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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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A meta-analysis on the prevalence of Charcot-Marie-Tooth disease and related inherited peripheral neuropathies. J Neurol 2023; 270:2468-2482. [PMID: 36631678 DOI: 10.1007/s00415-023-11559-8] [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: 12/05/2022] [Revised: 01/01/2023] [Accepted: 01/02/2023] [Indexed: 01/13/2023]
Abstract
BACKGROUND Charcot-Marie-Tooth disease and related inherited peripheral neuropathies (CMT&RIPNs) brings great suffering and heavy burden to patients, but its global prevalence rates have not been well described. METHODS We searched major English and Chinese databases for studies reporting the prevalence of CMT&RIPNs from the establishment of the databases to September 26, 2022. Based on the age, gender, study design, study region, and disease subtype, the included studies were correspondingly synthesized for meta-analyses on the overall prevalence and/or the subgroup analyses by using pool arcsine transformed proportions in the random-effects model. RESULTS Of the finally included 31 studies, 21 studied the whole age population and various types of CMT&RIPNs, and the others reported specific disease subtype(s) or adult or non-adult populations. The pooled prevalence was 17.69/100,000 (95% CI 12.32-24.33) for the whole age population and significantly higher for CMT1 [10.61/100,000 (95% CI 7.06-14.64)] than for other subtypes (P' < 0.001). Without statistical significance, the prevalence seemed higher in those aged ≥ 16 or 18 years (21.02/100,000) than in those aged < 16 years (16.13/100,000), in males (22.50/100,000) than in females (17.95/100,000), and in Northern Europe (30.97/100,000) than in other regions. CONCLUSION CMT&RIPNs are relatively more prevalent as CMT1 in the disease subtypes, and probably prevalent in older ages, males, and Northern Europe. More studies on the epidemiological characteristics of CMT&RIPNs with well-defined diagnosis criteria are needed to improve the prevalence evaluation and to arouse more attention to health care support.
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Ghaffar A, Dehghani-Sanij AA, Xie SQ. A review of gait disorders in the elderly and neurological patients for robot-assisted training. Disabil Rehabil Assist Technol 2019; 15:256-270. [PMID: 30777472 DOI: 10.1080/17483107.2019.1568594] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Purpose: Ambulation is an important objective for people with pathological gaits. Exoskeleton robots can assist these people to complete their activities of daily living. There are exoskeletons that have been presented in literature to assist the elderly and other pathological gait users. This article presents a review of the degree of support required in the elderly and neurological gait disorders found in the human population. This will help to advance the design of robot-assisted devices based on the needs of the end users.Methods: The articles included in this review are collected from different databases including Science Direct, Springer Link, Web of Science, Medline and PubMed and with the purpose to investigate the gait parameters of elderly and neurological patients. Studies were included after considering the full texts and only those which focus on spatiotemporal, kinematic and kinetic gait parameters were selected as they are most relevant to the scope of this review. A systematic review and meta-analysis were conducted.Results: The meta-analysis report on the spatiotemporal, kinematic and kinetic gait parameters of elderly and neurological patients revealed a significant difference based on the type and level of impairment. Healthy elderly population showed deviations in the gait parameters due to age, however, significant difference is observed in the gait parameters of the neurological patients.Conclusion: A level of agreement was observed in most of the studies however the review also noticed some controversies among different studies in the same group. The review on the spatiotemporal, kinematics and kinetic gait parameters will provide a summary of the fundamental needs of the users for the future design and development of robotic assistive devices.Implications for rehabilitationThe support requirements provide the foundation for designing assistive devices.The findings will be crucial in defining the design criteria for robot assistive devices.
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Affiliation(s)
- Asim Ghaffar
- School of Mechanical Engineering, University of Leeds, Leeds, UK.,Department of Mechanical and Mechatronics Engineering, University of Engineering and Technology, Lahore, Faisalabad Campus, Pakistan
| | | | - Sheng Quan Xie
- Faculty of Engineering, School of Electronic and Electrical Engineering and School of Mechanical Engineering, University of Leeds, Leeds, UK
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Lousa M, Vázquez-Huarte-Mendicoa C, Gutiérrez AJ, Saavedra P, Navarro B, Tugores A. Genetic epidemiology, demographic, and clinical characteristics of Charcot-Marie-tooth disease in the island of Gran Canaria (Spain). J Peripher Nerv Syst 2019; 24:131-138. [PMID: 30569560 DOI: 10.1111/jns.12299] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2018] [Revised: 11/07/2018] [Accepted: 12/16/2018] [Indexed: 02/01/2023]
Abstract
Charcot-Marie-Tooth (CMT) disease is the most common hereditary neuromuscular disorder. This study involves the entire known CMT patient registry in Gran Canaria, represented by 256 patients belonging to 79 unrelated families, who were clinically and genetically characterized, along with physical and neurophysiological evaluation on 181 and 165 patients, respectively. Complete genotyping showed an estimated prevalence of CMT disease of 30.08/100 000 (95% confidence interval [CI] = 26.5;33.9), corresponding mainly (78.5%) to CMT1A (23.6/100 000) and hereditary neuropathy with liability to pressure palsies [HNPP] 17.5%; 5.29/100 000). Most patients (198) with CMT1A carried the 17p11.2 duplication including the PMP22 gene, 45 patients with HNPP were all affected by deletion of the 17p11.2 locus, and 10 patients presented with axonal phenotypes: CMT2A (MFN2), CMT2N (AARS), and CMT1X (GJB1). Despite showing a classical CMT1A phenotype, we found a much earlier age of onset in our CMT1A patients, along with increased frequency of appearance of postural hand tremor. Bilateral tongue atrophy was an additional phenotype observed. Being this CMT1A group, one of the largest cohorts known to date, this study provided a unique opportunity to further define the clinical phenotype of CMT1A patients carrying the 17p11.2 duplication in a homogeneous ethnic group.
