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Benarroch E. What Is the Role of Nuclear Envelope Proteins in Neurologic Disorders? Neurology 2024; 102:e209202. [PMID: 38330281 DOI: 10.1212/wnl.0000000000209202] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2023] [Accepted: 12/12/2023] [Indexed: 02/10/2024] Open
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2
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Yoshida Y, Uchida K, Kodo K, Ishizaki-Asami R, Maeda J, Katsumata Y, Yuasa S, Fukuda K, Kosaki K, Watanabe Y, Nakagawa O, Yamagishi H. A genetic and developmental biological approach for a family with complex congenital heart diseases-evidence of digenic inheritance. Front Cardiovasc Med 2023; 10:1135141. [PMID: 37180804 PMCID: PMC10166836 DOI: 10.3389/fcvm.2023.1135141] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2022] [Accepted: 04/10/2023] [Indexed: 05/16/2023] Open
Abstract
Objective Congenital heart disease (CHD) is caused by cardiovascular developmental defects and has a global prevalence of ∼1%. The etiology of CHD is multifactorial and remains generally unknown, despite advances in analytical techniques based on next-generation sequencing (NGS). The aim of our study was to elucidate the multi-genetic origin and pathogenesis of an intriguing familial case with complex CHD. Methods We performed an original trio-based gene panel analysis using NGS of the family, including two siblings with CHD of single ventricular phenotype, and their unaffected parents. The pathogenicity of the detected rare variants was investigated in silico, and the functional effects of the variants were confirmed in vitro using luciferase assays. The combinatorial effect of gene alterations of the putative responsible genes was tested in vivo using genetically engineered mutant mice. Results NGS-based gene panel analyses revealed two heterozygous rare variants in NODAL and in TBX20 common to the siblings and to just one of parents. Both variants were suspected pathogenic in silico, and decreased transcriptional activities of downstream signaling pathways were observed in vitro. The analyses of Nodal and Tbx20 double mutant mice demonstrated that Nodal+/-Tbx20-/- embryos showed more severe defects than Nodal+/+Tbx20-/- embryos during early heart development. The expression of Pitx2, a known downstream target of Nodal, was downregulated in Tbx20-/- mutants. Conclusions Two rare variants on NODAL and TBX20 genes detected in this family were considered to be loss-of-function mutations. Our results suggest that NODAL and TBX20 may be complementary for the cardiac development, and a combinatorial loss-of-function of NODAL and TBX20 could be implicated in digenic inherence as the etiology of complex CHD associated with single ventricle defects in this family.
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Affiliation(s)
- Yu Yoshida
- Department of Pediatrics, Keio University School of Medicine, Tokyo, Japan
| | - Keiko Uchida
- Department of Pediatrics, Keio University School of Medicine, Tokyo, Japan
- Health Center, Keio University, Kanagawa, Japan
| | - Kazuki Kodo
- Department of Pediatrics, Keio University School of Medicine, Tokyo, Japan
| | | | - Jun Maeda
- Department of Pediatrics, Keio University School of Medicine, Tokyo, Japan
| | | | - Shinsuke Yuasa
- Department of Cardiology, Keio University School of Medicine, Tokyo, Japan
| | - Keiichi Fukuda
- Department of Cardiology, Keio University School of Medicine, Tokyo, Japan
| | - Kenjiro Kosaki
- Center for Medical Genetics, Keio University School of Medicine, Tokyo, Japan
| | - Yusuke Watanabe
- Department of Molecular Physiology, National Cerebral and Cardiovascular Center Research Institute, Osaka, Japan
| | - Osamu Nakagawa
- Department of Molecular Physiology, National Cerebral and Cardiovascular Center Research Institute, Osaka, Japan
| | - Hiroyuki Yamagishi
- Department of Pediatrics, Keio University School of Medicine, Tokyo, Japan
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3
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Saito R, Hara N, Tada M, Wakabayashi M, Miyashita A, Nishizawa M, Onodera O, Ikeuchi T, Kakita A. SYNE1-ataxia: clinicopathologic features of an autopsied patient with novel compound heterozygous mutations. J Neuropathol Exp Neurol 2023; 82:267-271. [PMID: 36525394 DOI: 10.1093/jnen/nlac120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Affiliation(s)
- Rie Saito
- Department of Pathology, Brain Research Institute, Niigata University, Niigata, Japan
| | - Norikazu Hara
- Department of Molecular Genetics, Brain Research Institute, Niigata University, Niigata, Japan
| | - Mari Tada
- Department of Pathology, Brain Research Institute, Niigata University, Niigata, Japan
| | | | - Akinori Miyashita
- Department of Molecular Genetics, Brain Research Institute, Niigata University, Niigata, Japan
| | - Masatoyo Nishizawa
- Department of Neurology, Brain Research Institute, Niigata University, Niigata, Japan
| | - Osamu Onodera
- Department of Neurology, Brain Research Institute, Niigata University, Niigata, Japan
| | - Takeshi Ikeuchi
- Department of Molecular Genetics, Brain Research Institute, Niigata University, Niigata, Japan
| | - Akiyoshi Kakita
- Department of Pathology, Brain Research Institute, Niigata University, Niigata, Japan
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ANO10 Function in Health and Disease. CEREBELLUM (LONDON, ENGLAND) 2022; 22:447-467. [PMID: 35648332 PMCID: PMC10126014 DOI: 10.1007/s12311-022-01395-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 03/14/2022] [Indexed: 10/18/2022]
Abstract
Anoctamin 10 (ANO10), also known as TMEM16K, is a transmembrane protein and member of the anoctamin family characterized by functional duality. Anoctamins manifest ion channel and phospholipid scrambling activities and are involved in many physiological processes such as cell division, migration, apoptosis, cell signalling, and developmental processes. Several diseases, including neurological, muscle, blood disorders, and cancer, have been associated with the anoctamin family proteins. ANO10, which is the main focus of the present review, exhibits both scrambling and chloride channel activity; calcium availability is necessary for protein activation in either case. Additional processes implicating ANO10 include endosomal sorting, spindle assembly, and calcium signalling. Dysregulation of calcium signalling in Purkinje cells due to ANO10 defects is proposed as the main mechanism leading to spinocerebellar ataxia autosomal recessive type 10 (SCAR10), a rare, slowly progressive spinocerebellar ataxia. Regulation of the endolysosomal pathway is an additional ANO10 function linked to SCAR10 aetiology. Further functional investigation is essential to unravel the ANO10 mechanism of action and involvement in disease development.
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Arias M, Mir P, Fernández-Matarrubia M, Arpa J, García-Ramos R, Blanco-Arias P, Quintans B, Sobrido MJ. Autosomal recessive spinocerebellar ataxia SCAR8/ARCA1: first families detected in Spain. NEUROLOGÍA (ENGLISH EDITION) 2022; 37:257-262. [PMID: 35595401 DOI: 10.1016/j.nrleng.2019.01.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2018] [Accepted: 01/16/2019] [Indexed: 11/18/2022] Open
Abstract
INTRODUCTION Autosomal recessive spinocerebellar ataxia type 8 (ARCA1/SCAR8) is caused by mutations of the SYNE1 gene. The disease was initially described in families from Quebec (Canada) with a phenotype of pure cerebellar syndrome, but in recent years has been reported with a more variable clinical phenotype in other countries. Cases have recently been described of muscular dystrophy, arthrogryposis, and cardiomyopathy due to SYNE1 mutations. OBJECTIVE To describe clinical and molecular findings from 4 patients (3 men and one woman) diagnosed with ARCA1/SCAR8 from 3 Spanish families from different regions. MATERIAL AND METHODS We describe the clinical, paraclinical, and genetic results from 4 patients diagnosed with ARCA1/SCAR8 at different Spanish neurology departments. RESULTS Onset occurred in the third or fourth decade of life in all patients. After 15 years of progression, 3 patients presented pure cerebellar syndrome, similar to the Canadian patients; the fourth patient, with over 30 years' progression, presented vertical gaze palsy, pyramidal signs, and moderate cognitive impairment. In all patients, MRI studies showed cerebellar atrophy. The genetic study revealed distinct pathogenic SYNE1 mutations in each family. CONCLUSIONS ARCA1/SCAR8 can be found worldwide and may be caused by many distinct mutations in the SYNE1 gene. The disease may manifest with a complex phenotype of varying severity.
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Affiliation(s)
- M Arias
- Servicio de Neurología, Complexo Hospitalario de Santiago de Compostela, Santiago de Compostela, La Coruña, Spain.
| | - P Mir
- Servicio de Neurología, Hospital Virgen del Rocío, Sevilla, Spain
| | | | - J Arpa
- Servicio de Neurología, Hospital Clínico San Carlos, Madrid, Spain
| | - R García-Ramos
- Servicio de Neurología, Hospital Clínico San Carlos, Madrid, Spain
| | - P Blanco-Arias
- Fundación Pública Galega de Medicina Xenómica, Santiago de Compostela, La Coruña, Spain
| | - B Quintans
- Grupo de Neurogenética, Instituto de Investigación Sanitaria de Santiago (IDIS)-Complexo Hospitalario Universitario, Santiago de Compostela, La Coruña, Spain; Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Instituto de Salud Carlos III, Madrid, Spain
| | - M J Sobrido
- Grupo de Neurogenética, Instituto de Investigación Sanitaria de Santiago (IDIS)-Complexo Hospitalario Universitario, Santiago de Compostela, La Coruña, Spain; Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Instituto de Salud Carlos III, Madrid, Spain
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Arias M, Mir P, Fernández-Matarrubia M, Arpa J, García-Ramos R, Blanco-Arias P, Quintans B, Sobrido MJ. Autosomal recessive spinocerebellar ataxia SCAR8/ARCA1: First families detected in Spain. Neurologia 2022; 37:257-262. [PMID: 31103315 DOI: 10.1016/j.nrl.2019.01.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2018] [Accepted: 01/16/2019] [Indexed: 12/28/2022] Open
Abstract
INTRODUCTION Autosomal recessive spinocerebellar ataxia type 8 (ARCA1/SCAR8) is caused by mutations of the SYNE1 gene. The disease was initially described in families from Quebec (Canada) with a phenotype of pure cerebellar syndrome, but in recent years has been reported with a more variable clinical phenotype in other countries. Cases have recently been described of muscular dystrophy, arthrogryposis, and cardiomyopathy due to SYNE1 mutations. OBJECTIVE To describe clinical and molecular findings from 4 patients (3 men and one woman) diagnosed with ARCA1/SCAR8 from 3 Spanish families from different regions. MATERIAL AND METHODS We describe the clinical, paraclinical, and genetic results from 4 patients diagnosed with ARCA1/SCAR8 at different Spanish neurology departments. RESULTS Onset occurred in the third or fourth decade of live in all patients. After 15 years of progression, 3 patients presented pure cerebellar syndrome, similar to the Canadian patients; the fourth patient, with over 30 years' progression, presented vertical gaze palsy, pyramidal signs, and moderate cognitive impairment. In all patients, MRI studies showed cerebellar atrophy. The genetic study revealed distinct pathogenic SYNE1 mutations in each family. CONCLUSIONS ARCA1/SCAR8 can be found worldwide and may be caused by many distinct mutations in the SYNE1 gene. The disease may manifest with a complex phenotype of varying severity.
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Affiliation(s)
- M Arias
- Servicio de Neurología, Complexo Hospitalario de Santiago de Compostela, Santiago de Compostela, La Coruña, España.
| | - P Mir
- Servicio de Neurología, Hospital Virgen del Rocío, Sevilla, España
| | | | - J Arpa
- Servicio de Neurología, Hospital Clínico San Carlos de, Madrid, España
| | - R García-Ramos
- Servicio de Neurología, Hospital Clínico San Carlos de, Madrid, España
| | - P Blanco-Arias
- Fundación Pública Galega de Medicina Xenómica, Santiago de Compostela, La Coruña, España
| | - B Quintans
- Grupo de Neurogenética, Instituto de Investigación Sanitaria de Santiago (IDIS)-Complexo Hospitalario Universitario, Santiago de Compostela, La Coruña, España; Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Instituto de Salud Carlos III, Madrid, España
| | - M J Sobrido
- Grupo de Neurogenética, Instituto de Investigación Sanitaria de Santiago (IDIS)-Complexo Hospitalario Universitario, Santiago de Compostela, La Coruña, España; Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Instituto de Salud Carlos III, Madrid, España
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7
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Dragašević-Mišković N, Stanković I, Milovanović A, Kostić VS. Autosomal recessive adult onset ataxia. J Neurol 2021; 269:504-533. [PMID: 34499204 DOI: 10.1007/s00415-021-10763-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Revised: 08/16/2021] [Accepted: 08/18/2021] [Indexed: 11/24/2022]
Abstract
Autosomal recessive ataxias (ARCA) represent a complex group of diseases ranging from primary ataxias to rare and complex metabolic disorders in which ataxia is a part of the clinical picture. Small number of ARCA manifest exclusively in adulthood, while majority of typical childhood onset ARCA may also start later with atypical clinical presentation. We have systematically searched the literature for ARCA with adult onset, both in the group of primary ataxias including those that are less frequently described in isolated or in a small number of families, and also in the group of complex and metabolic diseases in which ataxia is only part of the clinical picture. We propose an algorithm that could be used when encountering a patient with adult onset sporadic or recessive ataxia in whom the acquired causes are excluded. ARCA are frequently neglected in the differential diagnosis of adult-onset ataxias. Rising awareness of their clinical significance is important, not only because some of these disorders may be potentially treatable, but also for prognostic implications and inclusion of patients to future clinical trials with disease modifying agents.
