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Lopergolo D, Rosini F, Pretegiani E, Bargagli A, Serchi V, Rufa A. Autosomal recessive cerebellar ataxias: a diagnostic classification approach according to ocular features. Front Integr Neurosci 2024; 17:1275794. [PMID: 38390227 PMCID: PMC10883068 DOI: 10.3389/fnint.2023.1275794] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2023] [Accepted: 11/10/2023] [Indexed: 02/24/2024] Open
Abstract
Autosomal recessive cerebellar ataxias (ARCAs) are a heterogeneous group of neurodegenerative disorders affecting primarily the cerebellum and/or its afferent tracts, often accompanied by damage of other neurological or extra-neurological systems. Due to the overlap of clinical presentation among ARCAs and the variety of hereditary, acquired, and reversible etiologies that can determine cerebellar dysfunction, the differential diagnosis is challenging, but also urgent considering the ongoing development of promising target therapies. The examination of afferent and efferent visual system may provide neurophysiological and structural information related to cerebellar dysfunction and neurodegeneration thus allowing a possible diagnostic classification approach according to ocular features. While optic coherence tomography (OCT) is applied for the parametrization of the optic nerve and macular area, the eye movements analysis relies on a wide range of eye-tracker devices and the application of machine-learning techniques. We discuss the results of clinical and eye-tracking oculomotor examination, the OCT findings and some advancing of computer science in ARCAs thus providing evidence sustaining the identification of robust eye parameters as possible markers of ARCAs.
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Affiliation(s)
- Diego Lopergolo
- Department of Medicine, Surgery and Neurosciences, University of Siena, Siena, Italy
- UOC Neurologia e Malattie Neurometaboliche, Azienda Ospedaliero-Universitaria Senese, Siena, Italy
| | - Francesca Rosini
- UOC Stroke Unit, Department of Emergenza-Urgenza, Azienda Ospedaliero-Universitaria Senese, Siena, Italy
| | - Elena Pretegiani
- Unit of Neurology, Centre Hospitalier Universitaire Vaudoise Lausanne, Unit of Neurology and Cognitive Neurorehabilitation, Universitary Hospital of Fribourg, Fribourg, Switzerland
| | - Alessia Bargagli
- Evalab-Neurosense, Department of Medicine Surgery and Neuroscience, University of Siena, Siena, Italy
| | - Valeria Serchi
- Evalab-Neurosense, Department of Medicine Surgery and Neuroscience, University of Siena, Siena, Italy
| | - Alessandra Rufa
- Department of Medicine, Surgery and Neurosciences, University of Siena, Siena, Italy
- UOC Neurologia e Malattie Neurometaboliche, Azienda Ospedaliero-Universitaria Senese, Siena, Italy
- Evalab-Neurosense, Department of Medicine Surgery and Neuroscience, University of Siena, Siena, Italy
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Ekenstedt KJ, Minor KM, Shelton GD, Hammond JJ, Miller AD, Taylor SM, Huang Y, Mickelson JR. A SACS deletion variant in Great Pyrenees dogs causes autosomal recessive neuronal degeneration. Hum Genet 2023; 142:1587-1601. [PMID: 37758910 PMCID: PMC10602964 DOI: 10.1007/s00439-023-02599-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2023] [Accepted: 09/04/2023] [Indexed: 09/29/2023]
Abstract
ARSACS (autosomal recessive spastic ataxia of Charlevoix-Saguenay) is a human neurological disorder characterized by progressive cerebellar ataxia and peripheral neuropathy. A recently recognized disorder in Great Pyrenees dogs is similarly characterized by widespread central nervous system degeneration leading to progressive cerebellar ataxia and spasticity, combined with peripheral neuropathy. Onset of clinical signs occurred in puppies as young as 4 months of age, with slow progression over several years. A multi-generation pedigree suggested an autosomal recessive mode of inheritance. Histopathology revealed consistent cerebellar Purkinje cell degeneration, neuronal degeneration in brainstem nuclei, widespread spinal cord white matter degeneration, ganglion cell degeneration, inappropriately thin myelin sheaths or fully demyelinated peripheral nerve fibers, and normal or only mild patterns of denervation atrophy in skeletal muscles. Genome-wide single nucleotide polymorphism (SNP) genotype data was collected from 6 cases and 26 controls, where homozygosity mapping identified a 3.3 Mb region on CFA25 in which all cases were homozygous and all controls were either heterozygous or homozygous for alternate haplotypes. This region tagged the SACS gene where variants are known to cause ARSACS. Sanger sequencing of SACS in affected dogs identified a 4 bp deletion that causes a frame shift and truncates 343 amino acids from the C terminus of the encoded sacsin protein (p.Val4244AlafsTer32). Our clinical and histopathological descriptions of this canine disorder contribute to the description of human ARSACS and represents the first naturally occurring large animal model of this disorder.