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Affiliation(s)
- Manuel Lousa
- Department of Neurology, Complejo Hospitalario Universitario Insular-Materno Infantil, Las Palmas de Gran Canaria
| | | | - Antonio J Gutiérrez
- Department of Neurology, Complejo Hospitalario Universitario Insular-Materno Infantil, Las Palmas de Gran Canaria
| | - Pedro Saavedra
- Department of Mathematics, University of Las Palmas de Gran Canaria
| | - Beatriz Navarro
- Department of Neurophysiology, Complejo Hospitalario Universitario Insular-Materno Infantil, Las Palmas de Gran Canaria
| | - Antonio Tugores
- Research Unit, Complejo Hospitalario Universitario Insular-Materno Infantil, Las Palmas de Gran Canaria
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Report by the Spanish Foundation for the Brain on the social impact of amyotrophic lateral sclerosis and other neuromuscular disorders. NEUROLOGÍA (ENGLISH EDITION) 2018. [DOI: 10.1016/j.nrleng.2015.02.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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Intermediate Charcot–Marie–Tooth disease: an electrophysiological reappraisal and systematic review. J Neurol 2017; 264:1655-1677. [DOI: 10.1007/s00415-017-8474-3] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2017] [Revised: 03/23/2017] [Accepted: 03/24/2017] [Indexed: 01/13/2023]
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Braathen GJ, Høyer H, Busk ØL, Tveten K, Skjelbred CF, Russell MB. Variants in the genes DCTN2, DNAH10, LRIG3, and MYO1A are associated with intermediate Charcot-Marie-Tooth disease in a Norwegian family. Acta Neurol Scand 2016; 134:67-75. [PMID: 26517670 PMCID: PMC5057358 DOI: 10.1111/ane.12515] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/11/2015] [Indexed: 12/30/2022]
Abstract
Introduction Charcot–Marie–Tooth disease (CMT) is a heterogeneous inherited neuropathy. The number of known CMT genes is rapidly increasing mainly due to next‐generation sequencing technology, at present more than 70 CMT‐associated genes are known. We investigated whether variants in the DCTN2 could cause CMT. Material and methods Fifty‐nine Norwegian CMT families from the general population with unknown genotype were tested by targeted next‐generation sequencing (NGS) for variants in DCTN2 along with 32 CMT genes and 19 other genes causing other inherited neuropathies or neuronopathies, due to phenotypic overlap. In the family with the DCTN2 variant, exome sequencing was then carried out on all available eight family members to rule out the presence of more potential variants. Results Targeted NGS identified in one family a variant of DCTN2, c.337C>T, segregating with the phenotype in five affected members, while it was not present in the three unaffected members. The DCTN2 variant c.337C>T; p.(His113Tyr) was neither found in in‐house controls nor in SNP databases. Exome sequencing revealed a singular heterozygous shared haplotype containing four genes, DCTN2,DNAH10,LRIG3, and MYO1A, with novel sequence variants. The haplotype was shared by all the affected members, while the unaffected members did not have it. Conclusions This is the first time a haplotype on chromosome 12 containing sequence variants in the genes DCTN2,DNAH10,LRIG3, and MYO1A has been linked to an inherited neuropathy in humans.
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Affiliation(s)
- G. J. Braathen
- Head and Neck Research Group Research Centre Akershus University Hospital Lørenskog Oslo Norway
- Institute of Clinical Medicine Campus Akershus University Hospital University of Oslo Nordbyhagen Oslo Norway
- Section of Medical Genetics Department of Laboratory Medicine Telemark Hospital Skien Norway
| | - H. Høyer
- Head and Neck Research Group Research Centre Akershus University Hospital Lørenskog Oslo Norway
- Institute of Clinical Medicine Campus Akershus University Hospital University of Oslo Nordbyhagen Oslo Norway
- Section of Medical Genetics Department of Laboratory Medicine Telemark Hospital Skien Norway
| | - Ø. L. Busk
- Section of Medical Genetics Department of Laboratory Medicine Telemark Hospital Skien Norway
| | - K. Tveten
- Section of Medical Genetics Department of Laboratory Medicine Telemark Hospital Skien Norway
| | - C. F. Skjelbred
- Section of Medical Genetics Department of Laboratory Medicine Telemark Hospital Skien Norway
| | - M. B. Russell
- Head and Neck Research Group Research Centre Akershus University Hospital Lørenskog Oslo Norway
- Institute of Clinical Medicine Campus Akershus University Hospital University of Oslo Nordbyhagen Oslo Norway
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McCorquodale D, Pucillo EM, Johnson NE. Management of Charcot-Marie-Tooth disease: improving long-term care with a multidisciplinary approach. J Multidiscip Healthc 2016; 9:7-19. [PMID: 26855581 PMCID: PMC4725690 DOI: 10.2147/jmdh.s69979] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Charcot–Marie–Tooth (CMT) disease is the most common inherited neuropathy and one of the most common inherited diseases in humans. The diagnosis of CMT is traditionally made by the neurologic specialist, yet the optimal management of CMT patients includes genetic counselors, physical and occupational therapists, physiatrists, orthotists, mental health providers, and community resources. Rapidly developing genetic discoveries and novel gene discovery techniques continue to add a growing number of genetic subtypes of CMT. The first large clinical natural history and therapeutic trials have added to our knowledge of each CMT subtype and revealed how CMT impacts patient quality of life. In this review, we discuss several important trends in CMT research factors that will require a collaborative multidisciplinary approach. These include the development of large multicenter patient registries, standardized clinical instruments to assess disease progression and disability, and increasing recognition and use of patient-reported outcome measures. These developments will continue to guide strategies in long-term multidisciplinary efforts to maintain quality of life and preserve functionality in CMT patients.