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Affiliation(s)
- Nataša Dragašević-Mišković
- Neurology Clinic, Clinical Center of Serbia, School of Medicine, University of Belgrade, Dr Subotića 6, 11000, Belgrade, Serbia.
| | - Iva Stanković
- Neurology Clinic, Clinical Center of Serbia, School of Medicine, University of Belgrade, Dr Subotića 6, 11000, Belgrade, Serbia
| | - Andona Milovanović
- Neurology Clinic, Clinical Center of Serbia, School of Medicine, University of Belgrade, Dr Subotića 6, 11000, Belgrade, Serbia
| | - Vladimir S Kostić
- Neurology Clinic, Clinical Center of Serbia, School of Medicine, University of Belgrade, Dr Subotića 6, 11000, Belgrade, Serbia
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Valentina Castillo J, Catherine Díaz S, Bustamante ML, Ferreira MG, Teive HAG, Miranda M. Autosomal Recessive Cerebellar Ataxia 1: First Case Report Depicting a Variant in SYNE1 Gene in a Chilean Patient. THE CEREBELLUM 2021; 20:938-941. [PMID: 33651373 DOI: 10.1007/s12311-021-01250-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 02/22/2021] [Indexed: 10/22/2022]
Abstract
Autosomal recessive cerebellar ataxia type 1 (ARCA-1) or spinocerebellar ataxia autosomal recessive type 8 (SCAR8) is a slowly progressive neurodegenerative disorder that occurs due to mutations in the spectrin repeat containing nuclear envelope protein 1 (SYNE1) gene. Previously considered a rare cause of ARCA, related to French-Canadian patients from Beauce, Quebec, Canada, SYNE1 ataxia is now known to be of worldwide distribution. We present the case report of a 54-year-old male patient with the genetic diagnosis of SYNE1 ataxia, presenting with a SYNE1 gene mutation never described in Chilean population before.
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Affiliation(s)
- J Valentina Castillo
- Clinical Genetics Resident, Clinical Genetics Department, Clinical Hospital of the University of Chile, Santiago, Chile
| | - S Catherine Díaz
- Head of Genetics Unit, Roberto del Río Hospital, Genetics Section, 1085, Independencia, Santiago, Chile. .,Fundación Diagnosis, Santiago, Chile.
| | - María Leonor Bustamante
- Fundación Diagnosis, Santiago, Chile.,Human Genetics Program, Institute of Biomedical Sciences, School of Medicine, University of Chile, Santiago, Chile.,Department of Psychiatry and Mental Health, North Campus, School of Medicine, University of Chile, Santiago, Chile
| | - Matheus Gomes Ferreira
- Movement Disorders Unit, Neurology Service, Internal Medicine Department, Hospital de Clínicas, Federal University of Paraná, Curitiba, PR, Brazil
| | - Hélio A G Teive
- Movement Disorders Unit, Neurology Service, Internal Medicine Department, Hospital de Clínicas, Federal University of Paraná, Curitiba, PR, Brazil
| | - Marcelo Miranda
- Fundación Diagnosis, Santiago, Chile.,Neurology Unit, Las Condes Clinic, Santiago, Chile
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Szpisjak L, Szaraz G, Salamon A, Nemeth VL, Szepfalusi N, Veres G, Kincses B, Maroti Z, Kalmar T, Rydzanicz M, Ploski R, Klivenyi P, Zadori D. Eye-tracking-aided characterization of saccades and antisaccades in SYNE1 ataxia patients: a pilot study. BMC Neurosci 2021; 22:7. [PMID: 33526008 PMCID: PMC7852103 DOI: 10.1186/s12868-021-00612-9] [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: 09/17/2020] [Accepted: 01/13/2021] [Indexed: 11/11/2022] Open
Abstract
Background SYNE1 ataxia is an autosomal recessive hereditary condition, the main characteristic features of which are gait and limb ataxia and cerebellar dysarthria. Reports have revealed that the clinical phenotype of SYNE1 ataxia is more complex than the first published cases with pure cerebellar signs indicated. The aim of this study was to characterize eye movement alterations in the first diagnosed Hungarian SYNE1 ataxia patients. Results Saccades and antisaccades were examined with an eye tracker device in 3 SYNE1 (one patient has two frameshift mutations [c.8515_8516insA, p.Met2839Asnfs*53 and c.11594_11595insG, p.Glu3866*] in a compound heterozygous state, whereas two subjects have a splicing variant [c.23146-2A > G] in a homozygous state), 6 Friedreich ataxia (FA) patients and 12 healthy controls. Besides that, detailed clinical phenotyping and comprehensive neuropsychological assessment were carried out in all patients with ataxia. In addition to the characteristic cerebellar alterations, pyramidal signs and polyneuropathy were observed at least in 2 SYNE1 ataxia patients, for which no other underlying reason was found. The eye tracking assessment revealed hypometric saccades in the longer amplitude (18.4°) saccadic paradigm in all SYNE1 patients, whereas 2 out of 3 SYNE1 subjects performed slow saccades as well. In the antisaccade task, higher incorrect ratios of antisaccades were demonstrated in SYNE1 patients compared to healthy controls, showing inverse correlation with working memory test results. The corresponding data of FA patients was dispersed over a wide range, partially overlapping with control data. Conclusions The current study draws attention to the presence of eye movement disorders in patients with SYNE1 ataxia and demonstrates that alterations in the antisaccade paradigm may be related to working memory deficits.
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Affiliation(s)
- Laszlo Szpisjak
- Department of Neurology, University of Szeged, Semmelweis u. 6, 6725, Szeged, Hungary
| | - Gabor Szaraz
- Department of Neurology, University of Szeged, Semmelweis u. 6, 6725, Szeged, Hungary
| | - Andras Salamon
- Department of Neurology, University of Szeged, Semmelweis u. 6, 6725, Szeged, Hungary
| | - Viola L Nemeth
- Department of Neurology, University of Szeged, Semmelweis u. 6, 6725, Szeged, Hungary
| | - Noemi Szepfalusi
- Department of Neurology, University of Szeged, Semmelweis u. 6, 6725, Szeged, Hungary
| | - Gabor Veres
- Department of Neurology, University of Szeged, Semmelweis u. 6, 6725, Szeged, Hungary.,MTA-SZTE Neuroscience Research Group, Szeged, Hungary
| | - Balint Kincses
- Department of Psychiatry, University of Szeged, Szeged, Hungary
| | - Zoltan Maroti
- Genetic Diagnostic Laboratory, Department of Pediatrics and Pediatric Health Center, University of Szeged, Szeged, Hungary
| | - Tibor Kalmar
- Genetic Diagnostic Laboratory, Department of Pediatrics and Pediatric Health Center, University of Szeged, Szeged, Hungary
| | | | - Rafal Ploski
- Department of Medical Genetics, Medical University of Warsaw, Warsaw, Poland
| | - Peter Klivenyi
- Department of Neurology, University of Szeged, Semmelweis u. 6, 6725, Szeged, Hungary
| | - Denes Zadori
- Department of Neurology, University of Szeged, Semmelweis u. 6, 6725, Szeged, Hungary.
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Genetic and Epidemiological Study of Adult Ataxia and Spastic Paraplegia in Eastern Quebec. Can J Neurol Sci 2021; 48:655-665. [PMID: 33397523 DOI: 10.1017/cjn.2020.277] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
OBJECTIVE To estimate the minimum prevalence of adult hereditary ataxias (HA) and spastic paraplegias (HSP) in Eastern Quebec and to evaluate the proportion of associated mutations in identified genes. METHODS We conducted a descriptive cross-sectional study of patients who met clinical criteria for the diagnosis of HA (n = 241) and HSP (n = 115) in the East of the Quebec province between January 2007 and July 2019. The primary outcome was the prevalence per 100,000 persons with a 95% confidence interval (CI). The secondary outcome was the frequency of mutations identified by targeted next-generation sequencing (NGS) approach. Minimum carrier frequency for identified variants was calculated based on allele frequency values and the Hardy-Weinberg (HW) equation. RESULTS The minimum prevalence of HA in Eastern Quebec was estimated at 6.47/100 000 [95% CI; 6.44-6.51]; divided into 3.73/100 000 for autosomal recessive (AR) ataxias and 2.67/100 000 for autosomal dominant (AD) ataxias. The minimum prevalence of HSP was 4.17/100 000 [95% CI; 4.14-4.2]; with 2.05/100 000 for AD-HSP and 2.12/100 000 for AR-HSP. In total, 52.4% of patients had a confirmed genetic diagnosis. AR cerebellar ataxia type 1 (2.67/100 000) and AD spastic paraplegia SPG4 (1.18/100 000) were the most prevalent disorders identified. Mutations were identified in 23 genes and molecular alterations in 7 trinucleotides repeats expansion; the most common mutations were c.15705-12 A > G in SYNE1 and c.1529C > T (p.A510V) in SPG7. CONCLUSIONS We described the minimum prevalence of genetically defined adult HA and HSP in Eastern Quebec. This study provides a framework for international comparisons and service planning.
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Titlow J, Robertson F, Järvelin A, Ish-Horowicz D, Smith C, Gratton E, Davis I. Syncrip/hnRNP Q is required for activity-induced Msp300/Nesprin-1 expression and new synapse formation. J Cell Biol 2020; 219:133707. [PMID: 32040548 PMCID: PMC7055005 DOI: 10.1083/jcb.201903135] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2019] [Revised: 08/21/2019] [Accepted: 12/12/2019] [Indexed: 01/09/2023] Open
Abstract
Memory and learning involve activity-driven expression of proteins and cytoskeletal reorganization at new synapses, requiring posttranscriptional regulation of localized mRNA a long distance from corresponding nuclei. A key factor expressed early in synapse formation is Msp300/Nesprin-1, which organizes actin filaments around the new synapse. How Msp300 expression is regulated during synaptic plasticity is poorly understood. Here, we show that activity-dependent accumulation of Msp300 in the postsynaptic compartment of the Drosophila larval neuromuscular junction is regulated by the conserved RNA binding protein Syncrip/hnRNP Q. Syncrip (Syp) binds to msp300 transcripts and is essential for plasticity. Single-molecule imaging shows that msp300 is associated with Syp in vivo and forms ribosome-rich granules that contain the translation factor eIF4E. Elevated neural activity alters the dynamics of Syp and the number of msp300:Syp:eIF4E RNP granules at the synapse, suggesting that these particles facilitate translation. These results introduce Syp as an important early acting activity-dependent regulator of a plasticity gene that is strongly associated with human ataxias.
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Affiliation(s)
- Joshua Titlow
- Department of Biochemistry, University of Oxford, Oxford, UK
| | | | - Aino Järvelin
- Department of Biochemistry, University of Oxford, Oxford, UK
| | - David Ish-Horowicz
- Department of Biochemistry, University of Oxford, Oxford, UK.,Medical Research Council Lab for Molecular Cell Biology, University College London, London, UK
| | - Carlas Smith
- Centre for Neural Circuits and Behaviour, University of Oxford, Oxford, UK
| | - Enrico Gratton
- Laboratory for Fluorescence Dynamics, University of California Irvine, Irvine, CA
| | - Ilan Davis
- Department of Biochemistry, University of Oxford, Oxford, UK
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12
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Autosomal Recessive Cerebellar Ataxia Type 1: Phenotypic and Genetic Correlation in a Cohort of Chinese Patients with SYNE1 Variants. THE CEREBELLUM 2020; 20:74-82. [PMID: 32889669 DOI: 10.1007/s12311-020-01186-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 08/27/2020] [Indexed: 10/23/2022]
Abstract
Mutations in the synaptic nuclear envelope protein 1 (SYNE1) gene have been reported to cause autosomal recessive cerebellar ataxia (ARCA) type 1 with highly variable clinical phenotypes. The aim of this study was to describe the phenotypic-genetic spectrum of SYNE1-related ARCA1 patients in the Chinese population. We screened 158 unrelated patients with autosomal recessive or sporadic ataxia for variants in SYNE1 using next-generation sequencing. Pathogenicity assessment of SYNE1 variants was interpreted according to the American College of Medical Genetics standards and guidelines. We identified eight truncating variants and two missense variants spreading throughout the SYNE1 gene from six unrelated families, including nine novel variants and one reported variant. Of the six index patients, two patients showed the classical pure cerebellar ataxia, while four patients exhibited non-cerebellar phenotypes, including motor neuron symptoms, cognitive impairment, or mental retardation. The variants associated with motor neuron or cognition involvement tend to be located in the C-terminal region of SYNE1 protein, compared with the variants related to pure cerebellar ataxia. Our data indicating SYNE1 mutation is one of the more common causes of recessive ataxia in the Chinese population. The use of next-generation sequencing has enabled the rapid analysis of recessive ataxia and further expanded our understanding of genotype-phenotype correlation.