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Affiliation(s)
- Kari J Ekenstedt
- Department of Basic Medical Sciences, College of Veterinary Medicine, Purdue University, Lynn Hall, 625 Harrison Street, West Lafayette, IN, 47907, USA.
| | - Katie M Minor
- Department of Veterinary and Biomedical Sciences, College of Veterinary Medicine, University of Minnesota, Saint Paul, MN, 55108, USA
| | - G Diane Shelton
- Department of Pathology, School of Medicine, University of California San Diego, La Jolla, CA, 92093, USA
| | - James J Hammond
- Department of Neurology, Pieper Memorial Veterinary Center, Middletown, CT, 06457, USA
| | - Andrew D Miller
- Section of Anatomic Pathology, Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY, 14853, USA
| | - Susan M Taylor
- Department of Small Animal Clinical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, SK, S7N 5B4, Canada
| | - Yanyun Huang
- Prairie Diagnostic Services, Inc., Saskatoon, SK, S7N 5B4, Canada
| | - James R Mickelson
- Department of Veterinary and Biomedical Sciences, College of Veterinary Medicine, University of Minnesota, Saint Paul, MN, 55108, USA
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The J Domain of Sacsin Disrupts Intermediate Filament Assembly. Int J Mol Sci 2022; 23:ijms232415742. [PMID: 36555380 PMCID: PMC9779362 DOI: 10.3390/ijms232415742] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Revised: 12/01/2022] [Accepted: 12/07/2022] [Indexed: 12/14/2022] Open
Abstract
Autosomal Recessive Spastic Ataxia of the Charlevoix Saguenay (ARSACS) is caused by mutation in the SACS gene resulting in loss of function of the protein sacsin. A key feature is the formation of abnormal bundles of neurofilaments (NF) in neurons and vimentin intermediate filaments (IF) in cultured fibroblasts, suggesting a role of sacsin in IF homeostasis. Sacsin contains a J domain (SacsJ) homologous to Hsp40, that can interact with Hsp70 chaperones. The SacsJ domain resolved NF bundles in cultured Sacs-/- neurons. Having studied the mechanism using NF assembled in vitro from purified NF proteins, we report that the SacsJ domain interacts with NF proteins to disassemble NFL filaments, and to inhibit their initial assembly. A cell-penetrating peptide derived from this domain, SacsJ-myc-TAT was efficient in disassembling NF bundles in cultured Sacs-/- motor neurons, restoring the NF network; however, there was some loss of vimentin IF and NF in cultured Sacs+/+ fibroblasts and motor neurons, respectively. These results suggest that sacsin through its SacsJ domain is a key regulator of NF and vimentin IF networks in cells.