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Affiliation(s)
- Donald McCorquodale
- Department of Neurology, Eccles Institute of Human Genetics, University of Utah, Salt Lake City, UT, USA
| | - Evan M Pucillo
- Department of Neurology, Eccles Institute of Human Genetics, University of Utah, Salt Lake City, UT, USA
| | - Nicholas E Johnson
- Department of Neurology, Eccles Institute of Human Genetics, University of Utah, Salt Lake City, UT, USA
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Berciano J, Peeters K, García A, López-Alburquerque T, Gallardo E, Hernández-Fabián A, Pelayo-Negro AL, De Vriendt E, Infante J, Jordanova A. NEFL N98S mutation: another cause of dominant intermediate Charcot–Marie–Tooth disease with heterogeneous early-onset phenotype. J Neurol 2015; 263:361-369. [DOI: 10.1007/s00415-015-7985-z] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2015] [Accepted: 11/24/2015] [Indexed: 11/30/2022]
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Abrams CK, Freidin M. GJB1-associated X-linked Charcot-Marie-Tooth disease, a disorder affecting the central and peripheral nervous systems. Cell Tissue Res 2015; 360:659-73. [PMID: 25370202 DOI: 10.1007/s00441-014-2014-6] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2014] [Accepted: 09/22/2014] [Indexed: 11/24/2022]
Abstract
Charcot-Marie-Tooth disease (CMT) is a group of inherited diseases characterized by exclusive or predominant involvement of the peripheral nervous system. Mutations in GJB1, the gene encoding Connexin 32 (Cx32), a gap-junction channel forming protein, cause the most common X-linked form of CMT, CMT1X. Cx32 is expressed in Schwann cells and oligodendrocytes, the myelinating glia of the peripheral and central nervous systems, respectively. Thus, patients with CMT1X have both central and peripheral nervous system manifestations. Study of the genetics of CMT1X and the phenotypes of patients with this disorder suggest that the peripheral manifestations of CMT1X are likely to be due to loss of function, while in the CNS gain of function may contribute. Mice with targeted ablation of Gjb1 develop a peripheral neuropathy similar to that seen in patients with CMT1X, supporting loss of function as a mechanism for the peripheral manifestations of this disorder. Possible roles for Cx32 include the establishment of a reflexive gap junction pathway in the peripheral and central nervous system and of a panglial syncitium in the central nervous system.
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Affiliation(s)
- Charles K Abrams
- Departments of Neurology and Physiology & Pharmacology, State University of New York, Brooklyn, NY, 11203, USA,
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Report by the Spanish Foundation for the Brain on the social impact of amyotrophic lateral sclerosis and other neuromuscular disorders. Neurologia 2015; 33:35-46. [PMID: 25825074 DOI: 10.1016/j.nrl.2015.02.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2015] [Accepted: 02/07/2015] [Indexed: 12/12/2022] Open
Abstract
INTRODUCTION A thorough knowledge of the socioeconomic scope of neuromuscular disease is essential for managing resources and raising social awareness. DEVELOPMENT Our group reviewed current data on the epidemiology, mortality and dependence rates, and socioeconomic impact of amyotrophic lateral sclerosis and neuromuscular diseases in Spain. We also recorded how neurological care for these patients is organised. CONCLUSIONS Neuromuscular disorders are a very heterogeneous group of diseases, and some are very rare. These disorders account for between 2.8% and 18% of the total motives for a neurological consultation. In Spain, prevalence and incidence figures for amyotrophic lateral sclerosis are similar to those in other countries; however, figures for patients with other neuromuscular diseases are not known. Since the diseases are chronic, progressive, and debilitating, they cause considerable disability and dependence, which in turn directly affects healthcare and social costs associated with the disease. The costs generated by one patient with amyotrophic lateral sclerosis or Duchenne disease have been calculated at about 50 000 euros per year. Neuromuscular disease shows aetiological, diagnostic, and prognostic complexity, and it requires multidisciplinary management. Follow-up for these patients should be entrusted to specialised units.