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13
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Arias M. Keys to overcoming the challenge of diagnosing autosomal recessive spinocerebellar ataxia. NEUROLOGÍA (ENGLISH EDITION) 2019. [DOI: 10.1016/j.nrleng.2018.07.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022] Open
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14
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Indelicato E, Nachbauer W, Fauth C, Krabichler B, Schossig A, Eigentler A, Dichtl W, Wenning G, Wagner M, Fanciulli A, Janecke A, Boesch S. SYNE1-ataxia: Novel genotypic and phenotypic findings. Parkinsonism Relat Disord 2018; 62:210-214. [PMID: 30573412 DOI: 10.1016/j.parkreldis.2018.12.007] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/21/2018] [Revised: 12/07/2018] [Accepted: 12/10/2018] [Indexed: 11/19/2022]
Abstract
INTRODUCTION SYNE1 encodes nesprin-1, a scaffold protein which is involved in the binding between cytoskeleton, nuclear envelope and other subcellular compartments. In 2007, recessive truncating SYNE1 mutations have been linked to a genetic form of pure cerebellar ataxia with adult onset and mild phenotype. Subsequent reports described a number of patients with SYNE1-ataxia and widespread neurological involvement including features of motor neuron disease. Recently, heterozygote missense SYNE1 mutations have been associated with muscular disorders, such as Emery-Dreifuss muscular dystrophy, arthrogryposis multiplex congenita and dilated cardiomyopathy. METHODS Herein we describe novel genotypic and phenotypic findings in an independent cohort of 5 patients with SYNE1-ataxia referring to the Department of Neurology of the Innsbruck Medical University and performed a review of the related literature. RESULTS We report 3 novel mutations and describe for the first time myocardial involvement in a patient with a complicated spastic-ataxic phenotype and C-terminal mutation. In the literature, mutations associated with additional motor neuron signs spanned over the entire gene, but patients with a particularly severe phenotype and premature death bore C-terminal mutations. CONCLUSION Our findings support a genotype-phenotype correlation in SYNE1-ataxia and suggest the need for a systematic cardiologic evaluation in the setting of complicated spastic-ataxia phenotypes.
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Affiliation(s)
- Elisabetta Indelicato
- Department of Neurology, Innsbruck Medical University, Anichstraße 35, AT6020, Innsbruck, Austria
| | - Wolfgang Nachbauer
- Department of Neurology, Innsbruck Medical University, Anichstraße 35, AT6020, Innsbruck, Austria.
| | - Christine Fauth
- Division of Human Genetics, Innsbruck Medical University, Anichstraße 35, AT6020, Innsbruck, Austria
| | - Birgit Krabichler
- Division of Human Genetics, Innsbruck Medical University, Anichstraße 35, AT6020, Innsbruck, Austria
| | - Anna Schossig
- Division of Human Genetics, Innsbruck Medical University, Anichstraße 35, AT6020, Innsbruck, Austria
| | - Andreas Eigentler
- Department of Neurology, Innsbruck Medical University, Anichstraße 35, AT6020, Innsbruck, Austria
| | - Wolfgang Dichtl
- Department of Cardiology and Angiology, Innsbruck Medical University, Anichstraße 35, AT6020, Innsbruck, Austria
| | - Gregor Wenning
- Department of Neurology, Innsbruck Medical University, Anichstraße 35, AT6020, Innsbruck, Austria
| | - Michaela Wagner
- Department of Neuroradiology, Innsbruck Medical University, Anichstraße 35, AT6020, Innsbruck, Austria
| | - Alessandra Fanciulli
- Department of Neurology, Innsbruck Medical University, Anichstraße 35, AT6020, Innsbruck, Austria
| | - Andreas Janecke
- Division of Human Genetics, Innsbruck Medical University, Anichstraße 35, AT6020, Innsbruck, Austria
| | - Sylvia Boesch
- Department of Neurology, Innsbruck Medical University, Anichstraße 35, AT6020, Innsbruck, Austria
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15
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Janin A, Gache V. Nesprins and Lamins in Health and Diseases of Cardiac and Skeletal Muscles. Front Physiol 2018; 9:1277. [PMID: 30245638 PMCID: PMC6137955 DOI: 10.3389/fphys.2018.01277] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Accepted: 08/22/2018] [Indexed: 12/26/2022] Open
Abstract
Since the discovery of the inner nuclear transmembrane protein emerin in the early 1990s, nuclear envelope (NE) components and related involvement in nuclei integrity and functionality have been highly investigated. The NE is composed of two distinct lipid bilayers described as the inner (INM) and outer (ONM) nuclear membrane. NE proteins can be specifically “integrated” in the INM (such as emerin and SUN proteins) or in the ONM such as nesprins. Additionally, flanked to the INM, the nuclear lamina, a proteinaceous meshwork mainly composed of lamins A and C completes NE composition. This network of proteins physically interplays to guarantee NE integrity and most importantly, shape the bridge between cytoplasmic cytoskeletons networks (such as microtubules and actin) and the genome, through the anchorage to the heterochromatin. The essential network driving the connection of nucleoskeleton with cytoskeleton takes place in the perinuclear space (the space between ONM and INM) with the contribution of the LINC complex (for Linker of Nucleoskeleton to Cytoskeleton), hosting KASH and SUN proteins interactions. This close interplay between compartments has been related to diverse functions from nuclear integrity, activity and positioning through mechanotransduction pathways. At the same time, mutations in NE components genes coding for proteins such as lamins or nesprins, had been associated with a wide range of congenital diseases including cardiac and muscular diseases. Although most of these NE associated proteins are ubiquitously expressed, a large number of tissue-specific disorders have been associated with diverse pathogenic mutations. Thus, diagnosis and molecular explanation of this group of diseases, commonly called “nuclear envelopathies,” is currently challenging. This review aims, first, to give a better understanding of diverse functions of the LINC complex components, from the point of view of lamins and nesprins. Second, to summarize human congenital diseases with a special focus on muscle and heart abnormalities, caused by mutations in genes coding for these two types of NE associated proteins.
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Affiliation(s)
- Alexandre Janin
- CNRS UMR5310, INSERM U1217, Institut NeuroMyoGène, Université Claude Bernard Lyon 1, Université de Lyon, Lyon, France.,Laboratoire de Cardiogénétique Moléculaire, Centre de Biologie et Pathologie Est, Hospices Civils de Lyon, Bron, France
| | - Vincent Gache
- CNRS UMR5310, INSERM U1217, Institut NeuroMyoGène, Université Claude Bernard Lyon 1, Université de Lyon, Lyon, France
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16
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Potter C, Razafsky D, Wozniak D, Casey M, Penrose S, Ge X, Mahjoub MR, Hodzic D. The KASH-containing isoform of Nesprin1 giant associates with ciliary rootlets of ependymal cells. Neurobiol Dis 2018; 115:82-91. [PMID: 29630990 DOI: 10.1016/j.nbd.2018.04.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2017] [Revised: 02/25/2018] [Accepted: 04/04/2018] [Indexed: 12/14/2022] Open
Abstract
Biallelic nonsense mutations of SYNE1 underlie a variable array of cerebellar and non-cerebellar pathologies of unknown molecular etiology. SYNE1 encodes multiple isoforms of Nesprin1 that associate with the nuclear envelope, with large cerebellar synapses and with ciliary rootlets of photoreceptors. Using two novel mouse models, we determined the expression pattern of Nesprin1 isoforms in the cerebellum whose integrity and functions are invariably affected by SYNE1 mutations. We further show that a giant isoform of Nesprin1 associates with the ciliary rootlets of ependymal cells that line brain ventricles and establish that this giant ciliary isoform of Nesprin1 harbors a KASH domain. Whereas cerebellar phenotypes are not recapitulated in Nes1gSTOP/STOP mice, these mice display a significant increase of ventricular volume. Together, these data fuel novel hypotheses about the molecular pathogenesis of SYNE1 mutations and support that KASH proteins may localize beyond the nuclear envelope in vivo.
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Affiliation(s)
- C Potter
- Department of Developmental Biology, Washington University School of Medicine, 660 S. Euclid Ave, St Louis, MO 63110, USA
| | - D Razafsky
- Department of Developmental Biology, Washington University School of Medicine, 660 S. Euclid Ave, St Louis, MO 63110, USA
| | - D Wozniak
- Department of Psychiatry, Washington University School of Medicine, 660 S. Euclid Ave, St Louis, MO 63110, USA
| | - M Casey
- Department of Developmental Biology, Washington University School of Medicine, 660 S. Euclid Ave, St Louis, MO 63110, USA
| | - S Penrose
- Department of Developmental Biology, Washington University School of Medicine, 660 S. Euclid Ave, St Louis, MO 63110, USA
| | - X Ge
- Department of Radiology, Washington University School of Medicine, 660 S. Euclid Ave, St Louis, MO 63110, USA
| | - M R Mahjoub
- Department of Medicine, Washington University School of Medicine, 660 S. Euclid Ave, St Louis, MO 63110, USA
| | - D Hodzic
- Department of Developmental Biology, Washington University School of Medicine, 660 S. Euclid Ave, St Louis, MO 63110, USA.
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17
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Abstract
The autosomal-recessive cerebellar ataxias comprise more than half of the known genetic forms of ataxia and represent an extensive group of clinically heterogeneous disorders that can occur at any age but whose onset is typically prior to adulthood. In addition to ataxia, patients often present with polyneuropathy and clinical symptoms outside the nervous system. The most common of these diseases is Friedreich ataxia, caused by mutation of the frataxin gene, but recent advances in genetic analysis have greatly broadened the ever-expanding number of causative genes to over 50. In this review, the clinical neurogenetics of the recessive cerebellar ataxias will be discussed, including updates on recently identified novel ataxia genes, advancements in unraveling disease-specific molecular pathogenesis leading to ataxia, potential treatments under development, technologic improvements in diagnostic testing such as clinical exome sequencing, and what the future holds for clinicians and geneticists.
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Affiliation(s)
- Brent L Fogel
- Program in Neurogenetics, Departments of Neurology and Human Genetics, David Geffen School of Medicine, University of California, Los Angeles, CA, United States.
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18
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19
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Yoshinaga T, Nakamura K, Ishikawa M, Yamaguchi T, Takano K, Wakui K, Kosho T, Yoshida K, Fukushima Y, Sekijima Y. A novel frameshift mutation of SYNE1 in a Japanese family with autosomal recessive cerebellar ataxia type 8. Hum Genome Var 2017; 4:17052. [PMID: 29081981 PMCID: PMC5656760 DOI: 10.1038/hgv.2017.52] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2017] [Revised: 09/24/2017] [Accepted: 09/25/2017] [Indexed: 12/14/2022] Open
Abstract
A Japanese family with autosomal recessive cerebellar ataxia type 8 (SCAR8, MIM 610743) is described. We identified a novel SYNE1 frameshift deletion (c.6843del, p.Q2282Sfs*3). This family shared similar clinical manifestations characterized by adult-onset, relatively pure cerebellar ataxia with mild eye movement abnormality. Intelligence and bulbar and respiratory functions were unaffected. This study suggests the clinical utility of using panel-based exome sequencing for genetic diagnosis in hereditary ataxias in a cost-efficient manner.