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4
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Douglas VP, Douglas KAA, Miller JB, Gaier ED. Absent Foveal Avascular Zone in Autosomal Recessive Spastic Ataxia of Charlevoix-Saguenay. J Neuroophthalmol 2021; 41:e166-e168. [PMID: 32991389 PMCID: PMC8564680 DOI: 10.1097/wno.0000000000001050] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Affiliation(s)
- Vivian Paraskevi Douglas
- Harvard Retinal Imaging Lab (VPD, KAAD, JBM), Boston, Massachusetts; Department of Ophthalmology (VPD, KAAD, JBM, EDG), Harvard Medical School, Boston, Massachusetts; Retina Service (JBM), Massachusetts Eye and Ear, Boston, Massachusetts; Department of Ophthalmology (EDG), Boston Children's Hospital, Boston, Massachusetts; and Department of Brain and Cognitive Sciences (EDG), Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, Massachusetts
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de Freitas JL, Rezende Filho FM, Sallum JM, França MC, Pedroso JL, Barsottini OG. Ophthalmological changes in hereditary spastic paraplegia and other genetic diseases with spastic paraplegia. J Neurol Sci 2020; 409:116620. [DOI: 10.1016/j.jns.2019.116620] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2019] [Revised: 11/16/2019] [Accepted: 12/05/2019] [Indexed: 01/05/2023]
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Larivière R, Sgarioto N, Márquez BT, Gaudet R, Choquet K, McKinney RA, Watt AJ, Brais B. Sacs R272C missense homozygous mice develop an ataxia phenotype. Mol Brain 2019; 12:19. [PMID: 30866998 PMCID: PMC6416858 DOI: 10.1186/s13041-019-0438-3] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2018] [Accepted: 02/25/2019] [Indexed: 12/29/2022] Open
Abstract
Autosomal recessive spastic ataxia of Charlevoix-Saguenay (ARSACS [MIM 270550]) is an early-onset neurodegenerative disorder caused by mutations in the SACS gene. Over 200 SACS mutations have been identified. Most mutations lead to a complete loss of a sacsin, a large 520 kD protein, although some missense mutations are associated with low levels of sacsin expression. We previously showed that Sacs knock-out mice demonstrate early-onset ataxic phenotype with neurofilament bundling in many neuronal populations. To determine if the preservation of some mutated sacsin protein resulted in the same cellular and behavioral alterations, we generated mice expressing an R272C missense mutation, a homozygote mutation found in some affected patients. Though SacsR272C mice express 21% of wild type brain sacsin and sacsin is found in many neurons, they display similar abnormalities to Sacs knock-out mice, including the development of an ataxic phenotype, reduced Purkinje cell firing rates, and somatodendritic neurofilament bundles in Purkinje cells and other neurons. Together our results support that Sacs missense mutation largely lead to loss of sacsin function.
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Affiliation(s)
- Roxanne Larivière
- Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University, Room 622, 3801, University Street, Montreal, Québec, H3A 2B4, Canada
| | - Nicolas Sgarioto
- Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University, Room 622, 3801, University Street, Montreal, Québec, H3A 2B4, Canada
| | | | - Rébecca Gaudet
- Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University, Room 622, 3801, University Street, Montreal, Québec, H3A 2B4, Canada
| | - Karine Choquet
- Department of Human Genetics, Montreal Neurological Institute, McGill University, Montreal, Qc, Canada
| | - R Anne McKinney
- Department of Pharmacology and Therapeutics, McGill University, Montreal, Qc, Canada
| | - Alanna J Watt
- Department of Biology, McGill University, Montreal, Qc, Canada
| | - Bernard Brais
- Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University, Room 622, 3801, University Street, Montreal, Québec, H3A 2B4, Canada.
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7
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Artero Castro A, Machuca C, Rodriguez Jimenez FJ, Jendelova P, Erceg S. Short Review: Investigating ARSACS: models for understanding cerebellar degeneration. Neuropathol Appl Neurobiol 2019; 45:531-537. [PMID: 30636067 DOI: 10.1111/nan.12540] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2018] [Accepted: 12/19/2018] [Indexed: 11/29/2022]
Abstract
Autosomal recessive spastic ataxia of Charlevoix-Saguenay (ARSACS) is an early-onset neurodegenerative disease that includes progressive cerebellar dysfunction. ARSACS is caused by an autosomal recessive loss-of-function mutation in the SACS gene, which encodes for SACSIN. Although animal models are still necessary to investigate the role of SACSIN in the pathology of this disease, more reliable human cellular models need to be generated to better understand the cerebellar pathophysiology of ARSACS. The discovery of human induced pluripotent stem cells (hiPSC) has permitted the derivation of patient-specific cells. These cells have an unlimited self-renewing capacity and the ability to differentiate into different neural cell types, allowing studies of disease mechanism, drug discovery and cell replacement therapies. In this study, we discuss how the hiPSC-derived cerebellar organoid culture offers novel strategies for targeting the pathogenic mutations related to ARSACS. We also highlight the advantages and challenges of this 3D cellular model, as well as the questions that still remain unanswered.
