cell Biology, Research Institute GROW, University of Maastricht, Maastricht, The Netherlands
| | | | | | | | | | | | | | | | | | | |
Collapse
|
38
|
Lerman-Sagie T, Leshinsky-Silver E, Watemberg N, Luckman Y, Lev D. White matter involvement in mitochondrial diseases. Mol Genet Metab 2005; 84:127-36. [PMID: 15670718 DOI: 10.1016/j.ymgme.2004.09.008] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/13/2004] [Revised: 09/20/2004] [Accepted: 09/21/2004] [Indexed: 10/26/2022]
Abstract
White matter involvement is recently being realized as a common finding in mitochondrial disorders. It is considered an inherent part of the classical mitochondrial syndromes which are usually associated with alterations in the mitochondrial DNA such as: Leigh disease, Kearns-Sayre syndrome, mitochondrial encephalomyopathy lactic acidosis, and stroke like episodes, mitochondrial neuro-gastro-intestinal encephalomyopathy and Leber's hereditary optic neuropathy. White matter involvement is also described in mitochondrial disorders due to mutations in the nuclear DNA which are transmitted in an autosomal pattern. MRI findings suggestive of a mitochondrial disease are: small cyst-like lesions in abnormal white matter, involvement of both cerebral and cerebellar white matter, and a combination of a leukoencephalopathy with bilateral basal ganglia lesions. The clinical manifestations may be disproportionate to the extent of white matter involvement. Other organs may frequently be involved. The onset is often in infancy with a neurodegenerative course. The finding of a leukoencephalopathy in a patient with a complex neurologic picture and multisystem involvement should prompt a thorough mitochondrial evaluation.
Collapse
Affiliation(s)
- Tally Lerman-Sagie
- The Mitochondrial Disease Clinic, Metabolic-Neurogenetic Service, Wolfson Medical Center, Pediatric Neurology Unit, Holon, Israel.
| | | | | | | | | |
Collapse
|
39
|
Moraes CT, Atencio DP, Oca-Cossio J, Diaz F. Techniques and pitfalls in the detection of pathogenic mitochondrial DNA mutations. J Mol Diagn 2004; 5:197-208. [PMID: 14573777 PMCID: PMC1907336 DOI: 10.1016/s1525-1578(10)60474-6] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Mutations in the mitochondrial DNA (mtDNA) are now recognized as major contributors to human pathologies and possibly to normal aging. A large number of rearrangements and point mutations in protein coding and tRNA genes have been identified in patients with mitochondrial disorders. In this review, we discuss genotype-phenotype correlations in mitochondrial diseases and common techniques used to identify pathogenic mtDNA mutations in human tissues. Although most of these approaches employ standard molecular biology tools, the co-existence of wild-type and mutated mtDNA (mtDNA heteroplasmy) in diseased tissues complicates both the detection and accurate determination of the size of the mutated fractions. To address these problems, novel approaches were developed and are discussed in this review.
Collapse
Affiliation(s)
- Carlos T Moraes
- Department of Neurology, University of Miami School of Medicine, Miami, Florida 33136, USA.
| | | | | | | |
Collapse
|
40
|
McFarland R, Kirby DM, Fowler KJ, Ohtake A, Ryan MT, Amor DJ, Fletcher JM, Dixon JW, Collins FA, Turnbull DM, Taylor RW, Thorburn DR. De novo mutations in the mitochondrial ND3 gene as a cause of infantile mitochondrial encephalopathy and complex I deficiency. Ann Neurol 2004; 55:58-64. [PMID: 14705112 DOI: 10.1002/ana.10787] [Citation(s) in RCA: 135] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Both nuclear and mitochondrial DNA mutations can cause energy generation disorders. Respiratory chain complex I deficiency is the most common energy generation disorder and a frequent cause of infantile mitochondrial encephalopathies such as Leigh's disease and lethal infantile mitochondrial disease. Most such cases have been assumed to be caused by nuclear gene defects, but recently an increasing number have been shown to be caused by mutations in the mitochondrially encoded complex I subunit genes ND4, ND5, and ND6. We report the first four cases of infantile mitochondrial encephalopathies caused by mutations in the ND3 subunit gene. Three unrelated children have the same novel heteroplasmic mutation (T10158C), only the second mutation reported in ND3, and one has the previously identified T10191C mutation. Both mutations cause disproportionately greater reductions in enzyme activity than in the amount of fully assembled complex I, suggesting the ND3 subunit plays an unknown but important role in electron transport, proton pumping, or ubiquinone binding. Three cases appear to have a de novo mutation, with no mutation detected in maternal relatives. Mitochondrial DNA disease may be considerably more prevalent in the pediatric population than currently predicted and should be considered in patients with infantile mitochondrial encephalopathies and complex I deficiency.
