101
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Bargiela D, Shanmugarajah P, Lo C, Blakely EL, Taylor RW, Horvath R, Wharton S, Chinnery PF, Hadjivassiliou M. Mitochondrial pathology in progressive cerebellar ataxia. CEREBELLUM & ATAXIAS 2015; 2:16. [PMID: 26640698 PMCID: PMC4670505 DOI: 10.1186/s40673-015-0035-x] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 08/01/2015] [Accepted: 12/02/2015] [Indexed: 12/16/2022]
Abstract
BACKGROUND Mitochondrial disease can manifest as multi-organ disorder, often with neurological dysfunction. Cerebellar ataxia in isolation or in combination with other features can result from mitochondrial disease yet genetic testing using blood DNA is not sufficient to exclude this as a cause of ataxia. Muscle biopsy is a useful diagnostic tool for patients with ataxia suspected of mitochondrial disease. Our aim was to determine specific patient selection criteria for muscle biopsy to see how frequent mitochondrial mutations are responsible for progressive ataxia. We performed a two centre retrospective review of patients with unexplained progressive ataxia who underwent muscle biopsy for suspected mitochondrial disease between 2004 and 2014 (Sheffield and Newcastle Ataxia Centres). RESULTS A total of 126 patients were identified; 26 assessed in Newcastle and 100 in Sheffield. Twenty-four patients had pure ataxia and 102 had ataxia with additional features. The total number of patients with histologically suspected and/or genetically confirmed mitochondrial disease was 29/126 (23 %). CONCLUSIONS A large proportion of patients (23 %) with progressive ataxia who underwent muscle biopsy were found to have features of mitochondrial dysfunction, with molecular confirmation in some. Muscle biopsy is a helpful diagnostic tool for mitochondrial disease in patients with progressive ataxia.
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Affiliation(s)
- David Bargiela
- Institute of Genetic Medicine, Newcastle University, Newcastle upon Tyne, UK
| | - Priya Shanmugarajah
- Academic Department of Neurosciences, Royal Hallamshire Hospital, Glossop Road, Sheffield, S10 2JF UK
| | - Christine Lo
- Academic Department of Neurosciences, Royal Hallamshire Hospital, Glossop Road, Sheffield, S10 2JF UK
| | - Emma L Blakely
- Wellcome Trust Centre for Mitochondrial Research, Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, UK
| | - Robert W Taylor
- Wellcome Trust Centre for Mitochondrial Research, Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, UK
| | - Rita Horvath
- Institute of Human Genetics, Newcastle University, Newcastle upon Tyne, UK
| | - Stephen Wharton
- Department of Histopathology, Royal Hallamshire Hospital, Sheffield, UK
| | - Patrick F Chinnery
- Institute of Genetic Medicine, Newcastle University, Newcastle upon Tyne, UK
| | - Marios Hadjivassiliou
- Academic Department of Neurosciences, Royal Hallamshire Hospital, Glossop Road, Sheffield, S10 2JF UK
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102
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Choquet K, Tétreault M, Yang S, La Piana R, Dicaire MJ, Vanstone MR, Mathieu J, Bouchard JP, Rioux MF, Rouleau GA, Boycott KM, Majewski J, Brais B. SPG7 mutations explain a significant proportion of French Canadian spastic ataxia cases. Eur J Hum Genet 2015; 24:1016-21. [PMID: 26626314 DOI: 10.1038/ejhg.2015.240] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2015] [Revised: 10/01/2015] [Accepted: 10/14/2015] [Indexed: 12/13/2022] Open
Abstract
Hereditary cerebellar ataxias and hereditary spastic paraplegias are clinically and genetically heterogeneous and often overlapping neurological disorders. Mutations in SPG7 cause the autosomal recessive spastic paraplegia type 7 (SPG7), but recent studies indicate that they are also one of the most common causes of recessive cerebellar ataxia. In Quebec, a significant number of patients affected with cerebellar ataxia and spasticity remain without a molecular diagnosis. We performed whole-exome sequencing in three French Canadian (FC) patients affected with spastic ataxia and uncovered compound heterozygous variants in SPG7 in all three. Sanger sequencing of SPG7 exons and exon/intron boundaries was used to screen additional patients. In total, we identified recessive variants in SPG7 in 22 FC patients belonging to 12 families (38.7% of the families screened), including two novel variants. The p.(Ala510Val) variant was the most common in our cohort. Cerebellar features, including ataxia, were more pronounced than spasticity in this cohort. These results strongly suggest that variants affecting the function of SPG7 are the fourth most common form of recessive ataxia in FC patients. Thus, we propose that SPG7 mutations explain a significant proportion of FC spastic ataxia cases and that this gene should be considered in unresolved patients.
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Affiliation(s)
- Karine Choquet
- Neurogenetics of Motion Laboratory, Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University, Montreal, Québec, Canada.,Department of Human Genetics, Montreal Neurological Institute, McGill University, Montreal, Québec, Canada
| | - Martine Tétreault
- Department of Human Genetics, Montreal Neurological Institute, McGill University, Montreal, Québec, Canada.,McGill University and Genome Quebec Innovation Center, Montreal, Québec, Canada
| | - Sharon Yang
- Neurogenetics of Motion Laboratory, Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University, Montreal, Québec, Canada
| | - Roberta La Piana
- Neurogenetics of Motion Laboratory, Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University, Montreal, Québec, Canada
| | - Marie-Josée Dicaire
- Neurogenetics of Motion Laboratory, Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University, Montreal, Québec, Canada
| | - Megan R Vanstone
- Children's Hospital of Eastern Ontario Research Institute, University of Ottawa, Ottawa, Ontario, Canada
| | - Jean Mathieu
- Complexe Hospitalier de la Sagamie et Faculté de Médecine et des Sciences de la Santé de l'Université de Sherbrooke, Jonquière, Québec, Canada
| | - Jean-Pierre Bouchard
- Hôpital Enfant-Jésus, CHU de Québec et Département des Sciences Neurologiques, Faculté de Médecine de l'Université Laval, Québec, Québec, Canada
| | - Marie-France Rioux
- Centre Hospitalier Universitaire de Sherbrooke - Hôpital Fleurimont, Sherbrooke, Québec, Canada
| | - Guy A Rouleau
- Montreal Neurological Institute and Hospital and Department of Neurology and Neurosurgery, McGill University, Montreal, Québec, Canada
| | | | - Kym M Boycott
- Children's Hospital of Eastern Ontario Research Institute, University of Ottawa, Ottawa, Ontario, Canada
| | - Jacek Majewski
- Department of Human Genetics, Montreal Neurological Institute, McGill University, Montreal, Québec, Canada.,McGill University and Genome Quebec Innovation Center, Montreal, Québec, Canada
| | - Bernard Brais
- Neurogenetics of Motion Laboratory, Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University, Montreal, Québec, Canada.,Department of Human Genetics, Montreal Neurological Institute, McGill University, Montreal, Québec, Canada