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Affiliation(s)
- A Artero Castro
- Stem Cells Therapies in Neurodegenerative Diseases Lab, Research Center "Principe Felipe", Valencia, Spain
| | - C Machuca
- Stem Cells Therapies in Neurodegenerative Diseases Lab, Research Center "Principe Felipe", Valencia, Spain.,Unit of Genetics and Genomics of Neuromuscular and Neurodegenerative Disorders and Service of Genomics and Translational Genetics, Research Center "Principe Felipe", Valencia, Spain
| | - F J Rodriguez Jimenez
- Stem Cells Therapies in Neurodegenerative Diseases Lab, Research Center "Principe Felipe", Valencia, Spain
| | - P Jendelova
- Institute of Experimental Medicine, Department of Neuroscience, Academy of Science of the Czech Republic, Prague, Czech Republic
| | - S Erceg
- Stem Cells Therapies in Neurodegenerative Diseases Lab, Research Center "Principe Felipe", Valencia, Spain.,National Stem Cell Bank-Valencia Node, Platform for Proteomics, Genotyping and Cell Lines, PRB3, ISCIII, Research Center "Principe Felipe", Valencia, Spain
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8
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Ricca I, Morani F, Bacci GM, Nesti C, Caputo R, Tessa A, Santorelli FM. Clinical and molecular studies in two new cases of ARSACS. Neurogenetics 2019; 20:45-49. [PMID: 30680480 DOI: 10.1007/s10048-019-00564-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2018] [Accepted: 01/03/2019] [Indexed: 11/27/2022]
Abstract
Autosomal recessive spastic ataxia of Charlevoix-Saguenay (ARSACS) is an early-onset neurodevelopmental disorder characterized by the association of spastic ataxia and sensorimotor neuropathy. Additional features include retinal changes and cognitive impairment. Today, next-generation sequencing (NGS) techniques are allowing the rapid identification of a growing number of missense variants, even in less typical forms of the disease, but the pathogenic significance of these changes is often difficult to establish on the basis of classic bioinformatics criteria and genotype/phenotype correlations. Herein, we describe two novel cases of missense mutations in SACS. The two individuals were identified during the genetic screening of a large cohort of patients with inherited ataxias. We discuss how protein studies and specialized ophthalmological investigations could represent useful pointers for the interpretation of genetic data. Combination of these tools with NGS for rapid genotyping might help to identify new true ARSACS cases.
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Affiliation(s)
- Ivana Ricca
- Molecular Medicine, IRCCS Fondazione Stella Maris, via dei Giacinti 2 Calambrone, 56128, Pisa, Italy
| | - Federica Morani
- Molecular Medicine, IRCCS Fondazione Stella Maris, via dei Giacinti 2 Calambrone, 56128, Pisa, Italy
| | - Giacomo Maria Bacci
- Pediatric Ophthalmology Unit, Meyer Children's Hospital, University of Florence, Florence, Italy
| | - Claudia Nesti
- Molecular Medicine, IRCCS Fondazione Stella Maris, via dei Giacinti 2 Calambrone, 56128, Pisa, Italy
| | - Roberto Caputo
- Pediatric Ophthalmology Unit, Meyer Children's Hospital, University of Florence, Florence, Italy
| | - Alessandra Tessa
- Molecular Medicine, IRCCS Fondazione Stella Maris, via dei Giacinti 2 Calambrone, 56128, Pisa, Italy
| | - Filippo Maria Santorelli
- Molecular Medicine, IRCCS Fondazione Stella Maris, via dei Giacinti 2 Calambrone, 56128, Pisa, Italy.