Collapse
Affiliation(s)
- Robert McFarland
- Mitochondrial Research Group, School of Neurology, Neurobiology and Psychiatry, University of Newcastle upon Tyne, United Kingdom
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
41
|
Sudo A, Honzawa S, Nonaka I, Goto YI. Leigh syndrome caused by mitochondrial DNA G13513A mutation: frequency and clinical features in Japan. J Hum Genet 2004; 49:92-96. [PMID: 14730434 DOI: 10.1007/s10038-003-0116-1] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2003] [Accepted: 11/18/2003] [Indexed: 10/26/2022]
Abstract
The mitochondrial DNA (mtDNA) G13513A mutation in the ND5 subunit gene has been recently reported as a common cause of some phenotypes of mitochondrial myopathy. Until now, the prevalence and characteristics of this mutation in Leigh syndrome (LS) has not been determined. We screened 84 patients with Leigh syndrome (LS) and found the mutation in six (7%) of them. The proportions of mutant mtDNA in muscles were relatively low (42-70%). The onset of symptoms for patients with this mutation was from 9 months to 5 years. It should be noted that five patients had cardiac conduction abnormalities, particularly Wolff-Parkinson-White (WPW) syndrome (three patients). This study suggests that G13513A mutation is a frequent cause of LS and that patients with this mutation may have a characteristic clinical course.
Collapse
Affiliation(s)
- Akira Sudo
- Department of Mental Retardation and Birth Defect Research, National Institute of Neuroscience, NCNP, 4-1-1 Ogawahigashi, Kodaira, Tokyo 187-8502, Japan
- Department of Child Neurology, National Center Hospital for Mental, Nervous, and Muscular Disorders, National Center of Neurology and Psychiatry, Tokyo, Japan
| | - Shiho Honzawa
- Department of Mental Retardation and Birth Defect Research, National Institute of Neuroscience, NCNP, 4-1-1 Ogawahigashi, Kodaira, Tokyo 187-8502, Japan
- Department of Pediatrics, Koshigaya Hospital, Dokkyo University School of Medicine, Saitama, Japan
| | - Ikuya Nonaka
- Department of Child Neurology, National Center Hospital for Mental, Nervous, and Muscular Disorders, National Center of Neurology and Psychiatry, Tokyo, Japan
| | - Yu-Ichi Goto
- Department of Mental Retardation and Birth Defect Research, National Institute of Neuroscience, NCNP, 4-1-1 Ogawahigashi, Kodaira, Tokyo 187-8502, Japan.
| |
Collapse
|
42
|
Thyagarajan D, Byrne E. Mitochondrial disorders of the nervous system: clinical, biochemical, and molecular genetic features. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2003; 53:93-144. [PMID: 12512338 DOI: 10.1016/s0074-7742(02)53005-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/28/2023]
Affiliation(s)
- Dominic Thyagarajan
- Department of Neurology, Flinders Medical Centre, Bedford Park, South Australia 5042, Australia
| | | |
Collapse
|
43
|
Rossignol R, Faustin B, Rocher C, Malgat M, Mazat JP, Letellier T. Mitochondrial threshold effects. Biochem J 2003; 370:751-62. [PMID: 12467494 PMCID: PMC1223225 DOI: 10.1042/bj20021594] [Citation(s) in RCA: 559] [Impact Index Per Article: 26.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2002] [Revised: 12/04/2002] [Accepted: 12/06/2002] [Indexed: 01/20/2023]
Abstract
The study of mitochondrial diseases has revealed dramatic variability in the phenotypic presentation of mitochondrial genetic defects. To attempt to understand this variability, different authors have studied energy metabolism in transmitochondrial cell lines carrying different proportions of various pathogenic mutations in their mitochondrial DNA. The same kinds of experiments have been performed on isolated mitochondria and on tissue biopsies taken from patients with mitochondrial diseases. The results have shown that, in most cases, phenotypic manifestation of the genetic defect occurs only when a threshold level is exceeded, and this phenomenon has been named the 'phenotypic threshold effect'. Subsequently, several authors showed that it was possible to inhibit considerably the activity of a respiratory chain complex, up to a critical value, without affecting the rate of mitochondrial respiration or ATP synthesis. This phenomenon was called the 'biochemical threshold effect'. More recently, quantitative analysis of the effects of various mutations in mitochondrial DNA on the rate of mitochondrial protein synthesis has revealed the existence of a 'translational threshold effect'. In this review these different mitochondrial threshold effects are discussed, along with their molecular bases and the roles that they play in the presentation of mitochondrial diseases.