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Affiliation(s)
- Tsuneaki Yoshinaga
- Center for Medical Genetics, Shinshu University Hospital, Matsumoto, Japan.,Department of Medicine (Neurology and Rheumatology), Shinshu University School of Medicine, Matsumoto, Japan
| | - Katsuya Nakamura
- Center for Medical Genetics, Shinshu University Hospital, Matsumoto, Japan.,Department of Medicine (Neurology and Rheumatology), Shinshu University School of Medicine, Matsumoto, Japan
| | - Masumi Ishikawa
- Center for Medical Genetics, Shinshu University Hospital, Matsumoto, Japan
| | - Tomomi Yamaguchi
- Center for Medical Genetics, Shinshu University Hospital, Matsumoto, Japan.,Department of Medical Genetics, Shinshu University School of Medicine, Matsumoto, Japan
| | - Kyoko Takano
- Center for Medical Genetics, Shinshu University Hospital, Matsumoto, Japan.,Department of Medical Genetics, Shinshu University School of Medicine, Matsumoto, Japan
| | - Keiko Wakui
- Center for Medical Genetics, Shinshu University Hospital, Matsumoto, Japan.,Department of Medical Genetics, Shinshu University School of Medicine, Matsumoto, Japan
| | - Tomoki Kosho
- Center for Medical Genetics, Shinshu University Hospital, Matsumoto, Japan.,Department of Medical Genetics, Shinshu University School of Medicine, Matsumoto, Japan
| | - Kunihiro Yoshida
- Department of Medicine (Neurology and Rheumatology), Shinshu University School of Medicine, Matsumoto, Japan.,Division of Neurogenetics, Department of Brain Disease Research, Shinshu University School of Medicine, Matsumoto, Japan
| | - Yoshimitsu Fukushima
- Center for Medical Genetics, Shinshu University Hospital, Matsumoto, Japan.,Department of Medical Genetics, Shinshu University School of Medicine, Matsumoto, Japan
| | - Yoshiki Sekijima
- Department of Medicine (Neurology and Rheumatology), Shinshu University School of Medicine, Matsumoto, Japan
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20
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SYNE1 related cerebellar ataxia presents with variable phenotypes in a consanguineous family from Turkey. Neurol Sci 2017; 38:2203-2207. [PMID: 28687974 DOI: 10.1007/s10072-017-3049-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2017] [Accepted: 06/21/2017] [Indexed: 10/19/2022]
Abstract
SYNE1 related autosomal recessive cerebellar ataxia type 1 (ARCA1) is a late-onset cerebellar ataxia with slow progression originally demonstrated in French-Canadian populations of Quebec, Canada. Nevertheless, recent studies on SYNE1 ataxia have conveyed the condition from a geographically limited pure cerebellar recessive ataxia to a complex multisystem phenotype that is relatively common on the global scale. To determine the underlying genetic cause of the ataxia phenotype in a consanguineous family from Turkey presenting with very slow progressive cerebellar symptoms including dysarthria, dysmetria, and gait ataxia, we performed SNP-based linkage analysis in the family along with whole exome sequencing (WES) in two affected siblings. We identified a homozygous variant in SYNE1 (NM_033071.3: c.13086delC; p.His4362GlnfsX2) in all four affected siblings. This variant presented herein has originally been associated with only pure ataxia in a single case. We thus present segregation and phenotypic manifestations of this variant in four affected family members and further extend the pure ataxia phenotype with upper motor neuron involvement and peripheral neuropathy. Our findings in turn established a precise molecular diagnosis in this family, demonstrating the use of WES combined with linkage analysis in families as a powerful tool for establishing a quick and precise genetic diagnosis of complex neurological phenotypes.
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21
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Chen Z, Ren Z, Mei W, Ma Q, Shi Y, Zhang Y, Li S, Xiang L, Zhang J. A novel SYNE1 gene mutation in a Chinese family of Emery-Dreifuss muscular dystrophy-like. BMC MEDICAL GENETICS 2017; 18:63. [PMID: 28583108 PMCID: PMC5460548 DOI: 10.1186/s12881-017-0424-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/27/2016] [Accepted: 05/21/2017] [Indexed: 11/10/2022]
Abstract
BACKGROUND In the present study, a novel mutation in exon 46 at codon 2304 (G2304R) of the SYNE1 gene is described in a Chinese family (proband, mother, and sister) with Emery-Dreifuss muscular dystrophy-like, which clinically manifests as muscle weakness, muscle atrophy, joint contracture, and without significant cardiac abnormalities. METHODS Clinical examination and neuroimaging of the captured target region and high-throughput sequencing were performed in a family of four generations. Muscle changes were evaluated using magnetic resonance imaging and muscle biopsies. RESULTS Target region capture sequencing yielded a novel missense mutation in codon 2304 (G2304R), which is a heterozygous A to G point mutation at position 6910 (c.6910A > G) in exon 46 of SYNE1 leading to a glycine-to-arginine substitution (p.Gly2304Arg). The results were also identified by Sanger sequencing in three family members but not in the other three unaffected family members and 100 control subjects. CONCLUSIONS This mutation is probably pathogenic and is the first of its kind reported in a familial Emery-Dreifuss muscular dystrophy-like.
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Affiliation(s)
- Zuzhi Chen
- Department of Neurology, People's Hospital of Zhengzhou University, No. 7 Weiwu Road, Zhengzhou, Henan, 450003, China
| | - Zhixia Ren
- Department of Neurology, People's Hospital of Zhengzhou University, No. 7 Weiwu Road, Zhengzhou, Henan, 450003, China
| | - Wenli Mei
- Department of Neurology, People's Hospital of Zhengzhou University, No. 7 Weiwu Road, Zhengzhou, Henan, 450003, China
| | - Qiankun Ma
- Department of Neurology, People's Hospital of Zhengzhou University, No. 7 Weiwu Road, Zhengzhou, Henan, 450003, China
| | - Yingying Shi
- Department of Neurology, People's Hospital of Zhengzhou University, No. 7 Weiwu Road, Zhengzhou, Henan, 450003, China
| | - Yuanxing Zhang
- Department of Neurology, People's Hospital of Zhengzhou University, No. 7 Weiwu Road, Zhengzhou, Henan, 450003, China
| | - Shujian Li
- Department of Neurology, People's Hospital of Zhengzhou University, No. 7 Weiwu Road, Zhengzhou, Henan, 450003, China
| | - Li Xiang
- Department of Neurology, People's Hospital of Zhengzhou University, No. 7 Weiwu Road, Zhengzhou, Henan, 450003, China
| | - Jiewen Zhang
- Department of Neurology, People's Hospital of Zhengzhou University, No. 7 Weiwu Road, Zhengzhou, Henan, 450003, China.
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22
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Synofzik M, Schüle R. Overcoming the divide between ataxias and spastic paraplegias: Shared phenotypes, genes, and pathways. Mov Disord 2017; 32:332-345. [PMID: 28195350 PMCID: PMC6287914 DOI: 10.1002/mds.26944] [Citation(s) in RCA: 129] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2016] [Revised: 01/07/2017] [Accepted: 01/15/2017] [Indexed: 12/11/2022] Open
Abstract
Autosomal-dominant spinocerebellar ataxias, autosomal-recessive spinocerebellar ataxias, and hereditary spastic paraplegias have traditionally been designated in separate clinicogenetic disease classifications. This classification system still largely frames clinical thinking and genetic workup in clinical practice. Yet, with the advent of next-generation sequencing, phenotypically unbiased studies have revealed the limitations of this classification system. Various genes (eg, SPG7, SYNE1, PNPLA6) traditionally rooted in either the ataxia or hereditary spastic paraplegia classification system have now been shown to cause ataxia on the one end of the disease continuum and hereditary spastic paraplegia on the other. Other genes such as GBA2 and KIF1C were almost simultaneously published as both a hereditary spastic paraplegia and an ataxia gene. The variability and fluidity of observed phenotypes along the ataxia-spasticity spectrum warrants a rethinking of the traditional classification system. We propose to replace this divisive diagnosis-driven ataxia and hereditary spastic paraplegia classification system by a descriptive, unbiased approach of modular phenotyping. This approach is also open to expansion of the phenotype beyond ataxia and spasticity, which often occur as part of broader multisystem neuronal dysfunction. The concept of a continuous ataxia-spasticity disease spectrum is further supported by ataxias and hereditary spastic paraplegias sharing not only overlapping phenotypes and underlying genes, but also common cellular pathways and disease mechanisms. This suggests a shared vulnerability of cerebellar and corticospinal neurons for common pathophysiological processes. It might be this mechanistic overlap that drives their clinical overlap. A mechanistically inspired classification system will help to pave the way for mechanism-based strategies for drug development. © 2017 International Parkinson and Movement Disorder Society.
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Affiliation(s)
- Matthis Synofzik
- Department of Neurodegeneration, Hertie Institute for Clinical Brain Research (HIH), University of Tübingen, Tübingen, Germany
- German Center for Neurodegenerative Diseases (DZNE), Tübingen, Germany
| | - Rebecca Schüle
- Department of Neurodegeneration, Hertie Institute for Clinical Brain Research (HIH), University of Tübingen, Tübingen, Germany
- German Center for Neurodegenerative Diseases (DZNE), Tübingen, Germany
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23
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Algahtani H, Marzouk Y, Algahtani R, Salman S, Shirah B. Autosomal Recessive Cerebellar Ataxia type 1 mimicking multiple sclerosis: A report of two siblings with a novel mutation in SYNE1 gene in a Saudi family. J Neurol Sci 2016; 372:97-100. [PMID: 28017257 DOI: 10.1016/j.jns.2016.11.036] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2016] [Revised: 11/10/2016] [Accepted: 11/15/2016] [Indexed: 10/20/2022]
Abstract
Autosomal Recessive Cerebellar Ataxia type 1 (ARCA1), also known as recessive ataxia of Beauce, is an adult onset pure cerebellar ataxia that typically presents with cerebellar ataxia and/or dysarthria. A mutation in the synaptic nuclear envelope protein 1 (SYNE1) gene that is located on chromosome 6p25 results in premature termination of the protein. It was first reported in 2007 as the first identified gene responsible for a recessively inherited pure cerebellar ataxia. In this article, we are presenting two brothers with ARCA1 who were misdiagnosed and treated as multiple sclerosis for more than a decade. We are not only presenting a rare mutation in a Saudi family, but we are also expanding on the heterogeneity of the clinical presentation of this disorder and elaborating on the pathophysiology of neurological involvement. These cases illustrate that white matter abnormalities on MRI may occur in ARCA1. The clinical and radiological spectrum of ARCA1 indicate that this disease is more than a pure cerebellar degeneration. ARCA1 should be considered in the differential diagnosis of patients diagnosed with MS especially in the presence of strong family history. The disease is gradually progressive, and clinical features are atypical for MS. Applying diagnostic criteria for MS is extremely important for confirming or excluding the diagnosis. Detailed history and physical examination are of paramount importance to score the final diagnosis. Another less likely possibility is a chance association, which may question the biological relevance of our data. To confirm or exclude this possibility, further studies reporting different cohorts need to be conducted.
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Affiliation(s)
- Hussein Algahtani
- King Abdulaziz Medical City/King Saud bin Abdulaziz University for Health Sciences, Jeddah, Saudi Arabia.
| | - Yousef Marzouk
- King Saud bin Abdulaziz University for Health Sciences, Jeddah, Saudi Arabia
| | - Raghad Algahtani
- King Saud bin Abdulaziz University for Health Sciences, Jeddah, Saudi Arabia
| | - Sali Salman
- Batterjee Medical College, Jeddah, Saudi Arabia
| | - Bader Shirah
- King Abdullah International Medical Research Center/King Saud bin Abdulaziz University for Health Sciences, Jeddah, Saudi Arabia
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24
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Baumann M, Steichen-Gersdorf E, Krabichler B, Petersen BS, Weber U, Schmidt WM, Zschocke J, Müller T, Bittner RE, Janecke AR. Homozygous SYNE1 mutation causes congenital onset of muscular weakness with distal arthrogryposis: a genotype-phenotype correlation. Eur J Hum Genet 2016; 25:262-266. [PMID: 27782104 DOI: 10.1038/ejhg.2016.144] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2016] [Revised: 09/07/2016] [Accepted: 09/20/2016] [Indexed: 01/15/2023] Open
Abstract
The exceptionally large SYNE1 (spectrin repeat-containing nuclear envelope protein 1) gene encodes different nesprin-1 isoforms, which are differentially expressed in striated muscle and in cerebellar and cerebral neurons. Nesprin-1 isoforms can function in cytoskeletal, nuclear, and vesicle anchoring. SYNE1 variants have been associated with a spectrum of neurological and neuromuscular disease. Homozygosity mapping combined with exome sequencing identified a disease-causing nonsense mutation in the ultimate exon of full-length SYNE1 transcript in an 8-year-old boy with distal arthrogryposis and muscular hypotonia. mRNA analysis showed that the mutant transcript is expressed at wild-type levels. The variant truncates nesprin-1 isoforms for the C-terminal KASH (Klarsicht-ANC-Syne homology) domain. This is the third family with recessive arthrogryposis caused by homozygous distal-truncating SYNE1 variants. There is a SYNE1 genotype-phenotype correlation emerging, with more proximal homozygous SYNE1 variants causing recessive cerebellar ataxia of variable onset (SCAR8; ARCA-1).
