1
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van der Heul AMB, van Eijk RPA, Wadman RI, Asselman F, Cuppen I, Nievelstein RAJ, Gerrits E, van der Pol WL, van den Engel-Hoek L. Mastication in Patients with Spinal Muscular Atrophy Types 2 and 3 is Characterized by Abnormal Efficiency, Reduced Endurance, and Fatigue. Dysphagia 2021; 37:715-723. [PMID: 34392389 PMCID: PMC9345836 DOI: 10.1007/s00455-021-10351-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Accepted: 08/02/2021] [Indexed: 11/30/2022]
Abstract
Mastication problems can have a negative impact on the intake of food and quality of life. This cross-sectional study characterizes mastication problems using clinical and instrumental assessments in patients with spinal muscular atrophy (SMA) types 2 and 3 with self-reported bulbar problems. We included 27 patients (aged 13–67 years), 18 with SMA type 2 and 9 patients with SMA type 3 (of whom three were still ambulant) and applied a questionnaire, clinical mastication tests (TOMASS and 6-min mastication test), and muscle ultrasound of the mastication muscles. Non-ambulant patients demonstrated inefficient mastication as reflected by median z scores for masticatory cycles (z = 1.8), number of swallows (z = 4.3) and time needed to finish the cracker (z = 3.4), and limited endurance of continuous mastication as demonstrated by the median z scores of the 6-min mastication test (z = − 1.5). Patients reported increased fatigue directly after the 6-min mastication test as well as 5 min after completing the test (p < 0.001; p = 0.003). Reduced maximal mouth opening was associated with mastication problems (p < 0.001). Muscle ultrasound of the mastication muscles showed an abnormal muscle structure in 90% of both ambulant and non-ambulant patients. This study aims to understand the nature and underlying mechanisms of mastication problems in patients with SMA types 2 and 3 with reported bulbar problems.
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Affiliation(s)
- A M B van der Heul
- Department of Neurology & Neurosurgery, UMC Utrecht Brain Center, University Medical Center Utrecht, Utrecht, The Netherlands
| | - R P A van Eijk
- Department of Neurology & Neurosurgery, UMC Utrecht Brain Center, University Medical Center Utrecht, Utrecht, The Netherlands.,Biostatistics & Research Support, Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, Utrecht, The Netherlands
| | - R I Wadman
- Department of Neurology & Neurosurgery, UMC Utrecht Brain Center, University Medical Center Utrecht, Utrecht, The Netherlands
| | - F Asselman
- Department of Neurology & Neurosurgery, UMC Utrecht Brain Center, University Medical Center Utrecht, Utrecht, The Netherlands
| | - I Cuppen
- Department of Neurology & Neurosurgery, UMC Utrecht Brain Center, University Medical Center Utrecht, Utrecht, The Netherlands
| | - R A J Nievelstein
- Department of Radiology & Nuclear Medicine, Imaging & Oncology Division, University Medical Center Utrecht, Utrecht, The Netherlands
| | - E Gerrits
- Department of Languages, Literature and Communication, Utrecht Institute of Linguistics OTS, Utrecht University, Utrecht, The Netherlands
| | - W L van der Pol
- Department of Neurology & Neurosurgery, UMC Utrecht Brain Center, University Medical Center Utrecht, Utrecht, The Netherlands.
| | - L van den Engel-Hoek
- Department of Rehabilitation, Donders Center for Neuroscience, Radboud University Medical Center, Nijmegen, The Netherlands
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2
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Pro S, Tozzi AE, D'Amico A, Catteruccia M, Cherchi C, De Luca M, Nicita F, Diodato D, Cutrera R, Bertini E, Valeriani M. Age-related sensory neuropathy in patients with spinal muscular atrophy type 1. Muscle Nerve 2021; 64:599-603. [PMID: 34368972 DOI: 10.1002/mus.27389] [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: 10/02/2020] [Revised: 07/21/2021] [Accepted: 07/24/2021] [Indexed: 11/12/2022]
Abstract
INTRODUCTION/AIMS Spinal muscular atrophy type 1 (SMA 1) is a devastating motor neuron disorder that leads to progressive muscle weakness, respiratory failure and premature death. Although sensory electrophysiological changes have been anecdotally found in pediatric SMA 1 patients, the age of onset of sensory neuropathy remains unknown. METHODS Sensory nerve conduction studies of the median and sural nerves were performed in 28 consecutive SMA 1 patients of different ages. Sensory nerve conduction velocities and sensory nerve action potential (SNAP) amplitudes recorded in these patients were compared with those obtained from 93 healthy subjects stratified by age. RESULTS SNAP amplitudes decreased with increasing age in the sural and median nerves, without any significant difference between upper and lower limbs. DISCUSSION Our data suggest that sural and median nerve SNAP amplitudes are normal in younger patients, while an axonal neuropathy appears in older ones.
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Affiliation(s)
- Stefano Pro
- Neurophysiology Unit, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | - Alberto Eugenio Tozzi
- Predictive and Preventive Medicine Research Unit, Bambino Gesù Children Hospital, IRCCS, Rome, Italy
| | - Adele D'Amico
- Unit of Neuromuscular and Neurodegenerative Diseases, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | - Michela Catteruccia
- Unit of Neuromuscular and Neurodegenerative Diseases, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | - Claudio Cherchi
- Bronchopneumology Unit, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | | | - Francesco Nicita
- Unit of Neuromuscular and Neurodegenerative Diseases, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | - Daria Diodato
- Unit of Neuromuscular and Neurodegenerative Diseases, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | - Renato Cutrera
- Bronchopneumology Unit, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | - Enrico Bertini
- Unit of Neuromuscular and Neurodegenerative Diseases, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | - Massimiliano Valeriani
- Neurology Ward Unit, Bambino Gesù Hospital, Rome, Italy.,Center for Sensory-Motor Interaction, Aalborg University, Aalborg, Denmark
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3
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McGrattan KE, Graham RJ, DiDonato CJ, Darras BT. Dysphagia Phenotypes in Spinal Muscular Atrophy: The Past, Present, and Promise for the Future. AMERICAN JOURNAL OF SPEECH-LANGUAGE PATHOLOGY 2021; 30:1008-1022. [PMID: 33822657 PMCID: PMC8702868 DOI: 10.1044/2021_ajslp-20-00217] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2020] [Revised: 11/06/2020] [Accepted: 01/15/2021] [Indexed: 05/09/2023]
Abstract
Purpose The aim of this study was to provide clinicians with an overview of literature relating to dysphagia in spinal muscular atrophy (SMA) to guide assessment and treatment. Method In this clinical focus article, we review literature published in Scopus and PubMed between 1990 and 2020 pertaining to dysphagia in SMA across the life span. Original research articles that were published in English were included. Searches were conducted within four themes of inquiry: (a) etiology and phenotypes, (b) respiratory systemic deficits and management, (c) characteristics of natural history dysphagia and its treatment, and (d) dysphagia outcomes with disease-modifying therapies. Articles for the first two themes were selected by content experts who identified the most salient articles that would provide clinicians foundational background knowledge about SMA. Articles for the third theme were identified using search terms, including spinal muscular atrophy, swallow, dysphagia, bulbar, nutrition, g-tube, alternative nutrition, jaw, mouth, palate, OR mandible. Search terms for the fourth theme included spinal muscular atrophy AND nusinersen OR AVXS-101/onasemnogene abeparvovec-xioi. Review of Pertinent Literature Twenty-nine articles were identified. Findings across identified articles support the fact that patients with SMA who do not receive disease-modifying therapy exhibit clinically significant deficits in oropharyngeal swallow function. Few investigations provided systematic information regarding the underlying physiological deficits responsible for this loss in function, the timing of the degradation, or how disease-modifying therapies change these outcomes. Conclusion Future research outlining the physiological and functional oropharyngeal swallowing deficits among patients with SMA who receive disease-modifying therapy is critical in developing standards of dysphagia care to guide clinicians.