Collapse
Affiliation(s)
- Rodrigue Rossignol
- INSERM-EMI 9929, Physiologie mitochondriale, Université Victor Segalen-Bordeaux 2, 146 rue Léo-Saignat, F-33076 Bordeaux-cedex, France.
| | | | | | | | | | | |
Collapse
|
44
|
Akagi M, Inui K, Tsukamoto H, Sakai N, Muramatsu T, Yamada M, Matsuzaki K, Goto YI, Nonaka I, Okada S. A point mutation of mitochondrial ATPase 6 gene in Leigh syndrome. Neuromuscul Disord 2002; 12:53-5. [PMID: 11731285 DOI: 10.1016/s0960-8966(01)00242-5] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
A T-to-G transition at nucleotide 9176 (T9176G) in the mitochondrial adenosine triphosphate 6 gene (MTATP6) was detected in two siblings with Leigh syndrome. Heteroplasmy was observed in the mother's leukocytes. The T9176G mutation changes a highly conserved leucine residue to an arginine in subunit 6 of ATPase and is maternally inherited like mutations in the other mitochondrial genes. Another mutation in the same codon (T9176C) has been previously reported in Leigh syndrome. This gives strong support to the relevance of MTATP6 dysfunction in Leigh syndrome and the importance of leucine at that position.
Collapse
Affiliation(s)
- Motohiro Akagi
- Department of Developmental Medicine (Pediatrics), Osaka University, Graduate School of Medical Science, 2-2 Yamadaoka, Suita, Osaka, Japan
| | | | | | | | | | | | | | | | | | | |
Collapse
|
45
|
Schon EA, Santra S, Pallotti F, Girvin ME. Pathogenesis of primary defects in mitochondrial ATP synthesis. Semin Cell Dev Biol 2001; 12:441-8. [PMID: 11735378 DOI: 10.1006/scdb.2001.0281] [Citation(s) in RCA: 94] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Maternally inherited mutations in the mtDNA-encoded ATPase 6 subunit of complex V (ATP synthase) of the respiratory chain/oxidative phosphorylation system are responsible for a subgroup of severe and often-fatal disorders characterized predominantly by lesions in the brain, particularly in the striatum. These include NARP (neuropathy, ataxia, and retinitis pigmentosa), MILS (maternally inherited Leigh syndrome), and FBSN (familial bilateral striatal necrosis). Of the five known pathogenic mutations causing these disorders, four are located at two codons (156 and 217), each of which can suffer mutations converting a conserved leucine to either an arginine or a proline. Based on the accumulating data on both the structure of ATP synthase and the mechanism by which rotary catalysis couples proton flow to ATP synthesis, we propose a model that may help explain why mutations at codons 156 and 217 are pathogenic.
Collapse
Affiliation(s)
- E A Schon
- Columbia University College of Physicians and Surgeons, New York, NY, USA.
| | | | | | | |
Collapse
|
46
|
Abstract
The mitochondrial encephalomyopathies are a genetically heterogeneous group of disorders associated with impaired oxidative phosphorylation. Patients may exhibit a wide range of clinical symptoms and experience significant morbidity and mortality. There is currently no curative treatment. At present the majority of genetically defined mitochondrial encephalomyopathies are caused by mutations in mitochondrial DNA. The underlying molecular mechanisms and the complex relationship between genotype and phenotype in these mitochondrial DNA diseases remain only partially understood. We describe the key features of mitochondrial DNA genetics and outline some of the common disease phenotypes associated with mtDNA defects. A classification of pathogenic mitochondrial DNA point mutations which may have therapeutic implications is outlined.