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Affiliation(s)
- Matthias Baumann
- Department of Pediatrics I, Medical University of Innsbruck, Innsbruck, Austria
| | | | - Birgit Krabichler
- Division of Human Genetics, Medical University of Innsbruck, Innsbruck, Austria
| | - Britt-Sabina Petersen
- Institute of Clinical Molecular Biology, Christian-Albrechts-University Kiel, Kiel, Germany
| | - Ulrike Weber
- Department of Pediatrics, Krankenhaus Dornbirn, Dornbirn, Austria
| | - Wolfgang M Schmidt
- Neuromuscular Research Department, Center for Anatomy and Cell Biology, Medical University of Vienna, Vienna, Austria
| | - Johannes Zschocke
- Division of Human Genetics, Medical University of Innsbruck, Innsbruck, Austria
| | - Thomas Müller
- Department of Pediatrics I, Medical University of Innsbruck, Innsbruck, Austria
| | - Reginald E Bittner
- Neuromuscular Research Department, Center for Anatomy and Cell Biology, Medical University of Vienna, Vienna, Austria
| | - Andreas R Janecke
- Department of Pediatrics I, Medical University of Innsbruck, Innsbruck, Austria.,Division of Human Genetics, Medical University of Innsbruck, Innsbruck, Austria
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25
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Gama MTD, Houle G, Noreau A, Dionne-Laporte A, Dion PA, Rouleau GA, Barsottini OGP, Pedroso JL. SYNE1 mutations cause autosomal-recessive ataxia with retained reflexes in Brazilian patients. Mov Disord 2016; 31:1754-1756. [PMID: 27671794 DOI: 10.1002/mds.26810] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2016] [Revised: 08/21/2016] [Accepted: 08/30/2016] [Indexed: 11/09/2022] Open
Affiliation(s)
- Maria Thereza Drumond Gama
- Division of General Neurology and Ataxia Unit, Department of Neurology, Federal University of São Paulo (UNIFESP), São Paulo, Brazil
| | - Gabrielle Houle
- Montreal Neurological Institute, Department of Neurology and Neurosurgery, Montréal, Québec, Canada.,Department of Human Genetics, McGill University, Montréal, Québec, Canada
| | - Anne Noreau
- Montreal Neurological Institute, Department of Neurology and Neurosurgery, Montréal, Québec, Canada
| | - Alexandre Dionne-Laporte
- Montreal Neurological Institute, Department of Neurology and Neurosurgery, Montréal, Québec, Canada
| | - Patrick A Dion
- Montreal Neurological Institute, Department of Neurology and Neurosurgery, Montréal, Québec, Canada
| | - Guy A Rouleau
- Montreal Neurological Institute, Department of Neurology and Neurosurgery, Montréal, Québec, Canada
| | - Orlando G P Barsottini
- Division of General Neurology and Ataxia Unit, Department of Neurology, Federal University of São Paulo (UNIFESP), São Paulo, Brazil
| | - José Luiz Pedroso
- Division of General Neurology and Ataxia Unit, Department of Neurology, Federal University of São Paulo (UNIFESP), São Paulo, Brazil
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26
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Abstract
The nucleus is separated from the cytosol by the nuclear envelope, which is a double lipid bilayer composed of the outer nuclear membrane and the inner nuclear membrane. The intermediate filament proteins lamin A, lamin B, and lamin C form a network underlying the inner nuclear membrane. This proteinaceous network provides the nucleus with its strength, rigidity, and elasticity. Positioned within the inner nuclear membrane are more than 150 inner nuclear membrane proteins, many of which interact directly with lamins and require lamins for their inner nuclear membrane localization. Inner nuclear membrane proteins and the nuclear lamins define the nuclear lamina. These inner nuclear membrane proteins have tissue-specific expression and diverse functions including regulating cytoskeletal organization, nuclear architecture, cell cycle dynamics, and genomic organization. Loss or mutations in lamins and inner nuclear membrane proteins cause a wide spectrum of diseases. Here, I will review the functions of the well-studied nuclear lamina proteins and the diseases associated with loss or mutations in these proteins. © 2016 American Physiological Society. Compr Physiol 6:1655-1674, 2016.
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Affiliation(s)
- James M. Holaska
- Department of Pharmaceutical Sciences, University of the Sciences, Philadelphia, Pennsylvania, USA
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27
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Keys to overcoming the challenge of diagnosing autosomal recessive spinocerebellar ataxia. Neurologia 2016; 34:248-258. [PMID: 27460185 DOI: 10.1016/j.nrl.2016.06.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2016] [Revised: 06/06/2016] [Accepted: 06/09/2016] [Indexed: 11/22/2022] Open
Abstract
INTRODUCTION Autosomal recessive spinocerebellar ataxia refers to a large group of diseases affecting the cerebellum and/or its connections, although they may also involve other regions of the nervous system. These diseases are accompanied by a wide range of systemic manifestations (cardiopathies, endocrinopathies, skeletal deformities, and skin abnormalities). DEVELOPMENT This study reviews current knowledge of the most common forms of autosomal recessive spinocerebellar ataxia in order to provide tips that may facilitate diagnosis. CONCLUSIONS A thorough assessment of clinical phenotype (pure cerebellar or cerebellar-plus syndrome, with or without systemic manifestations), laboratory tests (vitamin E, acanthocytosis, albumin, cholesterol, phytanic acid, lactic acid, creatine kinase, cholestanol, coenzyme Q10, alpha-fetoprotein, copper, ceruloplasmin, chitotriosidase), nerve conduction studies (presence and type of neuropathy), and an magnetic resonance imaging study (presence of cerebellar atrophy, presence and location of signal alterations) may help establish a suspected diagnosis, which should be confirmed by detecting the underlying genetic mutation. A positive genetic test result is necessary to determine prognosis and provide adequate genetic counselling, and will also permit appropriate treatment of some entities (abetalipoproteinaemia, ataxia with vitamin E deficiency, Refsum disease, cerebrotendinous xanthomatosis, Niemann-Pick disease type C, Wilson disease). Without a genetic diagnosis, conducting basic research and therapeutic trials will not be possible.
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Mademan I, Harmuth F, Giordano I, Timmann D, Magri S, Deconinck T, Claaßen J, Jokisch D, Genc G, Di Bella D, Romito S, Schüle R, Züchner S, Taroni F, Klockgether T, Schöls L, De Jonghe P, Bauer P, Consortium E, Baets J, Synofzik M. Multisystemic SYNE1 ataxia: confirming the high frequency and extending the mutational and phenotypic spectrum. Brain 2016; 139:e46. [PMID: 27197992 DOI: 10.1093/brain/aww115] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2016] [Accepted: 04/06/2016] [Indexed: 02/01/2023] Open
Affiliation(s)
- Inès Mademan
- 1 Neurogenetics Group, Department of Molecular Genetics, VIB, Antwerpen, Belgium 2 Laboratory of Neurogenetics, Institute Born-Bunge, University of Antwerp, Belgium
| | - Florian Harmuth
- 3 Institute of Medical Genetics and Applied Genomics, University of Tübingen, Germany
| | - Ilaria Giordano
- 4 Department of Neurology, University Hospital of Bonn, Germany 5 German Research Centre for Neurodegenerative Diseases (DZNE), Bonn, Germany
| | - Dagmar Timmann
- 6 Department of Neurology, University of Duisburg-Essen, Essen, Germany
| | - Stefania Magri
- 7 Unit of Genetics of Neurodegenerative and Metabolic Diseases, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Tine Deconinck
- 1 Neurogenetics Group, Department of Molecular Genetics, VIB, Antwerpen, Belgium 2 Laboratory of Neurogenetics, Institute Born-Bunge, University of Antwerp, Belgium
| | - Jens Claaßen
- 6 Department of Neurology, University of Duisburg-Essen, Essen, Germany
| | - Daniel Jokisch
- 6 Department of Neurology, University of Duisburg-Essen, Essen, Germany
| | - Gencer Genc
- 8 Department of Neurology, Gumussuyu Military Hospital, Istanbul, Turkey
| | - Daniela Di Bella
- 7 Unit of Genetics of Neurodegenerative and Metabolic Diseases, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Silvia Romito
- 9 Division of Neurology, Department of Neuroscience, Azienda Ospedaliera Universitaria Integrata, Verona, Italy
| | - Rebecca Schüle
- 10 Department of Neurodegenerative Diseases, Hertie-Institute for Clinical Brain Research, University of Tübingen, Germany 11 German Research Centre for Neurodegenerative Diseases (DZNE), Tübingen, Germany
| | - Stephan Züchner
- 12 Dr John T. Macdonald Foundation Department of Human Genetics and John P. Hussman Institute for Human Genomics, University of Miami Miller School of Medicine, Miami, USA
| | - Franco Taroni
- 7 Unit of Genetics of Neurodegenerative and Metabolic Diseases, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Thomas Klockgether
- 4 Department of Neurology, University Hospital of Bonn, Germany 5 German Research Centre for Neurodegenerative Diseases (DZNE), Bonn, Germany
| | - Ludger Schöls
- 10 Department of Neurodegenerative Diseases, Hertie-Institute for Clinical Brain Research, University of Tübingen, Germany 11 German Research Centre for Neurodegenerative Diseases (DZNE), Tübingen, Germany
| | - Peter De Jonghe
- 1 Neurogenetics Group, Department of Molecular Genetics, VIB, Antwerpen, Belgium 2 Laboratory of Neurogenetics, Institute Born-Bunge, University of Antwerp, Belgium 13 Department of Neurology, Antwerp University Hospital, Belgium
| | - Peter Bauer
- 3 Institute of Medical Genetics and Applied Genomics, University of Tübingen, Germany
| | | | - Jonathan Baets
- 1 Neurogenetics Group, Department of Molecular Genetics, VIB, Antwerpen, Belgium 2 Laboratory of Neurogenetics, Institute Born-Bunge, University of Antwerp, Belgium 13 Department of Neurology, Antwerp University Hospital, Belgium
| | - Matthis Synofzik
- 10 Department of Neurodegenerative Diseases, Hertie-Institute for Clinical Brain Research, University of Tübingen, Germany 11 German Research Centre for Neurodegenerative Diseases (DZNE), Tübingen, Germany
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Wiethoff S, Hersheson J, Bettencourt C, Wood NW, Houlden H. Heterogeneity in clinical features and disease severity in ataxia-associated SYNE1 mutations. J Neurol 2016; 263:1503-10. [PMID: 27178001 PMCID: PMC4971038 DOI: 10.1007/s00415-016-8148-6] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2016] [Revised: 04/25/2016] [Accepted: 04/26/2016] [Indexed: 12/14/2022]
Abstract
The autosomal recessive spinocerebellar ataxias are an exciting field of study, with a growing number of causal genes and an expanding phenotypic spectrum. SYNE1 was originally discovered in 2007 as the causal gene underlying autosomal recessive spinocerebellar ataxia 1, a disease clinically thought to manifest with mainly pure cerebellar ataxia. Since the original report SYNE1 mutations have also been identified in families with motor neuronopathy and arthrogryposis but few families have been screened as the gene is very large at 146 exons in length. We screened 196 recessive and sporadic ataxia patients for mutations in SYNE1 using next generation sequencing in order to assess its frequency and extend the clinicogenetic spectrum. We identified four novel truncating mutations spread throughout the SYNE1 gene from three families living in London that originated from England, Turkey and Sri Lanka. The phenotype was mainly pure cerebellar ataxia in two families, cognitive decline was present in all three families, axonal neuropathy in one family and marked spasticity in the Turkish family, with a range of disease severities. Searching for genotype–phenotype correlations in the SYNE1 gene, defects located near the 3′ prime end of the gene are more frequently associated with motor neuron or neuromuscular involvement so far. Our data indicate SYNE1 mutations are not an uncommon cause of recessive ataxia with or without additional clinical features in patients from various ethnicities. The use of next generation sequencing allows the rapid analysis of large genes and will likely reveal more SYNE1 associated cases and further expand genotype–phenotype correlations.
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Affiliation(s)
- Sarah Wiethoff
- Department of Molecular Neuroscience, UCL Institute of Neurology, Queen Square, London, WC1N 3BG, UK.,Centre for Neurology and Hertie Institute for Clinical Brain Research, Eberhard-Karls-University, Tübingen, Germany
| | - Joshua Hersheson
- Department of Molecular Neuroscience, UCL Institute of Neurology, Queen Square, London, WC1N 3BG, UK
| | - Conceicao Bettencourt
- Department of Molecular Neuroscience, UCL Institute of Neurology, Queen Square, London, WC1N 3BG, UK
| | - Nicholas W Wood
- Department of Molecular Neuroscience, UCL Institute of Neurology, Queen Square, London, WC1N 3BG, UK.,Neurogenetics Laboratory, The National Hospital for Neurology and Neurosurgery, Queen Square, London, WC1N 3BG, UK
| | - Henry Houlden
- Department of Molecular Neuroscience, UCL Institute of Neurology, Queen Square, London, WC1N 3BG, UK. .,Neurogenetics Laboratory, The National Hospital for Neurology and Neurosurgery, Queen Square, London, WC1N 3BG, UK.