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103
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Pilliod J, Moutton S, Lavie J, Maurat E, Hubert C, Bellance N, Anheim M, Forlani S, Mochel F, N'Guyen K, Thauvin-Robinet C, Verny C, Milea D, Lesca G, Koenig M, Rodriguez D, Houcinat N, Van-Gils J, Durand CM, Guichet A, Barth M, Bonneau D, Convers P, Maillart E, Guyant-Marechal L, Hannequin D, Fromager G, Afenjar A, Chantot-Bastaraud S, Valence S, Charles P, Berquin P, Rooryck C, Bouron J, Brice A, Lacombe D, Rossignol R, Stevanin G, Benard G, Burglen L, Durr A, Goizet C, Coupry I. New practical definitions for the diagnosis of autosomal recessive spastic ataxia of Charlevoix-Saguenay. Ann Neurol 2015; 78:871-86. [PMID: 26288984 DOI: 10.1002/ana.24509] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2015] [Revised: 08/12/2015] [Accepted: 08/14/2015] [Indexed: 12/29/2022]
Abstract
OBJECTIVE Autosomal recessive spastic ataxia of Charlevoix-Saguenay (ARSACS) is caused by mutations in the SACS gene. SACS encodes sacsin, a protein whose function remains unknown, despite the description of numerous protein domains and the recent focus on its potential role in the regulation of mitochondrial physiology. This study aimed to identify new mutations in a large population of ataxic patients and to functionally analyze their cellular effects in the mitochondrial compartment. METHODS A total of 321 index patients with spastic ataxia selected from the SPATAX network were analyzed by direct sequencing of the SACS gene, and 156 patients from the ATAXIC project presenting with congenital ataxia were investigated either by targeted or whole exome sequencing. For functional analyses, primary cultures of fibroblasts were obtained from 11 patients carrying either mono- or biallelic variants, including 1 case harboring a large deletion encompassing the entire SACS gene. RESULTS We identified biallelic SACS variants in 33 patients from SPATAX, and in 5 nonprogressive ataxia patients from ATAXIC. Moreover, a drastic and recurrent alteration of the mitochondrial network was observed in 10 of the 11 patients tested. INTERPRETATION Our results permit extension of the clinical and mutational spectrum of ARSACS patients. Moreover, we suggest that the observed mitochondrial network anomalies could be used as a trait biomarker for the diagnosis of ARSACS when SACS molecular results are difficult to interpret (ie, missense variants and heterozygous truncating variant). Based on our findings, we propose new diagnostic definitions for ARSACS using clinical, genetic, and cellular criteria.
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Affiliation(s)
- Julie Pilliod
- Rare Diseases Laboratory: Genetics and Metabolism, University of Bordeaux, Bordeaux, France
| | - Sébastien Moutton
- Rare Diseases Laboratory: Genetics and Metabolism, University of Bordeaux, Bordeaux, France.,Medical Genetics Service, Pellegrin University Hospital Center, Bordeaux, France
| | - Julie Lavie
- Rare Diseases Laboratory: Genetics and Metabolism, University of Bordeaux, Bordeaux, France
| | - Elise Maurat
- Rare Diseases Laboratory: Genetics and Metabolism, University of Bordeaux, Bordeaux, France
| | - Christophe Hubert
- Functional Genomics Center, University of Bordeaux, Bordeaux, France
| | - Nadège Bellance
- Rare Diseases Laboratory: Genetics and Metabolism, University of Bordeaux, Bordeaux, France
| | - Mathieu Anheim
- Neurology Service, Strasbourg University Hospitals, Strasbourg, France.,Molecular Cell Biology Genetics Institute, INSERM U964/CNRS UMR7104, University of Strasbourg, Illkirch-Graffenstaden, France.,Strasbourg Federation of Translational Medicine, University of Strasbourg, Illkirch-Graffenstaden, France
| | - Sylvie Forlani
- Genetics Service, Pitié-Salpêtrière Hospital, Public Hospital Network of Paris, Paris, France
| | - Fanny Mochel
- Genetics Service, Pitié-Salpêtrière Hospital, Public Hospital Network of Paris, Paris, France.,Brain and Spinal Cord Institute, INSERM U1127, CNRS UMR7225, Sorbonne Universities-Pierre and Marie Curie University, Paris, France
| | - Karine N'Guyen
- Department of Medical Genetics, Timone Hospital, Marseille, France
| | | | - Christophe Verny
- Nantes Angers le Mans University and Neurology Service, CNRS UMR6214, INSERM U1083, University Hospital Center, Angers, France
| | - Dan Milea
- Ophthalmology Service, Angers University Hospital Center, Angers, France and Singapore National Eye Centre, Singapore Eye Research Institute, Duke-National University of Singapore, Singapore
| | - Gaëtan Lesca
- Genetics Service, Lyon University Hospital Center, Lyon, France
| | - Michel Koenig
- Molecular Genetics Laboratory, INSERM U827, Montpellier Regional University Hospital Center, Montpellier, France
| | - Diana Rodriguez
- Rare Diseases Reference Center "Defects and Congenital Diseases of the Cerebellum," Armand Trousseau Hospital, Public Hospital Network of Paris, Paris, France.,Robert Debré Hospital, INSERM U1141, Paris, France.,Genetics Service, Armand Trousseau Hospital, Public Hospital Network of Paris, Paris, France
| | - Nada Houcinat
- Medical Genetics Service, Pellegrin University Hospital Center, Bordeaux, France
| | - Julien Van-Gils
- Medical Genetics Service, Pellegrin University Hospital Center, Bordeaux, France
| | - Christelle M Durand
- Rare Diseases Laboratory: Genetics and Metabolism, University of Bordeaux, Bordeaux, France
| | - Agnès Guichet
- Neuropediatrics Service, Armand Trousseau Hospital, Public Hospital Network of Paris, Sorbonne Universities-Pierre and Marie Curie University, Paris, France
| | - Magalie Barth
- Neuropediatrics Service, Armand Trousseau Hospital, Public Hospital Network of Paris, Sorbonne Universities-Pierre and Marie Curie University, Paris, France
| | - Dominique Bonneau
- Neuropediatrics Service, Armand Trousseau Hospital, Public Hospital Network of Paris, Sorbonne Universities-Pierre and Marie Curie University, Paris, France
| | - Philippe Convers
- Nantes Angers le Mans University and Department of Biochemistry and Genetics, University Hospital Center, Angers, France
| | - Elisabeth Maillart
- Clinical Neurophysiology Service, Saint-Étienne University Hospital Center, Saint-Étienne, France
| | - Lucie Guyant-Marechal
- Neurology Service, Pitié-Salpêtrière Hospital, Public Hospital Network of Paris, Paris, France
| | - Didier Hannequin
- Neurology Service, Pitié-Salpêtrière Hospital, Public Hospital Network of Paris, Paris, France
| | | | - Alexandra Afenjar
- Rare Diseases Reference Center "Defects and Congenital Diseases of the Cerebellum," Armand Trousseau Hospital, Public Hospital Network of Paris, Paris, France.,Neurologist, Caen, France
| | - Sandra Chantot-Bastaraud
- Rare Diseases Reference Center "Defects and Congenital Diseases of the Cerebellum," Armand Trousseau Hospital, Public Hospital Network of Paris, Paris, France.,Neurologist, Caen, France
| | - Stéphanie Valence
- Rare Diseases Reference Center "Defects and Congenital Diseases of the Cerebellum," Armand Trousseau Hospital, Public Hospital Network of Paris, Paris, France.,Genetics Service, Armand Trousseau Hospital, Public Hospital Network of Paris, Paris, France
