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Romero VI, Sáenz S, Arias-Almeida B, DiCapua D, Hosomichi K. AARS and CACNA1A mutations: diagnostic insights into a case report of uncommon epileptic encephalopathy phenotypes in two siblings. Front Neurol 2024; 15:1376643. [PMID: 38689878 PMCID: PMC11059961 DOI: 10.3389/fneur.2024.1376643] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2024] [Accepted: 04/04/2024] [Indexed: 05/02/2024] Open
Abstract
Epilepsy, characterized by recurrent seizures, impacts 70-80% of patients, leading to cognitive deficits. The intricate relationship between seizure control and cognitive impairment remains complex. Epileptic encephalopathy (EE), an intensified form often rooted in genetic factors, is detectable through next-generation sequencing, aiding in precise diagnoses, family counseling, and potential treatment strategies. We present a case involving two sisters with refractory generalized seizures evolving into dysarthria, dysphagia, ataxia, and cognitive decline. Despite normal physical exams, abnormal electroencephalogram results consistent with epilepsy were noted. Whole Exome Sequencing identified heterozygous variants in the alanyl-tRNA synthetase (AARS) and Calcium Voltage-Gated Channel Subunit Alpha 1 (CACNA1A) genes. The AARS variant (c.C2083T, p.R695*) was maternal, while the CACNA1A variant (c.G7400C, p.R2467P) was paternal. Patients A and B exhibited a unique blend of neurological and psychiatric conditions, distinct from common disorders that begin adolescence, like Juvenile Myoclonic Epilepsy. Whole Exome Sequencing uncovered an AARS gene and CACNA1A gene, linked to various autosomal dominant phenotypes. Presence in both parents, coupled with familial reports of migraines and seizures, provides insight into accelerated symptom progression. This study underscores the importance of genetic testing in decoding complex phenotypes and emphasizes the value of documenting family history for anticipating related symptoms and future health risks.
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Affiliation(s)
- Vanessa I. Romero
- School of Medicine, Universidad San Francisco de Quito, Quito, Ecuador
| | - Samantha Sáenz
- School of Medicine, Universidad San Francisco de Quito, Quito, Ecuador
| | | | - Daniela DiCapua
- School of Medicine, Universidad San Francisco de Quito, Quito, Ecuador
- Neurology Service, Hospital de Especialidades Eugenio Espejo, Quito, Ecuador
| | - Kazuyoshi Hosomichi
- Laboratory of Computational Genomics, Tokyo University of Pharmacy and Life Sciences, Tokyo, Japan
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Della Marina A, Hentschel A, Czech A, Schara-Schmidt U, Preusse C, Laner A, Abicht A, Ruck T, Weis J, Choueiri C, Lochmüller H, Kölbel H, Roos A. Novel Genetic and Biochemical Insights into the Spectrum of NEFL-Associated Phenotypes. J Neuromuscul Dis 2024; 11:625-645. [PMID: 38578900 PMCID: PMC11091643 DOI: 10.3233/jnd-230230] [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] [Accepted: 03/06/2024] [Indexed: 04/07/2024]
Abstract
Background NEFL encodes for the neurofilament light chain protein. Pathogenic variants in NEFL cause demyelinating, axonal and intermediate forms of Charcot-Marie-Tooth disease (CMT) which present with a varying degree of severity and somatic mutations have not been described yet. Currently, 34 different CMT-causing pathogenic variants in NEFL in 174 patients have been reported. Muscular involvement was also described in CMT2E patients mostly as a secondary effect. Also, there are a few descriptions of a primary muscle vulnerability upon pathogenic NEFL variants. Objectives To expand the current knowledge on the genetic landscape, clinical presentation and muscle involvement in NEFL-related neurological diseases by retrospective case study and literature review. Methods We applied in-depth phenotyping of new and already reported cases, molecular genetic testing, light-, electron- and Coherent Anti-Stokes Raman Scattering-microscopic studies and proteomic profiling in addition to in silico modelling of NEFL-variants. Results We report on a boy with a muscular phenotype (weakness, myalgia and cramps, Z-band alterations and mini-cores in some myofibers) associated with the heterozygous p.(Phe104Val) NEFL-variant, which was previously described in a neuropathy case. Skeletal muscle proteomics findings indicated affection of cytoskeletal proteins. Moreover, we report on two further neuropathic patients (16 years old girl and her father) both carrying the heterozygous p.(Pro8Ser) variant, which has been identified as 15% somatic mosaic in the father. While the daughter presented with altered neurophysiology,neurogenic clump feet and gait disturbances, the father showed clinically only feet deformities. As missense variants affecting proline at amino acid position 8 are leading to neuropathic manifestations of different severities, in silico modelling of these different amino acid substitutions indicated variable pathogenic impact correlating with disease onset. Conclusions Our findings provide new morphological and biochemical insights into the vulnerability of denervated muscle (upon NEFL-associated neuropathy) as well as novel genetic findings expanding the current knowledge on NEFL-related neuromuscular phenotypes and their clinical manifestations. Along this line, our data show that even subtle expression of somatic NEFL variants can lead to neuromuscular symptoms.
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Affiliation(s)
- Adela Della Marina
- Department of Pediatric Neurology, Centre for Neuromuscular Disorders, Centre for Translational Neuro- and Behavioral Sciences, University Duisburg-Essen, Essen, Germany
| | - Andreas Hentschel
- Leibniz-Institut für Analytische Wissenschaften -ISAS- e.V., Dortmund, Germany
| | - Artur Czech
- Leibniz-Institut für Analytische Wissenschaften -ISAS- e.V., Dortmund, Germany
| | - Ulrike Schara-Schmidt
- Department of Pediatric Neurology, Centre for Neuromuscular Disorders, Centre for Translational Neuro- and Behavioral Sciences, University Duisburg-Essen, Essen, Germany
| | - Corinna Preusse
- Charité-Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health (BIH), Berlin, Germany
| | | | - Angela Abicht
- Medical Genetics Center, Munich, Germany
- Friedrich-Baur Institute, Ludwig Maximilian University, Munich, Germany
| | - Tobias Ruck
- Department of Neurology, Medical Faculty, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - Joachim Weis
- Institute of Neuropathology, RWTH Aachen University Hospital, Aachen, Germany
| | - Catherine Choueiri
- Children’s Hospital of Eastern Ontario Research Institute, Ottawa, ON, Canada
| | - Hanns Lochmüller
- Children’s Hospital of Eastern Ontario Research Institute, Ottawa, ON, Canada
- Division of Neurology, Department of Medicine, The Ottawa Hospital, Ottawa, Canada
- Brain and Mind Research Institute, University of Ottawa, Ottawa, Canada
| | - Heike Kölbel
- Department of Pediatric Neurology, Centre for Neuromuscular Disorders, Centre for Translational Neuro- and Behavioral Sciences, University Duisburg-Essen, Essen, Germany
| | - Andreas Roos
- Department of Pediatric Neurology, Centre for Neuromuscular Disorders, Centre for Translational Neuro- and Behavioral Sciences, University Duisburg-Essen, Essen, Germany
- Department of Neurology, Medical Faculty, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
- Children’s Hospital of Eastern Ontario Research Institute, Ottawa, ON, Canada
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Kotaich F, Caillol D, Bomont P. Neurofilaments in health and Charcot-Marie-Tooth disease. Front Cell Dev Biol 2023; 11:1275155. [PMID: 38164457 PMCID: PMC10758125 DOI: 10.3389/fcell.2023.1275155] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2023] [Accepted: 10/02/2023] [Indexed: 01/03/2024] Open
Abstract
Neurofilaments (NFs) are the most abundant component of mature neurons, that interconnect with actin and microtubules to form the cytoskeleton. Specifically expressed in the nervous system, NFs present the particularity within the Intermediate Filament family of being formed by four subunits, the neurofilament light (NF-L), medium (NF-M), heavy (NF-H) proteins and α-internexin or peripherin. Here, we review the current knowledge on NF proteins and neurofilaments, from their domain structures and their model of assembly to the dynamics of their transport and degradation along the axon. The formation of the filament and its behaviour are regulated by various determinants, including post-transcriptional (miRNA and RBP proteins) and post-translational (phosphorylation and ubiquitination) modifiers. Altogether, the complex set of modifications enable the neuron to establish a stable but elastic NF array constituting the structural scaffold of the axon, while permitting the local expression of NF proteins and providing the dynamics necessary to fulfil local demands and respond to stimuli and injury. Thus, in addition to their roles in mechano-resistance, radial axonal outgrowth and nerve conduction, NFs control microtubule dynamics, organelle distribution and neurotransmission at the synapse. We discuss how the studies of neurodegenerative diseases with NF aggregation shed light on the biology of NFs. In particular, the NEFL and NEFH genes are mutated in Charcot-Marie-Tooth (CMT) disease, the most common inherited neurological disorder of the peripheral nervous system. The clinical features of the CMT forms (axonal CMT2E, CMT2CC; demyelinating CMT1F; intermediate I-CMT) with symptoms affecting the central nervous system (CNS) will allow us to further investigate the physiological roles of NFs in the brain. Thus, NF-CMT mouse models exhibit various degrees of sensory-motor deficits associated with CNS symptoms. Cellular systems brought findings regarding the dominant effect of NF-L mutants on NF aggregation and transport, although these have been recently challenged. Neurofilament detection without NF-L in recessive CMT is puzzling, calling for a re-examination of the current model in which NF-L is indispensable for NF assembly. Overall, we discuss how the fundamental and translational fields are feeding each-other to increase but also challenge our knowledge of NF biology, and to develop therapeutic avenues for CMT and neurodegenerative diseases with NF aggregation.
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Affiliation(s)
| | | | - Pascale Bomont
- ERC team, NeuroMyoGene Institute-Pathophysiology and Genetics of Neuron and Muscle, Inserm U1315, CNRS UMR5261, University of Lyon 1, Lyon, France
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Manzoor U, Ali A, Ali SL, Abdelkarem O, Kanwal S, Alotaibi SS, Baazeem A, Baiduissenova A, Yktiyarov A, Hajar A, Olzhabay A. Mutational screening of GDAP1 in dysphonia associated with Charcot-Marie-Tooth disease: clinical insights and phenotypic effects. J Genet Eng Biotechnol 2023; 21:119. [PMID: 37966693 PMCID: PMC10651813 DOI: 10.1186/s43141-023-00568-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2022] [Accepted: 10/26/2023] [Indexed: 11/16/2023]
Abstract
INTRODUCTION Mutations in GDAP1 (Ganglioside-induced differentiation-associated protein 1) gene are linked to Charcot-Marie-Tooth disease (CMT), a Heterogenous group of disorders with multiple phenotypes, characterized by peripheral nerve dysfunction that can lead to vocal cord paralysis and diaphragmatic dysfunction. MAIN BODY All three affected children of this chosen family have manifested the same clinical symptoms with progressive weakness, mild sensory impairment, and absent tendon reflexes in their early years. Electrodiagnostic analysis displayed an axonal type of neuropathy in affected patients. Sequencing of the GDAP1 gene was requested for all members of the family. Diagnostic assessments included pulmonary and vocal cord function tests, as well as phrenic and peripheral nerve conduction studies. Pathogenicity of GDAP1 variant p.Pro419Leu with axonal CMT2 and autosomal recessive inheritance was confirmed via in silico analysis. Patients with GDAP1 mutations showed dysphonia, speech difficulties, and the characteristic symptoms of CMT. The severity of symptoms correlated with the presence of a type of GDAP1 mutation. Patients with normal vocal cords and pulmonary function exhibited milder symptoms compared to those with GDAP1 mutations. Our study provides clinical insights into the phenotypic effects of GDAP1 mutations in CMT patients. The findings highlight the adverse clinical course and severe disability associated with GDAP1 mutations, including weak limb and laryngeal muscles. CONCLUSION Patients with GDAP1 mutations and autosomal recessive neuropathy present with dysphonia and require interventions such as surgery, braces, physical therapy, and exercise. Early diagnosis and comprehensive clinical evaluations are crucial for managing CMT patients with GDAP1 mutations.
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Affiliation(s)
- Uzma Manzoor
- Department of Clinical Biochemistry, COMSATS University Islamabad, Sahiwal Campus, Sahiwal, Pakistan.
| | - Awais Ali
- Department of Biochemistry, Abdul wali Khan University Mardan, Mardan, 23200, Pakistan
| | - S Luqman Ali
- Department of Biochemistry, Abdul wali Khan University Mardan, Mardan, 23200, Pakistan
| | - Omneya Abdelkarem
- Department of Chemical Pathology, Medical Research Institute, Alexandria University, Alexandria, Egypt
| | - Sumaira Kanwal
- Department of Clinical Biochemistry, COMSATS University Islamabad, Sahiwal Campus, Sahiwal, Pakistan
| | - Saqer S Alotaibi
- Department of Biotechnology, College of Science, Taif University, P.O.Box 11099, 21944, Taif, Saudi Arabia
| | - Alaa Baazeem
- Department of Biology, College of Science, Taif University, P.O. Box 11099, 21944, Taif, Saudi Arabia
| | - Aliya Baiduissenova
- Department of Microbiology and Virology, Astana Medical University, Astana City, 010000, Kazakhstan
| | - Ayaz Yktiyarov
- Department of Microbiology and Virology, Astana Medical University, Astana City, 010000, Kazakhstan
| | - Azraida Hajar
- Department of Biology, Faculty of Sciences Semlalia, Cadi Ayyad University, Marrakech, Morocco
| | - Abay Olzhabay
- Department of Otorhinolaryngology, Astana Medical University, Astana City, 010000, Kazakhstan
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Morant L, Petrovic-Erfurth ML, Jordanova A. An Adapted GeneSwitch Toolkit for Comparable Cellular and Animal Models: A Proof of Concept in Modeling Charcot-Marie-Tooth Neuropathy. Int J Mol Sci 2023; 24:16138. [PMID: 38003325 PMCID: PMC10670994 DOI: 10.3390/ijms242216138] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2023] [Revised: 10/23/2023] [Accepted: 10/25/2023] [Indexed: 11/26/2023] Open
Abstract
Investigating the impact of disease-causing mutations, their affected pathways, and/or potential therapeutic strategies using disease modeling often requires the generation of different in vivo and in cellulo models. To date, several approaches have been established to induce transgene expression in a controlled manner in different model systems. Several rounds of subcloning are, however, required, depending on the model organism used, thus bringing labor-intensive experiments into the technical approach and analysis comparison. The GeneSwitch™ technology is an adapted version of the classical UAS-GAL4 inducible system, allowing the spatial and temporal modulation of transgene expression. It consists of three components: a plasmid encoding for the chimeric regulatory pSwitch protein, Mifepristone as an inducer, and an inducible plasmid. While the pSwitch-containing first plasmid can be used both in vivo and in cellulo, the inducible second plasmid can only be used in cellulo. This requires a specific subcloning strategy of the inducible plasmid tailored to the model organism used. To avoid this step and unify gene expression in the transgenic models generated, we replaced the backbone vector with standard pUAS-attB plasmid for both plasmids containing either the chimeric GeneSwitch™ cDNA sequence or the transgene cDNA sequence. We optimized this adapted system to regulate transgene expression in several mammalian cell lines. Moreover, we took advantage of this new system to generate unified cellular and fruit fly models for YARS1-induced Charco-Marie-Tooth neuropathy (CMT). These new models displayed the expected CMT-like phenotypes. In the N2a neuroblastoma cells expressing YARS1 transgenes, we observed the typical "teardrop" distribution of the synthetase that was perturbed when expressing the YARS1CMT mutation. In flies, the ubiquitous expression of YARS1CMT induced dose-dependent developmental lethality and pan-neuronal expression caused locomotor deficit, while expression of the wild-type allele was harmless. Our proof-of-concept disease modeling studies support the efficacy of the adapted transgenesis system as a powerful tool allowing the design of studies with optimal data comparability.
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Affiliation(s)
- Laura Morant
- Center for Molecular Neurology, VIB, University of Antwerp, 2610 Antwerpen, Belgium; (L.M.); (M.-L.P.-E.)
- Department of Biomedical Sciences, University of Antwerp, 2610 Antwerpen, Belgium
| | - Maria-Luise Petrovic-Erfurth
- Center for Molecular Neurology, VIB, University of Antwerp, 2610 Antwerpen, Belgium; (L.M.); (M.-L.P.-E.)