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Affiliation(s)
- Katlyn Elizabeth McGrattan
- Department of Speech-Language-Hearing Science, University of Minnesota, Minneapolis
- Department of Rehabilitation, Masonic Children's Hospital, Minneapolis, MN
| | - Robert J. Graham
- Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital, MA
| | - Christine J. DiDonato
- Department of Pediatrics, Northwestern University, Chicago, IL
- Human Molecular Genetics and Physiology Program, Anne & Robert H. Lurie Children's Hospital, Chicago, IL
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4
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Matesanz SE, Curry C, Gross B, Rubin AI, Linn R, Yum SW, Kichula EA. Clinical Course in a Patient With Spinal Muscular Atrophy Type 0 Treated With Nusinersen and Onasemnogene Abeparvovec. J Child Neurol 2020; 35:717-723. [PMID: 32515646 DOI: 10.1177/0883073820928784] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Spinal muscular atrophy type 0 is the most severe phenotype of the disease, with patients presenting with contractures, weakness, and respiratory failure at birth, and is typically fatal within weeks. We describe the case of a patient with spinal muscular atrophy type 0 who was treated with both nusinersen and onasemnogene abeparvovec. She has made modest motor improvements since treatment initiation with a 30-point improvement in CHOP-INTEND score, and continues to make motor gains at age 13 months without regression of function, although she remains profoundly weak. Although she has had motor improvements, she has also had continued systemic complications from her spinal muscular atrophy, including chronic respiratory failure, dysphagia, congenital heart malformation, digit necrosis, and diffuse macular rash. This case highlights the challenges in treating those with more severe disease phenotypes and raises questions of how some systemic complications may respond to current SMN replacement therapies.
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Affiliation(s)
- Susan E Matesanz
- Division of Neurology, 367873Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Candace Curry
- Neurology, 381778Mission Children's Specialists, Asheville, NC, USA
| | - Brianna Gross
- Division of Neurology, 367873Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Adam I Rubin
- Pathology and Laboratory Medicine, 14640University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA.,Dermatology, 14640University of Pennsylvania Perelman School of Medicine and Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Rebecca Linn
- Pathology and Laboratory Medicine, 14640University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA.,Department of Pathology, 367873Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Sabrina W Yum
- Division of Neurology, 367873Children's Hospital of Philadelphia, Philadelphia, PA, USA.,Division of Neurology, 14640University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
| | - Elizabeth A Kichula
- Division of Neurology, 367873Children's Hospital of Philadelphia, Philadelphia, PA, USA.,Division of Neurology, 14640University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
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5
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Shorrock HK, Gillingwater TH, Groen EJN. Molecular Mechanisms Underlying Sensory-Motor Circuit Dysfunction in SMA. Front Mol Neurosci 2019; 12:59. [PMID: 30886572 PMCID: PMC6409332 DOI: 10.3389/fnmol.2019.00059] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2018] [Accepted: 02/15/2019] [Indexed: 12/19/2022] Open
Abstract
Activation of skeletal muscle in response to acetylcholine release from the neuromuscular junction triggered by motor neuron firing forms the basis of all mammalian locomotion. Intricate feedback and control mechanisms, both from within the central nervous system and from sensory organs in the periphery, provide essential inputs that regulate and finetune motor neuron activity. Interestingly, in motor neuron diseases, such as spinal muscular atrophy (SMA), pathological studies in patients have identified alterations in multiple parts of the sensory-motor system. This has stimulated significant research efforts across a range of different animal models of SMA in order to understand these defects and their contribution to disease pathogenesis. Several recent studies have demonstrated that defects in sensory components of the sensory-motor system contribute to dysfunction of motor neurons early in the pathogenic process. In this review, we provide an overview of these findings, with a specific focus on studies that have provided mechanistic insights into the molecular processes that underlie dysfunction of the sensory-motor system in SMA. These findings highlight the role that cell types other than motor neurons play in SMA pathogenesis, and reinforce the need for therapeutic interventions that target and rescue the wide array of defects that occur in SMA.
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Affiliation(s)
- Hannah K Shorrock
- Edinburgh Medical School: Biomedical Sciences, The University of Edinburgh, Edinburgh, United Kingdom.,Euan MacDonald Centre for Motor Neurone Disease Research, The University of Edinburgh, Edinburgh, United Kingdom
| | - Thomas H Gillingwater
- Edinburgh Medical School: Biomedical Sciences, The University of Edinburgh, Edinburgh, United Kingdom.,Euan MacDonald Centre for Motor Neurone Disease Research, The University of Edinburgh, Edinburgh, United Kingdom
| | - Ewout J N Groen
- Edinburgh Medical School: Biomedical Sciences, The University of Edinburgh, Edinburgh, United Kingdom.,Euan MacDonald Centre for Motor Neurone Disease Research, The University of Edinburgh, Edinburgh, United Kingdom
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6
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Andrews JA, Shefner JM. Clinical neurophysiology of anterior horn cell disorders. HANDBOOK OF CLINICAL NEUROLOGY 2019; 161:317-326. [PMID: 31307610 DOI: 10.1016/b978-0-444-64142-7.00057-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
The development of neurophysiological techniques for clinical assessment in the 20th century is closely related to the study of anterior horn cell diseases. The effects of motor axon loss on nerve conduction velocity and compound motor amplitude were elucidated first in amyotrophic lateral sclerosis (ALS), as was the characterization of reinnervation as detected by needle electromyography. The same changes noted in early studies still play a major role in the diagnosis of anterior horn cell diseases. In addition, much of modern neurophysiological assessment of motor axon quantitation, ion channel changes in neurogenic disease, and cortical physiology studies to assess both network and excitability abnormalities have all been applied to ALS. In this chapter, we summarize the clinical attributes of ALS and Spinal Muscular Atrophy, and review how clinical neurophysiology is employed in the clinical and the research setting.
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Affiliation(s)
- Jinsy A Andrews
- The Neurological Institute, Columbia University, New York, NY, United States
| | - Jeremy M Shefner
- Department of Neurology, Barrow Neurological Institute, Phoenix, AZ, United States.
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7
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Surrey V, Zöller C, Lork AA, Moradi M, Balk S, Dombert B, Saal-Bauernschubert L, Briese M, Appenzeller S, Fischer U, Jablonka S. Impaired Local Translation of β-actin mRNA in Ighmbp2-Deficient Motoneurons: Implications for Spinal Muscular Atrophy with respiratory Distress (SMARD1). Neuroscience 2018; 386:24-40. [DOI: 10.1016/j.neuroscience.2018.06.019] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2018] [Revised: 06/03/2018] [Accepted: 06/11/2018] [Indexed: 12/31/2022]
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8
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Grotto S, Cuisset JM, Marret S, Drunat S, Faure P, Audebert-Bellanger S, Desguerre I, Flurin V, Grebille AG, Guerrot AM, Journel H, Morin G, Plessis G, Renolleau S, Roume J, Simon-Bouy B, Touraine R, Willems M, Frébourg T, Verspyck E, Saugier-Veber P. Type 0 Spinal Muscular Atrophy: Further Delineation of Prenatal and Postnatal Features in 16 Patients. J Neuromuscul Dis 2016; 3:487-495. [DOI: 10.3233/jnd-160177] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Affiliation(s)
- Sarah Grotto
- Department of Genetics, Normandy Center for Medical Genomics and Personalized Medicine, Rouen University Hospital, Rouen, France
| | - Jean-Marie Cuisset
- Department of Pediatric Neurology, Roger Salengro Hospital, Lille Regional University Hospital, Lille, France
| | - Stéphane Marret
- Department of Pediatric Intensive Care, Rouen University Hospital, Rouen, France
- Inserm ERI 28, Institute for Research and Innovation in Biomedicine, Rouen University, France
| | - Séverine Drunat
- Department of Genetics, Robert Debre University Hospital, APHP, Paris, France
| | - Patricia Faure
- Inserm U1079, Institute for Research and Innovation in Biomedicine, Rouen University, Rouen, France
| | | | - Isabelle Desguerre
- Department of Pediatric Neurology, Necker-Enfants Malades Hospital, APHP, Paris, France
| | - Vincent Flurin
- Department of Pediatric Intensive Care, Le Mans Hospital, Le Mans, France
| | - Anne-Gaëlle Grebille
- Department of Obstetrics and Gynecology, Saint-Brieuc Hospital, Saint-Brieuc, France
| | - Anne-Marie Guerrot
- Department of Genetics, Normandy Center for Medical Genomics and Personalized Medicine, Rouen University Hospital, Rouen, France
| | - Hubert Journel
- Department of Genetics, Vannes Bretagne-Atlantique Hospital, Vannes, France
| | - Gilles Morin
- Department of Genetics, Amiens University Hospital, Amiens, France
| | | | - Sylvain Renolleau
- Department of Pediatric Intensive Care, Armand-Trousseau Children’s Hospital, APHP, Paris, France
| | - Joëlle Roume
- Department of Genetics, Poissy-Saint-Germain-en-Laye Hospital, Poissy, France
| | | | - Renaud Touraine
- Department of Genetics, Saint-Etienne University Hospital, Saint-Priest-en-Jarez, France
| | - Marjolaine Willems
- Department of Genetics, Necker-Enfants Malades Hospital, APHP, Paris, France
| | - Thierry Frébourg
- Department of Genetics, Normandy Center for Medical Genomics and Personalized Medicine, Rouen University Hospital, Rouen, France
- Inserm U1079, Institute for Research and Innovation in Biomedicine, Rouen University, Rouen, France
| | - Eric Verspyck
- Department of Obstetrics and Gynecology, Rouen University Hospital, Rouen, France
| | - Pascale Saugier-Veber
- Department of Genetics, Normandy Center for Medical Genomics and Personalized Medicine, Rouen University Hospital, Rouen, France
- Inserm U1079, Institute for Research and Innovation in Biomedicine, Rouen University, Rouen, France
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9
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Moriyama H, Hayashi S, Inoue Y, Itoh M, Otsuka N. Sex differences in morphometric aspects of the peripheral nerves and related diseases. NeuroRehabilitation 2016; 39:413-22. [PMID: 27589511 PMCID: PMC5008230 DOI: 10.3233/nre-161372] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND The elucidation of the relationship between the morphology of the peripheral nerves and the diseases would be valuable in developing new medical treatments on the assumption that characteristics of the peripheral nerves in females are different from those in males. METHODS We used 13 kinds of the peripheral nerve. The materials were obtained from 10 Japanese female and male cadavers. We performed a morphometric analysis of nerve fibers. We estimated the total number of myelinated axons, and calculated the average transverse area and average circularity ratio of myelinated axons in the peripheral nerves. RESULTS There was no statistically significant difference in the total number, average transverse area, or average circularity ratio of myelinated axons between the female and male specimens except for the total number of myelinated axons in the vestibular nerve and the average circularity ratio of myelinated axons in the vagus nerve. CONCLUSIONS The lower number of myelinated axons in the female vestibular nerve may be one of the reasons why vestibular disorders have a female preponderance. Moreover, the higher average circularity ratio of myelinated axons in the male vagus nerve may be one reason why vagus nerve activity to modulate pain has a male preponderance.