| | - Perrine Charles
- Genetics Service, Pitié-Salpêtrière Hospital, Public Hospital Network of Paris, Paris, France
| | - Patrick Berquin
- Amiens University Hospital Center, Pediatric Neurology Activity Center, Amiens, France
| | - Caroline Rooryck
- Rare Diseases Laboratory: Genetics and Metabolism, University of Bordeaux, Bordeaux, France.,Medical Genetics Service, Pellegrin University Hospital Center, Bordeaux, France
| | - Julie Bouron
- Medical Genetics Service, Pellegrin University Hospital Center, Bordeaux, France
| | - Alexis Brice
- Genetics Service, Pitié-Salpêtrière Hospital, Public Hospital Network of Paris, Paris, France.,Brain and Spinal Cord Institute, INSERM U1127, CNRS UMR7225, Sorbonne Universities-Pierre and Marie Curie University, Paris, France
| | - Didier Lacombe
- Rare Diseases Laboratory: Genetics and Metabolism, University of Bordeaux, Bordeaux, France.,Medical Genetics Service, Pellegrin University Hospital Center, Bordeaux, France
| | - Rodrigue Rossignol
- Rare Diseases Laboratory: Genetics and Metabolism, University of Bordeaux, Bordeaux, France
| | - Giovanni Stevanin
- Genetics Service, Pitié-Salpêtrière Hospital, Public Hospital Network of Paris, Paris, France.,Brain and Spinal Cord Institute, INSERM U1127, CNRS UMR7225, Sorbonne Universities-Pierre and Marie Curie University, Paris, France.,Laboratory of Neurogenetics, Practical School of Higher Studies, Paris, France
| | - Giovanni Benard
- Rare Diseases Laboratory: Genetics and Metabolism, University of Bordeaux, Bordeaux, France
| | - Lydie Burglen
- Rare Diseases Reference Center "Defects and Congenital Diseases of the Cerebellum," Armand Trousseau Hospital, Public Hospital Network of Paris, Paris, France.,Robert Debré Hospital, INSERM U1141, Paris, France.,Neurologist, Caen, France
| | - Alexandra Durr
- Genetics Service, Pitié-Salpêtrière Hospital, Public Hospital Network of Paris, Paris, France.,Brain and Spinal Cord Institute, INSERM U1127, CNRS UMR7225, Sorbonne Universities-Pierre and Marie Curie University, Paris, France
| | - Cyril Goizet
- Rare Diseases Laboratory: Genetics and Metabolism, University of Bordeaux, Bordeaux, France.,Medical Genetics Service, Pellegrin University Hospital Center, Bordeaux, France
| | - Isabelle Coupry
- Rare Diseases Laboratory: Genetics and Metabolism, University of Bordeaux, Bordeaux, France
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104
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Vallat JM, Goizet C, Magy L, Mathis S. Too many numbers and complexity: time to update the classifications of neurogenetic disorders? J Med Genet 2015; 53:647-50. [DOI: 10.1136/jmedgenet-2015-103477] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2015] [Accepted: 10/03/2015] [Indexed: 11/03/2022]
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105
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Abnormal Paraplegin Expression in Swollen Neurites, τ- and α-Synuclein Pathology in a Case of Hereditary Spastic Paraplegia SPG7 with an Ala510Val Mutation. Int J Mol Sci 2015; 16:25050-66. [PMID: 26506339 PMCID: PMC4632789 DOI: 10.3390/ijms161025050] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2015] [Revised: 10/05/2015] [Accepted: 10/15/2015] [Indexed: 12/15/2022] Open
Abstract
Mutations in the SPG7 gene are the most frequent cause of autosomal recessive hereditary spastic paraplegias and spastic ataxias. Ala510Val is the most common SPG7 mutation, with a frequency of up to 1% in the general population. Here we report the clinical, genetic, and neuropathological findings in a homozygous Ala510Val SPG7 case with spastic ataxia. Neuron loss with associated gliosis was found in the inferior olivary nucleus, the dentate nucleus of the cerebellum, the substantia nigra and the basal nucleus of Meynert. Neurofilament and/or paraplegin accumulation was observed in swollen neurites in the cerebellar and cerebral cortex. This case also showed subcortical τ-pathology in an unique distribution pattern largely restricted to the brainstem. α-synuclein containing Lewy bodies (LBs) were observed in the brainstem and the cortex, compatible with a limbic pattern of Braak LB-Disease stage 4. Taken together, this case shows that the spectrum of pathologies in SPG7 can include neuron loss of the dentate nucleus and the inferior olivary nucleus as well as neuritic pathology. The progressive supranuclear palsy-like brainstem predominant pattern of τ pathology and α-synuclein containing Lewy bodies in our SPG7 cases may be either coincidental or related to SPG7 in addition to neuron loss and neuritic pathology.
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106
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Abstract
Mitochondrial dysfunction underlies many human disorders, including those that affect the visual system. The retinal ganglion cells, whose axons form the optic nerve, are often damaged by mitochondrial-related diseases which result in blindness. Both mitochondrial DNA (mtDNA) and nuclear gene mutations impacting many different mitochondrial processes can result in optic nerve disease. Of particular importance are mutations that impair mitochondrial network dynamics (fusion and fission), oxidative phosphorylation (OXPHOS), and formation of iron-sulfur complexes. Current genetic knowledge can inform genetic counseling and suggest strategies for novel gene-based therapies. Identifying new optic neuropathy-causing genes and defining the role of current and novel genes in disease will be important steps toward the development of effective and potentially neuroprotective therapies.
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Affiliation(s)
- Janey L Wiggs
- Department of Ophthalmology, Harvard Medical School and Massachusetts Eye and Ear, Boston, Massachusetts 02114;
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107
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Lightowlers RN, Taylor RW, Turnbull DM. Mutations causing mitochondrial disease: What is new and what challenges remain? Science 2015; 349:1494-9. [PMID: 26404827 DOI: 10.1126/science.aac7516] [Citation(s) in RCA: 218] [Impact Index Per Article: 24.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Mitochondrial diseases are among the most common and most complex of all inherited genetic diseases. The involvement of both the mitochondrial and nuclear genome presents unique challenges, but despite this there have been some remarkable advances in our knowledge of mitochondrial diseases over the past few years. A greater understanding of mitochondrial genetics has led to improved diagnosis as well as novel ways to prevent transmission of severe mitochondrial disease. These and other advances have had a major impact on patient care, but considerable challenges remain, particularly in the areas of therapies for those patients manifesting clinical symptoms associated with mitochondrial dysfunction and the tissue specificity seen in many mitochondrial disorders. This review highlights some important recent advances in mitochondrial disease but also stresses the areas where progress is essential.
