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Terkelsen T, Mikkelsen NS, Bak EN, Vad-Nielsen J, Blechingberg J, Weiss S, Drue SO, Andersen H, Andresen BS, Bak RO, Jensen UB. CRISPR activation to characterize splice-altering variants in easily accessible cells. Am J Hum Genet 2024; 111:309-322. [PMID: 38272032 PMCID: PMC10870130 DOI: 10.1016/j.ajhg.2023.12.024] [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: 07/10/2023] [Revised: 12/22/2023] [Accepted: 12/27/2023] [Indexed: 01/27/2024] Open
Abstract
Genetic variants that affect mRNA splicing are a major cause of hereditary disorders, but the spliceogenicity of variants is challenging to predict. RNA diagnostics of clinically accessible tissues enable rapid functional characterization of splice-altering variants within their natural genetic context. However, this analysis cannot be offered to all individuals as one in five human disease genes are not expressed in easily accessible cell types. To overcome this problem, we have used CRISPR activation (CRISPRa) based on a dCas9-VPR mRNA-based delivery platform to induce expression of the gene of interest in skin fibroblasts from individuals with suspected monogenic disorders. Using this ex vivo splicing assay, we characterized the splicing patterns associated with germline variants in the myelin protein zero gene (MPZ), which is exclusively expressed in Schwann cells of the peripheral nerves, and the spastin gene (SPAST), which is predominantly expressed in the central nervous system. After overnight incubation, CRISPRa strongly upregulated MPZ and SPAST transcription in skin fibroblasts, which enabled splice variant profiling using reverse transcription polymerase chain reaction, next-generation sequencing, and long-read sequencing. Our investigations show proof of principle of a promising genetic diagnostic tool that involves CRISPRa to activate gene expression in easily accessible cells to study the functional impact of genetic variants. The procedure is easy to perform in a diagnostic laboratory with equipment and reagents all readily available.
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Affiliation(s)
- Thorkild Terkelsen
- Department of Clinical Genetics, Aarhus University Hospital, Aarhus, Denmark; Department of Biomedicine, Aarhus University, Aarhus, Denmark.
| | | | - Ebbe Norskov Bak
- Department of Molecular Medicine, Aarhus University Hospital, Aarhus, Denmark
| | - Johan Vad-Nielsen
- Department of Molecular Medicine, Aarhus University Hospital, Aarhus, Denmark
| | - Jenny Blechingberg
- Department of Clinical Genetics, Aarhus University Hospital, Aarhus, Denmark
| | - Simone Weiss
- Department of Molecular Medicine, Aarhus University Hospital, Aarhus, Denmark
| | - Simon Opstrup Drue
- Department of Molecular Medicine, Aarhus University Hospital, Aarhus, Denmark
| | - Henning Andersen
- Department of Neurology, Aarhus University Hospital, Aarhus, Denmark
| | - Brage Storstein Andresen
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Odense, Denmark
| | - Rasmus O Bak
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | - Uffe Birk Jensen
- Department of Clinical Genetics, Aarhus University Hospital, Aarhus, Denmark; Department of Biomedicine, Aarhus University, Aarhus, Denmark.
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Gemignani F, Percesepe A, Gualandi F, Allegri I, Bellanova MF, Nuredini A, Saccani E, Ambrosini E, Barili V, Uliana V. Charcot-Marie-Tooth Disease with Myelin Protein Zero Mutation Presenting as Painful, Predominant Small-Fiber Neuropathy. Int J Mol Sci 2024; 25:1654. [PMID: 38338934 PMCID: PMC10855578 DOI: 10.3390/ijms25031654] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2023] [Revised: 01/16/2024] [Accepted: 01/20/2024] [Indexed: 02/12/2024] Open
Abstract
Charcot-Marie-Tooth disease (CMT) rarely presents with painful symptoms, which mainly occur in association with myelin protein zero (MPZ) gene mutations. We aimed to further characterize the features of painful neuropathic phenotypes in MPZ-related CMT. We report on a 58-year-old woman with a longstanding history of intermittent migrant pain and dysesthesias. Examination showed minimal clinical signs of neuropathy along with mild changes upon electroneurographic examination, consistent with an intermediate pattern, and small-fiber loss upon skin biopsy. Genetic testing identified the heterozygous variant p.Trp101Ter in MPZ. We identified another 20 CMT patients in the literature who presented with neuropathic pain as a main feature in association with MPZ mutations, mostly in the extracellular MPZ domain; the majority of these patients showed late onset (14/20), with motor-nerve-conduction velocities predominantly in the intermediate range (12/20). It is hypothesized that some MPZ mutations could manifest with, or predispose to, neuropathic pain. However, the mechanisms linking MPZ mutations and pain-generating nerve changes are unclear, as are the possible role of modifier factors. This peculiar CMT presentation may be diagnostically misleading, as it is suggestive of an acquired pain syndrome rather than of an inherited neuropathy.