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Affiliation(s)
- Hiroshi Moriyama
- Department of Anatomy, Showa University School of Medicine, Tokyo, Japan
| | - Shogo Hayashi
- Department of Anatomy, Tokyo Medical University, Tokyo, Japan
| | - Yuriko Inoue
- Department of Anatomy, Showa University School of Medicine, Tokyo, Japan
| | - Masahiro Itoh
- Department of Anatomy, Tokyo Medical University, Tokyo, Japan
| | - Naruhito Otsuka
- Department of Anatomy, Showa University School of Medicine, Tokyo, Japan
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10
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van Bruggen HW, Wadman RI, Bronkhorst EM, Leeuw M, Creugers N, Kalaykova SI, van der Pol WL, Steenks MH. Mandibular dysfunction as a reflection of bulbar involvement in SMA type 2 and 3. Neurology 2016; 86:552-9. [DOI: 10.1212/wnl.0000000000002348] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2015] [Accepted: 10/13/2015] [Indexed: 12/16/2022] Open
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Abstract
Spinal muscular atrophies (SMAs) are hereditary degenerative disorders of lower motor neurons associated with progressive muscle weakness and atrophy. Proximal 5q SMA is caused by decreased levels of the survival of motor neuron (SMN) protein and is the most common genetic cause of infant mortality. Its inheritance pattern is autosomal recessive, resulting from mutations involving the SMN1 gene on chromosome 5q13. Unlike other autosomal recessive diseases, the SMN gene has a unique structure (an inverted duplication) that presents potential therapeutic targets. Although there is currently no effective treatment of SMA, the field of translational research in this disorder is active and clinical trials are ongoing. Advances in the multidisciplinary supportive care of children with SMA also offer hope for improved life expectancy and quality of life.
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Affiliation(s)
- Basil T Darras
- Division of Clinical Neurology, Department of Neurology, Boston Children's Hospital, 300 Longwood Avenue, Fegan 11, Boston, MA 02115, USA.
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12
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Duman O, Uysal H, Skjei KL, Kizilay F, Karauzum S, Haspolat S. Sensorimotor polyneuropathy in patients with SMA type-1: Electroneuromyographic findings. Muscle Nerve 2013; 48:117-21. [DOI: 10.1002/mus.23722] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/08/2012] [Indexed: 12/12/2022]
Affiliation(s)
- Ozgur Duman
- Akdeniz University Hospital; H Block; Department of Child Neurology; Antalya Turkey
| | - Hilmi Uysal
- Akdeniz University Hospital; Department of Neurology; Antalya Turkey
| | - Karen L. Skjei
- Children Hospital of Philadelphia; Department of Neurology; Philadelphia Pennsylvania USA
| | - Ferah Kizilay
- Akdeniz University Hospital; Department of Neurology; Antalya Turkey
| | - Sibel Karauzum
- Akdeniz University Hospital; Department of Medical Biology and Genetics; Antalya Turkey
| | - Senay Haspolat
- Akdeniz University Hospital; H Block; Department of Child Neurology; Antalya Turkey
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13
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Fast motor axon loss in SMARD1 does not correspond to morphological and functional alterations of the NMJ. Neurobiol Dis 2013; 54:169-82. [PMID: 23295857 DOI: 10.1016/j.nbd.2012.12.010] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2012] [Revised: 11/30/2012] [Accepted: 12/21/2012] [Indexed: 11/20/2022] Open
Abstract
Spinal muscular atrophy with respiratory distress type 1 (SMARD1) is a childhood motoneuron disease caused by mutations in the gene encoding for IGHMBP2, an ATPase/Helicase. Paralysis of the diaphragm is an early and prominent clinical sign resulting both from denervation and myopathy. In skeletal muscles, muscle atrophy mainly results from loss of motoneuron cell bodies and axonal degeneration. Although it is well known that loss of motoneurons at the lumbar spinal cord is an early event in the pathogenesis of the disease, it is not clear whether the corresponding proximal axons and NMJs are also early affected. In order to address this question, we have investigated the time course of the disease progression at the level of the motoneuron cell body, proximal axon (ventral root), distal axon (sciatic nerve), NMJ, and muscle fiber in Nmd(2J) mice, a mouse model for SMARD1. Our results show an early and apparently parallel loss of motoneurons, proximal axons, and NMJs. In affected muscles, however, denervated fibers coexist with NMJs with normal morphology and unaltered neurotransmission. Furthermore, unaffected axons are able to sprout and reinnervate muscle fibers, suggesting selective vulnerability of neurons to Ighmbp2 deficiency. The preservation of the NMJ morphology and neurotransmission in the Nmd(2J) mouse until motor axon loss takes place, differs from that observed in SMA mouse models in which NMJ impairment is an early and more general phenomenon in affected muscles.
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14
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Yiu EM, Ryan MM. Genetic axonal neuropathies and neuronopathies of pre-natal and infantile onset. J Peripher Nerv Syst 2012; 17:285-300. [DOI: 10.1111/j.1529-8027.2012.00412.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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15
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Ammoun S, Schmid MC, Ristic N, Zhou L, Hilton D, Ercolano E, Carroll C, Hanemann CO. The role of insulin-like growth factors signaling in merlin-deficient human schwannomas. Glia 2012; 60:1721-33. [DOI: 10.1002/glia.22391] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2012] [Revised: 06/20/2012] [Accepted: 06/22/2012] [Indexed: 01/05/2023]
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16
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Locatelli D, d'Errico P, Capra S, Finardi A, Colciaghi F, Setola V, Terao M, Garattini E, Battaglia G. Spinal muscular atrophy pathogenic mutations impair the axonogenic properties of axonal-survival of motor neuron. J Neurochem 2012; 121:465-74. [PMID: 22324632 DOI: 10.1111/j.1471-4159.2012.07689.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The axonal survival of motor neuron (a-SMN) protein is a truncated isoform of SMN1, the spinal muscular atrophy (SMA) disease gene. a-SMN is selectively localized in axons and endowed with remarkable axonogenic properties. At present, the role of a-SMN in SMA is unknown. As a first step to verify a link between a-SMN and SMA, we investigated by means of over-expression experiments in neuroblastoma-spinal cord hybrid cell line (NSC34) whether SMA pathogenic mutations located in the N-terminal part of the protein affected a-SMN function. We demonstrated here that either SMN1 missense mutations or small intragenic re-arrangements located in the Tudor domain consistently altered the a-SMN capability of inducing axonal elongation in vitro. Mutated human a-SMN proteins determined in almost all NSC34 motor neurons the growth of short axons with prominent morphologic abnormalities. Our data indicate that the Tudor domain is critical in dictating a-SMN function possibly because it is an association domain for proteins involved in axon growth. They also indicate that Tudor domain mutations are functionally relevant not only for FL-SMN but also for a-SMN, raising the possibility that also a-SMN loss of function may contribute to the pathogenic steps leading to SMA.