- Department of Biomedical Sciences, University of Antwerp, 2610 Antwerpen, Belgium
| | - Albena Jordanova
- Center for Molecular Neurology, VIB, University of Antwerp, 2610 Antwerpen, Belgium; (L.M.); (M.-L.P.-E.)
- Department of Biomedical Sciences, University of Antwerp, 2610 Antwerpen, Belgium
- Molecular Medicine Center, Department of Medical Chemistry and Biochemistry, Faculty of Medicine, Medical University-Sofia, 1431 Sofia, Bulgaria
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Zhang Y, Pang D, Wang Z, Ma L, Chen Y, Yang L, Xiao W, Yuan H, Chang F, Ouyang H. An integrative analysis of genotype-phenotype correlation in Charcot Marie Tooth type 2A disease with MFN2 variants: A case and systematic review. Gene 2023; 883:147684. [PMID: 37536398 DOI: 10.1016/j.gene.2023.147684] [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: 05/16/2023] [Revised: 06/24/2023] [Accepted: 07/31/2023] [Indexed: 08/05/2023]
Abstract
Dominant genetic variants in the mitofusin 2 (MFN2) gene lead to Charcot-Marie-Tooth type 2A (CMT2A), a neurodegenerative disease caused by genetic defects that directly damage axons. In this study, we reported a proband with a pathogenic variant in the GTPase domain of MFN2, c.494A > G (p.His165Arg). To date, at least 184 distinct MFN2 variants identified in 944 independent probands have been reported in 131 references. However, the field of medical genetics has long been challenged by how genetic variation in the MFN2 gene is associated with disease phenotypes. Here, by collating the MFN2 variant data and patient clinical information from Leiden Open Variant Database 3.0, NCBI clinvar database, and available related references in PubMed, we determined the mutation frequency, age of onset, sex ratio, and geographical distribution. Furthermore, the results of an analysis examining the relationship between variants and phenotypes from multiple genetic perspectives indicated that insertion and deletions (indels), copy number variants (CNVs), duplication variants, and nonsense mutations in single nucleotide variants (SNVs) tend to be pathogenic, and the results emphasized the importance of the GTPase domain to the structure and function of MFN2. Overall, three reliable classification methods of MFN2 genotype-phenotype associations provide insights into the prediction of CMT2A disease severity. Of course, there are still many MFN2 variants that have not been given clear clinical significance, which requires clinicians to make more accurate clinical diagnoses.
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Affiliation(s)
- Yuanzhu Zhang
- Key Laboratory of Zoonosis Research, Ministry of Education, College of Animal Sciences, Jilin University, Changchun 130062, China.
| | - Daxin Pang
- Key Laboratory of Zoonosis Research, Ministry of Education, College of Animal Sciences, Jilin University, Changchun 130062, China; Chongqing Research Institute, Jilin University, Chongqing 401120, China; Chongqing Jitang Biotechnology Research Institute Co., Ltd., Chongqing 401120, China.
| | - Ziru Wang
- Key Laboratory of Zoonosis Research, Ministry of Education, College of Animal Sciences, Jilin University, Changchun 130062, China.
| | - Lerong Ma
- Key Laboratory of Zoonosis Research, Ministry of Education, College of Animal Sciences, Jilin University, Changchun 130062, China.
| | - Yiwu Chen
- Key Laboratory of Zoonosis Research, Ministry of Education, College of Animal Sciences, Jilin University, Changchun 130062, China.
| | - Lin Yang
- Key Laboratory of Zoonosis Research, Ministry of Education, College of Animal Sciences, Jilin University, Changchun 130062, China.
| | - Wenyu Xiao
- Key Laboratory of Zoonosis Research, Ministry of Education, College of Animal Sciences, Jilin University, Changchun 130062, China.
| | - Hongming Yuan
- Key Laboratory of Zoonosis Research, Ministry of Education, College of Animal Sciences, Jilin University, Changchun 130062, China; Chongqing Research Institute, Jilin University, Chongqing 401120, China.
| | - Fei Chang
- Department of Orthopedics, The Second Hospital of Jilin University, Changchun 130022, China.
| | - Hongsheng Ouyang
- Key Laboratory of Zoonosis Research, Ministry of Education, College of Animal Sciences, Jilin University, Changchun 130062, China; Chongqing Research Institute, Jilin University, Chongqing 401120, China; Chongqing Jitang Biotechnology Research Institute Co., Ltd., Chongqing 401120, China.
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Higuchi Y, Takashima H. Clinical genetics of Charcot-Marie-Tooth disease. J Hum Genet 2023; 68:199-214. [PMID: 35304567 DOI: 10.1038/s10038-022-01031-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Revised: 03/02/2022] [Accepted: 03/06/2022] [Indexed: 02/08/2023]
Abstract
Recent research in the field of inherited peripheral neuropathies (IPNs) such as Charcot-Marie-Tooth (CMT) disease has helped identify the causative genes provided better understanding of the pathogenesis, and unraveled potential novel therapeutic targets. Several reports have described the epidemiology, clinical characteristics, molecular pathogenesis, and novel causative genes for CMT/IPNs in Japan. Based on the functions of the causative genes identified so far, the following molecular and cellular mechanisms are believed to be involved in the causation of CMTs/IPNs: myelin assembly, cytoskeletal structure, myelin-specific transcription factor, nuclear related, endosomal sorting and cell signaling, proteasome and protein aggregation, mitochondria-related, motor proteins and axonal transport, tRNA synthetases and RNA metabolism, and ion channel-related mechanisms. In this article, we review the epidemiology, genetic diagnosis, and clinicogenetic characteristics of CMT in Japan. In addition, we discuss the newly identified novel causative genes for CMT/IPNs in Japan, namely MME and COA7. Identification of the new causes of CMT will facilitate in-depth characterization of the underlying molecular mechanisms of CMT, leading to the establishment of therapeutic approaches such as drug development and gene therapy.
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Affiliation(s)
- Yujiro Higuchi
- Department of Neurology and Geriatrics, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima, Japan
| | - Hiroshi Takashima
- Department of Neurology and Geriatrics, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima, Japan.
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Clinical and genetic characterization of NEFL-related neuropathy in Taiwan. J Formos Med Assoc 2023; 122:132-138. [PMID: 36031490 DOI: 10.1016/j.jfma.2022.08.008] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Revised: 06/20/2022] [Accepted: 08/09/2022] [Indexed: 02/01/2023] Open
Abstract
BACKGROUND Mutations in the neurofilament light polypeptide gene (NEFL) are an uncommon cause of Charcot-Marie-Tooth disease (CMT). The aim of this study is to elucidate the clinical characteristics and genetic spectrum of NEFL-related neuropathy in a Taiwanese CMT cohort. METHODS Mutational analysis of the coding regions of NEFL was performed by Sanger sequencing or targeted resequencing. Twenty-one patients from nine CMT pedigrees, identified from a cohort of 508 unrelated CMT patients, were found to have a NEFL mutation. Genetic, clinical and electrophysiological features were analyzed. RESULTS Six NEFL mutations were identified, including two novel ones (p.P8S, p.N98Y). NEFL p.E396K was the most common mutation, accounting for 33.3% of the patients in our cohort. All patients manifested sensorimotor polyneuropathy with a mean age of disease onset of 13.5 ± 9.6 (1-40) years. Their motor nerve conduction velocities (MNCVs) of the ulnar nerve ranged from 22.1 to 48.7 m/s. Seventy percent of the patients could be classified as intermediate CMT with ulnar MNCVs between 25 and 45 m/s. Six of the 21 patients (28.6%) had additional features of central nervous system (CNS) involvement, including motor developmental delay, spasticity, cerebellar signs, neuropathic pain and scoliosis. CONCLUSION NEFL mutations account for 1.8% (9/508) of the CMT patients in Taiwan. The present study delineates the clinical and genetic characteristics of NEFL-related neuropathy in Taiwan, and highlights that ulnar MNCV above 25 m/s and CNS involvement may serve as diagnostic clues for NEFL-related neuropathy.
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Intracellular Citrate/acetyl-CoA flux and endoplasmic reticulum acetylation: Connectivity is the answer. Mol Metab 2022; 67:101653. [PMID: 36513219 PMCID: PMC9792894 DOI: 10.1016/j.molmet.2022.101653] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/21/2022] [Revised: 11/29/2022] [Accepted: 12/05/2022] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND Key cellular metabolites reflecting the immediate activity of metabolic enzymes as well as the functional metabolic state of intracellular organelles can act as powerful signal regulators to ensure the activation of homeostatic responses. The citrate/acetyl-CoA pathway, initially recognized for its role in intermediate metabolism, has emerged as a fundamental branch of this nutrient-sensing homeostatic response. Emerging studies indicate that fluctuations in acetyl-CoA availability within different cellular organelles and compartments provides substrate-level regulation of many biological functions. A fundamental aspect of these regulatory functions involves Nε-lysine acetylation. SCOPE OF REVIEW Here, we will examine the emerging regulatory functions of the citrate/acetyl-CoA pathway and the specific role of the endoplasmic reticulum (ER) acetylation machinery in the maintenance of intracellular crosstalk and homeostasis. These functions will be analyzed in the context of associated human diseases and specific mouse models of dysfunctional ER acetylation and citrate/acetyl-CoA flux. A primary objective of this review is to highlight the complex yet integrated response of compartment- and organelle-specific Nε-lysine acetylation to the intracellular availability and flux of acetyl-CoA, linking this important post-translational modification to cellular metabolism. MAJOR CONCLUSIONS The ER acetylation machinery regulates the proteostatic functions of the organelle as well as the metabolic crosstalk between different intracellular organelles and compartments. This crosstalk enables the cell to impart adaptive responses within the ER and the secretory pathway. However, it also enables the ER to impart adaptive responses within different cellular organelles and compartments. Defects in the homeostatic balance of acetyl-CoA flux and ER acetylation reflect different but converging disease states in humans as well as converging phenotypes in relevant mouse models. In conclusion, citrate and acetyl-CoA should not only be seen as metabolic substrates of intermediate metabolism but also as signaling molecules that direct functional adaptation of the cell to both intracellular and extracellular messages. Future discoveries in CoA biology and acetylation are likely to yield novel therapeutic approaches.
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Setlere S, Jurcenko M, Gailite L, Rots D, Kenina V. Alanyl-tRNA Synthetase 1 Gene Variants in Hereditary Neuropathy. Neurol Genet 2022; 8:e200019. [PMID: 36092982 PMCID: PMC9450682 DOI: 10.1212/nxg.0000000000200019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Accepted: 07/01/2022] [Indexed: 11/15/2022]
Abstract
Background and ObjectivesOur objective was to report 2 novel variants and to reclassify previously reported alanyl-tRNA synthetase 1 (AARS1) variants associated with hereditary neuropathy and to summarize the clinical features of a previously published cohort of patients.MethodsWe performed detailed neurologic and electrophysiologic assessments and segregation analysis of 2 unrelated families with Charcot-Marie-Tooth (CMT) disease with novel variants in the AARS1 gene. Via literature search, we found studies that included neuropathy cases with AARS1 variants; we then reviewed and reclassified these variants.ResultsWe identified 2 CMT families harboring previously unreported likely pathogenic AARS1 variants: c.1823C>A p.(Thr608Lys) and c.1815C>G p.(His605Gln). In addition, we reinterpreted a total of 35 different AARS1 variants reported in cases with neuropathy from the literature: 9 variants fulfilled the current criteria for being (likely) pathogenic. We compiled and summarized standardized clinical and genotypic information for 90 affected individuals from 32 families with (likely) pathogenic AARS1 variants. Most experienced motor weakness and sensory loss in the lower limbs.DiscussionIn total, 11 AARS1 variants can currently be classified as pathogenic or likely pathogenic and are associated with sensorimotor axonal or intermediate, slowly progressive polyneuropathy with common asymmetry and variable age of symptom onset with no apparent involvement of other organ systems.
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11
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Nguyen‐Le T, Do MD, Le LHG, Nhat QNN, Hoang NTT, Van Le T, Mai TP. Genotype-phenotype characteristics of Vietnamese patients diagnosed with Charcot-Marie-Tooth disease. Brain Behav 2022; 12:e2744. [PMID: 35938991 PMCID: PMC9480926 DOI: 10.1002/brb3.2744] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/16/2022] [Revised: 06/28/2022] [Accepted: 07/26/2022] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Charcot-Marie-Tooth (CMT) disease is one of the most common hereditary neuropathies. Identifying causative mutations in CMT is essential as it provides important information for genetic diagnosis and counseling. However, genetic information of Vietnamese patients diagnosed with CMT is currently not available. METHODS In this study, we described the clinical profile and determined the mutation spectrum of CMT in a cohort of Vietnamese patients with CMT by using a combination of multiplex ligation-dependent probe amplification and next-generation sequencing targeting 11 genes PMP22, MPZ, EGR2, NEFL, MFN2, GDAP1, GARS, MTMR2, GJB1, RAB7A, LITAF. RESULTS In 31 CMT cases, the mutation detection rate was 42% and the most common genetic aberration was PMP22 duplication. The pedigree analysis showed two de novo mutations c.64C > A (p.P22T) and c.281delG (p.G94Afs*17) in the NEFL and PMP22 genes, respectively. CONCLUSION The results of this study once again emphasize the important role of molecular diagnosis and provide preliminary genetic data on Vietnamese patients with CMT.
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Affiliation(s)
- Trung‐Hieu Nguyen‐Le
- Faculty of MedicineUniversity of Medicine and Pharmacy at Ho Chi Minh CityVietnam
| | - Minh Duc Do
- Center for Molecular BiomedicineUniversity of Medicine and Pharmacy at Ho Chi Minh CityVietnam
| | - Linh Hoang Gia Le
- Center for Molecular BiomedicineUniversity of Medicine and Pharmacy at Ho Chi Minh CityVietnam
| | - Quynh Nhu Nguyen Nhat
- Center for Molecular BiomedicineUniversity of Medicine and Pharmacy at Ho Chi Minh CityVietnam
| | | | - Tuan Van Le
- Faculty of MedicineUniversity of Medicine and Pharmacy at Ho Chi Minh CityVietnam
| | - Thao Phuong Mai
- Faculty of MedicineUniversity of Medicine and Pharmacy at Ho Chi Minh CityVietnam
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12
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Baudou E, Cances C, Magdelaine C, Latour P, Louvier UW, Juntas-Morales R, Cintas P, Rivier F. Unexpected Intermediate Nerve Conduction Velocity Findings in Charcot-Marie-Tooth Syndromes Classified as Demyelinated or Axonal in a Pediatric Population. Neuropediatrics 2022; 53:182-187. [PMID: 35297028 DOI: 10.1055/s-0042-1743438] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
INTRODUCTION Among the hereditary motor and sensory neuropathies (HMSN), demyelinating forms are the best characterized, with a clear predominance of CMT1A. The axonal and intermediate forms are less described. The aim of this study is to report the genetic diagnosis of Charcot-Marie-Tooth (CMT) according to the nerve conduction velocity (NCV) findings in a pediatric population. METHODS We retrospectively described a population of HMSN children with a confirmed genetic diagnosis of demyelinated, intermediate, or axonal forms. We compared the results of the genetic analyses with those of motor NCV in median nerve according to whether they were below 25 m/s (demyelinating group); between 25 and 45 m/s (intermediate group), or above 45 m/s (axonal group). RESULTS Among the 143 children with an HMSN, 107 had a genetic diagnosis of which 61 had an electromyogram. On NCV findings: seven (11%) pertain to the axonal group, 20 (32%) to the intermediate group, and 34 (55%) to the demyelinating group. When NCV was above 45 m/s, CMT2A was the predominant genetic diagnosis (70%) when NCV were below 25 m/s, CMT1A was the predominant genetic diagnosis (71%). Intermediate NCV findings group was the more heterogeneous with seven genetic CMT subgroups (60% CMT1A, CMT1B, CMT1X, CMT2A, CMT2N, CMT4G). CONCLUSION Taking NCV values between 25 and 45 m/s to define an intermediate group of CMT in children leads to the inclusion of non-typically "intermediate", especially CMT1A. We emphasize the broad spectrum of NCV in CMT1A that justified the systematic search of PMP22 duplication/deletion screening before next generation sequencing panel.