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Affiliation(s)
- Franco Gemignani
- European Diagnostic Center, Polyclinic Dalla Rosa Prati, 43126 Parma, Italy
| | - Antonio Percesepe
- Medical Genetics Unit, Department of Medicine and Surgery, University of Parma, 43126 Parma, Italy
- Medical Genetics Unit, University Hospital of Parma, 43126 Parma, Italy
| | - Francesca Gualandi
- Medical Genetics Unit, Department of Mother and Child, Sant’Anna University Hospital of Ferrara, 44121 Ferrara, Italy
| | - Isabella Allegri
- Neurology Unit, Department of Specialized Medicine, University Hospital of Parma, 43126 Parma, Italy
| | - Maria Federica Bellanova
- Laboratory of Neuromuscular Histopathology, Department of Medicine and Surgery, University of Parma, 43126 Parma, Italy
| | - Andi Nuredini
- Neurology Unit, Department of Medicine and Surgery, University of Parma, 43126 Parma, Italy
| | - Elena Saccani
- Neurology Unit, Department of Specialized Medicine, University Hospital of Parma, 43126 Parma, Italy
| | - Enrico Ambrosini
- Medical Genetics Unit, University Hospital of Parma, 43126 Parma, Italy
| | - Valeria Barili
- Medical Genetics Unit, Department of Medicine and Surgery, University of Parma, 43126 Parma, Italy
| | - Vera Uliana
- Medical Genetics Unit, University Hospital of Parma, 43126 Parma, Italy
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Bremer J, Meinhardt A, Katona I, Senderek J, Kämmerer‐Gassler EK, Roos A, Ferbert A, Schröder JM, Nikolin S, Nolte K, Sellhaus B, Popzhelyazkova K, Tacke F, Schara‐Schmidt U, Neuen‐Jacob E, de Groote CC, de Jonghe P, Timmerman V, Baets J, Weis J. Myelin protein zero mutation-related hereditary neuropathies: Neuropathological insight from a new nerve biopsy cohort. Brain Pathol 2024; 34:e13200. [PMID: 37581289 PMCID: PMC10711263 DOI: 10.1111/bpa.13200] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Accepted: 07/19/2023] [Indexed: 08/16/2023] Open
Abstract
Myelin protein zero (MPZ/P0) is a major structural protein of peripheral nerve myelin. Disease-associated variants in the MPZ gene cause a wide phenotypic spectrum of inherited peripheral neuropathies. Previous nerve biopsy studies showed evidence for subtype-specific morphological features. Here, we aimed at enhancing the understanding of these subtype-specific features and pathophysiological aspects of MPZ neuropathies. We examined archival material from two Central European centers and systematically determined genetic, clinical, and neuropathological features of 21 patients with MPZ mutations compared to 16 controls. Cases were grouped based on nerve conduction data into congenital hypomyelinating neuropathy (CHN; n = 2), demyelinating Charcot-Marie-Tooth (CMT type 1; n = 11), intermediate (CMTi; n = 3), and axonal CMT (type 2; n = 5). Six cases had combined muscle and nerve biopsies and one underwent autopsy. We detected four MPZ gene variants not previously described in patients with neuropathy. Light and electron microscopy of nerve biopsies confirmed fewer myelinated fibers, more onion bulbs and reduced regeneration in demyelinating CMT1 compared to CMT2/CMTi. In addition, we observed significantly more denervated Schwann cells, more collagen pockets, fewer unmyelinated axons per Schwann cell unit and a higher density of Schwann cell nuclei in CMT1 compared to CMT2/CMTi. CHN was characterized by basal lamina onion bulb formation, a further increase in Schwann cell density and hypomyelination. Most late onset axonal neuropathy patients showed microangiopathy. In the autopsy case, we observed prominent neuromatous hyperinnervation of the spinal meninges. In four of the six muscle biopsies, we found marked structural mitochondrial abnormalities. These results show that MPZ alterations not only affect myelinated nerve fibers, leading to either primarily demyelinating or axonal changes, but also affect non-myelinated nerve fibers. The autopsy case offers insight into spinal nerve root pathology in MPZ neuropathy. Finally, our data suggest a peculiar association of MPZ mutations with mitochondrial alterations in muscle.
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Affiliation(s)
- Juliane Bremer
- Institute of NeuropathologyRWTH Aachen University HospitalAachenGermany
| | - Axel Meinhardt
- Institute of NeuropathologyRWTH Aachen University HospitalAachenGermany
| | - Istvan Katona
- Institute of NeuropathologyRWTH Aachen University HospitalAachenGermany
| | - Jan Senderek
- Friedrich Baur Institute at the Department of NeurologyUniversity Hospital, LMU MunichMunichGermany
| | | | - Andreas Roos
- Institute of NeuropathologyRWTH Aachen University HospitalAachenGermany
- Department of NeuropaediatricsUniversity of EssenEssenGermany
| | | | | | - Stefan Nikolin
- Institute of NeuropathologyRWTH Aachen University HospitalAachenGermany
| | - Kay Nolte
- Institute of NeuropathologyRWTH Aachen University HospitalAachenGermany
| | - Bernd Sellhaus
- Institute of NeuropathologyRWTH Aachen University HospitalAachenGermany
| | | | - Frank Tacke
- Department of Hepatology and Gastroenterology, Charité—Universitätsmedizin BerlinCampus Virchow‐Klinikum (CVK) and Campus Charité Mitte (CCM)BerlinGermany
| | | | - Eva Neuen‐Jacob
- Department of NeuropathologyUniversity Hospital, Heinrich‐Heine University DüsseldorfDüsseldorfGermany
| | - Chantal Ceuterick de Groote
- Laboratory of Neuromuscular Pathology, Institute Born‐Bunge, and Translational Neurosciences, Faculty of MedicineUniversity of AntwerpBelgium
| | - Peter de Jonghe
- Laboratory of Neuromuscular Pathology, Institute Born‐Bunge, and Translational Neurosciences, Faculty of MedicineUniversity of AntwerpBelgium
- Department of NeurologyUniversity Hospital AntwerpAntwerpBelgium
| | - Vincent Timmerman
- Laboratory of Neuromuscular Pathology, Institute Born‐Bunge, and Translational Neurosciences, Faculty of MedicineUniversity of AntwerpBelgium
- Peripheral Neuropathy Research Group, Department of Biomedical SciencesUniversity of AntwerpAntwerpBelgium