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Affiliation(s)
- Denise Locatelli
- Molecular Neuroanatomy and Pathogenesis Unit, Neurological Institute 'C. Besta', Milano, Italy
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Abstract
Spinal muscular atrophy, a hereditary degenerative disorder of lower motor neurons associated with progressive muscle weakness and atrophy, is the most common genetic cause of infant mortality. It is caused by decreased levels of the "survival of motor neuron" (SMN) protein. Its inheritance pattern is autosomal recessive, resulting from mutations involving the SMN1 gene on chromosome 5q13. However, unlike many other autosomal recessive diseases, the SMN gene involves a unique structure (an inverted duplication) that presents potential therapeutic targets. Although no effective treatment for spinal muscular atrophy exists, the field of translational research in spinal muscular atrophy is active, and clinical trials are ongoing. Advances in the multidisciplinary supportive care of children with spinal muscular atrophy also offer hope for improved life expectancy and quality of life.
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Sleigh JN, Gillingwater TH, Talbot K. The contribution of mouse models to understanding the pathogenesis of spinal muscular atrophy. Dis Model Mech 2011; 4:457-67. [PMID: 21708901 PMCID: PMC3124050 DOI: 10.1242/dmm.007245] [Citation(s) in RCA: 102] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Spinal muscular atrophy (SMA), which is caused by inactivating mutations in the survival motor neuron 1 (SMN1) gene, is characterized by loss of lower motor neurons in the spinal cord. The gene encoding SMN is very highly conserved in evolution, allowing the disease to be modeled in a range of species. The similarities in anatomy and physiology to the human neuromuscular system, coupled with the ease of genetic manipulation, make the mouse the most suitable model for exploring the basic pathogenesis of motor neuron loss and for testing potential treatments. Therapies that increase SMN levels, either through direct viral delivery or by enhancing full-length SMN protein expression from the SMN1 paralog, SMN2, are approaching the translational stage of development. It is therefore timely to consider the role of mouse models in addressing aspects of disease pathogenesis that are most relevant to SMA therapy. Here, we review evidence suggesting that the apparent selective vulnerability of motor neurons to SMN deficiency is relative rather than absolute, signifying that therapies will need to be delivered systemically. We also consider evidence from mouse models suggesting that SMN has its predominant action on the neuromuscular system in early postnatal life, during a discrete phase of development. Data from these experiments suggest that the timing of therapy to increase SMN levels might be crucial. The extent to which SMN is required for the maintenance of motor neurons in later life and whether augmenting its levels could treat degenerative motor neuron diseases, such as amyotrophic lateral sclerosis (ALS), requires further exploration.
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Affiliation(s)
- James N Sleigh
- MRC Functional Genomics Unit, Department of Physiology, Anatomy and Genetics, University of Oxford, South Parks Road, Oxford, OX1 3QX, UK
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19
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Fernández-Torre JL, Teja JL, Castellanos A, Figols J, Obeso T, Arteaga R. Spinal muscular atrophy type I mimicking critical illness neuropathy in a paediatric intensive care neonate: electrophysiological features. Brain Dev 2008; 30:599-602. [PMID: 18384992 DOI: 10.1016/j.braindev.2008.02.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/23/2007] [Revised: 02/14/2008] [Accepted: 02/20/2008] [Indexed: 11/29/2022]
Abstract
We report the case of a neonate with spinal muscular atrophy type I (SMA type I or Werdnig-Hoffman disease) who was initially misdiagnosis as having critical illness neuropathy. Electromyography (EMG) showed a moderate loss of voluntary and motor unit potentials of both neurogenic and myopathic appearance. Nerve conduction studies revealed the presence of a severe sensory-motor axonal neuropathy. Finally, a biopsy of quadriceps was compatible with the diagnosis of SMA type I. A genetic study confirmed the existence of a homozygous absence of exons 7 and 8 of the telomeric supervival motoneuron gene (SMN1 gene).
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Affiliation(s)
- José L Fernández-Torre
- Department of Clinical Neurophysiology, University Hospital Marqués de Valdecilla (IFIMAV), Avenida Valdecilla, s/n, 39008 Santander, Cantabria, Spain.
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20
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Chau V, Clément JF, Robitaille Y, D'Anjou G, Vanasse M. Congenital axonal neuropathy and encephalopathy. Pediatr Neurol 2008; 38:261-6. [PMID: 18358405 DOI: 10.1016/j.pediatrneurol.2007.11.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/19/2007] [Revised: 09/25/2007] [Accepted: 11/20/2007] [Indexed: 10/22/2022]
Abstract
Congenital axonal neuropathy associated with encephalopathy appears to be very rare. Only a few cases have been reported in the literature. In the last 25 years, we have seen seven patients affected by congenital axonal neuropathy with encephalopathy. Biopsies of their sural nerves revealed axonal atrophy and loss of large-diameter nerve fibers. All of these patients presented at birth or soon thereafter with hypotonia associated with distal weakness and diffuse areflexia. Central nervous system manifestations included microcephaly, seizures, and developmental delay. Outcomes were poor. Four children died before age 3 years from respiratory insufficiency or aspiration pneumonia. The three surviving patients manifested severe developmental delay. In our most recent patient, Western-blot analysis of snap-frozen specimens of the temporal and cerebellar cortex demonstrated an absence or marked decrease of microtubule-associated protein types 1A and 2, compared with age-matched control subjects. Calloso-splenial hypogenesis and neurofilament swellings were also documented in the deep white matter and adjacent cortex. The absence or hypo-expression of central nervous system microtubule-associated proteins has never been reported in congenital neuropathies, and may represent a new clinicopathologic entity.
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Affiliation(s)
- Vann Chau
- Division of Neurology, Department of Pediatrics, Centre Hospitalier Universitaire Sainte-Justine, University of Montreal, Montreal, Quebec, Canada
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21
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Moriyama H, Shimada K, Itoh M, Takahashi T, Otsuka N. Morphometric analysis of the inferior alveolar nerve fails to demonstrate sexual dimorphism. J Oral Maxillofac Surg 2007; 65:1555-61. [PMID: 17656283 DOI: 10.1016/j.joms.2007.05.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2006] [Revised: 09/04/2006] [Indexed: 11/23/2022]
Abstract
PURPOSE With regard to the incidence of inferior alveolar nerve (IAN) damage after an IAN block or following oral and maxillofacial surgical procedures, there are reports of sexual dimorphism, no sexual dimorphism, and little sexual dimorphism. However, details of the morphology and sexual dimorphism in the characteristics of the IAN have not been available in textbooks. We morphometrically analyzed the human IAN and clarified these issues. MATERIALS AND METHODS The materials were obtained from 22 cadavers (11 female and 11 male), aged 59 to 84 years (average age: 74.1 yr), and dentulous. The causes of death did not influence the nervous system, so the IANs were considered to be normal. Human IANs were resected at the mandibular foramen. We counted the myelinated axons and measured the transverse area, perimeter, and circularity ratio of the myelinated axons. RESULTS We estimated the average total number of myelinated axons in the female IAN to be 25,230, with an average transverse area of 34.1 microm(2), an average perimeter of 21.8 microm, and an average circularity ratio of 0.86, with the same measurements in the male IAN being 20,278, 31.7 microm(2), 20.7 microm, and 0.87, respectively. Our data showed no significant difference between the female and male specimens in any measured item (P < .05). CONCLUSIONS We assumed that the sex difference in the incidence of IAN damage was not affected by the morphometric findings. Our findings might partly explain why there is no significant sex difference in the incidence of IAN damage.
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Affiliation(s)
- Hiroshi Moriyama
- Department of Anatomy, Showa University School of Medicine, Tokyo, Japan.
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22
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Abstract
The clinical classification of spinal muscular atrophy, caused by deletion of the survival motor neuron 1 gene (SMN1), is based on age at onset and maximum function achieved. Evidence suggests that maximum function achieved is more closely related to life expectancy than age at onset. Therefore, it is important to wait for a period before assigning a patient to 1 of 5 classes of the disorder. Several diseases result from degeneration of the anterior horn cell but are not caused by SMN1. The classification for these conditions is evolving. This article offers an attempt at organizing one's thinking about this disease group.
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MESH Headings
- Adolescent
- Adult
- Age of Onset
- Child
- Child, Preschool
- Chromosomes, Human, Pair 5/genetics
- Cyclic AMP Response Element-Binding Protein/genetics
- Diagnosis, Differential
- Disease Progression
- Genetic Predisposition to Disease/genetics
- Humans
- Infant
- Infant, Newborn
- Life Expectancy
- Muscle, Skeletal/pathology
- Muscle, Skeletal/physiopathology
- Muscular Atrophy, Spinal/classification
- Muscular Atrophy, Spinal/diagnosis
- Muscular Atrophy, Spinal/genetics
- Nerve Tissue Proteins/genetics
- RNA-Binding Proteins/genetics
- SMN Complex Proteins
- Survival of Motor Neuron 1 Protein
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Affiliation(s)
- Barry S Russman
- Department of Neurology, Oregon Health and Science University, Shriners Hospital for Children-Portland, Portland, Oregon, USA.