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Affiliation(s)
- Robert N Lightowlers
- Wellcome Trust Centre for Mitochondrial Research, Institute for Cell and Molecular Biosciences and Institute of Neuroscience, Medical School, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
| | - Robert W Taylor
- Wellcome Trust Centre for Mitochondrial Research, Institute for Cell and Molecular Biosciences and Institute of Neuroscience, Medical School, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
| | - Doug M Turnbull
- Wellcome Trust Centre for Mitochondrial Research, Institute for Cell and Molecular Biosciences and Institute of Neuroscience, Medical School, Newcastle University, Newcastle upon Tyne NE2 4HH, UK.
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108
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Daoud H, Papadima EM, Ouled Amar Bencheikh B, Katsila T, Dionne-Laporte A, Spiegelman D, Dion PA, Patrinos GP, Orrù S, Rouleau GA. Identification of a novel homozygous SPG7 mutation by whole exome sequencing in a Greek family with a complicated form of hereditary spastic paraplegia. Eur J Med Genet 2015; 58:573-7. [PMID: 26260707 DOI: 10.1016/j.ejmg.2015.08.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2015] [Revised: 07/29/2015] [Accepted: 08/02/2015] [Indexed: 10/23/2022]
Abstract
We report the clinical description and genetic analyses of a Greek family with four individuals affected with a complicated form of hereditary spastic paraplegia (HSP) and a recessive pattern of inheritance. Exome sequencing of all affected individuals led to the identification of a homozygous 25 bp deletion predicted to lead to a frameshift and premature stop codon in the SPG7 gene, encoding paraplegin. This deletion, which is located in the first exon of the SPG7 gene, has not been previously reported and likely lead to the complete absence of the SPG7 protein. Interestingly, this family shows significant phenotypic heterogeneity further highlighting the clinical variability associated with SPG7 mutations. Our findings emphasize the clinical utility of whole exome sequencing for the molecular diagnosis of HSPs.
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Affiliation(s)
- Hussein Daoud
- Montreal Neurological Institute, Department of Neurology and Neurosurgery, McGill University, Montreal, Quebec, Canada
| | - Eleni Merkouri Papadima
- University of Patras School of Health Sciences, Department of Pharmacy, University Campus, Patras, Greece
| | - Bouchra Ouled Amar Bencheikh
- Montreal Neurological Institute, Department of Neurology and Neurosurgery, McGill University, Montreal, Quebec, Canada
| | - Theodora Katsila
- University of Patras School of Health Sciences, Department of Pharmacy, University Campus, Patras, Greece
| | - Alexandre Dionne-Laporte
- Montreal Neurological Institute, Department of Neurology and Neurosurgery, McGill University, Montreal, Quebec, Canada
| | - Dan Spiegelman
- Montreal Neurological Institute, Department of Neurology and Neurosurgery, McGill University, Montreal, Quebec, Canada
| | - Patrick A Dion
- Montreal Neurological Institute, Department of Neurology and Neurosurgery, McGill University, Montreal, Quebec, Canada
| | - George P Patrinos
- University of Patras School of Health Sciences, Department of Pharmacy, University Campus, Patras, Greece
| | - Sandro Orrù
- Genetica Medica, Dipartimento di Scienze Mediche, Università di Cagliari, Cagliari, Italy
| | - Guy A Rouleau
- Montreal Neurological Institute, Department of Neurology and Neurosurgery, McGill University, Montreal, Quebec, Canada.
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109
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Ahmed N, Ronchi D, Comi GP. Genes and Pathways Involved in Adult Onset Disorders Featuring Muscle Mitochondrial DNA Instability. Int J Mol Sci 2015; 16:18054-76. [PMID: 26251896 PMCID: PMC4581235 DOI: 10.3390/ijms160818054] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2015] [Revised: 07/27/2015] [Accepted: 07/28/2015] [Indexed: 12/31/2022] Open
Abstract
Replication and maintenance of mtDNA entirely relies on a set of proteins encoded by the nuclear genome, which include members of the core replicative machinery, proteins involved in the homeostasis of mitochondrial dNTPs pools or deputed to the control of mitochondrial dynamics and morphology. Mutations in their coding genes have been observed in familial and sporadic forms of pediatric and adult-onset clinical phenotypes featuring mtDNA instability. The list of defects involved in these disorders has recently expanded, including mutations in the exo-/endo-nuclease flap-processing proteins MGME1 and DNA2, supporting the notion that an enzymatic DNA repair system actively takes place in mitochondria. The results obtained in the last few years acknowledge the contribution of next-generation sequencing methods in the identification of new disease loci in small groups of patients and even single probands. Although heterogeneous, these genes can be conveniently classified according to the pathway to which they belong. The definition of the molecular and biochemical features of these pathways might be helpful for fundamental knowledge of these disorders, to accelerate genetic diagnosis of patients and the development of rational therapies. In this review, we discuss the molecular findings disclosed in adult patients with muscle pathology hallmarked by mtDNA instability.
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Affiliation(s)
- Naghia Ahmed
- Neurology Unit, IRCCS Foundation Ca' Granda Ospedale Maggiore Policlinico, Dino Ferrari Centre, Department of Pathophysiology and Transplantation, Università degli Studi di Milano, via Francesco Sforza 35, Milan 20122, Italy.
| | - Dario Ronchi
- Neurology Unit, IRCCS Foundation Ca' Granda Ospedale Maggiore Policlinico, Dino Ferrari Centre, Department of Pathophysiology and Transplantation, Università degli Studi di Milano, via Francesco Sforza 35, Milan 20122, Italy.
| | - Giacomo Pietro Comi
- Neurology Unit, IRCCS Foundation Ca' Granda Ospedale Maggiore Policlinico, Dino Ferrari Centre, Department of Pathophysiology and Transplantation, Università degli Studi di Milano, via Francesco Sforza 35, Milan 20122, Italy.
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110
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Mayr JA, Haack TB, Freisinger P, Karall D, Makowski C, Koch J, Feichtinger RG, Zimmermann FA, Rolinski B, Ahting U, Meitinger T, Prokisch H, Sperl W. Spectrum of combined respiratory chain defects. J Inherit Metab Dis 2015; 38:629-40. [PMID: 25778941 PMCID: PMC4493854 DOI: 10.1007/s10545-015-9831-y] [Citation(s) in RCA: 75] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/03/2014] [Revised: 02/20/2015] [Accepted: 02/23/2015] [Indexed: 01/22/2023]
Abstract
Inherited disorders of mitochondrial energy metabolism form a large and heterogeneous group of metabolic diseases. More than 250 gene defects have been reported to date and this number continues to grow. Mitochondrial diseases can be grouped into (1) disorders of oxidative phosphorylation (OXPHOS) subunits and their assembly factors, (2) defects of mitochondrial DNA, RNA and protein synthesis, (3) defects in the substrate-generating upstream reactions of OXPHOS, (4) defects in relevant cofactors and (5) defects in mitochondrial homeostasis. Deficiency of more than one respiratory chain enzyme is a common finding. Combined defects are found in 49 % of the known disease-causing genes of mitochondrial energy metabolism and in 57 % of patients with OXPHOS defects identified in our diagnostic centre. Combined defects of complexes I, III, IV and V are typically due to deficiency of mitochondrial DNA replication, RNA metabolism or translation. Defects in cofactors can result in combined defects of various combinations, and defects of mitochondrial homeostasis can result in a generalised decrease of all OXPHOS enzymes. Noteworthy, identification of combined defects can be complicated by different degrees of severity of each affected enzyme. Furthermore, even defects of single respiratory chain enzymes can result in combined defects due to aberrant formation of respiratory chain supercomplexes. Combined OXPHOS defects have a great variety of clinical manifestations in terms of onset, course severity and tissue involvement. They can present as classical encephalomyopathy but also with hepatopathy, nephropathy, haematologic findings and Perrault syndrome in a subset of disorders.