| | - Jonathan Baets
- Laboratory of Neuromuscular Pathology, Institute Born‐Bunge, and Translational Neurosciences, Faculty of MedicineUniversity of AntwerpBelgium
- Department of NeurologyUniversity Hospital AntwerpAntwerpBelgium
| | - Joachim Weis
- Institute of NeuropathologyRWTH Aachen University HospitalAachenGermany
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Kontogeorgiou Z, Kartanou C, Rentzos M, Kokotis P, Anagnostou E, Zambelis T, Chroni E, Dinopoulos A, Panas M, Koutsis G, Karadima G. Mutational screening of Greek patients with axonal Charcot-Marie-Tooth disease using targeted next-generation sequencing: Clinical and molecular spectrum delineation. J Peripher Nerv Syst 2023; 28:642-650. [PMID: 37747677 DOI: 10.1111/jns.12598] [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: 08/02/2023] [Revised: 09/04/2023] [Accepted: 09/22/2023] [Indexed: 09/26/2023]
Abstract
BACKGROUND AND AIMS Axonal forms of Charcot-Marie-Tooth disease (CMT) are classified as CMT2, distal hereditary motor neuropathy (dHMN) or hereditary sensory neuropathy (HSN) and can be caused by mutations in over 100 genes. We presently aimed to investigate for the first time the genetic landscape of axonal CMT in the Greek population. METHODS Sixty index patients with CMT2, dHMN or HSN were screened by a combination of Sanger sequencing (GJB1) and next-generation sequencing custom-made gene panel covering 24 commonly mutated genes in axonal CMT. RESULTS Overall, 20 variants classified as pathogenic or likely pathogenic were identified in heterozygous state in 20 index cases, representing 33.3% of the cohort. Of these, 14 were known pathogenic/likely pathogenic and six were designated as such according to ACMG classification, after in silico evaluation, testing for familial segregation and further literature review. The most frequently involved genes were GJB1 (11.7%), MPZ (5%) and MFN2 (5%), followed by DNM2 (3.3%) and LRSAM1 (3.3%). Single cases were identified with mutations in BSCL2, HSPB1 and GDAP1. INTERPRETATION A wide phenotypic variability in terms of severity and age of onset was noted. Given the limited number of genes tested, the diagnostic yield of the present panel compares favourably with studies in other European populations. Our study delineates the genetic and phenotypic variability of inherited axonal neuropathies in the Greek population and contributes to the pathogenicity characterization of further variants linked to axonal neuropathies.
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Affiliation(s)
- Zoi Kontogeorgiou
- Neurogenetics Unit, 1st Department of Neurology, Eginition Hospital, School of Medicine, National and Kapodistrian University of Athens, Athens, Greece
| | - Chrisoula Kartanou
- Neurogenetics Unit, 1st Department of Neurology, Eginition Hospital, School of Medicine, National and Kapodistrian University of Athens, Athens, Greece
| | - Michail Rentzos
- 1st Department of Neurology, Eginition Hospital, School of Medicine, National and Kapodistrian University of Athens, Athens, Greece
| | - Panagiotis Kokotis
- Clinical Neurophysiology Unit, 1st Department of Neurology, Eginition Hospital, School of Medicine, National and Kapodistrian University of Athens, Athens, Greece
| | - Evangelos Anagnostou
- Clinical Neurophysiology Unit, 1st Department of Neurology, Eginition Hospital, School of Medicine, National and Kapodistrian University of Athens, Athens, Greece
| | - Thomas Zambelis
- Clinical Neurophysiology Unit, 1st Department of Neurology, Eginition Hospital, School of Medicine, National and Kapodistrian University of Athens, Athens, Greece
| | - Elisabeth Chroni
- Department of Neurology, School of Medicine, University of Patras, Patras, Greece
| | - Argyris Dinopoulos
- 3rd Department of Pediatrics, General Hospital of Athens Attikon, Medical School, National and Kapodistrian University of Athens, Athens, Greece
| | - Marios Panas
- Neurogenetics Unit, 1st Department of Neurology, Eginition Hospital, School of Medicine, National and Kapodistrian University of Athens, Athens, Greece
| | - Georgios Koutsis
- Neurogenetics Unit, 1st Department of Neurology, Eginition Hospital, School of Medicine, National and Kapodistrian University of Athens, Athens, Greece
| | - Georgia Karadima
- Neurogenetics Unit, 1st Department of Neurology, Eginition Hospital, School of Medicine, National and Kapodistrian University of Athens, Athens, Greece
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5
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Sakakura M, Tanabe M, Mori M, Takahashi H, Mio K. Structural bases for the Charcot-Marie-Tooth disease induced by single amino acid substitutions of myelin protein zero. Structure 2023; 31:1452-1462.e4. [PMID: 37699394 DOI: 10.1016/j.str.2023.08.016] [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: 05/08/2023] [Revised: 07/28/2023] [Accepted: 08/17/2023] [Indexed: 09/14/2023]
Abstract
Myelin protein zero (MPZ or P0) is a transmembrane protein which functions to glue membranes in peripheral myelin. Inter-membrane adhesion is mediated by homophilic interactions between the extracellular domains (ECDs) of MPZ. Single amino acid substitutions in an ECD cause demyelinating neuropathy, Charcot-Marie-Tooth disease (CMT), with unknown mechanisms. In this study, by using a novel assay system "nanomyelin," we revealed that a stacked-rings-like ECD-8-mer is responsible for membrane adhesion. Two inter-ECD interactions, cis and head-to-head, are essential to constituting the 8-mer and to gluing the membranes. This result was reinforced by the observation that the CMT-related N87H substitution at the cis interface abolished membrane-adhesion activity. In contrast, the CMT-related D32G and E68V variants retained membrane-stacking activity, whereas their thermal stability was lower than that of the WT. Reduced thermal stability may lead to impairment of the long-term stability of ECD and the layered membranes of myelin.