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23
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Beattie CE, Carrel TL, McWhorter ML. Fishing for a mechanism: using zebrafish to understand spinal muscular atrophy. J Child Neurol 2007; 22:995-1003. [PMID: 17761655 DOI: 10.1177/0883073807305671] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Motoneuron diseases cause paralysis and death due to loss of motoneurons that innervate skeletal muscle. Spinal muscular atrophy is a human motoneuron disease that is genetically linked to the survival motor neuron gene (SMN). Although SMN was identified more than a decade ago, it remains unclear how decreased levels of the SMN protein cause spinal muscular atrophy. The use of animal models, however, offers a crucial tool in determining the function of SMN in this disease. In this review, we discuss our efforts to develop a zebrafish model of spinal muscular atrophy.
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Affiliation(s)
- Christine E Beattie
- Ohio State University Center for Molecular Neurobiology, Department of Neuroscience, Columbus, OH, USA.
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24
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Moriyama H, Itoh M, Shimada K, Otsuka N. Morphometric analysis of fibers of the human vestibular nerve: sex differences. Eur Arch Otorhinolaryngol 2006; 264:471-5. [PMID: 17115169 DOI: 10.1007/s00405-006-0197-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2006] [Accepted: 10/16/2006] [Indexed: 10/23/2022]
Abstract
The aim of this study was to analyze myelinated axons in the human vestibular nerve (VN). We assumed that a smaller total number and average transverse area of myelinated axons in the female than male VN, would partly explain the female preponderance of vestibular disorders. The materials were obtained from 24 cadavers (12 females and 12 males) aged 54-90 years (average 74.8 years). We counted the myelinated axons, measured the transverse area of the myelinated axons, and analyzed morphological differences between the female and male specimens. The total number differed significantly between the female and male specimens. The older generation of both sexes tended to have lower total counts, but there was no significant difference among the generations. The average transverse area of the myelinated axons did not differ significantly between the female and male specimens. The older generation of both sexes tended to have a smaller average transverse area, and there was a significant difference among the generations. The presented results indicated that the lower total number, not the average transverse area, of myelinated axons in the female VN might be one of the reasons why vestibular disorders have a female preponderance.
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Affiliation(s)
- Hiroshi Moriyama
- Department of Anatomy, Showa University School of Medicine, Tokyo, Japan.
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25
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Giavazzi A, Setola V, Simonati A, Battaglia G. Neuronal-specific roles of the survival motor neuron protein: evidence from survival motor neuron expression patterns in the developing human central nervous system. J Neuropathol Exp Neurol 2006; 65:267-77. [PMID: 16651888 DOI: 10.1097/01.jnen.0000205144.54457.a3] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Despite recent data on the cellular function of the survival motor neuron (SMN) gene, the spinal muscular atrophy (SMA) disease gene, the role of the SMN protein in motor neurons and hence in the pathogenesis of SMA is still unclear. The spatial and temporal expression of SMN in neurons, particularly during development, could help in verifying the hypotheses on the SMN protein functions so far proposed. We have therefore investigated the expression and subcellular localization of the SMN protein in the human central nervous system (CNS) during ontogenesis with immunocytochemical, confocal immunofluorescence, and Western blot experiments using a panel of anti-SMN antibodies recognizing the full-length SMN protein. The experiments not only revealed the early SMN expression in all neurons, but also demonstrated the progressive shift in SMN subcellular localization from mainly nuclear to cytoplasmic and then to axons during CNS maturation. This finding was present in selected neuronal cell populations and it was particularly conspicuous in motor neurons. Our data support the idea of a specific role for SMN in axons, which becomes predominant in the ontogenetic period encompassing axonogenesis and axonal sprouting. In addition, the asymmetric SMN staining demonstrated in the germinative neuroepithelium suggests a possible role for SMN in neuronal migration and/or differentiation.
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Affiliation(s)
- Alessio Giavazzi
- Molecular Neuroanatomy Lab, Department of Neurophysiology, Neurological Institute C. Besta, Milano, Italy
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26
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Abstract
Spinal muscular atrophy (SMA) is a hereditary neurodegenerative disease caused by homozygous deletions or mutations in the SMN1 gene on Chr.5q13. SMA spans from severe Werdnig-Hoffmann disease (SMA 1) to relatively benign Kugelberg-Welander disease (SMA 3). Onset before birth possibly aggravates the clinical course, because immature motoneurons do not show compensatory sprouting and collateral reinnervation, and motor units in SMA 1, in contrast to those in SMA 3, are not enlarged. Genetic evidence indicates that SMN2, a gene 99% identical to SMN1, can attenuate SMA severity: in patients, more SMN2 copies and higher SMN protein levels are correlated with milder SMA. There is evidence that SMN plays a role in motoneuron RNA metabolism, but it has also been linked to apoptosis. Several mouse models with motoneuron disease have been successfully treated with neurotrophic factors. None of these models is, however, homologous to SMA. Recently, genetic mouse models of SMA have been created by introducing human SMN2 transgenes into Smn knockout mice or by targeting the Smn gene knockout to neurons. These mice not only provide important insights into the pathogenesis of SMA but are also crucial for testing new therapeutic strategies. These include SMN gene transfer, molecules capable to up-regulate SMN expression and trophic or antiapoptotic factors.
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Affiliation(s)
- H Schmalbruch
- Department of Medical Physiology, University of Copenhagen, Denmark.
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27
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Jablonka S, Karle K, Sandner B, Andreassi C, von Au K, Sendtner M. Distinct and overlapping alterations in motor and sensory neurons in a mouse model of spinal muscular atrophy. Hum Mol Genet 2006; 15:511-8. [PMID: 16396995 DOI: 10.1093/hmg/ddi467] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Motor neuron degeneration is the predominant pathological feature of spinal muscular atrophy (SMA). In patients with severe forms of the disease, additional sensory abnormalities have been reported. However, it is not clear whether the loss of sensory neurons is a common feature in severe forms of the disease, how many neurons are lost and how loss of sensory neurons compares with motor neuron degeneration. We have analysed dorsal root ganglionic sensory neurons in Smn-/-;SMN2 mice, a model of type I SMA. In contrast to lumbar motor neurons, no loss of sensory neurons in the L5 dorsal root ganglia is found at post-natal days 3-5 when these mice are severely paralyzed and die from motor defects. Survival of cultured sensory neurons in the presence of NGF and other neurotrophic factors is not reduced in comparison to wild-type controls. However, isolated sensory neurons have shorter neurites and smaller growth cones, and beta-actin protein and beta-actin mRNA are reduced in sensory neurite terminals. In footpads of Smn-deficient mouse embryos, sensory nerve terminals are smaller, suggesting that Smn deficiency reduces neurite outgrowth during embryogenesis. These data indicate that pathological alterations in severe forms of SMA are not restricted to motor neurons, but the defects in the sensory neurons are milder than those in the motor neurons.
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MESH Headings
- Actins/metabolism
- Animals
- Cell Survival
- Cells, Cultured
- Cyclic AMP Response Element-Binding Protein/deficiency
- Cyclic AMP Response Element-Binding Protein/metabolism
- Disease Models, Animal
- Embryo, Mammalian/metabolism
- Foot/pathology
- Ganglia, Spinal/pathology
- Growth Cones/metabolism
- Heterogeneous-Nuclear Ribonucleoproteins/metabolism
- Mice
- Mice, Knockout
- Motor Neurons/metabolism
- Motor Neurons/pathology
- Muscular Atrophy, Spinal/metabolism
- Muscular Atrophy, Spinal/pathology
- Nerve Tissue Proteins/deficiency
- Nerve Tissue Proteins/metabolism
- Neurites/metabolism
- Neurons, Afferent/metabolism
- Neurons, Afferent/pathology
- Protein Transport
- RNA, Messenger/genetics
- RNA-Binding Proteins/metabolism
- SMN Complex Proteins
- Sensory Receptor Cells/pathology
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Affiliation(s)
- Sibylle Jablonka
- Institute for Clinical Neurobiology, Josef-Schneider-Str. 11, D-97080 Wuerzburg, Germany
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28
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Diers A, Kaczinski M, Grohmann K, Hübner C, Stoltenburg-Didinger G. The ultrastructure of peripheral nerve, motor end-plate and skeletal muscle in patients suffering from spinal muscular atrophy with respiratory distress type 1 (SMARD1). Acta Neuropathol 2005; 110:289-97. [PMID: 16025284 DOI: 10.1007/s00401-005-1056-y] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2005] [Revised: 06/06/2005] [Accepted: 06/06/2005] [Indexed: 11/26/2022]
Abstract
Spinal muscular atrophy with respiratory distress type 1 (SMARD1) is genetically and clinically distinct from classic spinal muscular atrophy (SMA1). It results from mutations in the gene encoding immunoglobulin mu-binding protein 2 (IGHMBP2) on chromosome 11q13. Patients develop distally pronounced muscular weakness and early involvement of the diaphragm, resulting in respiratory failure. Sensory and autonomic nerves are also affected at later stages of the disease. We investigated peripheral nerves, skeletal muscles and neuromuscular junctions (NMJ) ultrastructurally in five unrelated patients and three siblings with genetically confirmed SMARD1. In mixed motor and sensory nerves we detected Wallerian degeneration and axonal atrophy similar to the ultrastructural findings described in SMA1. Isolated axonal atrophy was evident in purely sensory nerves. All investigated NMJ of patients with SMARD1 were dysmorphic and lacked a terminal axon. Moreover, we also observed characteristics of neuropathies, such as abnormalities in myelination, that have not been described in spinal muscular atrophies so far. Based on these findings we conclude that impairment of IGHMBP2 function leads to axonal degeneration, abnormal myelin formation, and motor end-plate degeneration.