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Affiliation(s)
- Eloïse Baudou
- Unit of Pediatric Neurology, AOC (Atlantique-Occitanie-Caraïbes) Reference Centre for Neuromuscular Diseases, Hôpital des Enfants, CHU Toulouse, Toulouse Cedex, France
| | - Claude Cances
- Unit of Pediatric Neurology, AOC (Atlantique-Occitanie-Caraïbes) Reference Centre for Neuromuscular Diseases, Hôpital des Enfants, CHU Toulouse, Toulouse Cedex, France
| | - Corinne Magdelaine
- Service de Biochimie et de Génétique Moléculaire Centre de Biologie et de Recherche en Santé CBRS, CHU de Limoges-Hôpital Dupuytren, Limoges, France
| | - Philippe Latour
- Centre de Biologie et Pathologie Est-Service de Biochimie Biologie Moléculaire Grand Est CHU de Lyon HCL - GH Est, Bron France
| | - Ulrike Walther Louvier
- Department of Pediatric Neurology, AOC (Atlantique-Occitanie-Caraïbes) Reference Centers for Neuromuscular Diseases, CHU Montpellier, France
| | - Raul Juntas-Morales
- Department of Neurology, AOC (Atlantique-Occitanie-Caraïbes) Reference Centre for Neuromuscular Diseases, CHU Montpellier, France
| | - Pascal Cintas
- Department of Neurology, AOC (Atlantique-Occitanie-Caraïbes) Reference Centre for Neuromuscular Diseases, Pierre Paul Riquet Hospital, CHU Toulouse, France
| | - François Rivier
- Department of Pediatric Neurology, AOC (Atlantique-Occitanie-Caraïbes) Reference Centers for Neuromuscular Diseases, CHU Montpellier, France.,PhyMedExp, University of Montpellier, INSERM, CNRS, Montpellier, France
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13
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Kim HJ, Kim SB, Kim HS, Kwon HM, Park JH, Lee AJ, Lim SO, Nam SH, Hong YB, Chung KW, Choi BO. Phenotypic heterogeneity in patients with NEFL-related Charcot-Marie-Tooth disease. Mol Genet Genomic Med 2022; 10:e1870. [PMID: 35044100 PMCID: PMC8830812 DOI: 10.1002/mgg3.1870] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2021] [Revised: 09/12/2021] [Accepted: 12/20/2021] [Indexed: 11/28/2022] Open
Abstract
Charcot–Marie–Tooth disease (CMT) is the most common hereditary peripheral neuropathy. Mutations in the neurofilament light polypeptide (NEFL) gene produce diverse clinical phenotypes, including demyelinating (CMT1F), axonal (CMT2E), and intermediate (CMTDIG) neuropathies. From 2005 to 2020, 1,143 Korean CMT families underwent gene sequencing, and we investigated the clinical, genetic, and neuroimaging spectra of NEFL‐related CMT patients. Ten NEFL mutations in 17 families (1.49%) were identified, of which three (p.L312P, p.Y443N, and p.K467N) were novel. Eight de novo cases were identified at a rate of 0.47 based on a cosegregation analysis. The age of onset was ≤3 years in five cases (13.5%). The patients revealed additional features including delayed walking, ataxia, dysphagia, dysarthria, dementia, ptosis, waddling gait, tremor, hearing loss, and abnormal visual evoked potential. Signs of ataxia were found in 26 patients (70.3%). In leg MRI analyses, various degrees of intramuscular fat infiltration were found. All compartments were evenly affected in CMT1F patients. The anterior and anterolateral compartments were affected in CMT2E, and the posterior compartment was affected in CMTDIG. Thus, NEFL‐related CMT patients showed phenotypic heterogeneities. This study's clinical, genetic, and neuroimaging results could be helpful in the evaluation of novel NEFL variants and differential diagnosis against other CMT subtypes.
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Affiliation(s)
- Hye Jin Kim
- Department of Health Sciences and Technology, SAIHST, Sungkyunkwan University, Seoul, Korea.,Department of Neurology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Sang Beom Kim
- Department of Neurology, Kyung Hee University Hospital at Gangdong, Kyung Hee University School of Medicine, Seoul, Republic of Korea
| | - Hyun Su Kim
- Department of Radiology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Hye Mi Kwon
- Department of Neurology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Jae Hong Park
- Department of Neurology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Ah Jin Lee
- Department of Biological Sciences, Kongju National University, Gongju, Korea
| | - Si On Lim
- Department of Biological Sciences, Kongju National University, Gongju, Korea
| | - Soo Hyun Nam
- Stem Cell & Regenerative Medicine Institute, Samsung Medical Center, Seoul, Korea
| | - Young Bin Hong
- Department of Biochemistry, College of Medicine, Dong-A University, Busan, Korea
| | - Ki Wha Chung
- Department of Biological Sciences, Kongju National University, Gongju, Korea
| | - Byung-Ok Choi
- Department of Health Sciences and Technology, SAIHST, Sungkyunkwan University, Seoul, Korea.,Department of Neurology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.,Stem Cell & Regenerative Medicine Institute, Samsung Medical Center, Seoul, Korea
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14
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Huang H, Zhang Y, Yang M, Lian B, Guo R, Cao L. Case Report: Early-Onset Charcot-Marie-Tooth 2N With Reversible White Matter Lesions Repeatedly Mimicked Stroke or Encephalitis. Front Pediatr 2022; 10:935721. [PMID: 35911843 PMCID: PMC9326065 DOI: 10.3389/fped.2022.935721] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/04/2022] [Accepted: 06/14/2022] [Indexed: 02/05/2023] Open
Abstract
INTRODUCTION Charcot-Marie-Tooth (CMT) disease is a rare group of peripheral neuropathies with high clinical and genetic heterogeneity. CMT type 2N (CMT 2N) is a rare subtype of CMT with few clinical reports. The clinical presentation mimics that of other diseases, frequently leading to misdiagnoses. We present a case of CMT 2N with reversible white matter lesions (WMLs), which repeatedly mimicked stroke or encephalitis. We include a literature review to the improve management of this disease. CASE DESCRIPTION An 8-year-old boy was admitted to the hospital with slurred speech and limb weakness that had persisted for 1 day. Physical examination revealed lethargy, dysarthria, and a positive bilateral Babinski sign. Cerebrospinal fluid (CSF) analysis showed no abnormalities. Brain magnetic resonance imaging (MRI) revealed symmetrical abnormal signal areas in the paraventricular white matter and corpus callosum. The patient was suspected of having viral encephalitis and recovered rapidly after treatment.He was hospitalized 3 years later for limb weakness, barylalia, and facial paralysis persisting for 1 day. MRI showed an abnormal signal in the bilateral corona radiata. He was suspected of having a stroke or encephalitis. He was completely recovered after treatment.After a second 3-year span, he was admitted for another stroke-like episode. Physical examination revealed facial-lingual hemiparesis, mild atrophy of the left thenar muscle, decreased muscle strength in the extremities, and disappearance of the tendon reflex. MRI revealed more pronounced abnormal signals in the bilateral centrum semiovale and corpus callosum. Antibodies against autoimmune encephalitis were negative. A nerve conduction velocity (NCV) study showed motor and sensory four-limb nerve demyelination with axonal damage, most notably at the distal end. His symptoms were resolved after active treatment. A follow-up MRI showed the complete disappearance of the abnormal white matter signal. Whole exon sequencing showed a heterozygous mutation [c.2093C > T(p.Ser698Phe)] in the alanyl-tRNA synthetase 1 gene (AARS1). His mutation, clinical features, and electrophysiological testing led to a diagnosis of CMT 2N. DISCUSSION Early-Onset CMT 2N with reversible WMLs can often mimic stroke or encephalopathy. Affected individuals may show an atypical posterior reversible encephalopathy syndrome (PRES) on MRI. Careful family history assessment, physical examination, nerve conduction studies, MRIs, and genetic testing are essential for early diagnosis. Further studies are required to confirm these findings.
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Affiliation(s)
- Huasheng Huang
- Department of Neurology, Liuzhou People’s Hospital, Liuzhou, China
| | - Yu Zhang
- Nursing Department, Zhejiang Hospital, Hangzhou, China
- Teaching Office, The First Affiliated Hospital of Shenzhen University, Shenzhen, China
| | - Mingxiu Yang
- Department of Neurology, Liuzhou People’s Hospital, Liuzhou, China
| | - Baorong Lian
- Shantou University Medical College, Shantou University, Shantou, China
| | - Rui Guo
- Radiology Department, Liuzhou People’s Hospital, Liuzhou, China
| | - Liming Cao
- Department of Neurology, The First Affiliated Hospital of Shenzhen University, Shenzhen, China
- *Correspondence: Liming Cao,
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15
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Ma Y, Sun A, Zhang Y, Fan D, Liu X. The Genotype and Phenotype Features in a Large Chinese MFN2 Mutation Cohort. Front Neurol 2021; 12:757518. [PMID: 34721278 PMCID: PMC8548668 DOI: 10.3389/fneur.2021.757518] [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: 08/12/2021] [Accepted: 09/09/2021] [Indexed: 12/24/2022] Open
Abstract
Introduction: Charcot–Marie–Tooth disease type 2A (CMT2A) is a group of clinically and genetically heterogeneous disorders, which is mostly caused by mutations of the mitofusin2 (MFN2) gene. As the genotype–phenotype characteristics of CMT2A were still incompletely understood, we further explored the spectrum of CMT2A variants in China and demonstrated their phenotypic diversities. Methods: A total of 402 index patients/families with CMT throughout Mainland China were enrolled in this study. Among them, we analyzed 20 unrelated index cases with CMT2A by Sanger sequencing, next-generation sequencing, or whole-exome sequencing. Detailed clinical and genetic features of CMT2A patients were collected and analyzed. Of note, de novo mutations were not rare in MFN2 gene; we compared the clinical features of patients from the de novo group with those from the non-de novo group. Results: We identified 20 MFN2 variants, occupying 5.0% of CMT. Most patients presented with early onset and moderate phenotype with abnormal gait and foot drop as the main complaints at onset. Pyramidal signs accounts for 31.6% (6/19) in all patients, which is not uncommon. Four novel variants (p.Tyr752*, c.475-2A>G, p.Val99Met, and p.Arg275_Gln276insArg) were identified in the cohort. Besides, de novo variants occupied 35.0% (7/20) in our study with a much earlier age at onset compared with those in the non-de novo group (p = 0.021). Conclusion: Chinese CMT2A is a predominant typical pure CMT2A, with early onset and mild to moderate phenotype. Given the high frequency of de novo MFN2 mutations, genetic study should be considered for patients with early onset and severe idiopathic axonal neuropathy.
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Affiliation(s)
- Yan Ma
- Department of Neurology, Peking University Third Hospital, Beijing, China.,Beijing Municipal Key Laboratory of Biomarker and Translational Research in Neurodegenerative Diseases, Beijing, China.,Key Laboratory for Neuroscience, Ministry of Education/National Health Commission, Peking University, Beijing, China
| | - Aping Sun
- Department of Neurology, Peking University Third Hospital, Beijing, China.,Beijing Municipal Key Laboratory of Biomarker and Translational Research in Neurodegenerative Diseases, Beijing, China.,Key Laboratory for Neuroscience, Ministry of Education/National Health Commission, Peking University, Beijing, China
| | - Yingshuang Zhang
- Department of Neurology, Peking University Third Hospital, Beijing, China.,Beijing Municipal Key Laboratory of Biomarker and Translational Research in Neurodegenerative Diseases, Beijing, China.,Key Laboratory for Neuroscience, Ministry of Education/National Health Commission, Peking University, Beijing, China
| | - Dongsheng Fan
- Department of Neurology, Peking University Third Hospital, Beijing, China.,Beijing Municipal Key Laboratory of Biomarker and Translational Research in Neurodegenerative Diseases, Beijing, China.,Key Laboratory for Neuroscience, Ministry of Education/National Health Commission, Peking University, Beijing, China
| | - Xiaoxuan Liu
- Department of Neurology, Peking University Third Hospital, Beijing, China.,Beijing Municipal Key Laboratory of Biomarker and Translational Research in Neurodegenerative Diseases, Beijing, China.,Key Laboratory for Neuroscience, Ministry of Education/National Health Commission, Peking University, Beijing, China
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16
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Zuko A, Mallik M, Thompson R, Spaulding EL, Wienand AR, Been M, Tadenev ALD, van Bakel N, Sijlmans C, Santos LA, Bussmann J, Catinozzi M, Das S, Kulshrestha D, Burgess RW, Ignatova Z, Storkebaum E. tRNA overexpression rescues peripheral neuropathy caused by mutations in tRNA synthetase. Science 2021; 373:1161-1166. [PMID: 34516840 DOI: 10.1126/science.abb3356] [Citation(s) in RCA: 63] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
[Figure: see text].
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Affiliation(s)
- Amila Zuko
- Department of Molecular Neurobiology, Donders Institute for Brain, Cognition and Behaviour and Faculty of Science, Radboud University, Nijmegen, Netherlands
| | - Moushami Mallik
- Department of Molecular Neurobiology, Donders Institute for Brain, Cognition and Behaviour and Faculty of Science, Radboud University, Nijmegen, Netherlands.,Molecular Neurogenetics Laboratory, Max Planck Institute for Molecular Biomedicine, Münster, Germany
| | - Robin Thompson
- Biochemistry and Molecular Biology, Department of Chemistry, University of Hamburg, Hamburg, Germany
| | - Emily L Spaulding
- The Jackson Laboratory, Bar Harbor, ME, USA.,Graduate School of Biomedical Sciences and Engineering, University of Maine, Orono, ME, USA
| | - Anne R Wienand
- Department of Molecular Neurobiology, Donders Institute for Brain, Cognition and Behaviour and Faculty of Science, Radboud University, Nijmegen, Netherlands
| | - Marije Been
- Department of Molecular Neurobiology, Donders Institute for Brain, Cognition and Behaviour and Faculty of Science, Radboud University, Nijmegen, Netherlands
| | | | - Nick van Bakel
- Department of Molecular Neurobiology, Donders Institute for Brain, Cognition and Behaviour and Faculty of Science, Radboud University, Nijmegen, Netherlands
| | - Céline Sijlmans
- Department of Molecular Neurobiology, Donders Institute for Brain, Cognition and Behaviour and Faculty of Science, Radboud University, Nijmegen, Netherlands
| | - Leonardo A Santos
- Biochemistry and Molecular Biology, Department of Chemistry, University of Hamburg, Hamburg, Germany
| | - Julia Bussmann
- Molecular Neurogenetics Laboratory, Max Planck Institute for Molecular Biomedicine, Münster, Germany
| | - Marica Catinozzi
- Department of Molecular Neurobiology, Donders Institute for Brain, Cognition and Behaviour and Faculty of Science, Radboud University, Nijmegen, Netherlands.,Molecular Neurogenetics Laboratory, Max Planck Institute for Molecular Biomedicine, Münster, Germany
| | - Sarada Das
- Biochemistry and Molecular Biology, Department of Chemistry, University of Hamburg, Hamburg, Germany
| | - Divita Kulshrestha
- Department of Molecular Neurobiology, Donders Institute for Brain, Cognition and Behaviour and Faculty of Science, Radboud University, Nijmegen, Netherlands.,Molecular Neurogenetics Laboratory, Max Planck Institute for Molecular Biomedicine, Münster, Germany
| | - Robert W Burgess
- The Jackson Laboratory, Bar Harbor, ME, USA.,Graduate School of Biomedical Sciences and Engineering, University of Maine, Orono, ME, USA
| | - Zoya Ignatova
- Biochemistry and Molecular Biology, Department of Chemistry, University of Hamburg, Hamburg, Germany
| | - Erik Storkebaum
- Department of Molecular Neurobiology, Donders Institute for Brain, Cognition and Behaviour and Faculty of Science, Radboud University, Nijmegen, Netherlands.,Molecular Neurogenetics Laboratory, Max Planck Institute for Molecular Biomedicine, Münster, Germany
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17
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Stone EJ, Kolb SJ, Brown A. A review and analysis of the clinical literature on Charcot-Marie-Tooth disease caused by mutations in neurofilament protein L. Cytoskeleton (Hoboken) 2021; 78:97-110. [PMID: 33993654 PMCID: PMC10174713 DOI: 10.1002/cm.21676] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Revised: 05/05/2021] [Accepted: 05/06/2021] [Indexed: 01/22/2023]
Abstract
Charcot-Marie-Tooth disease (CMT) is one of the most common inherited neurological disorders and can be caused by mutations in over 100 different genes. One of the causative genes is NEFL on chromosome 8 which encodes neurofilament light protein (NEFL), one of five proteins that co-assemble to form neurofilaments. At least 34 different CMT-causing mutations in NEFL have been reported which span the head, rod, and tail domains of the protein. The majority of these mutations are inherited dominantly, but some are inherited recessively. The resulting disease is classified variably in clinical reports based on electrodiagnostic studies as either axonal (type 2; CMT2E), demyelinating (type 1; CMT1F), or a form intermediate between the two (dominant intermediate; DI-CMTG). In this article, we first present a brief introduction to CMT and neurofilaments. We then collate and analyze the data from the clinical literature on the disease classification, age of onset and electrodiagnostic test results for the various mutations. We find that mutations in the head, rod, and tail domains can all cause disease with early onset and profound neurological impairment, with a trend toward greater severity for head domain mutations. We also find that the disease classification does not correlate with specific mutation or domain. In fact, different individuals with the same mutation can be classified as having axonal, demyelinating, or dominant intermediate forms of the disease. This suggests that the classification of the disease as CMT2E, CMT1F or DI-CMTG has more to do with variable disease presentation than to differences in the underlying disease mechanism, which is most likely primarily axonal in all cases.