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Affiliation(s)
- Masayoshi Sakakura
- Graduate School of Medical Life Science, Yokohama City University, Yokohama 230-0045, Japan.
| | - Mikio Tanabe
- Structural Biology Research Center, Institute of Materials Structure Science, KEK/High Energy Accelerator Research Organization, Tsukuba 305-0801, Japan
| | - Masaki Mori
- Graduate School of Medical Life Science, Yokohama City University, Yokohama 230-0045, Japan
| | - Hideo Takahashi
- Graduate School of Medical Life Science, Yokohama City University, Yokohama 230-0045, Japan
| | - Kazuhiro Mio
- Graduate School of Medical Life Science, Yokohama City University, Yokohama 230-0045, Japan; AIST-UTokyo Advanced Operando-Measurement Technology Open Innovation Laboratory (OPERANDO-OIL), National Institute of Advanced Industrial Science and Technology (AIST), Kashiwa 277-0882, Japan
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6
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Cavaletti G, Forsey K, Alberti P. Toxic medications in Charcot-Marie-Tooth patients: A systematic review. J Peripher Nerv Syst 2023; 28:295-307. [PMID: 37249082 DOI: 10.1111/jns.12566] [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: 04/26/2023] [Revised: 05/23/2023] [Accepted: 05/26/2023] [Indexed: 05/31/2023]
Abstract
BACKGROUND AND AIMS Several widely used medications, with a relevant efficacy profile, are toxic to the peripheral nervous system and an even larger number of agents are suspected to be neurotoxic. There are concerns about the use of these drugs in patients with Charcot-Marie-Tooth disease (CMT), a hereditary motor and sensory neuropathy. This review provides evidence-based updated recommendations on this clinically relevant topic. METHODS A systematic review of the available studies/reports written in English was performed from July to September 2022 including in the search string all reported putative neurotoxic drugs. RESULTS The results of our systematic review provide evidence-based support for the statement that use of vincristine, and possibly paclitaxel, can occasionally induce an atypical, and more severe, course of drug-related peripheral neurotoxicity in CMT patients. It is therefore reasonable to recommend caution in the use of these compounds in CMT patients. However, no convincing evidence for a similar recommendation could be found for all other drugs. INTERPRETATION It is important that patients with CMT are not denied effective treatments that may prolong life expectancy for cancer or improve their health status if affected by non-oncological diseases. Accurate monitoring of peripheral nerve function in CMT patients treated with any neurotoxic agent remains mandatory to detect the earliest signs of neuropathy worsening and atypical clinical courses. Neurologists monitoring CMT patients as part of their normal care package or for natural history studies should keep detailed records of exposures to neurotoxic medications and support reporting of accelerated neuropathy progression if observed.
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Affiliation(s)
- Guido Cavaletti
- Experimental Neurology Unit, School of Medicine and Surgery, University of Milano-Bicocca, Monza, Italy
- Fondazione IRCCS San Gerardo dei Tintori, Monza, Italy
| | | | - Paola Alberti
- Experimental Neurology Unit, School of Medicine and Surgery, University of Milano-Bicocca, Monza, Italy
- Fondazione IRCCS San Gerardo dei Tintori, Monza, Italy
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7
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Cook S, Hooser BN, Williams DC, Kortz G, Aleman M, Minor K, Koziol J, Friedenberg SG, Cullen JN, Shelton GD, Ekenstedt KJ. Canine models of Charcot-Marie-Tooth: MTMR2, MPZ, and SH3TC2 variants in golden retrievers with congenital hypomyelinating polyneuropathy. Neuromuscul Disord 2023; 33:677-691. [PMID: 37400349 PMCID: PMC10530471 DOI: 10.1016/j.nmd.2023.06.007] [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: 03/23/2023] [Revised: 06/06/2023] [Accepted: 06/19/2023] [Indexed: 07/05/2023]
Abstract
Congenital hypomyelinating polyneuropathy (HPN) restricted to the peripheral nervous system was reported in 1989 in two Golden Retriever (GR) littermates. Recently, four additional cases of congenital HPN in young, unrelated GRs were diagnosed via neurological examination, electrodiagnostic evaluation, and peripheral nerve pathology. Whole-genome sequencing was performed on all four GRs, and variants from each dog were compared to variants found across >1,000 other dogs, all presumably unaffected with HPN. Likely causative variants were identified for each HPN-affected GR. Two cases shared a homozygous splice donor site variant in MTMR2, with a stop codon introduced within six codons following the inclusion of the intron. One case had a heterozygous MPZ isoleucine to threonine substitution. The last case had a homozygous SH3TC2 nonsense variant predicted to truncate approximately one-half of the protein. Haplotype analysis using 524 GR established the novelty of the identified variants. Each variant occurs within genes that are associated with the human Charcot-Marie-Tooth (CMT) group of heterogeneous diseases, affecting the peripheral nervous system. Testing a large GR population (n = >200) did not identify any dogs with these variants. Although these variants are rare within the general GR population, breeders should be cautious to avoid propagating these alleles.