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Parkinson MH, Bartmann AP, Clayton LMS, Nethisinghe S, Pfundt R, Chapple JP, Reilly MM, Manji H, Wood NJ, Bremner F, Giunti P. Optical coherence tomography in autosomal recessive spastic ataxia of Charlevoix-Saguenay. Brain 2018. [DOI: 10.1093/brain/awy028] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- Michael H Parkinson
- Department of Molecular Neuroscience, UCL Institute of Neurology, London, UK
- National Hospital for Neurology and Neurosurgery, Queen Square, London, UK
| | - Ana P Bartmann
- National Hospital for Neurology and Neurosurgery, Queen Square, London, UK
| | - Lisa M S Clayton
- National Hospital for Neurology and Neurosurgery, Queen Square, London, UK
| | - Suran Nethisinghe
- Department of Molecular Neuroscience, UCL Institute of Neurology, London, UK
| | - Rolph Pfundt
- Department of Human Genetics, Radboud University, Nijmegen Medical Centre, Nijmegen, The Netherlands
| | - J Paul Chapple
- William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, UK
| | - Mary M Reilly
- Department of Molecular Neuroscience, UCL Institute of Neurology, London, UK
- National Hospital for Neurology and Neurosurgery, Queen Square, London, UK
- MRC Centre for Neuromuscular Diseases, UCL Institute of Neurology, London, UK
| | - Hadi Manji
- National Hospital for Neurology and Neurosurgery, Queen Square, London, UK
| | - Nicholas J Wood
- Department of Molecular Neuroscience, UCL Institute of Neurology, London, UK
- National Hospital for Neurology and Neurosurgery, Queen Square, London, UK
| | - Fion Bremner
- National Hospital for Neurology and Neurosurgery, Queen Square, London, UK
| | - Paola Giunti
- Department of Molecular Neuroscience, UCL Institute of Neurology, London, UK
- National Hospital for Neurology and Neurosurgery, Queen Square, London, UK
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10
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Borruat FX, Holder GE, Bremner F. Inner Retinal Dysfunction in the Autosomal Recessive Spastic Ataxia of Charlevoix-Saguenay. Front Neurol 2017; 8:523. [PMID: 29075231 PMCID: PMC5643501 DOI: 10.3389/fneur.2017.00523] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2017] [Accepted: 09/20/2017] [Indexed: 11/25/2022] Open
Abstract
The autosomal recessive spastic ataxia of Charlevoix-Saguenay (ARSACS) is associated with structural retinal abnormalities either directly visible on funduscopy or revealed by optical coherence tomography (OCT). Most patients with ARSACS have a whitish peripapillary appearance corresponding to a thickening of the peripapillary retinal nerve fiber layer. OCT has also shown an absence of the physiological foveal depression. Abnormal electroretinography (ERG) has previously been reported in only two cases, without further details. This report describes a patient with ARSACS in whom careful full-field ERG revealed dysfunction of the retinal On− bipolar cells with sparing of photoreceptor function. This is the first report of inner retinal dysfunction in ARSACS.