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Affiliation(s)
- Johannes A Mayr
- Department of Paediatrics, Paracelsus Medical University, SALK Salzburg, Salzburg, 5020, Austria,
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111
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Gray and white matter alterations in hereditary spastic paraplegia type SPG4 and clinical correlations. J Neurol 2015; 262:1961-71. [PMID: 26050637 DOI: 10.1007/s00415-015-7791-7] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2014] [Revised: 05/20/2015] [Accepted: 05/21/2015] [Indexed: 12/14/2022]
Abstract
Hereditary spastic paraplegias (HSP) are a group of clinically and genetically heterogeneous disorders with the hallmark of progressive spastic gait disturbance. We used advanced neuroimaging to identify brain regions involved in SPG4, the most common HSP genotype. Additionally, we analyzed correlations between imaging and clinical findings. We performed 3T MRI scans including isotropic high-resolution 3D T1, T2-FLAIR, and DTI sequences in 15 adult patients with genetically confirmed SPG4 and 15 age- and sex-matched healthy controls. Brain volume loss of gray and white matter was evaluated through voxel-based morphometry (VBM) for supra- and infratentorial regions separately. DTI maps of axial diffusivity (AD), radial diffusivity (RD), mean diffusivity (MD), fractional anisotropy (FA), and measured anisotropy (MA1) were analyzed through tract-based special statistics (TBSS). VBM and TBSS revealed a widespread affection of gray and white matter in SPG4 including the corpus callosum, medio-dorsal thalamus, parieto-occipital regions, upper brainstem, cerebellum, and corticospinal tract. Significant correlations with correlation coefficients r > 0.6 between clinical data and DTI findings could be demonstrated for disease duration and disease severity as assessed by the spastic paraplegia rating scale for the pontine crossing tract (AD) and the corpus callosum (RD and FA). Imaging also provided evidence that SPG4 underlies a primarily axonal rather than demyelinating damage in accordance with post-mortem data. DTI is an attractive tool to assess subclinical affection in SPG4. The correlation of imaging findings with disease duration and severity suggests AD, RD, and FA as potential progression markers in interventional studies.
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Kumar KR, Blair NF, Sue CM. An Update on the Hereditary Spastic Paraplegias: New Genes and New Disease Models. Mov Disord Clin Pract 2015; 2:213-223. [PMID: 30838228 DOI: 10.1002/mdc3.12184] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2014] [Revised: 02/24/2015] [Accepted: 03/19/2015] [Indexed: 02/07/2023] Open
Abstract
Aims The hereditary spastic paraplegias (HSPs) are a heterogeneous group of disorders characterized by spasticity in the lower limbs. We provide an overview of HSP with an emphasis on recent developments. Methods A PubMed search using the term "hereditary spastic paraplegia" and "hereditary spastic paraparesis" was conducted for a period from January 2012 to January 2015. We discuss and critique the major studies in the field over this 36-month period. Results A total of 346 publications were identified, of which 47 were selected for review. We provide an update of the common forms of HSP and include patient videos. We also discuss how next-generation sequencing (NGS) has led to the accelerated discovery of new HSP genes, including B4GALNT1,DDHD1, C19orf12,GBA2,TECPR2,DDHD2, C12orf65,REEP2, and IBA57. Moreover, a single study alone identified 18 previously unknown putative HSP genes and created a model for the protein interactions of HSP, called the "HSPome." Many of the newly reported genes cause rare, complicated, autosomal recessive forms of HSP. NGS also has important clinical applications by facilitating the molecular diagnosis of HSP. Furthermore, common genetic forms of HSP have been studied using new disease models, such as neurons derived from induced pluripotent stem cells. These models have been used to elucidate important disease mechanisms and have served as platforms to screen for candidate drug compounds. Conclusion The field of HSP research has been progressing at a rapid pace. The challenge remains in translating these advances into new targeted disease therapies.
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Affiliation(s)
- Kishore R Kumar
- Departments of Neurology and Neurogenetics Kolling Institute of Medical Research and Royal North Shore Hospital University of Sydney Sydney New South Wales Australia
| | - Nicholas F Blair
- Departments of Neurology and Neurogenetics Kolling Institute of Medical Research and Royal North Shore Hospital University of Sydney Sydney New South Wales Australia
| | - Carolyn M Sue
- Departments of Neurology and Neurogenetics Kolling Institute of Medical Research and Royal North Shore Hospital University of Sydney Sydney New South Wales Australia
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De Silva D, Tu YT, Amunts A, Fontanesi F, Barrientos A. Mitochondrial ribosome assembly in health and disease. Cell Cycle 2015; 14:2226-50. [PMID: 26030272 DOI: 10.1080/15384101.2015.1053672] [Citation(s) in RCA: 130] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
The ribosome is a structurally and functionally conserved macromolecular machine universally responsible for catalyzing protein synthesis. Within eukaryotic cells, mitochondria contain their own ribosomes (mitoribosomes), which synthesize a handful of proteins, all essential for the biogenesis of the oxidative phosphorylation system. High-resolution cryo-EM structures of the yeast, porcine and human mitoribosomal subunits and of the entire human mitoribosome have uncovered a wealth of new information to illustrate their evolutionary divergence from their bacterial ancestors and their adaptation to synthesis of highly hydrophobic membrane proteins. With such structural data becoming available, one of the most important remaining questions is that of the mitoribosome assembly pathway and factors involved. The regulation of mitoribosome biogenesis is paramount to mitochondrial respiration, and thus to cell viability, growth and differentiation. Moreover, mutations affecting the rRNA and protein components produce severe human mitochondrial disorders. Despite its biological and biomedical significance, knowledge on mitoribosome biogenesis and its deviations from the much-studied bacterial ribosome assembly processes is scarce, especially the order of rRNA processing and assembly events and the regulatory factors required to achieve fully functional particles. This article focuses on summarizing the current available information on mitoribosome assembly pathway, factors that form the mitoribosome assembly machinery, and the effect of defective mitoribosome assembly on human health.