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MESH Headings
- Axons/pathology
- Axons/ultrastructure
- DNA-Binding Proteins/genetics
- Female
- Humans
- Infant
- Infant, Newborn
- Male
- Microscopy, Electron, Transmission
- Motor Neurons/pathology
- Motor Neurons/ultrastructure
- Muscle, Skeletal/pathology
- Muscle, Skeletal/physiopathology
- Muscle, Skeletal/ultrastructure
- Muscular Atrophy, Spinal/complications
- Muscular Atrophy, Spinal/pathology
- Muscular Atrophy, Spinal/physiopathology
- Mutation/genetics
- Nerve Fibers, Myelinated/pathology
- Nerve Fibers, Myelinated/ultrastructure
- Neuromuscular Junction/pathology
- Neuromuscular Junction/physiopathology
- Neuromuscular Junction/ultrastructure
- Neurons, Afferent/pathology
- Neurons, Afferent/ultrastructure
- Peripheral Nerves/pathology
- Peripheral Nerves/physiopathology
- Peripheral Nerves/ultrastructure
- Respiratory Distress Syndrome, Newborn/etiology
- Respiratory Distress Syndrome, Newborn/pathology
- Respiratory Distress Syndrome, Newborn/physiopathology
- Transcription Factors/genetics
- Wallerian Degeneration/pathology
- Wallerian Degeneration/physiopathology
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Affiliation(s)
- Alexander Diers
- Department of Paediatric Neurology, Charité, Medical Faculty, Humboldt University, Augustenburger Platz 1, 13353 Berlin, Germany.
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29
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30
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Anagnostou E, Miller SP, Guiot MC, Karpati G, Simard L, Dilenge ME, Shevell MI. Type I spinal muscular atrophy can mimic sensory-motor axonal neuropathy. J Child Neurol 2005; 20:147-50. [PMID: 15794183 DOI: 10.1177/08830738050200022101] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Spinal muscular atrophy is a group of allelic autosomal recessive disorders characterized by progressive motoneuron loss, symmetric weakness, and skeletal muscle atrophy. It is traditionally considered a pure lower motoneuron disorder, for which a current definitive diagnosis is now possible by molecular genetic testing. We report two newborns with a clinical phenotype consistent with that of spinal muscular atrophy type I and nerve conduction studies and electromyography suggesting more extensive sensory involvement than classically described with spinal muscular atrophy. Molecular testing confirmed spinal muscular atrophy in patient 1 but not in patient 2. Thus, in the setting of a suspected congenital axonal neuropathy, molecular testing might be necessary to distinguish spinal muscular atrophy type I from infantile polyneuropathy.
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Affiliation(s)
- Evdokia Anagnostou
- Division of Pediatric Neurology, Montreal Children's Hospital, Department of Neurology, McGill University, Montreal, Quebec
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31
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Grohmann K, Varon R, Stolz P, Schuelke M, Janetzki C, Bertini E, Bushby K, Muntoni F, Ouvrier R, Van Maldergem L, Goemans NMLA, Lochmüller H, Eichholz S, Adams C, Bosch F, Grattan-Smith P, Navarro C, Neitzel H, Polster T, Topaloğlu H, Steglich C, Guenther UP, Zerres K, Rudnik-Schöneborn S, Hübner C. Infantile spinal muscular atrophy with respiratory distress type 1 (SMARD1). Ann Neurol 2003; 54:719-24. [PMID: 14681881 DOI: 10.1002/ana.10755] [Citation(s) in RCA: 97] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Autosomal recessive spinal muscular atrophy with respiratory distress type 1 (SMARD1) is the second anterior horn cell disease in infants in which the genetic defect has been defined. SMARD1 results from mutations in the gene encoding the immunoglobulin micro-binding protein 2 (IGHMBP2) on chromosome 11q13. Our aim was to review the clinical features of 29 infants affected with SMARD1 and report on 26 novel IGHMBP2 mutations. Intrauterine growth retardation, weak cry, and foot deformities were the earliest symptoms of SMARD1. Most patients presented at the age of 1 to 6 months with respiratory distress due to diaphragmatic paralysis and progressive muscle weakness with predominantly distal lower limb muscle involvement. Sensory and autonomic nerves are also affected. Because of the poor prognosis, there is a demand for prenatal diagnosis, and clear diagnostic criteria for infantile SMARD1 are needed. The diagnosis of SMARD1 should be considered in infants with non-5q spinal muscular atrophy, neuropathy, and muscle weakness and/or respiratory distress of unclear cause. Furthermore, consanguineous parents of a child with sudden infant death syndrome should be examined for IGHMBP2 mutations.
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Affiliation(s)
- Katja Grohmann
- Department of Neuropediatrics, Charité, Campus Virchow-Klinikum, Humboldt University, Augustenburger Platz 1, 13353 Berlin, Germany
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32
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Cheliout-Heraut F, Barois A, Urtizberea A, Viollet L, Estournet-Mathiaud B. Evoked potentials in spinal muscular atrophy. J Child Neurol 2003; 18:383-90. [PMID: 12886971 DOI: 10.1177/08830738030180061101] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Visual evoked potentials, brainstem evoked responses, and somatosensory evoked potentials were evaluated in 22 children with spinal muscular atrophy, types I and II. Eleven of the children had the severe form of spinal muscular atrophy (type I) and 11 children had the intermediate form (type II). The results of visual evoked potentials, brainstem evoked responses, and somatosensory evoked potentials were compared with those obtained in a control group. Statistical analysis showed abnormalities in the different sensory modalities. A significant increase in the visual evoked potential latencies was observed and was found more often in patients with spinal muscular atrophy type I. Alterations of the somatosensory thalamocortical responses were also observed, as well as a delay in the central conduction time. Although spinal muscular atrophy is usually considered to be a purely motor disorder involving neurons of the spinal anterior horn and nuclei of the lower cranial nerves, lesions of the posterior roots, spinal ganglia, ascending tracts, lateral geniculated corpus, and thalamus have been reported. Our results suggest that sensory neuron degeneration occurs more commonly in spinal muscular atrophy than previously thought and that this process probably develops more slowly than motoneuron degeneration. Such degeneration may be associated with brain atrophy.
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Affiliation(s)
- Fawzia Cheliout-Heraut
- Service d'Explorations Fonctionnelles, Hôpital R. Poincaré, CHU Paris-Ouest, Garches, France.
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33
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Rudnik-Schöneborn S, Sztriha L, Aithala GR, Houge G, Laegreid LM, Seeger J, Huppke M, Wirth B, Zerres K. Extended phenotype of pontocerebellar hypoplasia with infantile spinal muscular atrophy. Am J Med Genet A 2003; 117A:10-7. [PMID: 12548734 DOI: 10.1002/ajmg.a.10863] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Pontocerebellar hypoplasia (PCH) is rarely associated with anterior horn cell disease and designated as PCH-1. This phenotype is characterized by severe muscle weakness and hypotonia starting prenatally or at birth with a life span not exceeding a few months in most cases. Milder disease courses with later onset and longer survival are normally not diagnosed as PCH-1. We describe the clinical and neuroradiological findings in nine patients out of six siblingships with evidence of cerebellar defects and early onset spinal muscular atrophy (SMA), representing a broad spectrum of clinical variability. In all patients, the diagnosis of SMA (Werdnig-Hoffmann disease) was made on the basis of electrophysiological data and muscle biopsy; however, genetic testing failed to confirm the diagnosis of infantile SMA with a gene defect on chromosome 5q and resulted in clinical reevaluation. Age at onset was after a normal period in the first months of life in three siblingships and pre- and postnatally in the other three families. Life span was 2-4 years in patients with later onset, and age at death occurred after birth or within months in the more severe group. Two siblingships showed discordant ages at death despite similar treatment. In contrast to the previous definition of PCH-1, our observations suggest the existence of milder phenotypes with pontocerebellar hypoplasia or olivopontocerebellar atrophy in combination with anterior horn cell loss. A pontine involvement is not necessarily seen by neuroimaging methods. The genetic basis of PCH-1 remains to be determined. The gene locus for infantile SMA on chromosome 5q could be excluded by linkage studies. Parental consanguinity and affected siblings make autosomal recessive inheritance most likely.