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Affiliation(s)
- Shawna Cook
- Department of Basic Medical Sciences, College of Veterinary Medicine, Purdue University, West Lafayette, IN, USA.
| | - Blair N Hooser
- Department of Basic Medical Sciences, College of Veterinary Medicine, Purdue University, West Lafayette, IN, USA
| | - D Colette Williams
- The William R. Pritchard Veterinary Medical Teaching Hospital, University of California, Davis, Davis, CA, USA
| | - Gregg Kortz
- VCA Sacramento Veterinary Referral Center, Sacramento CA, USA
| | - Monica Aleman
- The William R. Pritchard Veterinary Medical Teaching Hospital, University of California, Davis, Davis, CA, USA
| | - Katie Minor
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine, University of Minnesota, Saint Paul, MN, USA
| | - Jennifer Koziol
- School of Veterinary Medicine, Texas Tech University, Amarillo, TX, USA
| | - Steven G Friedenberg
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine, University of Minnesota, Saint Paul, MN, USA
| | - Jonah N Cullen
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine, University of Minnesota, Saint Paul, MN, USA
| | - G Diane Shelton
- Department of Pathology, School of Medicine, University of California San Diego, La Jolla, CA, USA
| | - Kari J Ekenstedt
- Department of Basic Medical Sciences, College of Veterinary Medicine, Purdue University, West Lafayette, IN, USA
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Okamoto Y, Takashima H. The Current State of Charcot-Marie-Tooth Disease Treatment. Genes (Basel) 2023; 14:1391. [PMID: 37510296 PMCID: PMC10379063 DOI: 10.3390/genes14071391] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2023] [Revised: 06/20/2023] [Accepted: 06/29/2023] [Indexed: 07/30/2023] Open
Abstract
Charcot-Marie-Tooth disease (CMT) and associated neuropathies are the most predominant genetically transmitted neuromuscular conditions; however, effective pharmacological treatments have not established. The extensive genetic heterogeneity of CMT, which impacts the peripheral nerves and causes lifelong disability, presents a significant barrier to the development of comprehensive treatments. An estimated 100 loci within the human genome are linked to various forms of CMT and its related inherited neuropathies. This review delves into prospective therapeutic strategies used for the most frequently encountered CMT variants, namely CMT1A, CMT1B, CMTX1, and CMT2A. Compounds such as PXT3003, which are being clinically and preclinically investigated, and a broad array of therapeutic agents and their corresponding mechanisms are discussed. Furthermore, the progress in established gene therapy techniques, including gene replacement via viral vectors, exon skipping using antisense oligonucleotides, splicing modification, and gene knockdown, are appraised. Each of these gene therapies has the potential for substantial advancements in future research.
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Affiliation(s)
- Yuji Okamoto
- Department of Neurology and Geriatrics, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima 890-8544, Japan
- Department of Physical Therapy, School of Health Sciences, Faculty of Medicine, Kagoshima University, Kagoshima 890-8544, Japan
| | - Hiroshi Takashima
- Department of Neurology and Geriatrics, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima 890-8544, Japan
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Iyer VG, Shields LB, Zhang YP, Shields CB. Clinical Features of a Newly Described Mutation of Myelin Protein Zero in a Family. Cureus 2023; 15:e39884. [PMID: 37404437 PMCID: PMC10315180 DOI: 10.7759/cureus.39884] [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] [Accepted: 05/25/2023] [Indexed: 07/06/2023] Open
Abstract
Charcot-Marie-Tooth (CMT) disease is the most common hereditary neuropathy. Duplication of the peripheral myelin protein-22 (PMP22) gene is the most frequent genetic abnormality in CMT disease. Although rare compared to PMP22 gene mutations, many different myelin protein zero (MPZ) gene mutations have been described in patients with CMT disease. MPZ gene mutations are known to cause hereditary neuropathies with heterogenous phenotypes ranging from early-onset severe demyelinating to adult-onset axonal forms. MPZ, the major protein component of peripheral nerve myelin, is important for myelin compaction. We report a family in which a mother and her son, both with adult-onset CMT disease, showed a newly described mutation p.Glu37Lys of the MPZ gene. The clinical features of the mother provided insight into the progression of the disease over decades, while features in the early stage of the disease could be studied in the son. Clinical, electrodiagnostic, and sonographic findings are described in the early and late stages of the disease. The MPZ gene mutation p.Glu37Lys is associated with clinical features of a progressive axonal type of adult-onset CMT disease.
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Affiliation(s)
| | - Lisa B Shields
- Norton Neuroscience Institute, Norton Healthcare, Louisville, USA
| | - Yi Ping Zhang
- Norton Neuroscience Institute, Norton Healthcare, Louisville, USA
| | - Christopher B Shields
- Norton Neuroscience Institute, Norton Healthcare, Louisville, USA
- Department of Neurological Surgery, University of Louisville School of Medicine, Louisville, USA
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10
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Lei L, Xiaobo L, Zhiqiang L, Yongzhi X, Shunxiang H, Huadong Z, Beisha T, Ruxu Z. Genotype-phenotype characteristics and baseline natural history of Chinese myelin protein zero gene related neuropathy patients. Eur J Neurol 2023; 30:1069-1079. [PMID: 36692866 DOI: 10.1111/ene.15700] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Revised: 12/24/2022] [Accepted: 12/30/2022] [Indexed: 01/25/2023]
Abstract
BACKGROUND AND PURPOSE The aim was to characterize the phenotypic and genotypic features of myelin protein zero (MPZ) related neuropathy and provide baseline data for longitudinal natural history studies or drug clinical trials. METHOD Clinical, neurophysiological and genetic data of 37 neuropathy patients with MPZ mutations were retrospectively collected. RESULTS Nineteen different MPZ mutations in 23 unrelated neuropathy families were detected, and the frequency of MPZ mutations was 5.84% in total. Mutations c.103_104InsTGGTTTACACCG, c.513dupG, c.521_557del and c.696_699delCAGT had not been reported previously. Hot spot mutation p.Thr124Met was detected in four unrelated families, and seven patients carried de novo mutations. The onset age indicated a bimodal distribution: prominent clustering in the first and fourth decades. The infantile-onset group included 12 families, the childhood-onset group consisted of two families and the adult-onset group included nine families. The Charcot-Marie-Tooth Disease Neuropathy Score ranged from 3 to 25 with a mean value of 15.85 ± 5.88. Mutations that changed the cysteine residue (p.Arg98Cys, p.Cys127Trp, p.Ser140Cys and p.Cys127Arg) in the extracellular region were more likely to cause severe early-onset Charcot-Marie-Tooth disease type 1B (CMT1B) or Dejerine-Sottas syndrome. Nonsense-mediated mRNA decay mutations p.Asp35delInsVVYTD, p.Leu174Argfs*66 and p.Leu172Alafs*63 were related to severe infantile-onset CMT1B or Dejerine-Sottas syndrome; however, mutation p.Val232Valfs*19 was associated with a relatively milder childhood-onset CMT1 phenotype. CONCLUSION Four novel MPZ mutations are reported that expand the genetic spectrum. De novo mutations accounted for 30.4% and were most related to a severe infantile-onset phenotype. Genetic and clinical data from this cohort will provide the baseline data necessary for clinical trials and natural history studies.