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Affiliation(s)
- Elizabeth J Stone
- Department of Neuroscience, Ohio State University, Columbus, Ohio, USA.,Neuroscience Graduate Program, Ohio State University, Columbus, Ohio, USA
| | - Stephen J Kolb
- Department of Neurology, Ohio State University, Columbus, Ohio, USA.,Department of Biological Chemistry and Pharmacology, Ohio State University, Columbus, Ohio, USA
| | - Anthony Brown
- Department of Neuroscience, Ohio State University, Columbus, Ohio, USA
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18
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Vinogradova ES, Nikonov OS, Nikonova EY. Associations between Neurological Diseases and Mutations in the Human Glycyl-tRNA Synthetase. BIOCHEMISTRY (MOSCOW) 2021; 86:S12-S23. [PMID: 33827397 PMCID: PMC7905983 DOI: 10.1134/s0006297921140029] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
Abstract
Aminoacyl-RNA synthetases (aaRSs) are among the key enzymes of protein biosynthesis. They are responsible for conducting the first step in the protein biosynthesis, namely attaching amino acids to the corresponding tRNA molecules both in cytoplasm and mitochondria. More and more research demonstrates that mutations in the genes encoding aaRSs lead to the development of various neurodegenerative diseases, such as incurable Charcot–Marie–Tooth disease (CMT) and distal spinal muscular atrophy. Some mutations result in the loss of tRNA aminoacylation activity, while other mutants retain their classical enzyme activity. In the latter case, disease manifestations are associated with additional neuron-specific functions of aaRSs. At present, seven aaRSs (GlyRS, TyrRS, AlaRS, HisRS, TrpRS, MetRS, and LysRS) are known to be involved in the CMT etiology with glycyl-tRNA synthetase (GlyRS) being the most studied of them.
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Affiliation(s)
| | - Oleg S Nikonov
- Institute of Protein Research, Pushchino, Moscow Region, 142290, Russia
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19
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Abstract
Charcot-Marie-Tooth disease (CMT) is a devastating motor and sensory neuropathy with an estimated 100,000 afflicted individuals in the US. Unexpectedly, aminoacyl-tRNA synthetases are the largest disease-associated protein family. A natural explanation is that the disease is associated with weak translation or mistranslation (caused by editing defects). However, our results with six different disease-causing mutants in AlaRS ruled out defects in aminoacylation or editing as causal factors. Instead, specific mutant proteins gained a neuropilin 1 (Nrp1)-AlaRS interaction. Previously a gain of Nrp1 interaction with a different disease-causing tRNA synthetase was mechanistically linked to the pathology of CMT. Thus, our results raise the possibility that pathological engagement of Nrp1 is common to at least a subset of tRNA synthetase-associated cases of CMT. Through dominant mutations, aminoacyl-tRNA synthetases constitute the largest protein family linked to Charcot-Marie-Tooth disease (CMT). An example is CMT subtype 2N (CMT2N), caused by individual mutations spread out in AlaRS, including three in the aminoacylation domain, thereby suggesting a role for a tRNA-charging defect. However, here we found that two are aminoacylation defective but that the most widely distributed R329H is normal as a purified protein in vitro and in unfractionated patient cell samples. Remarkably, in contrast to wild-type (WT) AlaRS, all three mutant proteins gained the ability to interact with neuropilin 1 (Nrp1), the receptor previously linked to CMT pathogenesis in GlyRS. The aberrant AlaRS-Nrp1 interaction is further confirmed in patient samples carrying the R329H mutation. However, CMT2N mutations outside the aminoacylation domain do not induce the Nrp1 interaction. Detailed biochemical and biophysical investigations, including X-ray crystallography, small-angle X-ray scattering, hydrogen-deuterium exchange (HDX), switchSENSE hydrodynamic diameter determinations, and protease digestions reveal a mutation-induced structural loosening of the aminoacylation domain that correlates with the Nrp1 interaction. The b1b2 domains of Nrp1 are responsible for the interaction with R329H AlaRS. The results suggest Nrp1 is more broadly associated with CMT-associated members of the tRNA synthetase family. Moreover, we revealed a distinct structural loosening effect induced by a mutation in the editing domain and a lack of conformational impact with C-Ala domain mutations, indicating mutations in the same protein may cause neuropathy through different mechanisms. Our results show that, as with other CMT-associated tRNA synthetases, aminoacylation per se is not relevant to the pathology.
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20
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Sheehan BK, Orefice NS, Peng Y, Shapiro SL, Puglielli L. ATG9A regulates proteostasis through reticulophagy receptors FAM134B and SEC62 and folding chaperones CALR and HSPB1. iScience 2021; 24:102315. [PMID: 33870132 PMCID: PMC8042170 DOI: 10.1016/j.isci.2021.102315] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Revised: 02/18/2021] [Accepted: 03/12/2021] [Indexed: 12/01/2022] Open
Abstract
The acetylation of ATG9A within the endoplasmic reticulum (ER) lumen regulates the induction of reticulophagy. ER acetylation is ensured by AT-1/SLC33A1, a membrane transporter that maintains the cytosol-to-ER flux of acetyl-CoA. Defective AT-1 activity, as caused by heterozygous/homozygous mutations and gene duplication events, results in severe disease phenotypes. Here, we show that although the acetylation of ATG9A occurs in the ER lumen, the induction of reticulophagy requires ATG9A to engage FAM134B and SEC62 on the cytosolic side of the ER. To address this conundrum, we resolved the ATG9A interactome in two mouse models of AT-1 dysregulation: AT-1 sTg, a model of systemic AT-1 overexpression with hyperacetylation of ATG9A, and AT-1S113R/+, a model of AT-1 haploinsufficiency with hypoacetylation of ATG9A. We identified CALR and HSPB1 as two ATG9A partners that regulate the induction of reticulophagy as a function of ATG9A acetylation and discovered that ATG9A associates with several proteins that maintain ER proteostasis. The ATG9A-FAM134B and ATG9A-SEC62 interaction requires specific structural features Opposite Ca++-binding EF hands regulate ATG9A-FAM134B interaction HSBP1 and CALR regulate ATG9A-mediated induction of reticulophagy Many of the proteins that ensure ER proteostasis display spatial vicinity/cross talk
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Affiliation(s)
- Brendan K Sheehan
- Department of Medicine, University of Wisconsin-Madison, Madison, WI 53705, USA.,Waisman Center, University of Wisconsin-Madison, Madison, WI 53705, USA
| | - Nicola S Orefice
- Department of Medicine, University of Wisconsin-Madison, Madison, WI 53705, USA.,Waisman Center, University of Wisconsin-Madison, Madison, WI 53705, USA
| | - Yajing Peng
- Department of Medicine, University of Wisconsin-Madison, Madison, WI 53705, USA.,Waisman Center, University of Wisconsin-Madison, Madison, WI 53705, USA
| | - Samantha L Shapiro
- Department of Medicine, University of Wisconsin-Madison, Madison, WI 53705, USA.,Waisman Center, University of Wisconsin-Madison, Madison, WI 53705, USA
| | - Luigi Puglielli
- Department of Medicine, University of Wisconsin-Madison, Madison, WI 53705, USA.,Waisman Center, University of Wisconsin-Madison, Madison, WI 53705, USA.,Geriatric Research Education Clinical Center, Veterans Affairs Medical Center, Madison, WI 53705, USA.,Department of Neuroscience, University of Wisconsin-Madison, Madison, WI 53705, USA
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21
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Beijer D, Baets J. The expanding genetic landscape of hereditary motor neuropathies. Brain 2021; 143:3540-3563. [PMID: 33210134 DOI: 10.1093/brain/awaa311] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Revised: 07/15/2020] [Accepted: 07/27/2020] [Indexed: 12/12/2022] Open
Abstract
Hereditary motor neuropathies are clinically and genetically diverse disorders characterized by length-dependent axonal degeneration of lower motor neurons. Although currently as many as 26 causal genes are known, there is considerable missing heritability compared to other inherited neuropathies such as Charcot-Marie-Tooth disease. Intriguingly, this genetic landscape spans a discrete number of key biological processes within the peripheral nerve. Also, in terms of underlying pathophysiology, hereditary motor neuropathies show striking overlap with several other neuromuscular and neurological disorders. In this review, we provide a current overview of the genetic spectrum of hereditary motor neuropathies highlighting recent reports of novel genes and mutations or recent discoveries in the underlying disease mechanisms. In addition, we link hereditary motor neuropathies with various related disorders by addressing the main affected pathways of disease divided into five major processes: axonal transport, tRNA aminoacylation, RNA metabolism and DNA integrity, ion channels and transporters and endoplasmic reticulum.
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Affiliation(s)
- Danique Beijer
- Translational Neurosciences, Faculty of Medicine and Health Sciences, University of Antwerp, Belgium.,Laboratory of Neuromuscular Pathology, Institute Born-Bunge, University of Antwerp, Belgium
| | - Jonathan Baets
- Translational Neurosciences, Faculty of Medicine and Health Sciences, University of Antwerp, Belgium.,Laboratory of Neuromuscular Pathology, Institute Born-Bunge, University of Antwerp, Belgium.,Neuromuscular Reference Centre, Department of Neurology, Antwerp University Hospital, Belgium
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22
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Moss KR, Bopp TS, Johnson AE, Höke A. New evidence for secondary axonal degeneration in demyelinating neuropathies. Neurosci Lett 2021; 744:135595. [PMID: 33359733 PMCID: PMC7852893 DOI: 10.1016/j.neulet.2020.135595] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2020] [Revised: 10/31/2020] [Accepted: 12/19/2020] [Indexed: 12/28/2022]
Abstract
Development of peripheral nervous system (PNS) myelin involves a coordinated series of events between growing axons and the Schwann cell (SC) progenitors that will eventually ensheath them. Myelin sheaths have evolved out of necessity to maintain rapid impulse propagation while accounting for body space constraints. However, myelinating SCs perform additional critical functions that are required to preserve axonal integrity including mitigating energy consumption by establishing the nodal architecture, regulating axon caliber by organizing axonal cytoskeleton networks, providing trophic and potentially metabolic support, possibly supplying genetic translation materials and protecting axons from toxic insults. The intermediate steps between the loss of these functions and the initiation of axon degeneration are unknown but the importance of these processes provides insightful clues. Prevalent demyelinating diseases of the PNS include the inherited neuropathies Charcot-Marie-Tooth Disease, Type 1 (CMT1) and Hereditary Neuropathy with Liability to Pressure Palsies (HNPP) and the inflammatory diseases Acute Inflammatory Demyelinating Polyneuropathy (AIDP) and Chronic Inflammatory Demyelinating Polyneuropathy (CIDP). Secondary axon degeneration is a common feature of demyelinating neuropathies and this process is often correlated with clinical deficits and long-lasting disability in patients. There is abundant electrophysiological and histological evidence for secondary axon degeneration in patients and rodent models of PNS demyelinating diseases. Fully understanding the involvement of secondary axon degeneration in these diseases is essential for expanding our knowledge of disease pathogenesis and prognosis, which will be essential for developing novel therapeutic strategies.
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Affiliation(s)
- Kathryn R Moss
- Department of Neurology, Neuromuscular Division, Johns Hopkins School of Medicine, Baltimore, MD, United States
| | - Taylor S Bopp
- Department of Neurology, Neuromuscular Division, Johns Hopkins School of Medicine, Baltimore, MD, United States
| | - Anna E Johnson
- Department of Neurology, Neuromuscular Division, Johns Hopkins School of Medicine, Baltimore, MD, United States
| | - Ahmet Höke
- Department of Neurology, Neuromuscular Division, Johns Hopkins School of Medicine, Baltimore, MD, United States.
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23
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The Neurochaperonopathies: Anomalies of the Chaperone System with Pathogenic Effects in Neurodegenerative and Neuromuscular Disorders. APPLIED SCIENCES-BASEL 2021. [DOI: 10.3390/app11030898] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The chaperone (or chaperoning) system (CS) constitutes molecular chaperones, co-chaperones, and chaperone co-factors, interactors and receptors, and its canonical role is protein quality control. A malfunction of the CS may cause diseases, known as the chaperonopathies. These are caused by qualitatively and/or quantitatively abnormal molecular chaperones. Since the CS is ubiquitous, chaperonopathies are systemic, affecting various tissues and organs, playing an etiologic-pathogenic role in diverse conditions. In this review, we focus on chaperonopathies involved in the pathogenic mechanisms of diseases of the central and peripheral nervous systems: the neurochaperonopathies (NCPs). Genetic NCPs are linked to pathogenic variants of chaperone genes encoding, for example, the small Hsp, Hsp10, Hsp40, Hsp60, and CCT-BBS (chaperonin-containing TCP-1- Bardet–Biedl syndrome) chaperones. Instead, the acquired NCPs are associated with malfunctional chaperones, such as Hsp70, Hsp90, and VCP/p97 with aberrant post-translational modifications. Awareness of the chaperonopathies as the underlying primary or secondary causes of disease will improve diagnosis and patient management and open the possibility of investigating and developing chaperonotherapy, namely treatment with the abnormal chaperone as the main target. Positive chaperonotherapy would apply in chaperonopathies by defect, i.e., chaperone insufficiency, and consist of chaperone replacement or boosting, whereas negative chaperonotherapy would be pertinent when a chaperone actively participates in the initiation and progression of the disease and must be blocked and eliminated.
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24
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Zhang H, Zhou ZW, Sun L. Aminoacyl-tRNA synthetases in Charcot-Marie-Tooth disease: A gain or a loss? J Neurochem 2020; 157:351-369. [PMID: 33236345 PMCID: PMC8247414 DOI: 10.1111/jnc.15249] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Revised: 11/17/2020] [Accepted: 11/19/2020] [Indexed: 01/05/2023]
Abstract
Charcot‐Marie‐Tooth disease (CMT) is one of the most common inherited neurodegenerative disorders with an increasing number of CMT‐associated variants identified as causative factors, however, there has been no effective therapy for CMT to date. Aminoacyl‐tRNA synthetases (aaRS) are essential enzymes in translation by charging amino acids onto their cognate tRNAs during protein synthesis. Dominant monoallelic variants of aaRSs have been largely implicated in CMT. Some aaRSs variants affect enzymatic activity, demonstrating a loss‐of‐function property. In contrast, loss of aminoacylation activity is neither necessary nor sufficient for some aaRSs variants to cause CMT. Instead, accumulating evidence from CMT patient samples, animal genetic studies or protein conformational analysis has pinpointed toxic gain‐of‐function of aaRSs variants in CMT, suggesting complicated mechanisms underlying the pathogenesis of CMT. In this review, we summarize the latest advances in studies on CMT‐linked aaRSs, with a particular focus on their functions. The current challenges, future direction and the promising candidates for potential treatment of CMT are also discussed. ![]()
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Affiliation(s)
- Han Zhang
- Institute of Medical Biology, Chinese Academy of Medical Sciences and Peking Union Medical College, Kunming, China
| | - Zhong-Wei Zhou
- School of Medicine, Sun Yat-sen University, Guangzhou, China
| | - Litao Sun
- School of Public Health (Shenzhen), Sun Yat-sen University, Guangzhou, China
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25
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Abstract
Among the 20 cytoplasmic aminoacyl-tRNA synthetases (aaRSs), alanyl-tRNA synthetase (AlaRS) has unique features. AlaRS is the only aaRS that exclusively recognizes a single G3:U70 wobble base pair in the acceptor stem of tRNA, which serves as the identity element for both the synthetic and the proofreading activities of the synthetase. The recognition is relaxed during evolution and eukaryotic AlaRS can mis-aminoacylate noncognate tRNAs with a G4:U69 base pair seemingly as a deliberate gain of function for unknown reasons. Unlike other class II aaRSs, dimerization of AlaRS is not necessarily required for aminoacylation possibly due to functional compensations from the C-terminal domain (C-Ala). In contrast to other 19 cytoplasmic aaRSs that append additional domains or motifs to acquire new functions during evolution, the functional expansion of AlaRS is likely achieved through transformations of the existing C-Ala. Given both essential canonical and diverse non-canonical roles of AlaRS, dysfunction of AlaRS leads to neurodegenerative disorders in human and various pathological phenotypes in mouse models. In this review, the uniqueness of AlaRS in both physiological and pathological events is systematically discussed, with a particular focus on its novel functions gained in evolution.