Collapse
Affiliation(s)
- T Pulkes
- Muscle and Neurogenetics Sections, University Department of Clinical Neurology, Institute of Neurology, University College London, Queen Square, WC1N 3BG, London, UK
| | | |
Collapse
|
47
|
Abstract
Mitochondrial diseases are a heterogeneous group of disorders with widely varying clinical features, due to defects in mitochondrial function. Involvement of both muscle and nerve is common in mitochondrial disease. In some cases, this involvement is subclinical or a minor part of a multisystem disorder, but myopathy and neuropathy are a major, often presenting, feature of a number of mitochondrial syndromes. In addition, mitochondrial dysfunction may play a role in a number of classic neuromuscular diseases. This article reviews the role of mitochondrial dysfunction in neuromuscular disease and discusses a rational approach to diagnosis and treatment of patients presenting with a neuromuscular syndrome due to mitochondrial disease.
Collapse
Affiliation(s)
- R A Nardin
- Department of Neurology, Beth Israel Deaconess Medical Center, Harvard Medical School, Harvard Institute of Medicine, Rm 858, 77 Avenue Louis Pasteur, Boston, Massachusetts 02115, USA
| | | |
Collapse
|
48
|
Kirby DM, Kahler SG, Freckmann ML, Reddihough D, Thorburn DR. Leigh disease caused by the mitochondrial DNA G14459A mutation in unrelated families. Ann Neurol 2001. [DOI: 10.1002/1531-8249(200007)48:1<102::aid-ana15>3.0.co;2-m] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
|
49
|
Carrozzo R, Murray J, Santorelli FM, Capaldi RA. The T9176G mutation of human mtDNA gives a fully assembled but inactive ATP synthase when modeled in Escherichia coli. FEBS Lett 2000; 486:297-9. [PMID: 11119722 DOI: 10.1016/s0014-5793(00)02244-4] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
A new mutation in human F(1)F(0) ATPase6, T9176G, which changes Leu 217 to an Arg, has been described in two siblings with Leigh syndrome [Carrozzo et al. (2000) Neurology, in press]. This mutation was modeled in Escherichia coli by changing Leu 259 (the equivalent residue) to Arg and the properties of the altered ECF(1)F(0) were compared to those of previously characterized ATPase6 mutants also modeled in the E. coli enzyme. The L259R change produced a fully assembled ECF(1)F(0) which had no significant ATP hydrolysis, ATP synthesis or proton pumping functions. This is very different from previously described human ATPase6 mutations. The presence of Arg at position 259 in subunit a did not make membranes permeable to protons. We conclude that the mutation inhibits functioning by blocking the rotary motor action of the enzyme.
Collapse
Affiliation(s)
- R Carrozzo
- Unita di Medicina Moleculare, Ospedale Pediatrico, Rome, Italy
| | | | | | | |
Collapse
|
50
|
Abstract
Leigh syndrome is a progressive neurodegenerative disease frequently associated with mitochondrial abnormalities. The mitochondrial DNA T9176C mutation in the adenosine triphosphatase 6 gene has recently been described as a cause of Leigh syndrome. Leukocyte DNA from 59 children with Leigh syndrome was screened for the T9176C mutation by conventional polymerase chain reaction methods. Two unrelated patients were found to be homoplasmic for this mutation in blood. Both patients had similar clinical and biochemical features. They had first presented acutely at 3 and 5 years, respectively, with ataxia and slurred speech. Magnetic resonance imaging changes were consistent with Leigh syndrome, and the cerebrospinal fluid lactate was elevated. They have both had relatively stable disease since the time of diagnosis. The mother of one of the children had presented at age 29 years with sudden onset of ataxia, headache, and blurred vision. She was heteroplasmic for the T9176C mutation. The T1976C is an important cause of Leigh syndrome especially in the subgroup of patients with more stable disease and normal respiratory chain enzyme analysis.
Collapse
Affiliation(s)
- C J Wilson
- Metabolic Unit, Great Ormond Street Hospital for Children, London, UK.
| | | | | | | | | |
Collapse
|