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Affiliation(s)
- Liu Lei
- Health Management Center, Third Xiangya Hospital, Central South University, Changsha, China
| | - Li Xiaobo
- Department of Neurology, Third Xiangya Hospital, Central South University, Changsha, China
| | - Lin Zhiqiang
- Department of Neurology, Third Xiangya Hospital, Central South University, Changsha, China
| | - Xie Yongzhi
- Department of Neurology, Third Xiangya Hospital, Central South University, Changsha, China
| | - Huang Shunxiang
- Department of Neurology, Third Xiangya Hospital, Central South University, Changsha, China
| | - Zhao Huadong
- Department of Neurology, Third Xiangya Hospital, Central South University, Changsha, China
| | - Tang Beisha
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, China
| | - Zhang Ruxu
- Department of Neurology, Third Xiangya Hospital, Central South University, Changsha, China
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11
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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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12
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Lupski JR. Biology in balance: human diploid genome integrity, gene dosage, and genomic medicine. Trends Genet 2022; 38:554-571. [PMID: 35450748 DOI: 10.1016/j.tig.2022.03.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2021] [Revised: 02/28/2022] [Accepted: 03/01/2022] [Indexed: 01/01/2023]
Abstract
The path to completion of the functional annotation of the haploid human genome reference build, exploration of the clan genomics hypothesis, understanding human gene and genome functional biology, and gene genome and organismal evolution, is in reach.
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Affiliation(s)
- James R Lupski
- Genetics & Genomics, Baylor College of Medicine and Texas Children's Hospital, Houston, TX 77030, USA.
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13
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Concomitant MPZ and MFN2 Gene Variants and Charcot Marie Tooth Disease in a Boy: Clinical and Genetic Analysis—Literature Review. Case Rep Pediatr 2022; 2022:3793226. [PMID: 35449525 PMCID: PMC9017559 DOI: 10.1155/2022/3793226] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2021] [Revised: 03/31/2022] [Accepted: 04/01/2022] [Indexed: 12/04/2022] Open
Abstract
Charcot- Marie- Tooth (CMT) disease includes a group of clinically and genetically heterogeneous neuropathic disorders with an estimated frequency of 1 on 2.500 individuals. CMTs are differently classified according to the age of onset, type of inheritance, and type of inheritance plus clinical features. For these disorders, more than 100 genes have been implicated as causal factors, with mutations in the PMP22 being one of the most common. The demyelinating type (CMT1) affects more than 30% of the CMTs patients and manifests with motor and sensory dysfunctions of the peripheral nervous system mainly starting with slow progressive weakness of the lower extremities. We report here a 12 year- old boy presenting with typical features of CMT1 type, hearing impairment, and inguinal hernia who at the next-generation sequence analysis displayed a concomitant presence of two variants: the c.233 C>T p.Ser 78Leu of the MPZ gene (NM_000530.6) characterized as pathogenetic and the c.1403 G>A p.Arg 468His of the MFN2 gene (NM_014874.3) characterized as VUS. Concomitant variant mutations in CMTs have been uncommonly reported. The role of these gene mutations on the clinical expression and a literature review on this topic is discussed.
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14
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Elderly patients with suspected Charcot-Marie-Tooth disease should be tested for the TTR gene for effective treatments. J Hum Genet 2022; 67:353-362. [PMID: 35027655 DOI: 10.1038/s10038-021-01005-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Revised: 11/30/2021] [Accepted: 12/03/2021] [Indexed: 01/23/2023]
Abstract
BACKGROUND AND AIMS Some hereditary transthyretin (ATTRv) amyloidosis patients are misdiagnosed as Charcot-Marie-Tooth disease (CMT) at onset. We assess the findings to identify ATTRv amyloidosis among patients with suspected CMT to screen transthyretin gene variants for treatments. METHODS We assessed clinical, cerebrospinal fluid, and electrophysiological findings by comparing ATTRv amyloidosis patients with suspected CMT (n = 10) and CMT patients (n = 489). RESULTS The median (interquartile range) age at onset of neurological symptoms was 69 (64.2-70) years in the ATTRv amyloidosis vs 12 (5-37.2) years in CMT group (Mann-Whitney U, p < 0.01). The proportion of patients with initial sensory symptoms was 70% in the ATTRv amyloidosis group vs 7.1% in CMT group (Fisher's exact, p < 0.01). The proportion of patients with histories of suspected chronic inflammatory demyelinating polyneuropathy (CIDP) were 50% in the ATTRv amyloidosis group vs 8.7% in CMT group (Fisher's exact, p < .01). Other measures and outcomes were not different between the two groups. Five of the six patients with ATTRv amyloidosis received treatment and survived. INTERPRETATION For effective treatments, the transthyretin gene should be screened in patients with suspected CMT with old age at onset of neurological symptoms, initial sensory symptoms, and histories of suspected CIDP.