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Chen M, Wu J, Liang N, Tang L, Chen Y, Chen H, Wei W, Wei T, Huang H, Yi X, Qi M. Identification of a novel SBF2 frameshift mutation in charcot-marie-tooth disease type 4B2 using whole-exome sequencing. GENOMICS PROTEOMICS & BIOINFORMATICS 2014; 12:221-7. [PMID: 25462154 PMCID: PMC4411414 DOI: 10.1016/j.gpb.2014.09.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/07/2014] [Revised: 09/15/2014] [Accepted: 09/18/2014] [Indexed: 12/16/2022]
Abstract
Charcot–Marie–Tooth disease type 4B2 with early-onset glaucoma (CMT4B2, OMIM 604563) is a genetically-heterogeneous childhood-onset neuromuscular disorder. Here, we report the case of a 15-year-old male adolescent with lower extremity weakness, gait abnormalities, foot deformities and early-onset glaucoma. Since clinical diagnosis alone was insufficient for providing pathogenetic evidence to indicate that the condition belonged to a consanguineous family, we applied whole-exome sequencing to samples from the patient, his parents and his younger brother, assuming that the patient’s condition is transmitted in an autosomal recessive pattern. A frame-shift mutation, c.4571delG (P.Gly1524Glufs∗42), was revealed in the CMT4B2-related gene SBF2 (also known as MTMR13, MIM 607697), and this mutation was found to be homozygous in the proband and heterozygous in his parents and younger brother. Together with the results of clinical diagnosis, this case was diagnosed as CMT4B2. Our finding further demonstrates the use of whole-exome sequencing in the diagnosis and treatment of rare diseases.
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Affiliation(s)
- Meiyan Chen
- BGI-Shenzhen, Shenzhen, Guangdong 518083, China
| | - Jing Wu
- BGI-Shenzhen, Shenzhen, Guangdong 518083, China
| | - Ning Liang
- School of Life Sciences, The Chinese University of Hong Kong, NT, Hong Kong SAR 999077, China
| | - Lihui Tang
- BGI-Shenzhen, Shenzhen, Guangdong 518083, China
| | - Yanhua Chen
- BGI-Shenzhen, Shenzhen, Guangdong 518083, China
| | | | - Wei Wei
- BGI-Shenzhen, Shenzhen, Guangdong 518083, China
| | - Tianying Wei
- Center for Genetic and Genomic Medicine, Zhejiang University School of Medicine, First Affiliated Hospital and James D. Watson Institute of Genome Sciences, Hangzhou 310006, China
| | - Hui Huang
- BGI-Shenzhen, Shenzhen, Guangdong 518083, China
| | - Xin Yi
- BGI-Shenzhen, Shenzhen, Guangdong 518083, China.
| | - Ming Qi
- BGI-Shenzhen, Shenzhen, Guangdong 518083, China; Center for Genetic and Genomic Medicine, Zhejiang University School of Medicine, First Affiliated Hospital and James D. Watson Institute of Genome Sciences, Hangzhou 310006, China; Department of Pathology, University of Rochester Medical Center, Rochester, NY 14642, USA.
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Sivera R, Sevilla T, Vílchez JJ, Martínez-Rubio D, Chumillas MJ, Vázquez JF, Muelas N, Bataller L, Millán JM, Palau F, Espinós C. Charcot-Marie-Tooth disease: genetic and clinical spectrum in a Spanish clinical series. Neurology 2013; 81:1617-25. [PMID: 24078732 PMCID: PMC3806911 DOI: 10.1212/wnl.0b013e3182a9f56a] [Citation(s) in RCA: 109] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2013] [Accepted: 07/30/2013] [Indexed: 11/15/2022] Open
Abstract
OBJECTIVES To determine the genetic distribution and the phenotypic correlation of an extensive series of patients with Charcot-Marie-Tooth disease in a geographically well-defined Mediterranean area. METHODS A thorough genetic screening, including most of the known genes involved in this disease, was performed and analyzed in this longitudinal descriptive study. Clinical data were analyzed and compared among the genetic subgroups. RESULTS Molecular diagnosis was accomplished in 365 of 438 patients (83.3%), with a higher success rate in demyelinating forms of the disease. The CMT1A duplication (PMP22 gene) was the most frequent genetic diagnosis (50.4%), followed by mutations in the GJB1 gene (15.3%), and in the GDAP1 gene (11.5%). Mutations in 13 other genes were identified, but were much less frequent. Sixteen novel mutations were detected and characterized phenotypically. CONCLUSIONS The relatively high frequency of GDAP1 mutations, coupled with the scarceness of MFN2 mutations (1.1%) and the high proportion of recessive inheritance (11.6%) in this series exemplify the particularity of the genetic distribution of Charcot-Marie-Tooth disease in this region.