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Synofzik M, Smets K, Mallaret M, Di Bella D, Gallenmüller C, Baets J, Schulze M, Magri S, Sarto E, Mustafa M, Deconinck T, Haack T, Züchner S, Gonzalez M, Timmann D, Stendel C, Klopstock T, Durr A, Tranchant C, Sturm M, Hamza W, Nanetti L, Mariotti C, Koenig M, Schöls L, Schüle R, de Jonghe P, Anheim M, Taroni F, Bauer P. SYNE1 ataxia is a common recessive ataxia with major non-cerebellar features: a large multi-centre study. ACTA ACUST UNITED AC 2016; 139:1378-93. [PMID: 27086870 DOI: 10.1093/brain/aww079] [Citation(s) in RCA: 79] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2015] [Accepted: 01/11/2016] [Indexed: 12/21/2022]
Abstract
Mutations in the synaptic nuclear envelope protein 1 (SYNE1) gene have been reported to cause a relatively pure, slowly progressive cerebellar recessive ataxia mostly identified in Quebec, Canada. Combining next-generation sequencing techniques and deep-phenotyping (clinics, magnetic resonance imaging, positron emission tomography, muscle histology), we here established the frequency, phenotypic spectrum and genetic spectrum of SYNE1 in a screening of 434 non-Canadian index patients from seven centres across Europe. Patients were screened by whole-exome sequencing or targeted panel sequencing, yielding 23 unrelated families with recessive truncating SYNE1 mutations (23/434 = 5.3%). In these families, 35 different mutations were identified, 34 of them not previously linked to human disease. While only 5/26 patients (19%) showed the classical SYNE1 phenotype of mildly progressive pure cerebellar ataxia, 21/26 (81%) exhibited additional complicating features, including motor neuron features in 15/26 (58%). In three patients, respiratory dysfunction was part of an early-onset multisystemic neuromuscular phenotype with mental retardation, leading to premature death at age 36 years in one of them. Positron emission tomography imaging confirmed hypometabolism in extra-cerebellar regions such as the brainstem. Muscle biopsy reliably showed severely reduced or absent SYNE1 staining, indicating its potential use as a non-genetic indicator for underlying SYNE1 mutations. Our findings, which present the largest systematic series of SYNE1 patients and mutations outside Canada, revise the view that SYNE1 ataxia causes mainly a relatively pure cerebellar recessive ataxia and that it is largely limited to Quebec. Instead, complex phenotypes with a wide range of extra-cerebellar neurological and non-neurological dysfunctions are frequent, including in particular motor neuron and brainstem dysfunction. The disease course in this multisystemic neurodegenerative disease can be fatal, including premature death due to respiratory dysfunction. With a relative frequency of ∼5%, SYNE1 is one of the more common recessive ataxias worldwide.
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Affiliation(s)
- Matthis Synofzik
- Department of Neurodegenerative Diseases, Hertie-Institute for Clinical Brain Research, University of Tübingen, Germany German Research Center for Neurodegenerative Diseases (DZNE), University of Tübingen, Germany
| | - Katrien Smets
- Neurogenetics Group, Department of Molecular Genetics, University of Antwerp, VIB Belgium Department of Neurology, Antwerp University Hospital, Belgium Laboratory of Neurogenetics, Institute Born-Bunge, University of Antwerp, Belgium
| | - Martial Mallaret
- Department of Neurology, Hôpital de Hautepierre, Strasbourg, France Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), INSERM-U964/CNRS-UMR7104/Université de Strasbourg, Collège de France, 67404 Illkirch, France
| | - Daniela Di Bella
- Unit of Genetics of Neurodegenerative and Metabolic Diseases, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Constanze Gallenmüller
- Department of Neurology with Friedrich-Baur-Institute, Ludwig-Maximilians-University, Munich, Germany German Research Center for Neurodegenerative Diseases (DZNE), Munich, Germany Munich Cluster for Systems Neurology (SyNergy), Munich, Germany
| | - Jonathan Baets
- Neurogenetics Group, Department of Molecular Genetics, University of Antwerp, VIB Belgium Department of Neurology, Antwerp University Hospital, Belgium Laboratory of Neurogenetics, Institute Born-Bunge, University of Antwerp, Belgium
| | - Martin Schulze
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Germany
| | - Stefania Magri
- Unit of Genetics of Neurodegenerative and Metabolic Diseases, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Elisa Sarto
- Unit of Genetics of Neurodegenerative and Metabolic Diseases, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Mona Mustafa
- Department of Nuclear Medicine, Ludwig-Maximilians-University, Munich, Germany
| | - Tine Deconinck
- Neurogenetics Group, Department of Molecular Genetics, University of Antwerp, VIB Belgium Laboratory of Neurogenetics, Institute Born-Bunge, University of Antwerp, Belgium
| | - Tobias Haack
- Institute of Human Genetics, Technische Universität München, 81675 Munich, Germany Institute of Human Genetics, Helmholtz Zentrum München, German Research Center for Environmental Health, 85764 Neuherberg, Germany
| | - Stephan Züchner
- Dr. John T. Macdonald Foundation Department of Human Genetics and John P. Hussman Institute for Human Genomics, University of Miami Miller School of Medicine, Miami, USA
| | - Michael Gonzalez
- Dr. John T. Macdonald Foundation Department of Human Genetics and John P. Hussman Institute for Human Genomics, University of Miami Miller School of Medicine, Miami, USA
| | - Dagmar Timmann
- Department of Neurology, University of Duisburg-Essen, Essen, Germany
| | - Claudia Stendel
- Department of Neurology with Friedrich-Baur-Institute, Ludwig-Maximilians-University, Munich, Germany German Research Center for Neurodegenerative Diseases (DZNE), Munich, Germany
| | - Thomas Klopstock
- Department of Neurology with Friedrich-Baur-Institute, Ludwig-Maximilians-University, Munich, Germany German Research Center for Neurodegenerative Diseases (DZNE), Munich, Germany Munich Cluster for Systems Neurology (SyNergy), Munich, Germany
| | - Alexandra Durr
- APHP Genetic department and Centre de Recherche de l'Institut du Cerveau et de la Moelle épinière (ICM), UPMC University Paris VI, UMR975; CNRS UMR 7225; INSERM U975; University Hospital Pitié-Salpêtrière, 75013 Paris, France
| | - Christine Tranchant
- Department of Neurology, Hôpital de Hautepierre, Strasbourg, France Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), INSERM-U964/CNRS-UMR7104/Université de Strasbourg, Collège de France, 67404 Illkirch, France
| | - Marc Sturm
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Germany
| | - Wahiba Hamza
- Laboratoire de Biologie Cellulaire et Moléculaire, Faculté des Sciences Biologiques, USTHB, Algiers, Algeria
| | - Lorenzo Nanetti
- Unit of Genetics of Neurodegenerative and Metabolic Diseases, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Caterina Mariotti
- Unit of Genetics of Neurodegenerative and Metabolic Diseases, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Michel Koenig
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), INSERM-U964/CNRS-UMR7104/Université de Strasbourg, Collège de France, 67404 Illkirch, France Laboratoire de Genetique de Maladies Rares, EA 7402, Institut Universitaire de Recherche Clinique, Université et CHU de Montpellier, 34093 Montpellier cedex 5, France
| | - Ludger Schöls
- Department of Neurodegenerative Diseases, Hertie-Institute for Clinical Brain Research, University of Tübingen, Germany German Research Center for Neurodegenerative Diseases (DZNE), University of Tübingen, Germany
| | - Rebecca Schüle
- Department of Neurodegenerative Diseases, Hertie-Institute for Clinical Brain Research, University of Tübingen, Germany German Research Center for Neurodegenerative Diseases (DZNE), University of Tübingen, Germany Dr. John T. Macdonald Foundation Department of Human Genetics and John P. Hussman Institute for Human Genomics, University of Miami Miller School of Medicine, Miami, USA
| | - Peter de Jonghe
- Neurogenetics Group, Department of Molecular Genetics, University of Antwerp, VIB Belgium Department of Neurology, Antwerp University Hospital, Belgium Laboratory of Neurogenetics, Institute Born-Bunge, University of Antwerp, Belgium
| | - Mathieu Anheim
- Department of Neurology, Hôpital de Hautepierre, Strasbourg, France Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), INSERM-U964/CNRS-UMR7104/Université de Strasbourg, Collège de France, 67404 Illkirch, France Fédération de Médecine Translationnelle de Strasbourg (FMTS), Université de Strasbourg, Strasbourg, France
| | - Franco Taroni
- Unit of Genetics of Neurodegenerative and Metabolic Diseases, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Peter Bauer
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Germany
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Grill B, Murphey RK, Borgen MA. The PHR proteins: intracellular signaling hubs in neuronal development and axon degeneration. Neural Dev 2016; 11:8. [PMID: 27008623 PMCID: PMC4806438 DOI: 10.1186/s13064-016-0063-0] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2015] [Accepted: 03/15/2016] [Indexed: 11/10/2022] Open
Abstract
During development, a coordinated and integrated series of events must be accomplished in order to generate functional neural circuits. Axons must navigate toward target cells, build synaptic connections, and terminate outgrowth. The PHR proteins (consisting of mammalian Phr1/MYCBP2, Drosophila Highwire and C. elegans RPM-1) function in each of these events in development. Here, we review PHR function across species, as well as the myriad of signaling pathways PHR proteins regulate. These findings collectively suggest that the PHR proteins are intracellular signaling hubs, a concept we explore in depth. Consistent with prominent developmental functions, genetic links have begun to emerge between PHR signaling networks and neurodevelopmental disorders, such as autism, schizophrenia and intellectual disability. Finally, we discuss the recent and important finding that PHR proteins regulate axon degeneration, which has further heightened interest in this fascinating group of molecules.
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Affiliation(s)
- Brock Grill
- Department of Neuroscience, The Scripps Research Institute, Scripps Florida, Jupiter, FL, 33458, USA.
| | - Rodney K Murphey
- Department of Biological Sciences, Florida Atlantic University, Jupiter, FL, 33458, USA
| | - Melissa A Borgen
- Department of Neuroscience, The Scripps Research Institute, Scripps Florida, Jupiter, FL, 33458, USA
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Hamza W, Ali Pacha L, Hamadouche T, Muller J, Drouot N, Ferrat F, Makri S, Chaouch M, Tazir M, Koenig M, Benhassine T. Molecular and clinical study of a cohort of 110 Algerian patients with autosomal recessive ataxia. BMC MEDICAL GENETICS 2015; 16:36. [PMID: 26068213 PMCID: PMC4630839 DOI: 10.1186/s12881-015-0180-3] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/15/2014] [Accepted: 05/29/2015] [Indexed: 12/12/2022]
Abstract
BACKGROUND Autosomal recessive cerebellar ataxias (ARCA) are a complex group of neurodegenerative disorders with great genetic and phenotypic heterogeneity, over 30 genes/loci have been associated with more than 20 different clinical forms of ARCA. Genetic heterogeneity combined with highly variable clinical expression of the cerebellar symptoms and overlapping features complicate furthermore the etiological diagnosis of ARCA. The determination of the most frequent mutations and corresponding ataxias, as well as particular features specific to a population, are mandatory to facilitate and speed up the diagnosis process, especially when an appropriate treatment is available. METHODS We explored 166 patients (115 families) refered to the neurology units of Algiers central hospitals (Algeria) with a cerebellar ataxia phenotype segregating as an autosomal recessive pattern of inheritance. Genomic DNA was extracted from peripheral blood samples and mutational screening was performed by PCR and direct sequencing or by targeted genomic capture and massive parallel sequencing of 57 genes associated with inherited cerebellar ataxia phenotypes. RESULTS In this work we report the clinical and molecular results obtained on a large cohort of Algerian patients (110 patients/76 families) with genetically determined autosomal recessive ataxia, representing 9 different types of ARCA and 23 different mutations, including 6 novel ones. The five most common ARCA in this cohort were Friedreich ataxia, ataxia with isolated vitamin E deficiency, ataxia with oculomotor apraxia type 2, autosomal recessive spastic ataxia of Charlevoix-Saguenay and ataxia with oculomotor apraxia type 1. CONCLUSION We report here a large cohort of patients with genetically determined autosomal recessive ataxia and the first study of the genetic context of ARCA in Algeria. This study showed that in Algerian patients, the two most common types of ataxia (Friedreich ataxia and ataxia with isolated vitamin E deficiency) coexist with forms that may be less common or underdiagnosed. To refine the genotype/phenotype correlation in rare and heteregeneous diseases as autosomal recessive ataxias, more extensive epidemiological investigations and reports are necessary as well as more accurate and detailed clinical characterizations. The use of standardized clinical and molecular protocols would thus enable a better knowledge of the different forms of ARCA.