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15
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Chen B, Zhang Z, Chen N, Li W, Pan H, Wang X, Ren Y, Shi Y, Tai H, Niu S. Two Novel Myelin Protein Zero Mutations in a Group of Chinese Patients. Front Neurol 2021; 12:734515. [PMID: 34925207 PMCID: PMC8674198 DOI: 10.3389/fneur.2021.734515] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Accepted: 11/01/2021] [Indexed: 11/13/2022] Open
Abstract
Mutations in the myelin protein zero gene are responsible for the autosomal dominant Charcot-Marie-Tooth disease (CMT). We summarized the genetic and clinical features of six unrelated Chinese families and the genetic spectrum of Chinese patients with myelin protein zero (MPZ) mutations. Our study reports data from a group of Chinese patients consisting of five males and one female with the age of disease onset ranging from 16 to 55 years. The initial symptom in all the patients was the weakness of the lower limbs. Electrophysiological presentations suggested chronic progressive sensorimotor demyelinating polyneuropathy. Overall six mutations were identified in the cohort, including four known mutations [c.103G>T (p.D35Y), c.233C>T (p.S78L), c.293G>A (p.R98H), and c.449-1G>T], and two novel mutations [c.67+4A>G with a mild CMT1B phenotype, and (c.79delG) p.A27fs with a rapidly progressive CMT1B phenotype]. According to the literature review, there are 35 Chinese families with 28 different MPZ mutations. The MPZ mutational spectrum in Chinese patients is very heterogeneous and differs from that of Japanese and Korean individuals, although they do share several common hot spot mutations.
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Affiliation(s)
- Bin Chen
- Department of Neurology, Beijing Tiantan Hospital, Capital Medical University, Beijing, China.,China National Clinical Research Center for Neurological Diseases, Beijing, China
| | - Zaiqiang Zhang
- Department of Neurology, Beijing Tiantan Hospital, Capital Medical University, Beijing, China.,China National Clinical Research Center for Neurological Diseases, Beijing, China
| | - Na Chen
- Department of Neurology, Beijing Tiantan Hospital, Capital Medical University, Beijing, China.,China National Clinical Research Center for Neurological Diseases, Beijing, China
| | - Wei Li
- Department of Neurology, Beijing Tiantan Hospital, Capital Medical University, Beijing, China.,China National Clinical Research Center for Neurological Diseases, Beijing, China.,Monogenic Disease Diagnosis Center for Neurological Disorders, Precision Medicine Research Center for Neurological Disorders, Beijing, China
| | - Hua Pan
- Department of Neurology, Beijing Tiantan Hospital, Capital Medical University, Beijing, China.,China National Clinical Research Center for Neurological Diseases, Beijing, China
| | - Xingao Wang
- Department of Neurology, Beijing Tiantan Hospital, Capital Medical University, Beijing, China.,China National Clinical Research Center for Neurological Diseases, Beijing, China
| | - Yuting Ren
- Department of Neurology, Beijing Tiantan Hospital, Capital Medical University, Beijing, China.,China National Clinical Research Center for Neurological Diseases, Beijing, China
| | - Yuzhi Shi
- Department of Neurology, Beijing Tiantan Hospital, Capital Medical University, Beijing, China.,China National Clinical Research Center for Neurological Diseases, Beijing, China
| | - Hongfei Tai
- Department of Neurology, Beijing Tiantan Hospital, Capital Medical University, Beijing, China.,China National Clinical Research Center for Neurological Diseases, Beijing, China
| | - Songtao Niu
- Department of Neurology, Beijing Tiantan Hospital, Capital Medical University, Beijing, China.,China National Clinical Research Center for Neurological Diseases, Beijing, China
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16
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Villar-Quiles RN, Le VT, Leonard-Louis S, Trang NT, Huong NT, Laddada L, Francou B, Maisonobe T, Azzedine H, Stojkovic T. Leukoencephalopathy and conduction blocks in PLEKHG5-associated intermediate CMT disease. Neuromuscul Disord 2021; 31:756-764. [PMID: 34244018 DOI: 10.1016/j.nmd.2021.06.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2021] [Revised: 06/03/2021] [Accepted: 06/07/2021] [Indexed: 02/05/2023]
Abstract
Biallelic variants in PLEKHG5 have been reported so far associated with different clinical phenotypes including Lower motor neuron disease (LMND) [also known as distal hereditary motor neuropathies (dHMN or HMN) or distal spinal muscular atrophy (DSMA4)] and intermediate Charcot-Marie-Tooth disease (CMT). We report four patients from two families presenting with intermediate CMT and atypical clinical and para-clinical findings. Patients presented with predominant distal weakness with none or mild sensory involvement and remain ambulant at last examination (22-36 years). Nerve conduction studies revealed, in all patients, intermediate motor nerve conduction velocities, reduced sensory amplitudes and multiple conduction blocks in upper limbs, outside of typical nerve compression sites. CK levels were strikingly elevated (1611-3867 U/L). CSF protein content was mildly elevated in two patients. Diffuse bilateral white matter lesions were detected in one patient. Genetic analysis revealed three novel frameshift variants c.1835_1860del and c.2308del (family 1) and c.104del (family 2). PLEKHG5-associated disease ranges from pure motor phenotypes with predominantly proximal involvement to intermediate CMT with predominant distal motor involvement and mild sensory symptoms. Leukoencephalopathy, elevated CK levels and the presence of conduction blocks associated with intermediate velocities in NCS are part of the phenotype and may arise suspicion of the disease, thus avoiding misdiagnosis and unnecessary therapeutics in these patients.