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Affiliation(s)
- Rafael Sivera
- From the Departments of Neurology (R.S., T.S., J.J.V., J.F.V., N.M., L.B.), Clinical Neurophysiology (M.J.C.), and Genetics (J.M.M.), Hospital Univesitari i Politècnic La Fe, Valencia; Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas (T.S., J.J.V., M.J.C., N.M., L.B.), Valencia; Departments of Medicine (T.S., J.J.V.) and Genetics (C.E.), University of Valencia; Program in Rare and Genetic Diseases (D.M.-R., F.P., C.E.), Centro de Investigación Príncipe Felipe (CIPF), Valencia; Centro de Investigación Biomédica en Red de Enfermedades Raras (D.M.-R., J.M.M., F.P., C.E.), Valencia; IBV-CSIC Associated Unit at CIPF (D.M.-R., F.P., C.E.), Valencia; and School of Medicine (F.P.), University of Castilla-La Mancha, Ciudad Real, Spain
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Õunpuu S, Garibay E, Solomito M, Bell K, Pierz K, Thomson J, Acsadi G, DeLuca P. A comprehensive evaluation of the variation in ankle function during gait in children and youth with Charcot-Marie-Tooth disease. Gait Posture 2013; 38:900-6. [PMID: 23702343 DOI: 10.1016/j.gaitpost.2013.04.016] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/06/2012] [Revised: 04/18/2013] [Accepted: 04/20/2013] [Indexed: 02/02/2023]
Abstract
A better understanding of gait dysfunction for children and youth with Charcot-Marie-Tooth (CMT) will assist in developing appropriate treatments and understanding prognosis for ambulation. The purpose of this retrospective study was to document the typical gait patterns in children and youth (12±4 years) with CMT using motion analysis and relate these findings back to the clinical assessment at the ankle. All patients underwent a motion analysis as a component of treatment decision-making. Lower extremity kinematics and kinetics were evaluated in comparison to a typically developing age-matched reference control group collected in the same gait laboratory. Three patient subgroups were defined based on peak ankle dorsiflexion in terminal stance: greater than typical (n=23), within typical range (n=30) and less than typical (n=13). The three subgroups showed statistically significant differences (p<0.004) in degree of impairment for ankle plantar flexor and dorsiflexor weakness and ankle plantar flexor contracture. Patients with excessive dorsiflexion in terminal stance had the greatest ankle plantar flexor weakness (median 2) and the greatest dorsiflexor weakness (median 4). Patients with less than typical dorsiflexion in terminal stance were the only patients with a plantar flexor contracture (-2±9°). Delayed peak dorsiflexion in stance was the most common kinematic finding and consistent with ankle plantar flexor weakness. All patients showed significantly less (p<0.001) peak ankle moments and power generation in terminal stance than the typically developing controls. We concluded that children and youth with CMT present differently in terms of impairment and associated gait issues which therefore require patient specific treatment strategies.
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Affiliation(s)
- Sylvia Õunpuu
- Center for Motion Analysis, Connecticut Children's Medical Center, Farmington, CT, United States.
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Pla-Martín D, Rueda CB, Estela A, Sánchez-Piris M, González-Sánchez P, Traba J, de la Fuente S, Scorrano L, Renau-Piqueras J, Alvarez J, Satrústegui J, Palau F. Silencing of the Charcot-Marie-Tooth disease-associated gene GDAP1 induces abnormal mitochondrial distribution and affects Ca2+ homeostasis by reducing store-operated Ca2+ entry. Neurobiol Dis 2013; 55:140-51. [PMID: 23542510 DOI: 10.1016/j.nbd.2013.03.010] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2013] [Revised: 03/04/2013] [Accepted: 03/19/2013] [Indexed: 11/25/2022] Open
Abstract
GDAP1 is an outer mitochondrial membrane protein that acts as a regulator of mitochondrial dynamics. Mutations of the GDAP1 gene cause Charcot-Marie-Tooth (CMT) neuropathy. We show that GDAP1 interacts with the vesicle-organelle trafficking proteins RAB6B and caytaxin, which suggests that GDAP1 may participate in the mitochondrial movement within the cell. GDAP1 silencing in the SH-SY5Y cell line induces abnormal distribution of the mitochondrial network, reduces the contact between mitochondria and endoplasmic reticulum (ER) and alters the mobilization of mitochondria towards plasma membrane upon depletion of ER-Ca(2+) stores. GDAP1 silencing does not affect mitochondrial Ca(2+) uptake, ER-Ca(2+), or Ca(2+) flow from ER to mitochondria, but reduces Ca(2+) inflow through store-operated Ca(2+) entry (SOCE) following mobilization of ER-Ca(2+) and SOCE-driven Ca(2+) entry in mitochondria. Our studies suggest that the pathophysiology of GDAP1-related CMT neuropathies may be associated with abnormal distribution and movement of mitochondria throughout cytoskeleton towards the ER and subplasmalemmal microdomains, resulting in a decrease in SOCE activity and impaired SOCE-driven Ca(2+) uptake in mitochondria.
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Affiliation(s)
- David Pla-Martín
- Laboratory of Genetics and Molecular Medicine, Instituto de Biomedicina de Valencia, CSIC, Valencia, Spain
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Neural and molecular features on Charcot-Marie-Tooth disease plasticity and therapy. Neural Plast 2012; 2012:171636. [PMID: 22745917 PMCID: PMC3382403 DOI: 10.1155/2012/171636] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2012] [Accepted: 04/16/2012] [Indexed: 12/21/2022] Open
Abstract
In the peripheral nervous system disorders plasticity is related to changes on the axon and Schwann cell biology, and the synaptic formations and connections, which could be also a focus for therapeutic research. Charcot-Marie-Tooth disease (CMT) represents a large group of inherited peripheral neuropathies that involve mainly both motor and sensory nerves and induce muscular atrophy and weakness. Genetic analysis has identified several pathways and molecular mechanisms involving myelin structure and proper nerve myelination, transcriptional regulation, protein turnover, vesicle trafficking, axonal transport and mitochondrial dynamics. These pathogenic mechanisms affect the continuous signaling and dialogue between the Schwann cell and the axon, having as final result the loss of myelin and nerve maintenance; however, some late onset axonal CMT neuropathies are a consequence of Schwann cell specific changes not affecting myelin. Comprehension of molecular pathways involved in Schwann cell-axonal interactions is likely not only to increase the understanding of nerve biology but also to identify the molecular targets and cell pathways to design novel therapeutic approaches for inherited neuropathies but also for most common peripheral neuropathies. These approaches should improve the plasticity of the synaptic connections at the neuromuscular junction and regenerate cell viability based on improving myelin and axon interaction.