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Affiliation(s)
- Dasmanthie De Silva
- a Department of Biochemistry and Molecular Biology ; University of Miami Miller School of Medicine ; Miami , FL USA
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Klebe S, Stevanin G, Depienne C. Clinical and genetic heterogeneity in hereditary spastic paraplegias: from SPG1 to SPG72 and still counting. Rev Neurol (Paris) 2015; 171:505-30. [PMID: 26008818 DOI: 10.1016/j.neurol.2015.02.017] [Citation(s) in RCA: 121] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2014] [Revised: 02/10/2015] [Accepted: 02/19/2015] [Indexed: 12/11/2022]
Abstract
Hereditary spastic paraplegias (HSPs) are genetically determined neurodegenerative disorders characterized by progressive weakness and spasticity of lower limbs, and are among the most clinically and genetically heterogeneous human diseases. All modes of inheritance have been described, and the recent technological revolution in molecular genetics has led to the identification of 76 different spastic gait disease-loci with 59 corresponding spastic paraplegia genes. Autosomal recessive HSP are usually associated with diverse additional features (referred to as complicated forms), contrary to autosomal dominant HSP, which are mostly pure. However, the identification of additional mutations and families has considerably enlarged the clinical spectra, and has revealed a huge clinical variability for almost all HSP; complicated forms have also been described for primary pure HSP subtypes, adding further complexity to the genotype-phenotype correlations. In addition, the introduction of next generation sequencing in clinical practice has revealed a genetic and phenotypic overlap with other neurodegenerative disorders (amyotrophic lateral sclerosis, neuropathies, cerebellar ataxias, etc.) and neurodevelopmental disorders, including intellectual disability. This review aims to describe the most recent advances in the field and to provide genotype-phenotype correlations that could help clinical diagnoses of this heterogeneous group of disorders.
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Affiliation(s)
- S Klebe
- Department of neurology, university hospital Würzburg, Josef-Schneider-Straße 11, 97080 Würzburg, Germany
| | - G Stevanin
- Sorbonne universités, UPMC université Paris 06, 91-105, boulevard de l'Hôpital, 75013 Paris, France; ICM, CNRS UMR 7225, Inserm U 1127, 47/83, boulevard de l'Hôpital, 75013 Paris, France; École pratique des hautes études, 4-14, rue Ferrus, 75014 Paris, France; Département de génétique, AP-HP, hôpital Pitié-Salpêtrière, 47/83, boulevard de l'Hôpital, 75013 Paris, France
| | - C Depienne
- Sorbonne universités, UPMC université Paris 06, 91-105, boulevard de l'Hôpital, 75013 Paris, France; ICM, CNRS UMR 7225, Inserm U 1127, 47/83, boulevard de l'Hôpital, 75013 Paris, France; Département de génétique, AP-HP, hôpital Pitié-Salpêtrière, 47/83, boulevard de l'Hôpital, 75013 Paris, France.
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Abstract
Recent advances in mitochondrial biology have revealed the high diversity and complexity of proteolytic enzymes that regulate mitochondrial function. We have classified mitochondrial proteases, or mitoproteases, on the basis of their function and location, and defined the human mitochondrial degradome as the complete set of mitoproteases that are encoded by the human genome. In addition to their nonspecific degradative functions, mitoproteases perform highly regulated proteolytic reactions that are important in mitochondrial function, integrity and homeostasis. These include protein synthesis, quality control, mitochondrial biogenesis and dynamics, mitophagy and apoptosis. Impaired or dysregulated function of mitoproteases is associated with ageing and with many pathological conditions such as neurodegenerative disorders, metabolic syndromes and cancer. A better understanding of the mitochondrial proteolytic landscape and its modulation may contribute to improving human lifespan and 'healthspan'.
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Gorman GS, Schaefer AM, Ng Y, Gomez N, Blakely EL, Alston CL, Feeney C, Horvath R, Yu-Wai-Man P, Chinnery PF, Taylor RW, Turnbull DM, McFarland R. Prevalence of nuclear and mitochondrial DNA mutations related to adult mitochondrial disease. Ann Neurol 2015; 77:753-9. [PMID: 25652200 PMCID: PMC4737121 DOI: 10.1002/ana.24362] [Citation(s) in RCA: 615] [Impact Index Per Article: 68.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2014] [Revised: 11/30/2014] [Accepted: 01/08/2015] [Indexed: 01/17/2023]
Abstract
OBJECTIVE The prevalence of mitochondrial disease has proven difficult to establish, predominantly as a result of clinical and genetic heterogeneity. The phenotypic spectrum of mitochondrial disease has expanded significantly since the original reports that associated classic clinical syndromes with mitochondrial DNA (mtDNA) rearrangements and point mutations. The revolution in genetic technologies has allowed interrogation of the nuclear genome in a manner that has dramatically improved the diagnosis of mitochondrial disorders. We comprehensively assessed the prevalence of all forms of adult mitochondrial disease to include pathogenic mutations in both nuclear and mtDNA. METHODS Adults with suspected mitochondrial disease in the North East of England were referred to a single neurology center from 1990 to 2014. For the midyear period of 2011, we evaluated the minimum prevalence of symptomatic nuclear DNA mutations and symptomatic and asymptomatic mtDNA mutations causing mitochondrial diseases. RESULTS The minimum prevalence rate for mtDNA mutations was 1 in 5,000 (20 per 100,000), comparable with our previously published prevalence rates. In this population, nuclear mutations were responsible for clinically overt adult mitochondrial disease in 2.9 per 100,000 adults. INTERPRETATION Combined, our data confirm that the total prevalence of adult mitochondrial disease, including pathogenic mutations of both the mitochondrial and nuclear genomes (≈1 in 4,300), is among the commonest adult forms of inherited neurological disorders. These figures hold important implications for the evaluation of interventions, provision of evidence-based health policies, and planning of future services.
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Affiliation(s)
- Gráinne S Gorman
- Wellcome Centre for Mitochondrial Research, Newcastle University, Newcastle upon Tyne, United Kingdom; Institute of Neuroscience, Henry Wellcome Building for Neuroecology, Newcastle upon Tyne, United Kingdom
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Gomez CM, Kawakami H. Neurogenetics: The expanding horizons of diagnosis and disease pathogenesis. Neurology 2015; 84:1070-1. [PMID: 25681450 DOI: 10.1212/wnl.0000000000001372] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Affiliation(s)
- Christopher M Gomez
- From the Department of Neurology (C.M.G.), The University of Chicago, IL; and the Department of Epidemiology (H.K.), Research Institute for Radiation Biology & Medicine, Hiroshima University, Japan.
| | - Hideshi Kawakami
- From the Department of Neurology (C.M.G.), The University of Chicago, IL; and the Department of Epidemiology (H.K.), Research Institute for Radiation Biology & Medicine, Hiroshima University, Japan
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Delving into the complexity of hereditary spastic paraplegias: how unexpected phenotypes and inheritance modes are revolutionizing their nosology. Hum Genet 2015; 134:511-38. [PMID: 25758904 PMCID: PMC4424374 DOI: 10.1007/s00439-015-1536-7] [Citation(s) in RCA: 103] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2014] [Accepted: 02/23/2015] [Indexed: 12/11/2022]
Abstract
Hereditary spastic paraplegias (HSP) are rare neurodegenerative diseases sharing the degeneration of the corticospinal tracts as the main pathological characteristic. They are considered one of the most heterogeneous neurological disorders. All modes of inheritance have been described for the 84 different loci and 67 known causative genes implicated up to now. Recent advances in molecular genetics have revealed clinico-genetic heterogeneity of these disorders including their clinical and genetic overlap with other diseases of the nervous system. The systematic analysis of a large set of genes, including exome sequencing, is unmasking unusual phenotypes or inheritance modes associated with mutations in HSP genes and related genes involved in various neurological diseases. A new nosology may emerge after integration and understanding of these new data to replace the current classification. Collectively, functions of the known genes implicate the disturbance of intracellular membrane dynamics and trafficking as the consequence of alterations of cytoskeletal dynamics, lipid metabolism and organelle structures, which represent in fact a relatively small number of cellular processes that could help to find common curative approaches, which are still lacking.