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Affiliation(s)
- Rocio-Nur Villar-Quiles
- Reference Center for Neuromuscular Disorders, APHP(,) Pitié-Salpêtrière Hospital, Paris, France; Centre de Recherche en Myologie, GH Pitié-Salpêtrière, Sorbonne Université-Inserm UMRS974, Paris(,) France
| | - Van Thuy Le
- Neurology department, Hanoi Medical University Hospital, Hanoi, Viet Nam
| | - Sarah Leonard-Louis
- Reference Center for Neuromuscular Disorders, APHP(,) Pitié-Salpêtrière Hospital, Paris, France
| | - Nguyen Thi Trang
- Genetics department, Hanoi Medical University Hospital, Hanoi Medical University Hanoi, Viet Nam
| | - Nguyen Thi Huong
- Neurology department, Hanoi Medical University Hospital, Hanoi, Viet Nam; Vinmec International Hospital, Hanoi, Viet Nam
| | - Lilia Laddada
- Department of Molecular Genetics Pharmacogenomics and Hormonology, APHP, Bicêtre Hospital, Paris, France; Plateforme d'expertise maladies rares AP-HP. Université Paris-Saclay(,) Le Kremlin Bicêtre(,) France
| | - Bruno Francou
- Department of Molecular Genetics Pharmacogenomics and Hormonology, APHP, Bicêtre Hospital, Paris, France
| | - Thierry Maisonobe
- Department of Neurophysiology, APHP, Hôpital Pitié Salpêtrière, Paris, France
| | - Hamid Azzedine
- Department of Pathology and Neuropathology, AMC, Amsterdam, Netherlands
| | - Tanya Stojkovic
- Reference Center for Neuromuscular Disorders, APHP(,) Pitié-Salpêtrière Hospital, Paris, France; Centre de Recherche en Myologie, GH Pitié-Salpêtrière, Sorbonne Université-Inserm UMRS974, Paris(,) France.
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17
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Taniguchi T, Ando M, Okamoto Y, Yoshimura A, Higuchi Y, Hashiguchi A, Shiga K, Hayashida A, Hatano T, Ishiura H, Mitsui J, Hattori N, Mizuno T, Nakagawa M, Tsuji S, Takashima H. Genetic spectrum of Charcot-Marie-Tooth disease associated with myelin protein zero gene variants in Japan. Clin Genet 2020; 99:359-375. [PMID: 33179255 PMCID: PMC7898366 DOI: 10.1111/cge.13881] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2020] [Revised: 11/04/2020] [Accepted: 11/04/2020] [Indexed: 12/24/2022]
Abstract
We aimed to reveal the genetic features associated with MPZ variants in Japan. From April 2007 to August 2017, 64 patients with 23 reported MPZ variants and 21 patients with 17 novel MPZ variants were investigated retrospectively. Variation in MPZ variants and the pathogenicity of novel variants was examined according to the American College of Medical Genetics standards and guidelines. Age of onset, cranial nerve involvement, serum creatine kinase (CK), and cerebrospinal fluid (CSF) protein were also analyzed. We identified 64 CMT patients with reported MPZ variants. The common variants observed in Japan were different from those observed in other countries. We identified 11 novel pathogenic variants from 13 patients. Six novel MPZ variants in eight patients were classified as likely benign or uncertain significance. Cranial nerve involvement was confirmed in 20 patients. Of 30 patients in whom serum CK levels were evaluated, eight had elevated levels. Most of the patients had age of onset >20 years. In another subset of 30 patients, 18 had elevated CSF protein levels; four of these patients had spinal diseases and two had enlarged nerve root or cauda equina. Our results suggest genetic diversity across patients with MPZ variants.
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Affiliation(s)
- Takaki Taniguchi
- Department of Neurology and Geriatrics, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima, Japan
| | - Masahiro Ando
- 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.,Department of Physical Therapy, School of Health Sciences, Faculty of Medicine, Kagoshima University, Kagoshima, Japan
| | - Akiko Yoshimura
- 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
| | - Akihiro Hashiguchi
- Department of Neurology and Geriatrics, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima, Japan
| | - Kensuke Shiga
- Department of Neurology, Matsushita Memorial Hospital, Osaka, Japan.,Department of Neurology, Kyoto prefectural University of Medicine, Kyoto, Japan
| | - Arisa Hayashida
- Department of Neurology, Juntendo University School of Medicine, Tokyo, Japan
| | - Taku Hatano
- Department of Neurology, Juntendo University School of Medicine, Tokyo, Japan
| | - Hiroyuki Ishiura
- Department of Molecular Neurology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Jun Mitsui
- Department of Molecular Neurology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Nobutaka Hattori
- Department of Neurology, Juntendo University School of Medicine, Tokyo, Japan
| | - Toshiki Mizuno
- Department of Neurology, Kyoto prefectural University of Medicine, Kyoto, Japan
| | - Masanori Nakagawa
- Department of Neurology, Kyoto prefectural University of Medicine, Kyoto, Japan.,North Medical Center, Kyoto prefectural University of Medicine, Kyoto, Japan
| | - Shoji Tsuji
- Department of Molecular Neurology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.,Institute of Medical Genomics, International University of Health and Welfare, Chiba, Japan
| | - Hiroshi Takashima
- Department of Neurology and Geriatrics, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima, Japan
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