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Berciano J, Sevilla T, Casasnovas C, Sivera R, Vílchez J, Infante J, Ramón C, Pelayo-Negro A, Illa I. Guía diagnóstica en el paciente con enfermedad de Charcot-Marie-Tooth. Neurologia 2012; 27:169-78. [DOI: 10.1016/j.nrl.2011.04.015] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2011] [Accepted: 04/14/2011] [Indexed: 01/31/2023] Open
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Berciano J, Sevilla T, Casasnovas C, Sivera R, Vílchez J, Infante J, Ramón C, Pelayo-Negro A, Illa I. Guidelines for molecular diagnosis of Charcot-Marie-Tooth disease. NEUROLOGÍA (ENGLISH EDITION) 2012. [DOI: 10.1016/j.nrleng.2012.04.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022] Open
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Abstract
BACKGROUND Charcot-Marie-Tooth disease (CMT) is the most common inherited disorder of the peripheral nervous system. The frequency of different CMT genotypes has been estimated in clinic populations, but prevalence data from the general population is lacking. Point mutations in the mitofusin 2 (MFN2) gene has been identified exclusively in Charcot-Marie-Tooth disease type 2 (CMT2), and in a single family with intermediate CMT. MFN2 point mutations are probably the most common cause of CMT2. The CMT phenotype caused by mutation in the myelin protein zero (MPZ) gene varies considerably, from early onset and severe forms to late onset and milder forms. The mechanism is not well understood. The myelin protein zero (P(0) ) mediates adhesion in the spiral wraps of the Schwann cell's myelin sheath. X-linked Charcot-Marie Tooth disease (CMTX) is caused by mutations in the connexin32 (cx32) gene that encodes a polypeptide which is arranged in hexameric array and form gap junctions. AIMS Estimate prevalence of CMT. Estimate frequency of Peripheral Myelin Protein 22 (PMP22) duplication and point mutations, insertions and deletions in Cx32, Early growth response 2 (EGR2), MFN2, MPZ, PMP22 and Small integral membrane protein of lysosome/late endosome (SIMPLE) genes. Description of novel mutations in Cx32, MFN2 and MPZ. Description of de novo mutations in MFN2. MATERIAL AND METHODS Our population based genetic epidemiological survey included persons with CMT residing in eastern Akershus County, Norway. The participants were interviewed and examined by one geneticist/neurologist, and classified clinically, neurophysiologically and genetically. Two-hundred and thirty-two consecutive unselected and unrelated CMT families with available DNA from all regions in Norway were included in the MFN2 study. We screened for point mutations in the MFN2 gene. We describe four novel mutations, two in the connexin32 gene and two in the MPZ gene. RESULTS A total of 245 affected from 116 CMT families from the general population of eastern Akershus county were included in the genetic epidemiological survey. In the general population 1 per 1214 persons (95% CI 1062-1366) has CMT. Charcot-Marie-Tooth disease type 1 (CMT1), CMT2 and intermediate CMT were found in 48.2%, 49.4% and 2.4% of the families, respectively. A mutation in the investigated genes was found in 27.2% of the CMT families and in 28.6% of the affected. The prevalence of the PMP22 duplication and mutations in the Cx32, MPZ and MFN2 genes was found in 13.6%, 6.2%, 1.2%, 6.2% of the families, and in 19.6%, 4.8%, 1.1%, 3.2% of the affected, respectively. None of the families had point mutations, insertions or deletions in the EGR2, PMP22 or SIMPLE genes. Four known and three novel mitofusin 2 (MFN2) point mutations in 8 unrelated Norwegian CMT families were identified. The novel point mutations were not found in 100 healthy controls. This corresponds to 3.4% (8/232) of CMT families having point mutations in MFN2. The phenotypes were compatible with CMT1 in two families, CMT2 in four families, intermediate CMT in one family and distal hereditary motor neuronopathy (dHMN) in one family. A point mutation in the MFN2 gene was found in 2.3% of CMT1, 5.5% of CMT2, 12.5% of intermediate CMT and 6.7% of dHMN families. Two novel missense mutations in the MPZ gene were identified. Family 1 had a c.368G>A (Gly123Asp) transition while family 2 and 3 had a c.103G>A (Asp35Asn) transition. The affected in family 1 had early onset and severe symptoms compatible with Dejerine-Sottas syndrome (DSS), while affected in family 2 and 3 had late onset, milder symptoms and axonal neuropathy compatible with CMT2. Two novel connexin32 mutations that cause early onset X-linked CMT were identified. Family 1 had a deletion c.225delG (R75fsX83) which causes a frameshift and premature stop codon at position 247 while family 2 had a c.536G>A (Cys179Tyr) transition which causes a change of the highly conserved cysteine residue, i.e. disruption of at least one of three disulfide bridges. The mean age at onset was in the first decade and the nerve conduction velocities were in the intermediate range. DISCUSSION Charcot-Marie-Tooth disease is the most common inherited neuropathy. At present 47 hereditary neuropathy genes are known, and an examination of all known genes would probably only identify mutations in approximately 50% of those with CMT. Thus, it is likely that at least 30-50 CMT genes are yet to be identified. The identified known and novel point mutations in the MFN2 gene expand the clinical spectrum from CMT2 and intermediate CMT to also include possibly