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Affiliation(s)
| | - Graham E Holder
- Moorfields Eye Hospital, London, United Kingdom.,University College London Institute of Ophthalmology, London, United Kingdom
| | - Fion Bremner
- The National Hospital for Neurology and Neurosurgery, London, United Kingdom
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11
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Tranchant C, Anheim M. Movement disorders in mitochondrial diseases. Rev Neurol (Paris) 2016; 172:524-529. [PMID: 27476418 DOI: 10.1016/j.neurol.2016.07.003] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2016] [Accepted: 07/07/2016] [Indexed: 01/30/2023]
Abstract
Mitochondrial diseases (MIDs) are a large group of heterogeneous disorders due to mutations in either mitochondrial DNA (mtDNA) or nuclear DNA (nDNA) genes, the latter encoding proteins involved in mitochondrial function. A multisystem clinical picture that involves several organs, including both the peripheral and central nervous systems, is a common presentation of MID. Movement disorders, even isolated ones, are not rare. Cerebellar ataxia is common in myoclonic epilepsy with ragged red fibers (MERFF) due to mutations in the mitochondrial transfer RNA (tRNA) lysine gene, in Kearns-Sayre syndrome due to mtDNA deletions, in sensory ataxic neuropathy with dysarthria and ophthalmoplegia (SANDO) due to nuclear POLG1 gene mutations, and also in ARCA2, Friedreich's ataxia, SPG7, SCA28 and autosomal-recessive spastic ataxia of Charlevoix-Saguenay (ARSACS) due to mutations in nuclear genes involved in mitochondrial morphology or function. Myoclonus is a key feature of MERFF, but may also be encountered in mitochondrial encephalomyopathy, lactic acidosis and stroke-like episodes (MELAS), ARCA2, POLG1 mutations and Leigh syndrome. Dystonia is common in Leigh syndrome (which may be caused by 75 different genes) and in Leber hereditary ocular neuropathy (LHON) plus disease, due to mutations in mtDNA genes that encode subunits of NADH dehydrogenase, as well as in ARCA2, pantothenate kinase-associated neurodegeneration (PKAN), mitochondrial membrane protein-associated neurodegeneration (MPAN) and POLG1 mutations. Other movement disorders are rarer (such as parkinsonism, tremor, chorea). Although parkinsonism is more frequent in POLG1 mutations, and myoclonus in MERFF, most movement disorders are found either isolated or combined in numerous MIDs. The presence of associated neurological signs, whether central or peripheral, or of evocative magnetic resonance imaging (MRI) abnormalities (striatal necrosis) should prompt a search for MID. In cases of a particular clinical spectrum (LHON, MERFF, Kearns-Sayre, SANDO, SPG7, ARCA2, ARSACS), a search for the most frequently implicated mutation(s) is recommended. In other cases, muscle biopsies followed by metabolic and genetic studies may be useful for arriving at a diagnosis.
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Affiliation(s)
- C Tranchant
- Service de neurologie, hôpital de Hautepierre, 1, avenue Molière, 67000 Strasbourg, France; Fédération de médecine translationnelle, 67000 Strasbourg, France.
| | - M Anheim
- Service de neurologie, hôpital de Hautepierre, 1, avenue Molière, 67000 Strasbourg, France; Fédération de médecine translationnelle, 67000 Strasbourg, France
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12
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Shah CT, Ward TS, Matsumoto JA, Shildkrot Y. Foveal hypoplasia in autosomal recessive spastic ataxia of Charlevoix-Saguenay. J AAPOS 2016; 20:81-3. [PMID: 26917082 DOI: 10.1016/j.jaapos.2015.10.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/17/2015] [Revised: 10/07/2015] [Accepted: 10/07/2015] [Indexed: 10/22/2022]
Abstract
A 14-year-old boy presented with a presumed diagnosis of autosomal recessive spastic ataxia of Charlevoix-Saguenay (ARSACS). The neurological examination, nerve conduction study, and brain imaging results were all consistent with the diagnosis. The ophthalmologic examination was notable for a prominent myelinated nerve fiber layer extending from the disk along the major temporal arcades in both eyes. Loss of foveal depression was noted clinically and on spectral domain optical coherence tomography. This case highlights a novel finding that may aid in the diagnosis of ARSACS.
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Affiliation(s)
- Christopher T Shah
- Department of Ophthalmology, University of Virginia, Charlottesville, Virginia
| | - Tyson S Ward
- Department of Ophthalmology, University of Virginia, Charlottesville, Virginia
| | - Julie A Matsumoto
- Department of Radiology and Medical Imaging, University of Virginia, Charlottesville, Virginia
| | - Yevgeniy Shildkrot
- Department of Ophthalmology, University of Virginia, Charlottesville, Virginia.