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34
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Hanemann CO, Ludolph AC. Hereditary motor neuropathies and motor neuron diseases: which is which. AMYOTROPHIC LATERAL SCLEROSIS AND OTHER MOTOR NEURON DISORDERS : OFFICIAL PUBLICATION OF THE WORLD FEDERATION OF NEUROLOGY, RESEARCH GROUP ON MOTOR NEURON DISEASES 2002; 3:186-9. [PMID: 12710507 DOI: 10.1080/146608202760839003] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
When Charcot first defined amyotrophic lateral sclerosis (ALS) he used the clinical and neuropathological pattern of vulnerability as a guideline. Similarly other motor neuron diseases such as the spinal muscular atrophies (SMA) and the motor neuropathies (MN) were grouped following clinical criteria. However, ever since the etiology of these diseases has started to be disclosed by genetics, we have learnt that the limits of the syndromes are not as well defined as our forefathers thought. A mutation leading to ALS can also be associated with the clinical picture of spinal muscular atrophy; even more unexpected is the overlap of the so-called motor neuropathies with the clinical syndrome of slowly progressive ALS or that primary lateral sclerosis (PLS) can be caused by the same gene as that responsible for some cases of ALS. In this review we summarise recent work showing that there is a considerable overlap between CMT, MN, SMA, ALS and PLS. Insights into these phenotypes should lead to study of the variants of motor neuron disease and possibly to a reclassification. This comprehensive review should help to improve understanding of the pathogenesis of motor neuron degeneration and finally may aid the research for urgently needed new treatment strategies, perhaps with validity for the entire group of motor neuron diseases.
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Affiliation(s)
- Clemens O Hanemann
- Department of Neurology, University of Ulm, Oberer Eselsberg 45, 89081 Ulm, Germany
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Abstract
Inherited neuropathies are common and are usually caused by mutations in genes that are expressed by myelinating Schwann cells or neurons, which is the biological basis for long-standing distinction between primary demyelinating and axonal neuropathies. Neuropathies can be isolated, the primary manifestation of a more complex syndrome, or overshadowed by other aspects of the inherited disease. Increasing knowledge of the molecular-genetic causes of inherited neuropathies facilitates faster, more accurate diagnosis, and sets the stage for development of specific therapeutic interventions.
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Affiliation(s)
- Kleopas A Kleopa
- University of Pennsylvania Medical Center, 3400 Spruce Street, 3 West Gates, Philadelphia, PA 19104, USA.
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Nicole S, Diaz CC, Frugier T, Melki J. Spinal muscular atrophy: recent advances and future prospects. Muscle Nerve 2002; 26:4-13. [PMID: 12115944 DOI: 10.1002/mus.10110] [Citation(s) in RCA: 77] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Spinal muscular atrophies (SMA) are characterized by degeneration of lower motor neurons associated with muscle paralysis and atrophy. Childhood SMA is a frequent recessive autosomal disorder and represents one of the most common genetic causes of death in childhood. Mutations of the SMN1 gene are responsible for SMA. The knowledge of the genetic basis of SMA, a better understanding of SMN function, and the recent generation of SMA mouse models represent major advances in the field of SMA. These are starting points towards understanding the pathophysiology of SMA and developing therapeutic strategies for this devastating neurodegenerative disease, for which no curative treatment is known so far.
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Affiliation(s)
- Sophie Nicole
- Molecular Neurogenetics Laboratory, Institut National de la Santé et de la Recherche Médicale (INSERM), Université d'Evry, E.9913, Genopole, 2 rue Gaston Crémieux, CP 5724, 91057 Evry, France
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Abstract
Spinal muscular atrophies (SMA) are characterized by degeneration of lower motor neurons associated with muscle paralysis and atrophy. Childhood SMA is a common recessive autosomal disorder and represents one of the most common genetic causes of death in childhood. The pathophysiology remains unknown, and no curative treatment is available so far. The last 10 years have seen major advances in the field of SMA, which are starting points towards understanding the SMA pathogenesis and developing therapeutic strategies for this devastating neurodegenerative disease.
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Affiliation(s)
- Carmen Cifuentes-Diaz
- Molecular Neurogenetics Laboratory, Institut National de la Santé et de la Recherche Médicale, Université d'Evry, Genopole, France
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Mohan U, Misra VP, Britto J, Muntoni F, King RH, Thomas PK. Inherited early onset severe axonal polyneuropathy with respiratory failure and autonomic involvement. Neuromuscul Disord 2001; 11:395-9. [PMID: 11369191 DOI: 10.1016/s0960-8966(00)00210-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
We report dizygotic twins who first presented at the age of 6 months with severe diaphragmatic weakness and marked abnormalities of autonomic function. A female sibling had earlier died from a disorder with similar clinical features. Both twins had a severe axonal polyneuropathy with generalized hypotonic limb weakness together with diaphragmatic paralysis resulting in respiratory failure. Associated features were tachycardia, increased sweating, elevated body temperature, and hypertension, suggesting autonomic dysfunction. Nerve conduction studies indicated an axonopathy affecting both motor and sensory nerve fibres. Sural nerve biopsy in one twin performed at the age of 7 months showed a reduced population of myelinated nerve fibres, particularly those of larger diameter, with no indication of hypomyelination, demyelination or axonal atrophy. Examples of axonal forms of hereditary motor and sensory neuropathy (HMSN) with onset in infancy are very rare and autonomic involvement associated with this condition has not so far been described.
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Affiliation(s)
- U Mohan
- Department of Paediatrics, St Mary's Hospital, London, UK
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39
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Abstract
Two patients with acute generalized weakness and areflexia are presented. The electrophysiologic studies in both revealed evidence of decreased conduction velocity and mixed axonal and demyelinating neuropathy, suggestive of the diagnosis of Guillain-Barré syndrome. The young ages of the patients and their failure to respond to immunoglobulin therapy were the major clues to the final diagnosis of spinal muscular atrophy type I. Blood for DNA study revealed homozygous deletion mutation in exons 7 and 8 of the survival motor neuron gene. This diagnosis should be considered in every child under 1 year of age who presents with acute weakness because Guillain-Barré syndrome in this age group is rare.
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Affiliation(s)
- S Ravid
- Division of Pediatric Neurology, Schneider Children's Hospital, New Hyde Park, NY 11040, USA
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Wilmshurst JM, Bye A, Rittey C, Adams C, Hahn AF, Ramsay D, Pamphlett R, Pollard JD, Ouvrier R. Severe infantile axonal neuropathy with respiratory failure. Muscle Nerve 2001; 24:760-8. [PMID: 11360259 DOI: 10.1002/mus.1067] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
We describe 5 infants (4 male, 1 female) with a severe intractable form of motor-sensory axonal neuropathy. All became ventilator-dependent, 4 have since died and 1 remains static. Diaphragmatic paralysis was an early feature with generalized neuropathy evolving rapidly. Nerve conduction studies and biopsies were consistent with axonal disease. This disorder could be a new condition or part of the spectrum of inherited neuropathies of the axonal degenerative type. It may be that there is a "switching-off" in the infant's Schwann cell-axonal interactions in utero or in the early postnatal period, resulting in severe progressive deterioration and then a static period without recovery.