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Affiliation(s)
- Han Zhang
- Institute of Medical Biology, Chinese Academy of Medical Sciences and Peking Union Medical College, Kunming, Yunnan, China
| | - Xiang-Lei Yang
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, California, USA
| | - Litao Sun
- School of Public Health (Shenzhen), Sun Yat-sen University, Guangdong, China
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26
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Chen CX, Li JQ, Dong HL, Liu GL, Bai G, Wu ZY. Identification and functional characterization of novel GDAP1 variants in Chinese patients with Charcot-Marie-Tooth disease. Ann Clin Transl Neurol 2020; 7:2381-2392. [PMID: 33136338 PMCID: PMC7732252 DOI: 10.1002/acn3.51233] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Revised: 09/14/2020] [Accepted: 10/01/2020] [Indexed: 12/12/2022] Open
Abstract
Objective To identify and characterize the pathogenicity of novel variants in Chinese patients with Charcot–Marie–Tooth disease. Methods Multiplex ligation‐dependent probe amplification (MLPA) and whole‐exome sequencing (WES) were performed in 30 unrelated CMT patients. Minigene assay was used to verify the effect of a novel splicing variant (c.694+1G>A) on pre‐mRNA. Primary fibroblast cell lines were established from skin biopsies to characterize the biological effects of the novel variants p.L26R and p.S169fs. The mitochondrial structure was observed by an electron microscope. The expression level of protein was analyzed by Western Blotting. Mitochondrial dynamics and mitochondrial membrane potential (MMP, Δψm) were analyzed via immunofluorescence study. Mitochondrial ATP levels were analyzed via bioluminescence assay. The rate of oxygen consumption was measured with a Seahorse Bioscience XF‐96 extracellular flux analyzer. Results We identified 10 pathogenic variants in three known CMT related genes, including three novel variants (p.L26R, p.S169fs, c.694+1G>A) and one known pathogenic variant (p.R120W) in GDAP1. Further, we described the clinical features of patients carrying pathogenic variants in GDAP1 and found that almost all Chinese CMT patients with GDAP1 variants present axonal type. The effect of c.694+1G>A on pre‐mRNA was verified via minigene splice assay. Cellular biological effects showed ultrastructure damage of mitochondrial, reduced protein levels, different patterns of mitochondrial dynamics, decreased mitochondrial membrane potential (Δψm), ATP content, and defects in respiratory capacity in the patient carrying p.L26R and p.S169fs in GDAP1. Interpretation Our results broaden the genetic spectrum of GDAP1 and provided functional evidence for mitochondrial pathways in the pathogenesis of GDAP1 variants.
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Affiliation(s)
- Cong-Xin Chen
- Department of Neurology and Research Center of Neurology in Second Affiliated Hospital, and Key Laboratory of Medical Neurobiology of Zhejiang Province, Zhejiang University School of Medicine, Hangzhou, China.,Department of Neurology and Institute of Neurology, First Affiliated Hospital, Fujian Medical University, Fuzhou, China
| | - Jia-Qi Li
- Department of Neurology and Research Center of Neurology in Second Affiliated Hospital, and Key Laboratory of Medical Neurobiology of Zhejiang Province, Zhejiang University School of Medicine, Hangzhou, China
| | - Hai-Lin Dong
- Department of Neurology and Research Center of Neurology in Second Affiliated Hospital, and Key Laboratory of Medical Neurobiology of Zhejiang Province, Zhejiang University School of Medicine, Hangzhou, China
| | - Gong-Lu Liu
- Department of Neurology and Research Center of Neurology in Second Affiliated Hospital, and Key Laboratory of Medical Neurobiology of Zhejiang Province, Zhejiang University School of Medicine, Hangzhou, China
| | - Ge Bai
- NHC and CAMS Key Laboratory of Medical Neurobiology, MOE Frontier Science Center for Brain Research and Brain-Machine Integration, School of Brain Science and Brain Medicine, Zhejiang University, Hangzhou, China
| | - Zhi-Ying Wu
- Department of Neurology and Research Center of Neurology in Second Affiliated Hospital, and Key Laboratory of Medical Neurobiology of Zhejiang Province, Zhejiang University School of Medicine, Hangzhou, China
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27
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Taga A, Cornblath DR. A novel HSPB1 mutation associated with a late onset CMT2 phenotype: Case presentation and systematic review of the literature. J Peripher Nerv Syst 2020; 25:223-229. [PMID: 32639100 DOI: 10.1111/jns.12395] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Revised: 05/20/2020] [Accepted: 05/21/2020] [Indexed: 02/06/2023]
Abstract
Mutations in the HSPB1 gene are associated with Charcot-Marie-Tooth (CMT) disease type 2F (CMT2F) and distal hereditary motor neuropathy type 2 (dHMN2). More than 18 pathogenic mutations spanning across the whole HSPB1 gene have been reported. Three family members with a novel p.P57S (c.169C>T) HSPB1 mutation resulting in a late onset axonal neuropathy with heterogeneous clinical and electrophysiological features are detailed. We systematically reviewed published case reports and case series on HSPB1 mutations. While a genotype-phenotype correlation was not obvious, we identified a common phenotype, which included adult onset, male predominance, motor more frequently than sensory involvement, distal and symmetric distribution with preferential involvement of plantar flexors, and a motor and axonal electrophysiological picture.
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Affiliation(s)
- Arens Taga
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - David R Cornblath
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
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28
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Muranova LK, Sudnitsyna MV, Strelkov SV, Gusev NB. Mutations in HspB1 and hereditary neuropathies. Cell Stress Chaperones 2020; 25:655-665. [PMID: 32301006 PMCID: PMC7332652 DOI: 10.1007/s12192-020-01099-9] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/12/2020] [Indexed: 12/12/2022] Open
Abstract
Charcot-Marie-Tooth (CMT) disease is major hereditary neuropathy. CMT has been linked to mutations in a range of proteins, including the small heat shock protein HspB1. Here we review the properties of several HspB1 mutants associated with CMT. In vitro, mutations in the N-terminal domain lead to a formation of larger HspB1 oligomers when compared with the wild-type (WT) protein. These mutants are resistant to phosphorylation-induced dissociation and reveal lower chaperone-like activity than the WT on a range of model substrates. Mutations in the α-crystallin domain lead to the formation of yet larger HspB1 oligomers tending to dissociate at low protein concentration and having variable chaperone-like activity. Mutations in the conservative IPV motif within the C-terminal domain induce the formation of very large oligomers with low chaperone-like activity. Most mutants interact with a partner small heat shock protein, HspB6, in a manner different from that of the WT protein. The link between the altered physico-chemical properties and the pathological CMT phenotype is a subject of discussion. Certain HspB1 mutations appear to have an effect on cytoskeletal elements such as intermediate filaments and/or microtubules, and by this means damage the axonal transport. In addition, mutations of HspB1 can affect the metabolism in astroglia and indirectly modulate the viability of motor neurons. While the mechanisms of pathological mutations in HspB1 are likely to vary greatly across different mutations, further in vitro and in vivo studies are required for a better understanding of the CMT disease at molecular level.
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Affiliation(s)
- Lydia K Muranova
- Department of Biochemistry, School of Biology, Moscow State University, Moscow, Russian Federation, 119991
| | - Maria V Sudnitsyna
- Department of Biochemistry, School of Biology, Moscow State University, Moscow, Russian Federation, 119991
| | - Sergei V Strelkov
- Department of Pharmaceutical and Pharmacological Sciences, Laboratory for Biocrystallography, KU Leuven, 3000, Leuven, Belgium
| | - Nikolai B Gusev
- Department of Biochemistry, School of Biology, Moscow State University, Moscow, Russian Federation, 119991.
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29
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Vendredy L, Adriaenssens E, Timmerman V. Small heat shock proteins in neurodegenerative diseases. Cell Stress Chaperones 2020; 25:679-699. [PMID: 32323160 PMCID: PMC7332613 DOI: 10.1007/s12192-020-01101-4] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/12/2020] [Indexed: 02/06/2023] Open
Abstract
Small heat shock proteins are ubiquitously expressed chaperones, yet mutations in some of them cause tissue-specific diseases. Here, we will discuss how small heat shock proteins give rise to neurodegenerative disorders themselves while we will also highlight how these proteins can fulfil protective functions in neurodegenerative disorders caused by protein aggregation. The first half of this paper will be focused on how mutations in HSPB1, HSPB3, and HSPB8 are linked to inherited peripheral neuropathies like Charcot-Marie-Tooth (CMT) disease and distal hereditary motor neuropathy (dHMN). The second part of the paper will discuss how small heat shock proteins are linked to neurodegenerative disorders like Alzheimer's, Parkinson's, and Huntington's disease.
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Affiliation(s)
- Leen Vendredy
- Department of Biomedical Sciences and Institute Born Bunge, Peripheral Neuropathy Research Group, University of Antwerp, Antwerp, Belgium
| | - Elias Adriaenssens
- Department of Biomedical Sciences and Institute Born Bunge, Peripheral Neuropathy Research Group, University of Antwerp, Antwerp, Belgium
| | - Vincent Timmerman
- Department of Biomedical Sciences and Institute Born Bunge, Peripheral Neuropathy Research Group, University of Antwerp, Antwerp, Belgium.
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30
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Alanyl-tRNA synthetase 1 (AARS1) gene mutation in a family with intermediate Charcot-Marie-Tooth neuropathy. Genes Genomics 2020; 42:663-672. [PMID: 32314272 DOI: 10.1007/s13258-020-00933-9] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2020] [Accepted: 03/31/2020] [Indexed: 10/24/2022]
Abstract
BACKGROUND Alanyl-tRNA synthetase 1 (AARS1) gene encodes a ubiquitously expressed class II enzyme that catalyzes the attachment of alanine to the cognate tRNA. AARS1 mutations are frequently responsible for autosomal dominant Charcot-Marie-Tooth disease type 2N (CMT2N). OBJECTIVE To identify pathogenic mutation in the Korean patients with CMT and distal hereditary motor neuronopathy (dHMN). METHODS We screened AARS1 mutations in 373 unrelated CMT families including 318 axonal CMT, 36 dHMN, and 19 intermediate CMT (Int-CMT) who were negative for 17p12 (PMP22) duplication or deletion using whole exome sequencing and targeted sequencing of CMT-related genes. RESULTS This study identified an early onset Int-CMT family harboring an AARS1 p.Arg329His mutation which was previously reported as pathogenic in French and Australian families. The mutation was located in the highly conserved tRNA binding domain and several in silico analyses suggested pathogenic prediction of the mutations. The patients harboring p.Arg329His showed clinically similar phenotypes of the early onset and electrophysiological intermediate type as those in Australian patients with same mutation. We also found a novel c.2564A>G (p.Gln855Arg) in a CMT2 patient, but its' pathogenic role was uncertain (variant of uncertain significance). CONCLUSION This study suggests that the frequency of the AARS1 mutations appears to be quite low in Korean CMT. This is the first report of the AARS1 mutation in Korean CMT patients and will be helpful for the exact molecular diagnosis and treatment of Int-CMT patients.
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31
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Neuromuscular Diseases Due to Chaperone Mutations: A Review and Some New Results. Int J Mol Sci 2020; 21:ijms21041409. [PMID: 32093037 PMCID: PMC7073051 DOI: 10.3390/ijms21041409] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2020] [Revised: 02/12/2020] [Accepted: 02/13/2020] [Indexed: 12/12/2022] Open
Abstract
Skeletal muscle and the nervous system depend on efficient protein quality control, and they express chaperones and cochaperones at high levels to maintain protein homeostasis. Mutations in many of these proteins cause neuromuscular diseases, myopathies, and hereditary motor and sensorimotor neuropathies. In this review, we cover mutations in DNAJB6, DNAJB2, αB-crystallin (CRYAB, HSPB5), HSPB1, HSPB3, HSPB8, and BAG3, and discuss the molecular mechanisms by which they cause neuromuscular disease. In addition, previously unpublished results are presented, showing downstream effects of BAG3 p.P209L on DNAJB6 turnover and localization.
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32
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Martin PB, Hicks AN, Holbrook SE, Cox GA. Overlapping spectrums: The clinicogenetic commonalities between Charcot-Marie-Tooth and other neurodegenerative diseases. Brain Res 2020; 1727:146532. [PMID: 31678418 PMCID: PMC6939129 DOI: 10.1016/j.brainres.2019.146532] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2019] [Revised: 10/20/2019] [Accepted: 10/22/2019] [Indexed: 12/11/2022]
Abstract
Charcot-Marie-Tooth (CMT) disease is a progressive and heterogeneous inherited peripheral neuropathy. A myriad of genetic factors have been identified that contribute to the degeneration of motor and sensory axons in a length-dependent manner. Emerging biological themes underlying disease include defects in axonal trafficking, dysfunction in RNA metabolism and protein homeostasis, as well deficits in the cellular stress response. Moreover, genetic contributions to CMT can have overlap with other neuropathies, motor neuron diseases (MNDs) and neurodegenerative disorders. Recent progress in understanding the molecular biology of CMT and overlapping syndromes aids in the search for necessary therapeutic targets.
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Affiliation(s)
- Paige B Martin
- The Jackson Laboratory, Bar Harbor, ME 04609, USA; Graduate School of Biomedical Sciences and Engineering, University of Maine, Orono, ME 04469, USA
| | - Amy N Hicks
- The Jackson Laboratory, Bar Harbor, ME 04609, USA
| | - Sarah E Holbrook
- The Jackson Laboratory, Bar Harbor, ME 04609, USA; Graduate School of Biomedical Sciences and Engineering, University of Maine, Orono, ME 04469, USA
| | - Gregory A Cox
- The Jackson Laboratory, Bar Harbor, ME 04609, USA; Graduate School of Biomedical Sciences and Engineering, University of Maine, Orono, ME 04469, USA.
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33
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Sundal C, Carmona S, Yhr M, Almström O, Ljungberg M, Hardy J, Hedberg-Oldfors C, Fred Å, Brás J, Oldfors A, Andersen O, Guerreiro R. An AARS variant as the likely cause of Swedish type hereditary diffuse leukoencephalopathy with spheroids. Acta Neuropathol Commun 2019; 7:188. [PMID: 31775912 PMCID: PMC6880494 DOI: 10.1186/s40478-019-0843-y] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2019] [Accepted: 11/07/2019] [Indexed: 12/12/2022] Open
Abstract
Swedish type Hereditary Diffuse Leukoencephalopathy with Spheroids (HDLS-S) is a severe adult-onset leukoencephalopathy with the histopathological hallmark of neuraxonal degeneration with spheroids, described in a large family with a dominant inheritance pattern. The initial stage of the disease is dominated by frontal lobe symptoms that develop into a rapidly advancing encephalopathy with pyramidal, deep sensory, extrapyramidal and optic tract symptoms. Median survival is less than 10 years. Recently, pathogenic mutations in CSF1R were reported in a clinically and histologically similar leukoencephalopathy segregating in several families. Still, the cause of HDLS-S remained elusive since its initial description in 1984, with no CSF1R mutations identified in the family. Here we update the original findings associated with HDLS-S after a systematic and recent assessment of several family members. We also report the results from exome sequencing analyses indicating the p.Cys152Phe variant in the alanyl tRNA synthetase (AARS) gene as the probable cause of this disease. The variant affects an amino acid located in the aminoacylation domain of the protein and does not cause differences in splicing or expression in the brain. Brain pathology in one case after 10 years of disease duration showed the end stage of the disease to be characterized by widespread liquefaction of the white matter leaving only some macrophages and glial cells behind the centrifugally progressing front. These results point to AARS as a candidate gene for rapidly progressing adult-onset CSF1R-negative leukoencephalopathies.