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Pfeffer G, Pyle A, Griffin H, Miller J, Wilson V, Turnbull L, Fawcett K, Sims D, Eglon G, Hadjivassiliou M, Horvath R, Németh A, Chinnery PF. SPG7 mutations are a common cause of undiagnosed ataxia. Neurology 2015; 84:1174-6. [PMID: 25681447 PMCID: PMC4371411 DOI: 10.1212/wnl.0000000000001369] [Citation(s) in RCA: 80] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/05/2022] Open
Affiliation(s)
- Gerald Pfeffer
- From the Wellcome Trust Centre for Mitochondrial Research (G.P., A.P., H.G., V.W., L.T., G.E., R.H., P.F.C.) and Institute of Genetic Medicine (G.P., A.P., H.G., R.H., P.F.C.), Newcastle University, Newcastle-upon-Tyne; John Radcliffe Hospital (J.M., K.F., D.S., A.N.), University of Oxford; Royal Hallamshire Hospital (M.H.), University of Sheffield; and Churchill Hospital (A.N.), Oxford, UK
| | - Angela Pyle
- From the Wellcome Trust Centre for Mitochondrial Research (G.P., A.P., H.G., V.W., L.T., G.E., R.H., P.F.C.) and Institute of Genetic Medicine (G.P., A.P., H.G., R.H., P.F.C.), Newcastle University, Newcastle-upon-Tyne; John Radcliffe Hospital (J.M., K.F., D.S., A.N.), University of Oxford; Royal Hallamshire Hospital (M.H.), University of Sheffield; and Churchill Hospital (A.N.), Oxford, UK
| | - Helen Griffin
- From the Wellcome Trust Centre for Mitochondrial Research (G.P., A.P., H.G., V.W., L.T., G.E., R.H., P.F.C.) and Institute of Genetic Medicine (G.P., A.P., H.G., R.H., P.F.C.), Newcastle University, Newcastle-upon-Tyne; John Radcliffe Hospital (J.M., K.F., D.S., A.N.), University of Oxford; Royal Hallamshire Hospital (M.H.), University of Sheffield; and Churchill Hospital (A.N.), Oxford, UK
| | - Jack Miller
- From the Wellcome Trust Centre for Mitochondrial Research (G.P., A.P., H.G., V.W., L.T., G.E., R.H., P.F.C.) and Institute of Genetic Medicine (G.P., A.P., H.G., R.H., P.F.C.), Newcastle University, Newcastle-upon-Tyne; John Radcliffe Hospital (J.M., K.F., D.S., A.N.), University of Oxford; Royal Hallamshire Hospital (M.H.), University of Sheffield; and Churchill Hospital (A.N.), Oxford, UK
| | - Valerie Wilson
- From the Wellcome Trust Centre for Mitochondrial Research (G.P., A.P., H.G., V.W., L.T., G.E., R.H., P.F.C.) and Institute of Genetic Medicine (G.P., A.P., H.G., R.H., P.F.C.), Newcastle University, Newcastle-upon-Tyne; John Radcliffe Hospital (J.M., K.F., D.S., A.N.), University of Oxford; Royal Hallamshire Hospital (M.H.), University of Sheffield; and Churchill Hospital (A.N.), Oxford, UK
| | - Lisa Turnbull
- From the Wellcome Trust Centre for Mitochondrial Research (G.P., A.P., H.G., V.W., L.T., G.E., R.H., P.F.C.) and Institute of Genetic Medicine (G.P., A.P., H.G., R.H., P.F.C.), Newcastle University, Newcastle-upon-Tyne; John Radcliffe Hospital (J.M., K.F., D.S., A.N.), University of Oxford; Royal Hallamshire Hospital (M.H.), University of Sheffield; and Churchill Hospital (A.N.), Oxford, UK
| | - Katherine Fawcett
- From the Wellcome Trust Centre for Mitochondrial Research (G.P., A.P., H.G., V.W., L.T., G.E., R.H., P.F.C.) and Institute of Genetic Medicine (G.P., A.P., H.G., R.H., P.F.C.), Newcastle University, Newcastle-upon-Tyne; John Radcliffe Hospital (J.M., K.F., D.S., A.N.), University of Oxford; Royal Hallamshire Hospital (M.H.), University of Sheffield; and Churchill Hospital (A.N.), Oxford, UK
| | - David Sims
- From the Wellcome Trust Centre for Mitochondrial Research (G.P., A.P., H.G., V.W., L.T., G.E., R.H., P.F.C.) and Institute of Genetic Medicine (G.P., A.P., H.G., R.H., P.F.C.), Newcastle University, Newcastle-upon-Tyne; John Radcliffe Hospital (J.M., K.F., D.S., A.N.), University of Oxford; Royal Hallamshire Hospital (M.H.), University of Sheffield; and Churchill Hospital (A.N.), Oxford, UK
| | - Gail Eglon
- From the Wellcome Trust Centre for Mitochondrial Research (G.P., A.P., H.G., V.W., L.T., G.E., R.H., P.F.C.) and Institute of Genetic Medicine (G.P., A.P., H.G., R.H., P.F.C.), Newcastle University, Newcastle-upon-Tyne; John Radcliffe Hospital (J.M., K.F., D.S., A.N.), University of Oxford; Royal Hallamshire Hospital (M.H.), University of Sheffield; and Churchill Hospital (A.N.), Oxford, UK
| | - Marios Hadjivassiliou
- From the Wellcome Trust Centre for Mitochondrial Research (G.P., A.P., H.G., V.W., L.T., G.E., R.H., P.F.C.) and Institute of Genetic Medicine (G.P., A.P., H.G., R.H., P.F.C.), Newcastle University, Newcastle-upon-Tyne; John Radcliffe Hospital (J.M., K.F., D.S., A.N.), University of Oxford; Royal Hallamshire Hospital (M.H.), University of Sheffield; and Churchill Hospital (A.N.), Oxford, UK
| | - Rita Horvath
- From the Wellcome Trust Centre for Mitochondrial Research (G.P., A.P., H.G., V.W., L.T., G.E., R.H., P.F.C.) and Institute of Genetic Medicine (G.P., A.P., H.G., R.H., P.F.C.), Newcastle University, Newcastle-upon-Tyne; John Radcliffe Hospital (J.M., K.F., D.S., A.N.), University of Oxford; Royal Hallamshire Hospital (M.H.), University of Sheffield; and Churchill Hospital (A.N.), Oxford, UK
| | - Andrea Németh
- From the Wellcome Trust Centre for Mitochondrial Research (G.P., A.P., H.G., V.W., L.T., G.E., R.H., P.F.C.) and Institute of Genetic Medicine (G.P., A.P., H.G., R.H., P.F.C.), Newcastle University, Newcastle-upon-Tyne; John Radcliffe Hospital (J.M., K.F., D.S., A.N.), University of Oxford; Royal Hallamshire Hospital (M.H.), University of Sheffield; and Churchill Hospital (A.N.), Oxford, UK
| | - Patrick F Chinnery
- From the Wellcome Trust Centre for Mitochondrial Research (G.P., A.P., H.G., V.W., L.T., G.E., R.H., P.F.C.) and Institute of Genetic Medicine (G.P., A.P., H.G., R.H., P.F.C.), Newcastle University, Newcastle-upon-Tyne; John Radcliffe Hospital (J.M., K.F., D.S., A.N.), University of Oxford; Royal Hallamshire Hospital (M.H.), University of Sheffield; and Churchill Hospital (A.N.), Oxford, UK.