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Affiliation(s)
- J M Wilmshurst
- Institute for Neuromuscular Research, Children's Hospital at Westmead, P.O. Box 3515, Parramatta, NSW 2124, Australia
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Kelter AR, Herchenbach J, Wirth B. The transcription factor-like nuclear regulator (TFNR) contains a novel 55-amino-acid motif repeated nine times and maps closely to SMN1. Genomics 2000; 70:315-26. [PMID: 11161782 DOI: 10.1006/geno.2000.6396] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The transcription factor-like nuclear regulator (TFNR) is a novel human gene that maps on 5q13, distal to the duplicated region that includes SMN1, the spinal muscular atrophy (SMA) determining gene. The location of TFNR allowed us to design an evolutionary model of the SMA region. The 9.5-kb TFNR transcript is highly expressed in cerebellum and weakly in all other tissues tested. TFNR encodes a protein of 2254 amino acids (aa) and contains nine repeats of a novel 55-aa motif, of yet unknown function. The coding region is organized in 32 exons. Alternative splicing of exon 15 results in a truncated protein of 796 aa. TFNR comprises a series of polypeptides that range from 55 to 250 kDa. Immunocytological studies showed that the TFNR protein is present exclusively in the nucleus, where it is concentrated in several nuclear structures. Amino acids 155-474 show significant homology to TFC5, a subunit of the yeast transcription factor TFIIIB, suggesting that TFNR is a putative transcription factor. Based on its proximity to SMN1 and its expression pattern, TFNR may be a candidate gene for atypical forms of SMA with cerebral atrophy and axonal neuropathy that have been shown to carry large deletions in the SMA region.
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Affiliation(s)
- A R Kelter
- Institute of Human Genetics, Wilhelmstrasse 31, Bonn, D-53111, Germany
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Gérard B, Ginet N, Matthijs G, Evrard P, Baumann C, Da Silva F, Gérard-Blanluet M, Mayer M, Grandchamp B, Elion J. Genotype determination at the survival motor neuron locus in a normal population and SMA carriers using competitive PCR and primer extension. Hum Mutat 2000; 16:253-63. [PMID: 10980532 DOI: 10.1002/1098-1004(200009)16:3<253::aid-humu8>3.0.co;2-8] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Precise quantitation of SMN1 copy number is of great interest in many clinical applications such as direct detection of SMA carriers or detection of an SMA-affected patient with a hemizygous deletion of the SMN1 gene. We describe a method that combines two independent nonradioactive PCR assays: determination of the relative ratio of the SMN1 and SMN2 genes using a primer extension assay and of the total SMN copy number using competitive PCR. Consistency of the results of two independent approaches ensures the reliability of the deduced genotype and thus avoids false interpretation of borderline results that can occur in quantitative assays. In all, 135 subjects were tested, including 91 normal controls and 44 SMA-affected children or SMA carriers. Two main genotypes were observed in controls: 2T/2C (45%) and 2T/1C (32%). A wide variability at the SMN locus is observed with nine different genotypes and up to six SMN genes. SMA carriers showed three frequent genotypes, 1T/2C (50%), 1T/3C (29%), and 1T/1C (18%). Normal chromosomes with two SMN1 genes per chromosome are not infrequent and thus, about 3% of SMA carriers are not detected using SMN1 copy number quantitation. Finally, as this method does not detect point mutations (4% of SMN1 gene mutations), reliability ranges from 93% to 100% depending on data available from the propositus.
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Affiliation(s)
- B Gérard
- Service de Biochimie Génétique, Hôpital Robert Debré, Paris, France.
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43
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Abstract
Polyneuropathies are relatively uncommon in early infancy and the majority of affected children are found to have hypomyelinating neuropathies. Axonal sensorimotor neuropathies have been described in childhood but the majority of affected children present at or after 6 months of age, have nonprogressive courses, and achieve the ability to walk, albeit late. Here we present three infants with infantile progressive axonal polyneuropathy from two families with nonconsanguineous parents. Each child presented shortly after the neonatal period and with rapid progression to quadriplegia. Involvement of the lower cranial nerves, phrenic nerves, or both was present in each child. Electrophysiology was diagnostic in each child. While the diagnosis of spinal muscular atrophy was considered in each case, clinical presentation, biopsies, and genetic testing were inconsistent with this diagnosis. Recognition of this early form of progressive axonal neuropathy is important as respiratory compromise occurred early and the condition showed familial inheritance in two of our patients.
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Affiliation(s)
- T J Geller
- Department of Neurology, Cardinal Glennon Children's Hospital, Saint Louis University, Health Sciences Center, MO, USA
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44
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Abstract
Spinal muscular atrophy (SMA) is characterized by degeneration of motor neurons in the spinal cord, causing progressive weakness of the limbs and trunk, followed by muscle atrophy. SMA is one of the most frequent autosomal recessive diseases, with a carrier frequency of 1 in 50 and the most common genetic cause of childhood mortality. The phenotype is extremely variable, and patients have been classified in type I-III SMA based on age at onset and clinical course. All three types of SMA are caused by mutations in the survival motor neuron gene (SMN1). There are two almost identical copies, SMN1 and SMN2, present on chromosome 5q13. Only homozygous absence of SMN1 is responsible for SMA, while homozygous absence of SMN2, found in about 5% of controls, has no clinical phenotype. Ninety-six percent of SMA patients display mutations in SMN1, while 4% are unlinked to 5q13. Of the 5q13-linked SMA patients, 96.4% show homozygous absence of SMN1 exons 7 and 8 or exon 7 only, whereas 3. 6% present a compound heterozygosity with a subtle mutation on one chromosome and a deletion/gene conversion on the other chromosome. Among the 23 different subtle mutations described so far, the Y272C missense mutation is the most frequent one, at 20%. Given this uniform mutation spectrum, direct molecular genetic testing is an easy and rapid analysis for most of the SMA patients. Direct testing of heterozygotes, while not trivial, is compromised by the presence of two SMN1 copies per chromosome in about 4% of individuals. The number of SMN2 copies modulates the SMA phenotype. Nevertheless, it should not be used for prediction of severity of the SMA.
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Affiliation(s)
- B Wirth
- Institute of Human Genetics, Bonn, Germany.
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Stevens G, Yawitch T, Rodda J, Verhaart S, Krause A. Different molecular basis for spinal muscular atrophy in South African black patients. ACTA ACUST UNITED AC 1999. [DOI: 10.1002/(sici)1096-8628(19991029)86:5<420::aid-ajmg5>3.0.co;2-s] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Zerres K, Davies KE. 59th ENMC International Workshop: Spinal Muscular Atrophies: recent progress and revised diagnostic criteria 17-19 April 1998, Soestduinen, The Netherlands. Neuromuscul Disord 1999; 9:272-8. [PMID: 10399757 DOI: 10.1016/s0960-8966(99)00016-4] [Citation(s) in RCA: 116] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Affiliation(s)
- K Zerres
- Institute for Human Genetics, Technical University, Aachen Germany
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47
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Omran H, Ketelsen UP, Heinen F, Sauer M, Rudnik-Schöneborn S, Wirth B, Zerres K, Kratzer W, Korinthenberg R. Axonal neuropathy and predominance of type II myofibers in infantile spinal muscular atrophy. J Child Neurol 1998; 13:327-31. [PMID: 9701481 DOI: 10.1177/088307389801300704] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Two affected siblings with infantile spinal muscular atrophy (SMA I) presented with generalized muscular hypotonia, which progressed to early death. Quadriceps muscle biopsy did not show the typical neurogenic pattern of spinal muscular atrophy. The histochemical fiber type determination revealed a predominance of type II fibers without type I hypertrophy, an unprecedented finding in spinal muscular atrophy. Sural nerve biopsy exhibited findings typical for axonal neuropathy. In one patient, electrical stimulation of peripheral nerves showed an inexcitability of motor and sensory nerves. Genetic studies revealed homozygous deletions of the telomeric survival motor neuron (SMN) gene and the neuronal apoptosis inhibitory protein (NAIP) gene in the affected children. This is the second case report of molecular genetically proven spinal muscular atrophy associated with axonal neuropathy. We conclude atypical findings on muscle biopsy and evidence of axonal neuropathy are compatible with the diagnosis of infantile spinal muscular atrophy.
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Affiliation(s)
- H Omran
- Department of Neuropediatrics and Muscular Diseases, Albert-Ludwigs-Universität, Freiburg, Germany
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48
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Abstract
Advances in molecular genetics have disclosed many different explanations for allelic heterogeneity, how different clinical syndromes arise from mutations in the same gene. The converse, how similar clinical syndromes arise from mutations of different genes on different chromosomes is called locus heterogeneity. Both, however, give rise to some disease-defining mutations, as in childhood spinal muscular atrophy or Duchenne muscular dystrophy. Nevertheless, new problems have been created, including what might be called "diagnosis by the number," diverse syndromes from mutations in the same gene without current explanation, or siblings with different clinical syndromes. These discoveries have transformed the clinical neurology of heritable diseases. They also provide clinicians with new responsibilities and opportunities in defining clinical syndromes and influencing the evolution of our clinical language.
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Affiliation(s)
- L P Rowland
- Department of Neurology, Columbia University College of Physicians and Surgeons, New York, NY, USA
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49
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Millichap JG. Spinal Muscular Atrophy and Arthrogryposis. Pediatr Neurol Briefs 1997. [DOI: 10.15844/pedneurbriefs-11-10-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
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