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Affiliation(s)
- Christina Sundal
- Department of Clinical Neurology, Institute of Neuroscience and Physiology, the Sahlgrenska Academy, University of Gothenburg, Gröna Stråket 11, 3rd floor, Sahlgrenska University Hospital, 413 45, Göteborg, Sweden
| | - Susana Carmona
- Center for Neurodegenerative Science, Van Andel Institute, 333 Bostwick Ave. N.E, Grand Rapids, MI, 49503-2518, USA
| | - Maria Yhr
- Department of Laboratory Medicine, Institute of Biomedicine, the Sahlgrenska Academy, University of Gothenburg, Göteborg, Sweden
| | - Odd Almström
- Department of Clinical Neurology, Institute of Neuroscience and Physiology, the Sahlgrenska Academy, University of Gothenburg, Gröna Stråket 11, 3rd floor, Sahlgrenska University Hospital, 413 45, Göteborg, Sweden
| | - Maria Ljungberg
- Department of Radiation Physics, Institute of Clinical Sciences, the Sahlgrenska Academy, University of Gothenburg, Göteborg, Sweden
| | - John Hardy
- Department of Neurodegenerative Disease, Reta Lila Weston Laboratories, Queen Square Genomics, UCL Dementia Research Institute, London, UK
| | - Carola Hedberg-Oldfors
- Department of Laboratory Medicine, Institute of Biomedicine, the Sahlgrenska Academy, University of Gothenburg, Göteborg, Sweden
| | - Åsa Fred
- Department of Pathology, Hospital of Halland, Halmstad, Sweden
| | - José Brás
- Center for Neurodegenerative Science, Van Andel Institute, 333 Bostwick Ave. N.E, Grand Rapids, MI, 49503-2518, USA
- Division of Psychiatry and Behavioral Medicine, Michigan State University College of Human Medicine, Grand Rapids, MI, USA
| | - Anders Oldfors
- Department of Laboratory Medicine, Institute of Biomedicine, the Sahlgrenska Academy, University of Gothenburg, Göteborg, Sweden
| | - Oluf Andersen
- Department of Clinical Neurology, Institute of Neuroscience and Physiology, the Sahlgrenska Academy, University of Gothenburg, Gröna Stråket 11, 3rd floor, Sahlgrenska University Hospital, 413 45, Göteborg, Sweden.
| | - Rita Guerreiro
- Center for Neurodegenerative Science, Van Andel Institute, 333 Bostwick Ave. N.E, Grand Rapids, MI, 49503-2518, USA.
- Division of Psychiatry and Behavioral Medicine, Michigan State University College of Human Medicine, Grand Rapids, MI, USA.
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34
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Lee DC, Dankwa L, Edmundson C, Cornblath DR, Scherer SS. Yield of next-generation neuropathy gene panels in axonal neuropathies. J Peripher Nerv Syst 2019; 24:324-329. [PMID: 31701603 DOI: 10.1111/jns.12356] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2019] [Revised: 10/31/2019] [Accepted: 11/01/2019] [Indexed: 12/28/2022]
Abstract
The use and utility of targeted gene panels for diagnosing the type of Charcot-Marie-Tooth have grown rapidly because commercial gene panels that contain most of the relevant genes are available and affordable for many patients. We used a targeted gene panel to analyze 175 patients who had an unexplained axonal polyneuropathy affecting large myelinated axons, 86 of whom reported a family history of neuropathy, and 89 of whom did not. In patients reporting a family history, the panel identified a pathogenic variant causing the neuropathy in six cases (7%); in patients not reporting a family history, the gene panel identified pathogenic variants causing neuropathy in two patients (2%). Interpretation in a tertiary referral setting, current gene panels identify the genetic cause of neuropathy in a small minority of patients who have an unexplained axonal neuropathy, even in those reporting a family history.
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Affiliation(s)
- Diana C Lee
- Department of Neurology, The Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania
| | - Lois Dankwa
- Department of Neurology, The Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania
| | - Christyn Edmundson
- Department of Neurology, The Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania
| | - David R Cornblath
- Department of Neurology, The Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Steven S Scherer
- Department of Neurology, The Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania
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Stone EJ, Uchida A, Brown A. Charcot-Marie-Tooth disease Type 2E/1F mutant neurofilament proteins assemble into neurofilaments. Cytoskeleton (Hoboken) 2019; 76:423-439. [PMID: 31574566 DOI: 10.1002/cm.21566] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2019] [Revised: 08/30/2019] [Accepted: 09/13/2019] [Indexed: 11/12/2022]
Abstract
Charcot-Marie-Tooth disease Type 2E/1F (CMT2E/1F) is a peripheral neuropathy caused by mutations in neurofilament protein L (NFL), which is one of five neurofilament subunit proteins that co-assemble to form neurofilaments in vivo. Prior studies on cultured cells have shown that CMT2E/1F mutations disrupt neurofilament assembly and lead to protein aggregation, suggesting a possible disease mechanism. However, electron microscopy of axons in peripheral nerve biopsies from patients has revealed accumulations of neurofilament polymers of normal appearance and no evidence of protein aggregates. To reconcile these observations, we reexamined the assembly of seven CMT2E/1F NFL mutants in cultured cells. None of the mutants assembled into homopolymers in SW13vim- cells, but P8R, P22S, L268/269P, and P440/441L mutant NFL assembled into heteropolymers in the presence of neurofilament protein M (NFM) alone, and N98S, Q332/333P, and E396/397K mutant NFL assembled in the presence of NFM and peripherin. P8R, P22S, N98S, L268/269P, E396/397K, and P440/441L mutant NFL co-assembled into neurofilaments with endogenous NFL, NFM, and α-internexin in cultured neurons, although the N98S and E396/397K mutants showed reduced filament incorporation, and the Q332/333P mutant showed limited incorporation. We conclude that all the mutants are capable of assembling into neurofilaments, but for some of the mutants this was dependent on the identity of the other neurofilament proteins available for co-assembly, and most likely also their relative expression level. Thus, caution should be exercised when drawing conclusions about the assembly capacity of CMT2E/1F mutants based on transient transfections in cultured cells.
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Affiliation(s)
- Elizabeth J Stone
- Department of Neuroscience, Ohio State University, Columbus, Ohio.,Neuroscience Graduate Program, Ohio State University, Columbus, Ohio
| | - Atsuko Uchida
- Department of Neuroscience, Ohio State University, Columbus, Ohio
| | - Anthony Brown
- Department of Neuroscience, Ohio State University, Columbus, Ohio
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Charcot-Marie-Tooth 2F (Hsp27 mutations): A review. Neurobiol Dis 2019; 130:104505. [PMID: 31212070 DOI: 10.1016/j.nbd.2019.104505] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2019] [Revised: 06/11/2019] [Accepted: 06/13/2019] [Indexed: 12/13/2022] Open
Abstract
Charcot-Marie-Tooth disease is a commonly inherited form of neuropathy. Although named over 100 years ago, identification of subtypes of Charcot-Marie-Tooth has rapidly expanded in the preceding decades with the advancement of genetic sequencing, including type 2F (CMT2F), due to mutations in heat shock protein 27 (Hsp27). However, despite CMT being one of the most common inherited neurological diseases, definitive mechanistic models of pathology and effective treatments for CMT2F are lacking. This review extensively profiles the published literature on CMT2F and distal hereditary motor neuropathy II (dHMN II), a similar neuropathy with exclusively motor symptoms that is also due to mutations in Hsp27. This includes a review of case reports and sequencing studies detailing disease course. Included are tables listing of all known published mutations of Hsp27 that cause symptoms of CMT2F and dHMN II. Furthermore, pathological mechanisms are assessed. While many groups have established pathologies relating to defective chaperone function, cellular neurofilament and microtubule structure and function, and mitochondrial and metabolic dysfunction, there are still discrepancies in results between different model systems. Moreover, initial mouse models have also produced promising results with similar phenotypes to humans, however discrepancies still exist. Both patient-focused and scientific studies have demonstrated variability in phenotypes even considering specific mutations. Given the clinical heterogeneity in presentation, CMT2F and dHMN II likely result from similar pathological mechanisms of the same general disease process that may present distinctly due to other genetic and environment influences. Determining how these influences exert their effects to produce pathology contributing to the disease phenotype will be a major future challenge ahead in the field.
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Hsu Y, Lin K, Guo Y, Tsai Y, Liao Y, Lee Y. Mutation spectrum of Charcot-Marie-Tooth disease among the Han Chinese in Taiwan. Ann Clin Transl Neurol 2019; 6:1090-1101. [PMID: 31211173 PMCID: PMC6562034 DOI: 10.1002/acn3.50797] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2019] [Revised: 04/25/2019] [Accepted: 05/02/2019] [Indexed: 12/25/2022] Open
Abstract
Objective Charcot‐Marie‐Tooth disease (CMT) is a clinically and genetically heterogeneous group of inherited neuropathies. Mutations in more than 90 genes have been implicated in CMT; however, the mutational spectrum of CMT in Chinese population remains obscure. This study aims to provide a comprehensive overview of the frequency of mutations in Taiwanese patients with CMT and look for genotype‐phenotype correlations. Methods Mutational analyses were performed on 427 unrelated Taiwanese patients with CMT by polymorphic microsatellite markers analysis or real‐time fluorescent PCR for PMP22 duplication, Sanger sequencing for GJB1 mutations, and targeted sequencing covering 124 genes causing or relevant to inherited neuropathies. We also correlated the genotypes with the phenotypic features, such as age at disease onset and ulnar motor nerve conduction velocity. Results Pathogenic mutations were identified in 312 patients (73.1%; 312/427), including 208 patients with a PMP22 duplication, 40 patients with a GJB1 mutation, and 64 patients with a mutation in one of other 18 CMT genes. A confirmed molecular diagnosis was achieved in 84.4% (266/315) of the patients with demyelinating CMT and 41.1% (46/112) of the patients with axonal CMT. Mutations in MPZ, MFN2, or NEFL are the most frequent disease causes in patients with infantile‐onset CMT (≤2 years), while PMP22 duplications and mutations in GJB1, MFN2, or MPZ are the frequent causes among patients with childhood‐ or adolescence‐onset CMT (3–9 years). Interpretation This study provides a genotype‐phenotype landscape of CMT in Taiwan and highlights the unique spectrum of CMT genes frequencies among patients of Chinese origin.
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Affiliation(s)
- Yun‐Hsin Hsu
- Division of Neurology, Department of Internal MedicineTaipei Veterans General Hospital Su‐Ao BranchYilanTaiwan
- Neurological Institute, Taichung Veterans General HospitalTaichungTaiwan
| | - Kon‐Ping Lin
- Neurological Institute, Taipei Veterans General HospitalTaipeiTaiwan
- Department of NeurologyNational Yang‐Ming University School of MedicineTaipeiTaiwan
| | - Yuh‐Cherng Guo
- Institute of Clinical MedicineNational Yang‐Ming UniversityTaipeiTaiwan
- Department of NeurologyChina Medical University HospitalTaichungTaiwan
- School of Medicine, College of MedicineChina Medical UniversityTaichungTaiwan
| | - Yu‐Shuen Tsai
- Institute of Biomedical InformaticsNational Yang‐Ming UniversityTaipeiTaiwan
- Center for Systems and Synthetic BiologyNational Yang‐Ming UniversityTaipeiTaiwan
| | - Yi‐Chu Liao
- Neurological Institute, Taipei Veterans General HospitalTaipeiTaiwan
- Department of NeurologyNational Yang‐Ming University School of MedicineTaipeiTaiwan
- Brain Research CenterNational Yang‐Ming University School of MedicineTaipeiTaiwan
| | - Yi‐Chung Lee
- Neurological Institute, Taipei Veterans General HospitalTaipeiTaiwan
- Department of NeurologyNational Yang‐Ming University School of MedicineTaipeiTaiwan
- Brain Research CenterNational Yang‐Ming University School of MedicineTaipeiTaiwan
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Imaizumi N, Takeuchi Y, Hirano H, Torii T, Seki Y, Morimoto T, Miyamoto Y, Sakagami H, Yamauchi J. Data on the effects of Charcot-Marie-Tooth disease type 2N-associated AARS missense mutation (Arg329-to-His) on the cell biological properties. Data Brief 2019; 25:104029. [PMID: 31194127 PMCID: PMC6554220 DOI: 10.1016/j.dib.2019.104029] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2018] [Revised: 03/28/2019] [Accepted: 05/14/2019] [Indexed: 11/27/2022] Open
Abstract
Charcot-Marie-Tooth (CMT) diseases are genetic neuropathies in the peripheral nervous system (PNS). Type 1 CMT diseases are neuropathies in Schwann cells, PNS myelinating glial cells, whereas type 2 CMT diseases are axonal neuropathies. In addition, there are other types of categories in CMT diseases. CMT diseases are associated with approximately 100 responsible genes. Taiwanese mutation (Asn71-to-Tyr) of alanyl-tRNA synthetase (AARS) in type 2N CMT disease has been reported to have several pathological effects on properties of AARS proteins themselves [1]. Also, some mutations in other responsible genes affect cell biological properties of their gene products [2,3]. Herein we provide the data regarding the effects of another type 2N CMT disease-associated AARS mutation (Arg329-to-His) in French family on the cellular properties.
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Affiliation(s)
- Naoko Imaizumi
- Laboratory of Molecular Neuroscience and Neurology, Tokyo University of Pharmacy and Life Sciences, Hachioji, Tokyo 192-0355, Japan
| | - Yu Takeuchi
- Laboratory of Molecular Neuroscience and Neurology, Tokyo University of Pharmacy and Life Sciences, Hachioji, Tokyo 192-0355, Japan
| | - Haruka Hirano
- Laboratory of Molecular Neuroscience and Neurology, Tokyo University of Pharmacy and Life Sciences, Hachioji, Tokyo 192-0355, Japan
| | - Tomohiro Torii
- Department of Neuroscience, Baylor College of Medicine, Houston, TX 77030, USA
| | - Yoichi Seki
- Laboratory of Molecular Neuroscience and Neurology, Tokyo University of Pharmacy and Life Sciences, Hachioji, Tokyo 192-0355, Japan
| | - Takako Morimoto
- Laboratory of Molecular Neuroscience and Neurology, Tokyo University of Pharmacy and Life Sciences, Hachioji, Tokyo 192-0355, Japan
| | - Yuki Miyamoto
- Department of Pharmacology, National Research Institute for Child Health and Development, Setagaya, Tokyo 157-8535, Japan
| | - Hiroyuki Sakagami
- Department of Anatomy, Kitasato University School of Medicine, Sagamihara, Kanagawa 252-0734, Japan
| | - Junji Yamauchi
- Laboratory of Molecular Neuroscience and Neurology, Tokyo University of Pharmacy and Life Sciences, Hachioji, Tokyo 192-0355, Japan.,Department of Pharmacology, National Research Institute for Child Health and Development, Setagaya, Tokyo 157-8535, Japan
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Novel GDAP1 Mutation in a Vietnamese Family with Charcot-Marie-Tooth Disease. BIOMED RESEARCH INTERNATIONAL 2019; 2019:7132494. [PMID: 31179332 PMCID: PMC6507255 DOI: 10.1155/2019/7132494] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/15/2018] [Revised: 12/21/2018] [Accepted: 04/14/2019] [Indexed: 01/09/2023]
Abstract
Background Mutations of GDAP1 gene cause autosomal dominant and autosomal recessive Charcot-Marie-Tooth (CMT) disease and over 80 different mutations have been identified so far. This study analyzed the clinical and genetic characteristics of a Vietnamese CMT family that was affected by a novel GDAP1 mutation. Methods We present three children of a family with progressive weakness, mild sensory loss, and absent tendon reflexes. Electrodiagnostic analyses displayed an axonal type of neuropathy in affected patients. Sequencing of GDAP1 gene was requested for all members of the family. Results All affected individuals manifested identical clinical symptoms of motor and sensory impairments within the first three years of life, and nerve conduction study indicated the axonal degeneration. A homozygous GDAP1 variant (c.667_671dup) was found in the three affected children as recessive inheritance pattern. The mutation leads to a premature termination codon that shortens GDAP1 protein (p.Gln224Hisfs∗37). Further testing showed heterozygous c.667_671dup variant in the parents. Discussion Our study expands the mutational spectrum of GDAP1-related CMT disease with the new and unreported GDAP1 variant. Alterations in GDAP1 gene should be evaluated as CMT causing variants in the Vietnamese population, predominantly axonal form of neuropathy in CMT disease.