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Affiliation(s)
- Wahiba Hamza
- Laboratoire de Biologie Cellulaire et Moléculaire, Faculté des Sciences Biologiques, USTHB, Alger, Algeria.
| | - Lamia Ali Pacha
- Service de Neurologie, CHU Mustapha Bacha, Alger, Algeria. .,Laboratoire de Neurosciences, Université d'Alger 1, Alger, Algeria.
| | - Tarik Hamadouche
- Laboratoire de Neurosciences, Université d'Alger 1, Alger, Algeria. .,Laboratoire de Biologie Moléculaire, Faculté des Sciences, UMBB, Boumerdes, Algeria.
| | - Jean Muller
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, CNRS/Université de Strasbourg UMR7104, INSERM U964, Illkirch, France. .,Laboratoire de Diagnostic Génétique, Hôpitaux Universitaires de Strasbourg, Strasbourg, France.
| | - Nathalie Drouot
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, CNRS/Université de Strasbourg UMR7104, INSERM U964, Illkirch, France.
| | - Farida Ferrat
- Service de Neurologie, CHU Ben Aknoun, Alger, Algeria.
| | - Samira Makri
- Service de Neurologie, EHS Ali Aït Idir, Alger, Algeria.
| | | | - Meriem Tazir
- Service de Neurologie, CHU Mustapha Bacha, Alger, Algeria. .,Laboratoire de Neurosciences, Université d'Alger 1, Alger, Algeria.
| | - Michel Koenig
- Laboratoire de Génétique de Maladies Rares, Institut Universitaire de Recherche Clinique, Université de Montpellier, CHU de Montpellier, Montpellier, France.
| | - Traki Benhassine
- Laboratoire de Biologie Cellulaire et Moléculaire, Faculté des Sciences Biologiques, USTHB, Alger, Algeria.
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Wang JY, Yu IS, Huang CC, Chen CY, Wang WP, Lin SW, Jeang KT, Chi YH. Sun1 deficiency leads to cerebellar ataxia in mice. Dis Model Mech 2015; 8:957-67. [PMID: 26035387 PMCID: PMC4527285 DOI: 10.1242/dmm.019240] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2014] [Accepted: 04/23/2015] [Indexed: 01/22/2023] Open
Abstract
Migration and organization of the nucleus are essential for the proliferation and differentiation of cells, including neurons. However, the relationship between the positioning of the nucleus and cellular morphogenesis remains poorly understood. Inherited recessive cerebellar ataxia has been attributed to mutations in SYNE1, a component of the linker of nucleoskeleton and cytoskeleton (LINC) complex. Regardless, Syne1-mutant mice present with normal cerebellar development. The Sad1-Unc-84 homology (SUN)-domain proteins are located at the inner nuclear membrane and recruit Syne proteins through the KASH domain to the outer nuclear membrane. Here, we report an unrecognized contribution of Sun1 and Sun2 to the postnatal development of murine cerebellum. Mice depleted of Sun1 showed a marked reduction in the cerebellar volume, and this phenotype is exacerbated with additional loss of a Sun2 allele. Consistent with these histological changes, Sun1(-/-) and Sun1(-/-)Sun2(+/-) mice exhibited defective motor coordination. Results of immunohistochemical analyses suggested that Sun1 is highly expressed in Purkinje cells and recruits Syne2 to the periphery of the nucleus. Approximately 33% of Purkinje cells in Sun1(-/-) mice and 66% of Purkinje cells in Sun1(-/-)Sun2(+/-) mice were absent from the surface of the internal granule layer (IGL), whereas the proliferation and migration of granule neurons were unaffected. Furthermore, the Sun1(-/-)Sun2(+/-) Purkinje cells exhibited retarded primary dendrite specification, reduced dendritic complexity and aberrant patterning of synapses. Our findings reveal a cell-type-specific role for Sun1 and Sun2 in nucleokinesis during cerebellar development, and we propose the use of Sun-deficient mice as a model for studying cerebellar ataxia that is associated with mutation of human SYNE genes or loss of Purkinje cells.
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Affiliation(s)
- Jing-Ya Wang
- Institute of Biotechnology and Pharmaceutical Research, National Health Research Institutes, Zhunan, Miaoli County 35053, Taiwan
| | - I-Shing Yu
- Department of Clinical Laboratory Sciences and Medical Biotechnology, National Taiwan University Hospital, Taipei 10048, Taiwan Center of Genomic Medicine, National Taiwan University Hospital, College of Medicine, National Taiwan University, Taipei 10048, Taiwan
| | - Chien-Chi Huang
- Institute of Molecular and Genomic Medicine, National Health Research Institutes, Zhunan, Miaoli County 35053, Taiwan
| | - Chia-Yen Chen
- Laboratory of Molecular Microbiology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Wan-Ping Wang
- Institute of Biotechnology and Pharmaceutical Research, National Health Research Institutes, Zhunan, Miaoli County 35053, Taiwan
| | - Shu-Wha Lin
- Department of Clinical Laboratory Sciences and Medical Biotechnology, National Taiwan University Hospital, Taipei 10048, Taiwan Center of Genomic Medicine, National Taiwan University Hospital, College of Medicine, National Taiwan University, Taipei 10048, Taiwan Department of Laboratory Medicine, National Taiwan University Hospital, Taipei 10048, Taiwan
| | - Kuan-Teh Jeang
- Laboratory of Molecular Microbiology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Ya-Hui Chi
- Institute of Biotechnology and Pharmaceutical Research, National Health Research Institutes, Zhunan, Miaoli County 35053, Taiwan Graduate Institute of Basic Medical Science, China Medical University, Taichung 40402, Taiwan
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Abstract
Abstract:Background:The growing number of spastic ataxia of Charlevoix-Saguenay (SACS) gene mutations reported worldwide has broadened the clinical phenotype of autosomal recessive spastic ataxia of Charlevoix-Saguenay (ARSACS). The identification of Quebec ARSACS cases without two knownSACSmutation led to the development of a multi-modal genomic strategy to uncover mutations in this large gene and explore phenotype variability.Methods:Search forSACSmutations by combining various methods on 20 cases with a classical French-Canadian ARSACS phenotype without two mutations and a group of 104 sporadic or recessive spastic ataxia cases of unknown cause. Western blot on lymphoblast protein from cases with different genotypes was probed to establish if they still expressed sacsin.Results:A total of 12 mutations, including 7 novels, were uncovered in Quebec ARSACS cases. The screening of 104 spastic ataxia cases of unknown cause for 98SACSmutations did not uncover carriers of two mutations. Compounds heterozygotes for one missenseSACSmutation were found to minimally express sacsin.Conclusions:The large number ofSACSmutations present even in Quebec suggests that the size of the gene alone may explain the great genotypic diversity. This study does not support an expanding ARSACS phenotype in the French-Canadian population. Most mutations lead to loss of function, though phenotypic variability in other populations may reflect partial loss of function with preservation of some sacsin expression. Our results also highlight the challenge ofSACSmutation screening and the necessity to develop new generation sequencing methods to ensure low cost complete gene sequencing.
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Morel V, Lepicard S, Rey AN, Parmentier ML, Schaeffer L. Drosophila Nesprin-1 controls glutamate receptor density at neuromuscular junctions. Cell Mol Life Sci 2014; 71:3363-79. [PMID: 24492984 PMCID: PMC11113563 DOI: 10.1007/s00018-014-1566-7] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2013] [Revised: 12/20/2013] [Accepted: 01/16/2014] [Indexed: 01/06/2023]
Abstract
Nesprin-1 is a core component of a protein complex connecting nuclei to cytoskeleton termed LINC (linker of nucleoskeleton and cytoskeleton). Nesprin-1 is anchored to the nuclear envelope by its C-terminal KASH domain, the disruption of which has been associated with neuronal and neuromuscular pathologies, including autosomal recessive cerebellar ataxia and Emery-Dreifuss muscular dystrophy. Here, we describe a new and unexpected role of Drosophila Nesprin-1, Msp-300, in neuromuscular junction. We show that larvae carrying a deletion of Msp-300 KASH domain (Msp-300 (∆KASH) ) present a locomotion defect suggestive of a myasthenia, and demonstrate the importance of muscle Msp-300 for this phenotype, using tissue-specific RNAi knock-down. We show that Msp-300 (∆KASH) mutants display abnormal neurotransmission at the larval neuromuscular junction, as well as an imbalance in postsynaptic glutamate receptor composition with a decreased percentage of GluRIIA-containing receptors. We could rescue Msp-300 (∆KASH) locomotion phenotypes by GluRIIA overexpression, suggesting that the locomotion impairment associated with the KASH domain deletion is due to a reduction in junctional GluRIIA. In summary, we found that Msp-300 controls GluRIIA density at the neuromuscular junction. Our results suggest that Drosophila is a valuable model for further deciphering how Nesprin-1 and LINC disruption may lead to neuronal and neuromuscular pathologies.
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Affiliation(s)
- Véronique Morel
- Equipe Différenciation Neuromusculaire, CNRS, UMR5239, Ecole Normale Supérieure-Lyon, 46 allée d'Italie, 69364, Lyon Cedex 07, France,
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Lin DJ, Hermann KL, Schmahmann JD. Multiple system atrophy of the cerebellar type: clinical state of the art. Mov Disord 2014; 29:294-304. [PMID: 24615754 DOI: 10.1002/mds.25847] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2013] [Revised: 12/27/2013] [Accepted: 01/27/2014] [Indexed: 01/21/2023] Open
Abstract
Multiple system atrophy (MSA) is a late-onset, sporadic neurodegenerative disorder clinically characterized by autonomic failure and either poorly levodopa-responsive parkinsonism or cerebellar ataxia. It is neuropathologically defined by widespread and abundant central nervous system α-synuclein-positive glial cytoplasmic inclusions and striatonigral and/or olivopontocerebellar neurodegeneration. There are two clinical subtypes of MSA distinguished by the predominant motor features: the parkinsonian variant (MSA-P) and the cerebellar variant (MSA-C). Despite recent progress in understanding the pathobiology of MSA, investigations into the symptomatology and natural history of the cerebellar variant of the disease have been limited. MSA-C presents a unique challenge to both clinicians and researchers alike. A key question is how to distinguish early in the disease course between MSA-C and other causes of adult-onset cerebellar ataxia. This is a particularly difficult question, because the clinical framework for conceptualizing and studying sporadic adult-onset ataxias continues to undergo flux. To date, several investigations have attempted to identify clinical features, imaging, and other biomarkers that may be predictive of MSA-C. This review presents a clinically oriented overview of our current understanding of MSA-C with a focus on evidence for distinguishing MSA-C from other sporadic, adult-onset ataxias.
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Affiliation(s)
- David J Lin
- Ataxia Unit, Laboratory for Neuroanatomy and Cerebellar Neurobiology, Department of Neurology, Massachusetts General Hospital, Boston, Massachusetts, USA
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Votsi C, Christodoulou K. Molecular diagnosis of autosomal recessive cerebellar ataxia in the whole exome/genome sequencing era. World J Neurol 2013; 3:115-128. [DOI: 10.5316/wjn.v3.i4.115] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/28/2013] [Revised: 08/30/2013] [Accepted: 10/16/2013] [Indexed: 02/06/2023] Open
Abstract
Autosomal recessive cerebellar ataxias (ARCA) are a clinically and genetically heterogeneous group of rare neurodegenerative disorders characterized by autosomal recessive inheritance and an early age of onset. Progressive ataxia is usually the prominent symptom and is often associated with other neurological or additional features. ARCA classification still remains controversial even though different approaches have been proposed over the years. Furthermore, ARCA molecular diagnosis has been a challenge due to phenotypic overlap and increased genetic heterogeneity observed within this group of disorders. Friedreich’s ataxia and ataxia telangiectasia have been reported as the most frequent and well-studied forms of ARCA. Significant progress in understanding the genetic etiologies of the ARCA has been achieved during the last 15 years. The methodological revolution that has been observed in genetics over the last few years has contributed significantly to the molecular diagnosis of rare diseases including the ARCAs. Development of high throughput technologies has resulted in the identification of new ARCA genes and novel mutations in known ARCA genes. Therefore, an improvement in the molecular diagnosis of ARCA is expected. Moreover, based on the fact that many patients still remain undiagnosed, additional forms of ataxia are expected to be identified. We hereby review the current knowledge on the ARCAs, focused on the genetic findings of the most common forms that were molecularly characterized before the whole exome/genome era, as well as the most recently described forms that have been elucidated with the use of these novel technologies. The significant contribution of whole-exome sequencing or whole-genome sequencing in the molecular diagnosis of ARCAs is discussed.
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Tranchant C. [Have centers of rare neurological diseases changed their practices and management of the hereditary cerebellar ataxias?]. Rev Neurol (Paris) 2013; 169 Suppl 1:S23-7. [PMID: 23452767 DOI: 10.1016/s0035-3787(13)70056-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The classification and management of hereditary cerebellar ataxias have been considerably changed by advances made in the field of genetics. Given the numerous genes implicated in the disorders, genetic analysis, which alone can confirm the diagnosis, needs to be based on phenotypically precise studies. Diagnostic algorithms including both recessive and dominant forms of ataxia have been proposed. The range of disease effects has been further expanded in the light of evidence of ataxias associated with permutations of the Fragile X gene, and ataxias linked to mutations of the nuclear genes coding for structural proteins of mitochondrial DNA. In the field of therapeutics, several studies are currently ongoing for Friedreich's ataxia.
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Affiliation(s)
- C Tranchant
- Centre de compétence des maladies neurologiques génétiques rares, Service de Neurologie, Hôpital de Hautepierre, avenue Molière, 67100 Strasbourg, France.