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Horga A, Pitceathly RDS, Blake JC, Woodward CE, Zapater P, Fratter C, Mudanohwo EE, Plant GT, Houlden H, Sweeney MG, Hanna MG, Reilly MM. Peripheral neuropathy predicts nuclear gene defect in patients with mitochondrial ophthalmoplegia. ACTA ACUST UNITED AC 2014; 137:3200-12. [PMID: 25281868 PMCID: PMC4240292 DOI: 10.1093/brain/awu279] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Mitochondrial ophthalmoplegia is a genetically heterogeneous disorder. Horga et al. investigate whether peripheral neuropathy can predict the underlying genetic defect in patients with progressive external ophthalmoplegia. Results indicate that neuropathy is highly predictive of a nuclear DNA defect and that it is rarely associated with single mitochondrial DNA deletions. Progressive external ophthalmoplegia is a common clinical feature in mitochondrial disease caused by nuclear DNA defects and single, large-scale mitochondrial DNA deletions and is less frequently associated with point mutations of mitochondrial DNA. Peripheral neuropathy is also a frequent manifestation of mitochondrial disease, although its prevalence and characteristics varies considerably among the different syndromes and genetic aetiologies. Based on clinical observations, we systematically investigated whether the presence of peripheral neuropathy could predict the underlying genetic defect in patients with progressive external ophthalmoplegia. We analysed detailed demographic, clinical and neurophysiological data from 116 patients with genetically-defined mitochondrial disease and progressive external ophthalmoplegia. Seventy-eight patients (67%) had a single mitochondrial DNA deletion, 12 (10%) had a point mutation of mitochondrial DNA and 26 (22%) had mutations in either POLG, C10orf2 or RRM2B, or had multiple mitochondrial DNA deletions in muscle without an identified nuclear gene defect. Seventy-seven patients had neurophysiological studies; of these, 16 patients (21%) had a large-fibre peripheral neuropathy. The prevalence of peripheral neuropathy was significantly lower in patients with a single mitochondrial DNA deletion (2%) as compared to those with a point mutation of mitochondrial DNA or with a nuclear DNA defect (44% and 52%, respectively; P < 0.001). Univariate analyses revealed significant differences in the distribution of other clinical features between genotypes, including age at disease onset, gender, family history, progressive external ophthalmoplegia at clinical presentation, hearing loss, pigmentary retinopathy and extrapyramidal features. However, binomial logistic regression analysis identified peripheral neuropathy as the only independent predictor associated with a nuclear DNA defect (P = 0.002; odds ratio 8.43, 95% confidence interval 2.24–31.76). Multinomial logistic regression analysis identified peripheral neuropathy, family history and hearing loss as significant predictors of the genotype, and the same three variables showed the highest performance in genotype classification in a decision tree analysis. Of these variables, peripheral neuropathy had the highest specificity (91%), negative predictive value (83%) and positive likelihood ratio (5.87) for the diagnosis of a nuclear DNA defect. These results indicate that peripheral neuropathy is a rare finding in patients with single mitochondrial DNA deletions but that it is highly predictive of an underlying nuclear DNA defect. This observation may facilitate the development of diagnostic algorithms. We suggest that nuclear gene testing may enable a more rapid diagnosis and avoid muscle biopsy in patients with progressive external ophthalmoplegia and peripheral neuropathy.
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Affiliation(s)
- Alejandro Horga
- 1 MRC Centre for Neuromuscular Diseases, UCL Institute of Neurology and National Hospital for Neurology and Neurosurgery, Queen Square, London, WC1N 3BG, UK
| | - Robert D S Pitceathly
- 1 MRC Centre for Neuromuscular Diseases, UCL Institute of Neurology and National Hospital for Neurology and Neurosurgery, Queen Square, London, WC1N 3BG, UK
| | - Julian C Blake
- 2 Department of Clinical Neurophysiology, Norfolk and Norwich University Hospital, Norwich, NR4 7UY, UK
| | - Catherine E Woodward
- 3 Neurogenetics Unit, National Hospital for Neurology and Neurosurgery, Queen Square, London, WC1N 3BG, UK
| | - Pedro Zapater
- 4 Clinical Pharmacology Section, Hospital General Universitario, Alicante, 03010, Spain
| | - Carl Fratter
- 5 Oxford Medical Genetics Laboratories, Oxford University Hospitals NHS Trust, Oxford, OX3 7LE, UK
| | - Ese E Mudanohwo
- 3 Neurogenetics Unit, National Hospital for Neurology and Neurosurgery, Queen Square, London, WC1N 3BG, UK
| | - Gordon T Plant
- 6 National Hospital for Neurology and Neurosurgery, Queen Square, London, WC1N 3BG, UK
| | - Henry Houlden
- 1 MRC Centre for Neuromuscular Diseases, UCL Institute of Neurology and National Hospital for Neurology and Neurosurgery, Queen Square, London, WC1N 3BG, UK
| | - Mary G Sweeney
- 3 Neurogenetics Unit, National Hospital for Neurology and Neurosurgery, Queen Square, London, WC1N 3BG, UK
| | - Michael G Hanna
- 1 MRC Centre for Neuromuscular Diseases, UCL Institute of Neurology and National Hospital for Neurology and Neurosurgery, Queen Square, London, WC1N 3BG, UK
| | - Mary M Reilly
- 1 MRC Centre for Neuromuscular Diseases, UCL Institute of Neurology and National Hospital for Neurology and Neurosurgery, Queen Square, London, WC1N 3BG, UK
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Yu-Wai-Man P, Carelli V, Chinnery PF. 197th ENMC international workshop: Neuromuscular disorders of mitochondrial fusion and fission – OPA1 and MFN2 molecular mechanisms and therapeutic strategies. Neuromuscul Disord 2014; 24:736-42. [DOI: 10.1016/j.nmd.2014.05.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2014] [Accepted: 05/12/2014] [Indexed: 11/26/2022]
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Early-onset optic neuropathy as initial clinical presentation in SPG7. J Neurol 2014; 261:1820-1. [PMID: 25034272 DOI: 10.1007/s00415-014-7432-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2014] [Revised: 07/01/2014] [Accepted: 07/02/2014] [Indexed: 10/25/2022]
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