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Wei N, Zhang Q, Yang XL. Neurodegenerative Charcot-Marie-Tooth disease as a case study to decipher novel functions of aminoacyl-tRNA synthetases. J Biol Chem 2019; 294:5321-5339. [PMID: 30643024 DOI: 10.1074/jbc.rev118.002955] [Citation(s) in RCA: 60] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Aminoacyl-tRNA synthetases (aaRSs) are essential enzymes that catalyze the first reaction in protein biosynthesis, namely the charging of transfer RNAs (tRNAs) with their cognate amino acids. aaRSs have been increasingly implicated in dominantly and recessively inherited human diseases. The most common aaRS-associated monogenic disorder is the incurable neurodegenerative disease Charcot-Marie-Tooth neuropathy (CMT), caused by dominant mono-allelic mutations in aaRSs. With six currently known members (GlyRS, TyrRS, AlaRS, HisRS, TrpRS, and MetRS), aaRSs represent the largest protein family implicated in CMT etiology. After the initial discovery linking aaRSs to CMT, the field has progressed from understanding whether impaired tRNA charging is a critical component of this disease to elucidating the specific pathways affected by CMT-causing mutations in aaRSs. Although many aaRS CMT mutants result in loss of tRNA aminoacylation function, animal genetics studies demonstrated that dominant mutations in GlyRS cause CMT through toxic gain-of-function effects, which also may apply to other aaRS-linked CMT subtypes. The CMT-causing mechanism is likely to be multifactorial and involves multiple cellular compartments, including the nucleus and the extracellular space, where the normal WT enzymes also appear. Thus, the association of aaRSs with neuropathy is relevant to discoveries indicating that aaRSs also have nonenzymatic regulatory functions that coordinate protein synthesis with other biological processes. Through genetic, functional, and structural analyses, commonalities among different mutations and different aaRS-linked CMT subtypes have begun to emerge, providing insights into the nonenzymatic functions of aaRSs and the pathogenesis of aaRS-linked CMT to guide therapeutic development to treat this disease.
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Affiliation(s)
- Na Wei
- From the Department of Molecular Medicine, The Scripps Research Institute, La Jolla, California 92037
| | - Qian Zhang
- From the Department of Molecular Medicine, The Scripps Research Institute, La Jolla, California 92037
| | - Xiang-Lei Yang
- From the Department of Molecular Medicine, The Scripps Research Institute, La Jolla, California 92037
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Tatsumi Y, Matsumoto N, Iibe N, Watanabe N, Torii T, Sango K, Homma K, Miyamoto Y, Sakagami H, Yamauchi J. CMT type 2N disease-associated AARS mutant inhibits neurite growth that can be reversed by valproic acid. Neurosci Res 2018; 139:69-78. [PMID: 30261202 DOI: 10.1016/j.neures.2018.09.016] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2018] [Revised: 09/06/2018] [Accepted: 09/17/2018] [Indexed: 12/27/2022]
Abstract
Charcot-Marie-Tooth (CMT) disease is composed of a heterogeneous group of hereditary peripheral neuropathies. The peripheral nervous system primarily comprises two types of cells: neuronal cells and myelinating glial Schwann cells. CMT2 N is an autosomal dominant disease and its responsible gene encodes alanyl-tRNA synthetase (AARS), which is a family of cytoplasmic aminoacyl-tRNA synthetases. CMT2 N is associated with the mutation, including a missense mutation, which is known to decrease the enzymatic activity of AARS, but whether and how its mutation affects AARS localization and neuronal process formation remains to be understood. First, we show that the AARS mutant harboring Asn71-to-Tyr (N71Y) is not localized in cytoplasm. The expression of AARS mutant proteins in COS-7 cells mainly leads to localization into lysosome, whereas the wild type is indeed localized in cytoplasm. Second, in N1E-115 cells as the neuronal cell model, cells expressing the N71Y mutant do not have the ability to grow processes. Third, pretreatment with antiepileptic valproic acid reverses the inhibitory effect of the N71Y mutant on process growth. Taken together, the N71Y mutation of AARS leads to abnormal intracellular localization, inhibiting process growth, yet this inhibition is reversed by valproic acid.
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Affiliation(s)
- Yuriko Tatsumi
- Laboratory of Molecular Neuroscience and Neurology, Tokyo University of Pharmacy and Life Sciences, Hachioji, Tokyo, 192-0392, Japan
| | - Naoto Matsumoto
- Laboratory of Molecular Neuroscience and Neurology, Tokyo University of Pharmacy and Life Sciences, Hachioji, Tokyo, 192-0392, Japan
| | - Noriko Iibe
- Laboratory of Molecular Neuroscience and Neurology, Tokyo University of Pharmacy and Life Sciences, Hachioji, Tokyo, 192-0392, Japan
| | - Natsumi Watanabe
- Laboratory of Molecular Neuroscience and Neurology, Tokyo University of Pharmacy and Life Sciences, Hachioji, Tokyo, 192-0392, Japan
| | - Tomohiro Torii
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Kazunori Sango
- Department of Sensory and Motor Systems, Tokyo Metropolitan Institute of Medical Science, Setagaya, Tokyo, 156-8506, Japan
| | - Keiichi Homma
- Department of Life Science and Informatics, Maebashi Institute of Technology, Maebashi, Gunma, 371-0816, Japan
| | - Yuki Miyamoto
- Laboratory of Molecular Neuroscience and Neurology, Tokyo University of Pharmacy and Life Sciences, Hachioji, Tokyo, 192-0392, Japan; Department of Pharmacology, National Research Institute for Child Health and Development, Setagaya, Tokyo, 157-8535, Japan
| | - Hiroyuki Sakagami
- Department of Anatomy, Kitasato University School of Medicine, Sagamihara, Kanagawa, 252-0734, Japan
| | - Junji Yamauchi
- Laboratory of Molecular Neuroscience and Neurology, Tokyo University of Pharmacy and Life Sciences, Hachioji, Tokyo, 192-0392, Japan; Department of Pharmacology, National Research Institute for Child Health and Development, Setagaya, Tokyo, 157-8535, Japan.
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Fuchs SA, Schene IF, Kok G, Jansen JM, Nikkels PGJ, van Gassen KLI, Terheggen-Lagro SWJ, van der Crabben SN, Hoeks SE, Niers LEM, Wolf NI, de Vries MC, Koolen DA, Houwen RHJ, Mulder MF, van Hasselt PM. Aminoacyl-tRNA synthetase deficiencies in search of common themes. Genet Med 2018; 21:319-330. [PMID: 29875423 PMCID: PMC7091658 DOI: 10.1038/s41436-018-0048-y] [Citation(s) in RCA: 67] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2017] [Accepted: 04/10/2018] [Indexed: 12/22/2022] Open
Abstract
Purpose Pathogenic variations in genes encoding aminoacyl-tRNA synthetases (ARSs) are increasingly associated with human disease. Clinical features of autosomal recessive ARS deficiencies appear very diverse and without apparent logic. We searched for common clinical patterns to improve disease recognition, insight into pathophysiology, and clinical care. Methods Symptoms were analyzed in all patients with recessive ARS deficiencies reported in literature, supplemented with unreported patients evaluated in our hospital. Results In literature, we identified 107 patients with AARS, DARS, GARS, HARS, IARS, KARS, LARS, MARS, RARS, SARS, VARS, YARS, and QARS deficiencies. Common symptoms (defined as present in ≥4/13 ARS deficiencies) included abnormalities of the central nervous system and/or senses (13/13), failure to thrive, gastrointestinal symptoms, dysmaturity, liver disease, and facial dysmorphisms. Deep phenotyping of 5 additional patients with unreported compound heterozygous pathogenic variations in IARS, LARS, KARS, and QARS extended the common phenotype with lung disease, hypoalbuminemia, anemia, and renal tubulopathy. Conclusion We propose a common clinical phenotype for recessive ARS deficiencies, resulting from insufficient aminoacylation activity to meet translational demand in specific organs or periods of life. Assuming residual ARS activity, adequate protein/amino acid supply seems essential instead of the traditional replacement of protein by glucose in patients with metabolic diseases.
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Affiliation(s)
- Sabine A Fuchs
- Department of Metabolic Diseases, Wilhelmina Children's Hospital, University Medical Center Utrecht, Lundlaan 6, Utrecht, 3584 EA, The Netherlands.
| | - Imre F Schene
- Department of Metabolic Diseases, Wilhelmina Children's Hospital, University Medical Center Utrecht, Lundlaan 6, Utrecht, 3584 EA, The Netherlands
| | - Gautam Kok
- Department of Metabolic Diseases, Wilhelmina Children's Hospital, University Medical Center Utrecht, Lundlaan 6, Utrecht, 3584 EA, The Netherlands
| | - Jurriaan M Jansen
- Department of Metabolic Diseases, Wilhelmina Children's Hospital, University Medical Center Utrecht, Lundlaan 6, Utrecht, 3584 EA, The Netherlands
| | - Peter G J Nikkels
- Department of Pathology, University Medical Center Utrecht, Lundlaan 6, Utrecht, 3584 EA, The Netherlands
| | - Koen L I van Gassen
- Department of Genetics, University Medical Centre Utrecht, Lundlaan 6, Utrecht, 3584 EA, The Netherlands
| | - Suzanne W J Terheggen-Lagro
- Department of Pediatric Pulmonology, Academic Medical Center Amsterdam, Meibergdreef 9, Amsterdam, 1105 AZ, The Netherlands
| | - Saskia N van der Crabben
- Department of Clinical Genetics, VU University Medical Center, De Boelelaan 1117, Amsterdam, 1081HV, The Netherlands
| | - Sanne E Hoeks
- Department of Neonatology, University Medical Center Utrecht, Lundlaan 6, Utrecht, 3584 EA, The Netherlands
| | - Laetitia E M Niers
- Department of Pediatrics, Maxima Medical Centre Veldhoven, De Run 4600, Veldhoven, 5504 DB, The Netherlands
| | - Nicole I Wolf
- Department of Child Neurology, VU University Medical Center, De Boelelaan 1117, Amsterdam, 1081HV, The Netherlands
| | - Maaike C de Vries
- Nijmegen Centre for Mitochondrial Disorders at Department of Pediatrics, Radboud University Nijmegen Centre, Nijmegen, The Netherlands
| | - David A Koolen
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, 6500 HB, The Netherlands
| | - Roderick H J Houwen
- Division of Pediatric Gastroenterology, Wilhelmina Children's Hospital, University Medical Center Utrecht, Lundlaan 6, Utrecht, 3584 EA, The Netherlands
| | - Margot F Mulder
- Department of Pediatrics, VU University Medical Center, De Boelelaan 1117, Amsterdam, 1081HV, The Netherlands
| | - Peter M van Hasselt
- Department of Metabolic Diseases, Wilhelmina Children's Hospital, University Medical Center Utrecht, Lundlaan 6, Utrecht, 3584 EA, The Netherlands
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Tanabe H, Higuchi Y, Yuan JH, Hashiguchi A, Yoshimura A, Ishihara S, Nozuma S, Okamoto Y, Matsuura E, Ishiura H, Mitsui J, Takashima R, Kokubun N, Maeda K, Asano Y, Sunami Y, Kono Y, Ishigaki Y, Yanamoto S, Fukae J, Kida H, Morita M, Tsuji S, Takashima H. Clinical and genetic features of Charcot-Marie-Tooth disease 2F and hereditary motor neuropathy 2B in Japan. J Peripher Nerv Syst 2018; 23:40-48. [PMID: 29381233 PMCID: PMC5873406 DOI: 10.1111/jns.12252] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2017] [Revised: 01/23/2018] [Accepted: 01/23/2018] [Indexed: 12/12/2022]
Abstract
Mutations in small heat shock protein beta‐1 (HspB1) have been linked to Charcot‐Marie‐Tooth (CMT) disease type 2F and distal hereditary motor neuropathy type 2B. Only four cases with HSPB1 mutations have been reported to date in Japan. In this study between April 2007 and October 2014, we conducted gene panel sequencing in a case series of 1,030 patients with inherited peripheral neuropathies (IPNs) using DNA microarray, targeted resequencing, and whole‐exome sequencing. We identified HSPB1 variants in 1.3% (13 of 1,030) of the patients with IPNs, who exhibited a male predominance. Based on neurological and electrophysiological findings, seven patients were diagnosed with CMT disease type 2F, whereas the remaining six patients were diagnosed with distal hereditary motor neuropathy type 2B. P39L, R127W, S135C, R140G, K141Q, T151I, and P182A mutations identified in 12 patients were described previously, whereas a novel K123* variant with unknown significance was found in 1 patient. Diabetes and impaired glucose tolerance were detected in 6 of the 13 patients. Our findings suggest that HSPB1 mutations result in two phenotypes of inherited neuropathies and extend the phenotypic spectrum of HSPB1‐related disorders.