CMT1 and the dHMN phenotypes. Thus, genetic analyses of the MFN2 gene should not be restricted to persons with CMT2. The phenotypic variation caused by different missense mutations in the MPZ gene is likely caused by different conformational changes of the MPZ protein which affects the functional tetramers. Severe changes of the MPZ protein cause dysfunctional tetramers and predominantly uncompacted myelin, i.e. the severe phenotypes congenital hypomyelinating neuropathy and DSS, while milder changes cause the phenotypes CMT1 and CMT2. The two novel mutations in the connexin32 gene are more severe than the majority of previously described mutations possibly due to the severe structural change of the gap junction they encode. CONCLUSION Charcot-Marie-Tooth disease is the most common inherited disorder of the peripheral nervous system with an estimated prevalence of 1 in 1214. CMT1 and CMT2 are equally frequent in the general population. The prevalence of PMP22 duplication and of mutations in Cx32, MPZ and MFN2 is 19.6%, 4.8%, 1.1% and 3.2%, respectively. The ratio of probable de novo mutations in CMT families was estimated to be 22.7%. Genotype- phenotype correlations for seven novel mutations in the genes Cx32 (2), MFN2 (3) and MPZ (2) are described. Two novel phenotypes were ascribed to the MFN2 gene, however further studies are needed to confirm that MFN2 mutations can cause CMT1 and dHMN.
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Affiliation(s)
- G J Braathen
- Head and Neck Research Group, Research Centre, Akershus University Hospital, Lørenskog, Norway.
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Espinós C, Calpena E, Martínez-Rubio D, Lupo V. Autosomal Recessive Charcot-Marie-Tooth Neuropathy. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2012; 724:61-75. [DOI: 10.1007/978-1-4614-0653-2_5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
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Berciano J, Gallardo E, García A, Pelayo-Negro AL, Infante J, Combarros O. New insights into the pathophysiology of pes cavus in Charcot–Marie–Tooth disease type 1A duplication. J Neurol 2011; 258:1594-602. [DOI: 10.1007/s00415-011-6094-x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2011] [Revised: 05/04/2011] [Accepted: 05/04/2011] [Indexed: 11/28/2022]
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Enfermedad de Charcot-Marie-Tooth: revisión con énfasis en la fisiopatología del pie cavo. Rev Esp Cir Ortop Traumatol (Engl Ed) 2011. [DOI: 10.1016/j.recot.2010.09.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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Mladenovic J, Milic Rasic V, Keckarevic Markovic M, Romac S, Todorovic S, Rakocevic Stojanovic V, Kisic Tepavcevic D, Hofman A, Pekmezovic T. Epidemiology of Charcot-Marie-Tooth Disease in the Population of Belgrade, Serbia. Neuroepidemiology 2011; 36:177-82. [DOI: 10.1159/000327029] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2010] [Accepted: 03/03/2011] [Indexed: 11/19/2022] Open
Affiliation(s)
- J Mladenovic
- PCR Center, Faculty of Biology, University of Belgrade, Belgrade, Serbia
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Berciano J, Gallardo E, García A, Pelayo-Negro A, Infante J, Combarros O. Charcot-Marie-Tooth disease: a review with emphasis on the pathophysiology of pes cavus. Rev Esp Cir Ortop Traumatol (Engl Ed) 2011. [DOI: 10.1016/s1988-8856(11)70296-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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Braathen GJ, Sand JC, Lobato A, Høyer H, Russell MB. Genetic epidemiology of Charcot-Marie-Tooth in the general population. Eur J Neurol 2011; 18:39-48. [PMID: 20482598 DOI: 10.1111/j.1468-1331.2010.03037.x] [Citation(s) in RCA: 110] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
BACKGROUND AND PURPOSE the frequency of different Charcot-Marie-Tooth (CMT) genotypes has been estimated in clinic populations, but prevalence data from the general population are lacking. METHODS our population-based genetic epidemiological survey included persons with CMT residing in eastern Akershus County, Norway. The participants were interviewed and examined by one geneticist/neurologist and classified clinically, neurophysiologically and genetically. RESULTS two hundred and forty-five persons from 116 families had CMT. This corresponds to 1 per 1214 persons (95% CI 1062-1366) have CMT in the general population. CMT1 (motor conduction velocity (MCV) <38 m/s), CMT2 (MCV >38 m/s) and CMT intermediate (MCV 25-45 m/s) were found in 48.2%, 49.4% and 2.4% of the families. A total of 27.2% of the families and 28.6% of the affected had a mutation in the investigated CMT genes. The prevalence of the peripheral myelin protein 22 (PMP22) duplication and point mutation in the connexin32 (Cx32), myelin protein zero (MPZ) and mitofusin2 (MFN2) genes was found in 13.6%, 6.2%, 1.2%, 6.2% of the families, and in 19.6%, 4.8%, 1.1%, 3.2% of the affected, respectively. None of the families had point mutations in the early growth response 2 (EGR2), PMP22 or small integral membrane protein of lysosome/late endosome (SIMPLE) genes. CONCLUSIONS CMT is the most common inherited neuropathy. At present, 43 CMT genes are known, and an examination of all known genes would probably only identify mutations in approximately 50% of those with CMT. Thus, it is probable that at least 30-50 CMT genes are yet to be identified.