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LINC complexes mediate the positioning of cone photoreceptor nuclei in mouse retina. PLoS One 2012; 7:e47180. [PMID: 23071752 PMCID: PMC3465324 DOI: 10.1371/journal.pone.0047180] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2012] [Accepted: 09/10/2012] [Indexed: 11/19/2022] Open
Abstract
It has long been observed that many neuronal types position their nuclei within restricted cytoplasmic boundaries. A striking example is the apical localization of cone photoreceptors nuclei at the outer edge of the outer nuclear layer of mammalian retinas. Yet, little is known about how such nuclear spatial confinement is achieved and further maintained. Linkers of the Nucleoskeleton to the Cytoskeleton (LINC complexes) consist of evolutionary-conserved macromolecular assemblies that span the nuclear envelope to connect the nucleus with the peripheral cytoskeleton. Here, we applied a new transgenic strategy to disrupt LINC complexes either in cones or rods. In adult cones, we observed a drastic nuclear mislocalization on the basal side of the ONL that affected cone terminals overall architecture. We further provide evidence that this phenotype may stem from the inability of cone precursor nuclei to migrate towards the apical side of the outer nuclear layer during early postnatal retinal development. By contrast, disruption of LINC complexes within rod photoreceptors, whose nuclei are scattered across the outer nuclear layer, had no effect on the positioning of their nuclei thereby emphasizing differential requirements for LINC complexes by different neuronal types. We further show that Sun1, a component of LINC complexes, but not A-type lamins, which interact with LINC complexes at the nuclear envelope, participate in cone nuclei positioning. This study provides key mechanistic aspects underlying the well-known spatial confinement of cone nuclei as well as a new mouse model to evaluate the pathological relevance of nuclear mispositioning.
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Abstract
The hereditary cerebellar ataxias are a clinically and genetically heterogeneous group of disorders that primarily affect the cerebellum; often there are additional features such as neuropathy, cognitive decline, or maculopathy that help define the clinical subtype of ataxia. They are commonly classified according to their mode of inheritance into autosomal dominant, autosomal recessive, X-linked, and mitochondrial forms. Great advances have been made in understanding the genetics of cerebellar ataxias in the last 15 years. At least 36 different forms of ADCA are known, 20 autosomal-recessive, two X-linked, and several forms of ataxia associated with mitochondrial defects are known to date. However, in about 40 % of suspected genetically determined ataxia cases, the underlying genetic defect remains undetermined. Although the majority of disease genes have been found in the last two decades, over the last 2 years the genetics has undergone a methodological revolution. New DNA sequencing technologies are enabling us to investigate the whole or large targeted proportions of the genome in a rapid, affordable, and comprehensive way. Exome and targeted sequencing has recently identified four new genes causing ataxia: TGM6, ANO10, SYT14, and rundataxin. This approach is likely to continue to discover new ataxia genes and make screening of existing genes more effective. Translating the genetic findings into isolated and overlapping disease pathways will help stratify patient groups and identify therapeutic targets for ataxia that have so far remained undiscovered.
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Affiliation(s)
- Anna Sailer
- Department of Molecular Neuroscience, Institute of Neurology, Queen Square, London WC1N 3BG, United Kingdom
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The ataxias. Neurogenetics 2012. [DOI: 10.1017/cbo9781139087711.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Fogel BL, Lee JY, Lane J, Wahnich A, Chan S, Huang A, Osborn GE, Klein E, Mamah C, Perlman S, Geschwind DH, Coppola G. Mutations in rare ataxia genes are uncommon causes of sporadic cerebellar ataxia. Mov Disord 2012; 27:442-6. [PMID: 22287014 PMCID: PMC3323119 DOI: 10.1002/mds.24064] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2011] [Revised: 11/11/2011] [Accepted: 11/14/2011] [Indexed: 11/09/2022] Open
Abstract
BACKGROUND Sporadic-onset ataxia is common in a tertiary care setting but a significant percentage remains unidentified despite extensive evaluation. Rare genetic ataxias, reported only in specific populations or families, may contribute to a percentage of sporadic ataxia. METHODS Patients with adult-onset sporadic ataxia, who tested negative for common genetic ataxias (SCA1, SCA2, SCA3, SCA6, SCA7, and/or Friedreich ataxia), were evaluated using a stratified screening approach for variants in 7 rare ataxia genes. RESULTS We screened patients for published mutations in SYNE1 (n = 80) and TGM6 (n = 118), copy number variations in LMNB1 (n = 40) and SETX (n = 11), sequence variants in SACS (n = 39) and PDYN (n = 119), and the pentanucleotide insertion of spinocerebellar ataxia type 31 (n = 101). Overall, we identified 1 patient with a LMNB1 duplication, 1 patient with a PDYN variant, and 1 compound SACS heterozygote, including a novel variant. CONCLUSIONS The rare genetic ataxias examined here do not significantly contribute to sporadic cerebellar ataxia in our tertiary care population.
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Affiliation(s)
- Brent L Fogel
- Program in Neurogenetics, Department of Neurology, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, California 90095, USA.
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Affiliation(s)
- Mathieu Anheim
- Assistance Publique-Hôpitaux de Paris, Pitié-Salpêtrière Hospital, Department of Genetics and Cytogenetics, Paris, France.
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De Michele G, Filla A. Other autosomal recessive and childhood ataxias. HANDBOOK OF CLINICAL NEUROLOGY 2012; 103:343-57. [PMID: 21827899 DOI: 10.1016/b978-0-444-51892-7.00021-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The label of "early-onset cerebellar ataxia with retained tendon reflexes" (EOCA) has been created to differentiate it from Friedreich ataxia (FRDA) patients with preserved knee jerks and absence of cardiomyopathy, optic atrophy, and diabetes mellitus. However, EOCA is a heterogeneous syndrome and several FRDA patients present with an EOCA-like phenotype. Cerebellar ataxia with hypogonadism is another heterogeneous syndrome for which no locus has been mapped yet. Two peculiar ataxic syndromes have been identified in genetically isolated populations: autosomal recessive ataxia of Charlevoix-Saguenay (ARSACS) in Quebec and infantile-onset spinocerebellar ataxia (IOSCA) in Finland. Both conditions present usually within the second year of life. ARSACS is characterized by marked spasticity and IOSCA by a complex phenotype which includes, besides ataxia, epilepsy, optic atrophy, ophthalmoplegia, hearing loss, and areflexia. The responsible genes are SACS, encoding sacsin, a protein which may act as a chaperone, and C10orf2, encoding Twinkle, a mitochondrial DNA-specific helicase. Marinesco-Sjögren syndrome, clinically characterized by cerebellar ataxia, cataracts, myopathy, and mental retardation, is genetically heterogeneous. One gene, SIL1, encodes a nucleotide exchange factor for the heat-shock protein 70 chaperone HSPA5. Five conditions account for most cases of progressive myoclonic ataxia: Unverricht-Lundborg disease, Lafora disease, myoclonic epilepsy with ragged-red fibers, neuronal ceroid lipofuscinoses, and sialidoses.
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MacLellan MJ, Dupré N, McFadyen BJ. Increased Obstacle Clearance in People with ARCA-1 Results in Part from Voluntary Coordination Changes Between the Thigh and Shank Segments. THE CEREBELLUM 2011; 10:732-44. [DOI: 10.1007/s12311-011-0283-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Zühlke C, Kreuz F, Bürk K. [Clinical details and genetics of recessive ataxias]. DER NERVENARZT 2011; 82:447-458. [PMID: 20640395 DOI: 10.1007/s00115-010-3079-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Autosomal recessive cerebellar ataxias (ARCA) are a heterogeneous group of rare neurological diseases affecting both the central and the peripheral nervous systems. They are characterized by autosomal recessive inheritance, progressive ataxia and degeneration of the cerebellum and spinal cord. Onset is generally before the third decade of life. The most frequent of these rare disorders in the Caucasian population is Friedreich's ataxia followed by ataxias with oculomotor apraxia. ARCAs are caused by mutations at specific loci but not every affected gene is known to date. Clinical diagnosis can be confirmed by ancillary tests (biochemical, neuroimaging and electrophysiological investigations) and mutation analyses if the causative gene has been identified. Correct clinical and genetic diagnosis is necessary for prognosis, genetic counseling and pharmacological treatment. For the majority of ARCAs a curative treatment is not available.
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Affiliation(s)
- C Zühlke
- Institut für Humangenetik, Universität zu Lübeck, Ratzeburger Allee 160, 23538, Lübeck.
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Laforce R, Buteau JP, Bouchard JP, Rouleau GA, Bouchard RW, Dupré N. Cognitive impairment in ARCA-1, a newly discovered pure cerebellar ataxia syndrome. THE CEREBELLUM 2011; 9:443-53. [PMID: 20559786 DOI: 10.1007/s12311-010-0184-7] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Cerebellar contribution to non-motor functions has been supported by several animal, human and functional neuroimaging studies. Which cognitive skills and to what extent the cerebrocerebellar loops contribute remain unclear, however. Among other reasons, this may be explained by the fact that authors have studied patients with extracerebellar lesions. The goal of this study was to explore the role of the cerebellum in cognition and affect in patients with autosomal recessive cerebellar ataxia type 1 (ARCA-1), a newly described inherited cerebellar disease characterised by middle-age onset of ataxia as well as pure, severe and diffuse cerebellar atrophy. To this end, the performance of 21 ARCA-1 patients was compared to that of 21 normal controls paired for age and education on a 3-h battery of attention, executive, visuospatial and memory skills. Results indicated similar IQ, naming and declarative memory abilities between groups. ARCA-1 patients showed significant deficits in attention (attention span, speed of information processing, sustained attention), verbal working memory and visuospatial/visuoconstructional skills (3-D drawings, copy of a complex figure). Functional brain imaging in a subset of patients showed diffuse severe cerebellar hypometabolism associated with a small area of right parietal hypometabolism. None of the patients presented a significant affective syndrome. Correlational analyses suggested that cognitive deficits could not be explained by the severity of motor deficits, duration of disease or mood. Altogether, this study confirms that pure cerebellar damage as seen in ARCA-1 is associated with significant cognitive impairments but not with psychiatric comorbidity. These deficits are correlated with an overall moderate impact on patient's autonomy. Our data favour an indirect participation of the dorsolateral prefrontal and posterior parietal cortical areas to the cerebrocerebellar circuit.
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Affiliation(s)
- Robert Laforce
- Département des Sciences Neurologiques Centre Hospitalier Affilié (Enfant-Jésus), Université Laval, 1401, 18ième rue, Laval, QC, Canada G1J 1Z4.
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Anheim M. [Autosomal recessive cerebellar ataxias]. Rev Neurol (Paris) 2010; 167:372-84. [PMID: 21087783 DOI: 10.1016/j.neurol.2010.07.021] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2010] [Revised: 04/13/2010] [Accepted: 07/20/2010] [Indexed: 11/25/2022]
Abstract
INTRODUCTION Autosomal recessive cerebellar ataxias (ARCA) are heterogeneous and complex inherited neurodegenerative diseases that may affect the cerebellum and/or the spinocerebellar tract, the posterior column of the spinal cord and the peripheral nerves. Cerebellar ataxia is frequently proeminent and mostly associated with several neurological or extra-neurological signs, leading to a major disability before the age of 30. STATE OF ART Friedreich's ataxia (FRDA) is clearly the most frequent ARCA and several rarer entities have been described during the past fifteen years such as ataxia with oculomotor apraxia type 1 (AOA1) and type 2 (AOA2), ataxia with vitamin E deficiency (AVED) and autosomal recessive spastic ataxia of Charlevoix-Saguenay (ARSACS). The ACAR are characterized by both allelic and non-allelic genetic heterogeneity. They may be divided into three groups: spino-cerebellar ataxia with pure sensory neuropathy; cerebellar ataxia with sensori-motor axonal neuropathy; pure cerebellar ataxia (i.e. ataxia of purely cerebellar origin that may be associated with other symptoms). Common physiological pathways are involved in several ARCA, such as DNA repair deficiency (AOA1, ataxia telangiectasia [AT]…), RNA termination disorder (AOA2), mitochondrial defect (FRDA, sensory ataxic neuropathy with dysarthria and ophthalmoplegia [Sando]…), lipoprotein assembly defects (AVED, abetalipoproteinemia [ABL]), chaperon protein disorders (ARSACS, Marinesco-Sjögren syndrome [MSS]) or peroxysomal diseases (Refsum disease [RD]). PERSPECTIVES New nanotechnology methods and high throughput gene analysis as well as bioinformatics should lead to the identification of several new ARCAs in the next few years despite the rarity of these entities. However, the challenge of the next decades will be the discovery of efficient treatments for these disabling neurodegenerative disorders. CONCLUSION Clinicians should be aware of the more frequent ARCAs, especially FRDA, in addition to ARCAs for which treatment is available (FRDA, AVED, ABL and RD for instance).
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Affiliation(s)
- M Anheim
- Service de neurogénétique, hôpital de la Pitié-Salpêtrière, 75651 Paris, France.
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