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Affiliation(s)
- Hajime Tanabe
- Department of Neurology and Geriatrics, Kagoshima University, Graduate School of Medical and Dental Sciences, Kagoshima, Japan
| | - Yujiro Higuchi
- Department of Neurology and Geriatrics, Kagoshima University, Graduate School of Medical and Dental Sciences, Kagoshima, Japan
| | - Jun-Hui Yuan
- Department of Neurology and Geriatrics, Kagoshima University, Graduate School of Medical and Dental Sciences, Kagoshima, Japan
| | - Akihiro Hashiguchi
- Department of Neurology and Geriatrics, Kagoshima University, Graduate School of Medical and Dental Sciences, Kagoshima, Japan
| | - Akiko Yoshimura
- Department of Neurology and Geriatrics, Kagoshima University, Graduate School of Medical and Dental Sciences, Kagoshima, Japan
| | - Satoshi Ishihara
- Department of Neurology and Geriatrics, Kagoshima University, Graduate School of Medical and Dental Sciences, Kagoshima, Japan.,Department of Cardiovascular Medicine, Nephrology and Neurology, Graduate School of Medicine, University of the Ryukyus, Okinawa, Japan
| | - Satoshi Nozuma
- Department of Neurology and Geriatrics, Kagoshima University, Graduate School of Medical and Dental Sciences, Kagoshima, Japan
| | - Yuji Okamoto
- Department of Neurology and Geriatrics, Kagoshima University, Graduate School of Medical and Dental Sciences, Kagoshima, Japan
| | - Eiji Matsuura
- Department of Neurology and Geriatrics, Kagoshima University, Graduate School of Medical and Dental Sciences, Kagoshima, Japan
| | - Hiroyuki Ishiura
- Department of Neurology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Jun Mitsui
- Department of Neurology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | | | - Norito Kokubun
- Department of Neurology, Dokkyo Medical University, Tochigi, Japan
| | - Kengo Maeda
- Department of Neurology, National Hospital Organization Higashi-ohmi General Medical Center, Shiga, Japan
| | - Yuri Asano
- Department of Neurology, Tokyo Metropolitan Neurological Hospital, Tokyo, Japan
| | - Yoko Sunami
- Department of Neurology, Tokyo Metropolitan Neurological Hospital, Tokyo, Japan
| | - Yu Kono
- Department of Neurology, The Jikei University School of Medicine, Tokyo, Japan
| | | | - Shosaburo Yanamoto
- Department of Neurology, Fukuoka University School of Medicine, Fukuoka, Japan
| | - Jiro Fukae
- Department of Neurology, Fukuoka University School of Medicine, Fukuoka, Japan
| | - Hiroshi Kida
- Division of Respirology, Neurology, and Rheumatology, Department of Medicine, Kurume University School of Medicine, Fukuoka, Japan
| | - Mitsuya Morita
- Division of Neurology, Jichi Medical University, Tochigi, Japan
| | - Shoji Tsuji
- Department of Neurology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Hiroshi Takashima
- Department of Neurology and Geriatrics, Kagoshima University, Graduate School of Medical and Dental Sciences, Kagoshima, Japan
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Pakhrin PS, Xie Y, Hu Z, Li X, Liu L, Huang S, Wang B, Yang Z, Zhang J, Liu X, Xia K, Tang B, Zhang R. Genotype–phenotype correlation and frequency of distribution in a cohort of Chinese Charcot–Marie–Tooth patients associated with GDAP1 mutations. J Neurol 2018; 265:637-646. [DOI: 10.1007/s00415-018-8743-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2017] [Revised: 12/13/2017] [Accepted: 01/07/2018] [Indexed: 01/08/2023]
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Dohrn MF, Glöckle N, Mulahasanovic L, Heller C, Mohr J, Bauer C, Riesch E, Becker A, Battke F, Hörtnagel K, Hornemann T, Suriyanarayanan S, Blankenburg M, Schulz JB, Claeys KG, Gess B, Katona I, Ferbert A, Vittore D, Grimm A, Wolking S, Schöls L, Lerche H, Korenke GC, Fischer D, Schrank B, Kotzaeridou U, Kurlemann G, Dräger B, Schirmacher A, Young P, Schlotter-Weigel B, Biskup S. Frequent genes in rare diseases: panel-based next generation sequencing to disclose causal mutations in hereditary neuropathies. J Neurochem 2017; 143:507-522. [DOI: 10.1111/jnc.14217] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2017] [Revised: 08/30/2017] [Accepted: 09/07/2017] [Indexed: 12/26/2022]
Affiliation(s)
- Maike F. Dohrn
- CeGaT GmbH and Praxis für Humangenetik Tübingen; Tuebingen Germany
- Department of Neurology; Medical Faculty; RWTH Aachen University; Aachen Germany
| | - Nicola Glöckle
- CeGaT GmbH and Praxis für Humangenetik Tübingen; Tuebingen Germany
| | | | - Corina Heller
- CeGaT GmbH and Praxis für Humangenetik Tübingen; Tuebingen Germany
| | - Julia Mohr
- CeGaT GmbH and Praxis für Humangenetik Tübingen; Tuebingen Germany
| | - Christine Bauer
- CeGaT GmbH and Praxis für Humangenetik Tübingen; Tuebingen Germany
| | - Erik Riesch
- CeGaT GmbH and Praxis für Humangenetik Tübingen; Tuebingen Germany
| | - Andrea Becker
- CeGaT GmbH and Praxis für Humangenetik Tübingen; Tuebingen Germany
| | - Florian Battke
- CeGaT GmbH and Praxis für Humangenetik Tübingen; Tuebingen Germany
| | | | - Thorsten Hornemann
- Institute for Clinical Chemistry; University Hospital Zürich; Zurich Switzerland
| | | | - Markus Blankenburg
- Department of Pediatric Neurology Klinikum Stuttgart; Olgahospital, Stuttgart Germany
- Faculty of Health; Witten/Herdecke University; Witten Germany
| | - Jörg B. Schulz
- Department of Neurology; Medical Faculty; RWTH Aachen University; Aachen Germany
- JARA-BRAIN Institute Molecular Neuroscience and Neuroimaging; Forschungszentrum Jülich GmbH and RWTH Aachen University; Aachen Germany
| | - Kristl G. Claeys
- Department of Neurology; University Hospitals Leuven and University of Leuven (KU Leuven); Leuven Belgium
| | - Burkhard Gess
- Department of Neurology; Medical Faculty; RWTH Aachen University; Aachen Germany
| | - Istvan Katona
- Institute of Neuropathology; Medical Faculty; RWTH Aachen University; Aachen Germany
| | | | - Debora Vittore
- Department of Neurology and Epileptology; Hertie Institute for Clinical Brain Research; University of Tübingen; Tuebingen Germany
| | - Alexander Grimm
- Department of Neurology and Epileptology; Hertie Institute for Clinical Brain Research; University of Tübingen; Tuebingen Germany
| | - Stefan Wolking
- Department of Neurology and Epileptology; Hertie Institute for Clinical Brain Research; University of Tübingen; Tuebingen Germany
| | - Ludger Schöls
- Department of Neurology and Epileptology; Hertie Institute for Clinical Brain Research; University of Tübingen; Tuebingen Germany
| | - Holger Lerche
- Department of Neurology and Epileptology; Hertie Institute for Clinical Brain Research; University of Tübingen; Tuebingen Germany
| | | | - Dirk Fischer
- Department of Neurology; University of Basel Hospital; Basel Switzerland
| | - Bertold Schrank
- Department of Neurology; Deutsche Klinik für Diagnostik; Wiesbaden Germany
| | - Urania Kotzaeridou
- Department of General Pediatrics; Division of Inherited Metabolic Diseases; University Children's Hospital; Heidelberg Germany
| | - Gerhard Kurlemann
- Department of Neuropediatrics; University Hospital Münster; Muenster Germany
| | - Bianca Dräger
- Department of Sleep Medicine and Neuromuscular Disorders; University Hospital Münster; Muenster Germany
| | - Anja Schirmacher
- Department of Sleep Medicine and Neuromuscular Disorders; University Hospital Münster; Muenster Germany
| | - Peter Young
- Department of Sleep Medicine and Neuromuscular Disorders; University Hospital Münster; Muenster Germany
| | - Beate Schlotter-Weigel
- Department of Neurology; Friedrich-Baur-Institute; Ludwig-Maximilians-University of Munich; Munich Germany
| | - Saskia Biskup
- CeGaT GmbH and Praxis für Humangenetik Tübingen; Tuebingen Germany
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46
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A novel homozygous nonsense mutation in NEFL causes autosomal recessive Charcot-Marie-Tooth disease. Neuromuscul Disord 2017; 28:44-47. [PMID: 29191368 DOI: 10.1016/j.nmd.2017.09.018] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2017] [Revised: 09/23/2017] [Accepted: 09/28/2017] [Indexed: 11/22/2022]
Abstract
The neurofilament light polypeptide (NEFL) gene mutations cause mainly autosomal dominant Charcot-Marie-Tooth disease (CMT) and rarely the recessive forms of CMT. We describe a 13-year-old girl born of consanguineous parents. She presented an early onset of gait disturbance with weakness in lower extremities during the first decade. Nerve conduction velocity of median nerve was 24 m/s and amplitude of compound muscle action potential was 2.2 mV. Sensory nerve action potential was not recordable. Sural nerve biopsy showed severe loss of the large myelinated fibers. Electron microscopy revealed absence of neurofilaments in both myelinated and unmyelinated axons. Genetic analysis identified a novel homozygous nonsense mutation in NEFL c.487G>T (p.Glu163*) as the potential causative mutation in this patient. Our study expands the mutation spectrum of NEFL-related neuropathy.
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47
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Adriaenssens E, Geuens T, Baets J, Echaniz-Laguna A, Timmerman V. Novel insights in the disease biology of mutant small heat shock proteins in neuromuscular diseases. Brain 2017; 140:2541-2549. [PMID: 28969372 DOI: 10.1093/brain/awx187] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2017] [Accepted: 06/11/2017] [Indexed: 12/12/2022] Open
Abstract
Small heat shock proteins are molecular chaperones that exert diverse cellular functions. To date, mutations in the coding regions of HSPB1 (Hsp27) and HSPB8 (Hsp22) were reported to cause distal hereditary motor neuropathy and Charcot-Marie-Tooth disease. Recently, the clinical spectrum of HSPB1 and HSPB8 mutations was expanded to also include myopathies. Here we provide an update on the molecular genetics and biology of small heat shock protein mutations in neuromuscular diseases.
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Affiliation(s)
- Elias Adriaenssens
- Peripheral Neuropathy Research Group, Institute Born Bunge, University of Antwerp, Antwerpen, Belgium
| | - Thomas Geuens
- Peripheral Neuropathy Research Group, Institute Born Bunge, University of Antwerp, Antwerpen, Belgium
| | - Jonathan Baets
- Neurogenetics Group, Center for Molecular Neurology, VIB, Antwerpen, Belgium.,Laboratory of Neuromuscular Pathology, Institute Born-Bunge, University of Antwerp, Antwerpen, Belgium.,Neuromuscular Reference Centre, Department of Neurology, Antwerp University Hospital, Antwerpen, Belgium
| | - Andoni Echaniz-Laguna
- Department of Neurology, Neuromuscular Disease Center (CERNEST), Strasbourg University Hospital, Strasbourg, France
| | - Vincent Timmerman
- Peripheral Neuropathy Research Group, Institute Born Bunge, University of Antwerp, Antwerpen, Belgium
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48
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Meyer-Schuman R, Antonellis A. Emerging mechanisms of aminoacyl-tRNA synthetase mutations in recessive and dominant human disease. Hum Mol Genet 2017; 26:R114-R127. [PMID: 28633377 PMCID: PMC5886470 DOI: 10.1093/hmg/ddx231] [Citation(s) in RCA: 112] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2017] [Revised: 06/09/2017] [Accepted: 06/12/2017] [Indexed: 12/29/2022] Open
Abstract
Aminoacyl-tRNA synthetases (ARSs) are responsible for charging amino acids to cognate tRNA molecules, which is the essential first step of protein translation. Interestingly, mutations in genes encoding ARS enzymes have been implicated in a broad spectrum of human inherited diseases. Bi-allelic mutations in ARSs typically cause severe, early-onset, recessive diseases that affect a wide range of tissues. The vast majority of these mutations show loss-of-function effects and impair protein translation. However, it is not clear how a subset cause tissue-specific phenotypes. In contrast, dominant ARS-mediated diseases specifically affect the peripheral nervous system-most commonly causing axonal peripheral neuropathy-and usually manifest later in life. These neuropathies are linked to heterozygosity for missense mutations in five ARS genes, which points to a shared mechanism of disease. However, it is not clear if a loss-of-function mechanism or a toxic gain-of-function mechanism is responsible for ARS-mediated neuropathy, or if a combination of these mechanisms operate on a mutation-specific basis. Here, we review our current understanding of recessive and dominant ARS-mediated disease. We also propose future directions for defining the molecular mechanisms of ARS mutations toward designing therapies for affected patient populations.
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Affiliation(s)
- Rebecca Meyer-Schuman
- Department of Human Genetics, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | - Anthony Antonellis
- Department of Human Genetics, University of Michigan Medical School, Ann Arbor, MI 48109, USA
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49
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Similar clinical, pathological, and genetic features in Chinese patients with autosomal recessive and dominant Charcot–Marie–Tooth disease type 2K. Neuromuscul Disord 2017; 27:760-765. [DOI: 10.1016/j.nmd.2017.04.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2016] [Revised: 03/24/2017] [Accepted: 04/04/2017] [Indexed: 11/22/2022]
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50
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Horga A, Laurà M, Jaunmuktane Z, Jerath NU, Gonzalez MA, Polke JM, Poh R, Blake JC, Liu YT, Wiethoff S, Bettencourt C, Lunn MP, Manji H, Hanna MG, Houlden H, Brandner S, Züchner S, Shy M, Reilly MM. Genetic and clinical characteristics of NEFL-related Charcot-Marie-Tooth disease. J Neurol Neurosurg Psychiatry 2017; 88:575-585. [PMID: 28501821 PMCID: PMC5580821 DOI: 10.1136/jnnp-2016-315077] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/13/2016] [Revised: 01/20/2017] [Accepted: 01/24/2017] [Indexed: 11/03/2022]
Abstract
OBJECTIVES To analyse and describe the clinical and genetic spectrum of Charcot-Marie-Tooth disease (CMT) caused by mutations in the neurofilament light polypeptide gene (NEFL). METHODS Combined analysis of newly identified patients with NEFL-related CMT and all previously reported cases from the literature. RESULTS Five new unrelated patients with CMT carrying the NEFL mutations P8R and N98S and the novel variant L311P were identified. Combined data from these cases and 62 kindreds from the literature revealed four common mutations (P8R, P22S, N98S and E396K) and three mutational hotspots accounting for 37 (55%) and 50 (75%) kindreds, respectively. Eight patients had de novo mutations. Loss of large-myelinated fibres was a uniform feature in a total of 21 sural nerve biopsies and 'onion bulb' formations and/or thin myelin sheaths were observed in 14 (67%) of them. The neurophysiological phenotype was broad but most patients with E90K and N98S had upper limb motor conduction velocities <38 m/s. Age of onset was ≤3 years in 25 cases. Pyramidal tract signs were described in 13 patients and 7 patients were initially diagnosed with or tested for inherited ataxia. Patients with E90K and N98S frequently presented before age 3 years and developed hearing loss or other neurological features including ataxia and/or cerebellar atrophy on brain MRI. CONCLUSIONS NEFL-related CMT is clinically and genetically heterogeneous. Based on this study, however, we propose mutational hotspots and relevant clinical-genetic associations that may be helpful in the evaluation of NEFL sequence variants and the differential diagnosis with other forms of CMT.
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Affiliation(s)
- Alejandro Horga
- MRC Centre for Neuromuscular Diseases, UCL Institute of Neurology, London, UK.,Department of Neurology, Hospital Clinico Universitario San Carlos, Madrid, Spain
| | - Matilde Laurà
- MRC Centre for Neuromuscular Diseases, UCL Institute of Neurology, London, UK.,UCL Institute of Neurology, MRC Centre for Neuromuscular Diseases, National Hospital for Neurology and Neurosurgery, London, UK
| | - Zane Jaunmuktane
- Division of Neuropathology and Department of Neurodegenerative Disease, The National Hospital for Neurology and Neurosurgery and UCL Institute of Neurology, London, UK
| | | | - Michael A Gonzalez
- Department of Human Genetics and Hussman Institute for Human Genomics, Miller School of Medicine, University of Miami, Miami, Florida, USA.,The Genesis Project Foundation, The Genesis Project Foundation, Miami, Florida, USA
| | - James M Polke
- Department of Neurogenetics, The National Hospital for Neurology and Neurosurgery and UCL Institute of Neurology, London, UK.,Neurogenetics Unit, National Hospital for Neurology and Neurosurgery, London, UK
| | - Roy Poh
- Department of Neurogenetics, The National Hospital for Neurology and Neurosurgery and UCL Institute of Neurology, London, UK
| | - Julian C Blake
- Department of Clinical Neurophysiology, National Hospital for Neurology and Neurosurgery (and Norfolk and Norwich University Hospital), London, UK
| | - Yo-Tsen Liu
- MRC Centre for Neuromuscular Diseases, UCL Institute of Neurology, London, UK.,Department of Neurology, Neurological Institute, Taipei Veterans General Hospital, Taipei, Taiwan
| | - Sarah Wiethoff
- Department of Molecular Neuroscience, UCL Institute of Neurology, London, UK
| | | | - Michael Pt Lunn
- Department of Neurology, National Hospital for Neurology and Neurosurgery, London, UK
| | - Hadi Manji
- MRC Centre for Neuromuscular Diseases, UCL Institute of Neurology, London, UK
| | - Michael G Hanna
- MRC Centre for Neuromuscular Diseases, UCL Institute of Neurology, London, UK
| | - Henry Houlden
- MRC Centre for Neuromuscular Diseases, UCL Institute of Neurology and National Hospital for Neurology and Neurosurgery, London, UK
| | - Sebastian Brandner
- Division of Neuropatholgoy, UCL Institute of Neurology and National Hospital for Neurology and Neurosurgery, London, UK
| | | | - Michael Shy
- Department of Neurology, University of Iowa, Iowa City, Iowa, USA.,Wayne State University, Michigan, Michigan, USA
| | - Mary M Reilly
- MRC Centre for Neuromuscular Diseases, UCL Institute of Neurology, London, UK.,MRC Centre for Neuromuscular Diseases, UCL Institute of Neurology and National Hospital for Neurology and Neurosurgery, London, UK
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