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13
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Subramony S, Moscovich M, Ashizawa T. Genetics and Clinical Features of Inherited Ataxias. Mov Disord 2015. [DOI: 10.1016/b978-0-12-405195-9.00062-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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14
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Larivière R, Gaudet R, Gentil BJ, Girard M, Conte TC, Minotti S, Leclerc-Desaulniers K, Gehring K, McKinney RA, Shoubridge EA, McPherson PS, Durham HD, Brais B. Sacs knockout mice present pathophysiological defects underlying autosomal recessive spastic ataxia of Charlevoix-Saguenay. Hum Mol Genet 2014; 24:727-39. [PMID: 25260547 DOI: 10.1093/hmg/ddu491] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Autosomal recessive spastic ataxia of Charlevoix-Saguenay (ARSACS [MIM 270550]) is an early-onset neurodegenerative disorder caused by mutations in the SACS gene. Over 170 SACS mutations have been reported worldwide and are thought to cause loss of function of sacsin, a poorly characterized and massive 520 kDa protein. To establish an animal model and to examine the pathophysiological basis of ARSACS, we generated Sacs knockout (Sacs(-/-)) mice. Null animals displayed an abnormal gait with progressive motor, cerebellar and peripheral nerve dysfunctions highly reminiscent of ARSACS. These clinical features were accompanied by an early onset, progressive loss of cerebellar Purkinje cells followed by spinal motor neuron loss and peripheral neuropathy. Importantly, loss of sacsin function resulted in abnormal accumulation of non-phosphorylated neurofilament (NF) bundles in the somatodendritic regions of vulnerable neuronal populations, a phenotype also observed in an ARSACS brain. Moreover, motor neurons cultured from Sacs(-/-) embryos exhibited a similar NF rearrangement with significant reduction in mitochondrial motility and elongated mitochondria. The data points to alterations in the NF cytoskeleton and defects in mitochondrial dynamics as the underlying pathophysiological basis of ARSACS.
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Affiliation(s)
- Roxanne Larivière
- Department of Neurology and Neurosurgery, Laboratory of Neurogenetics of Motion and
| | - Rébecca Gaudet
- Department of Neurology and Neurosurgery, Laboratory of Neurogenetics of Motion and
| | - Benoit J Gentil
- Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University, Montreal, QC, Canada H3A 2B4
| | - Martine Girard
- Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University, Montreal, QC, Canada H3A 2B4
| | | | - Sandra Minotti
- Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University, Montreal, QC, Canada H3A 2B4
| | | | - Kalle Gehring
- Groupe de Recherche Axé sur la Structure des Protéines, Department of Biochemistry and
| | - R Anne McKinney
- Department of Pharmacology, McGill University, Montreal, QC, Canada H3G 0B1
| | - Eric A Shoubridge
- Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University, Montreal, QC, Canada H3A 2B4
| | - Peter S McPherson
- Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University, Montreal, QC, Canada H3A 2B4
| | - Heather D Durham
- Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University, Montreal, QC, Canada H3A 2B4
| | - Bernard Brais
- Department of Neurology and Neurosurgery, Laboratory of Neurogenetics of Motion and
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Abstract
Ophthalmic findings are common features of neurodegenerative disorders and, in addition to being clinically important, have emerged as potentially useful biomarkers of disease progression in several conditions. Clinically, these visual system abnormalities can be a clue to diagnosis, as well as being a prominent cause of disability in affected patients. In this Review, we describe the various afferent visual system and other ophthalmic features of inherited neurodegenerative disorders, including the muscular dystrophies, Friedreich ataxia, the spinocerebellar ataxias, hereditary spastic paraplegia, Charcot-Marie-Tooth disease, and other conditions. We focus on the expanding role of optical coherence tomography in diagnostic imaging of the retina and optic nerve head, and the possible use of ophthalmic findings as biomarkers of disease severity in hereditary neurodegenerative disorders. In addition, we discuss the ophthalmic manifestations and treatment implications of mitochondrial dysfunction, which is a feature of many inherited neurodegenerative diseases.
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Yu-Wai-Man P, Pyle A, Griffin H, Santibanez-Korev M, Horvath R, Chinnery PF. Abnormal retinal thickening is a common feature among patients with ARSACS-related phenotypes. Br J Ophthalmol 2014; 98:711-3. [PMID: 24457356 PMCID: PMC3995215 DOI: 10.1136/bjophthalmol-2013-304534] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Affiliation(s)
- Patrick Yu-Wai-Man
- Wellcome Trust Centre for Mitochondrial Research, Institute of Genetic Medicine, Newcastle University, , Newcastle upon Tyne, Tyne and Wear, UK
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