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Affiliation(s)
- G J Braathen
- Faculty Division Akershus University Hospital, University of Oslo, Norway.
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Lupo V, Galindo MI, Martínez-Rubio D, Sevilla T, Vílchez JJ, Palau F, Espinós C. Missense mutations in the SH3TC2 protein causing Charcot-Marie-Tooth disease type 4C affect its localization in the plasma membrane and endocytic pathway. Hum Mol Genet 2009; 18:4603-14. [PMID: 19744956 DOI: 10.1093/hmg/ddp427] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Mutations in SH3TC2 (KIAA1985) cause Charcot-Marie-Tooth disease (CMT) type 4C, a demyelinating inherited neuropathy characterized by early-onset and scoliosis. Here we demonstrate that the SH3TC2 protein is present in several components of the endocytic pathway including early endosomes, late endosomes and clathrin-coated vesicles close to the trans-Golgi network and in the plasma membrane. Myristoylation of SH3TC2 in glycine 2 is necessary but not sufficient for the proper location of the protein in the cell membranes. In addition to myristoylation, correct anchoring also needs the presence of SH3 and TPR domains. Mutations that cause a stop codon and produce premature truncations that remove most of the TPR domains are expressed as the wild-type protein. In contrast, missense mutations in or around the region of the first-TPR domain are absent from early endosomes, reduced in plasma membrane and late endosomes and are variably present in clathrin-coated vesicles. Our findings suggest that the endocytic and membrane trafficking pathway is involved in the pathogenesis of CMT4C disease. We postulate that missense mutations of SH3TC2 could impair communication between the Schwann cell and the axon causing an abnormal myelin formation.
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Affiliation(s)
- Vincenzo Lupo
- Genetics and Molecular Medicine Unit, Instituto de Biomedicina de Valencia (IBV), CSIC, Valencia 46010, Spain
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The role of mitochondrial network dynamics in the pathogenesis of Charcot-Marie-Tooth disease. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2009; 652:129-37. [PMID: 20225023 DOI: 10.1007/978-90-481-2813-6_9] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Mitochondrial dysfunction plays a relevant role in the pathogenesis of neurological and neuromuscular diseases. Mitochondria may be involved as a primary defect of either the mtDNA or nuclear genome encoded subunits of the respiratory chain. These organelles have also been directly involved in the pathogenesis of Mendelian neurodegenerative disorders caused by mutations in nuclear-encoded proteins targeted to mitochondria, such as Friedreich ataxia, hereditary spastic paraplegia, or some monogenic forms of Parkinson disease. In addition, mitochondria also participate in the pathogenic mechanisms affecting neurodegenerative disorders such Huntington disease or amyotrophic lateral sclerosis. Cell death in neurodegeneration associated with neurological diseases usually occurs by apoptosis being the most common route the intrinsic mitochondria pathway. Along with regulation of apoptosis, mitochondria also modulate cell pathogenesis by means of energy production, reactive oxygen species (ROS) generation, and calcium buffering. Mitochondria form dynamic tubular networks that continually change their shape and move throughout the cell. Here we review the critical role of mitochondria in monogenic neuromuscular disorders, especially inherited peripheral neuropathies caused by abnormal mitochondrial network dynamics. In yeast, at least three proteins are required for mitochondrial fusion, Fzo1, Ugo1 and Mgm1. The human counterparts of Fzo1p and Mgm1p, MFN1/MFN2 and OPA1 respectively, are related to human disease. Mutations in the MFN2 gene cause the most frequent form of autosomal dominant axonal Charcot-Marie-Tooth disease, CMT2A. Mutations in OPA1 cause autosomal dominant optic atrophy (ADOA). For the opposite process of mitochondrial fission, four proteins are at least involved in yeast. Very recently a mutation in the DRP1 gene (the human homologue of yeast Dnm1) has been reported in an infant with a syndrome with encephalopathy, optic atrophy and lactic acidosis. GDAP1 has been recently related to the mitochondrial fission in mammalian cells and, interestingly, mutations in the GDAP1 gene are the cause of the most common form of autosomal recessive CMT, either axonal or demyelinating. These and other disorders are the most recent instances of disease related with mitochondrial abnormal motility, fusion and fission. We propose that the pathomechanisms underlying these disorders also include a complex relationship between mitochondrial dynamics and transport across the axon.
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Romero de Ávila G, Pazos Otero N, Martínez Vázquez C, Fernández J, Navarro C. Artropatía de Charcot y úlceras neuropáticas plantares causadas por neuropatía autosómica sensorial hereditaria. Rev Clin Esp 2008; 208:373-4. [DOI: 10.1157/13124326] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Gallardo E, Claeys KG, Nelis E, García A, Canga A, Combarros O, Timmerman V, Jonghe P, Berciano J. Magnetic resonance imaging findings of leg musculature in Charcot-Marie-Tooth disease type 2 due to dynamin 2 mutation. J Neurol 2008; 255:986-92. [DOI: 10.1007/s00415-008-0808-8] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2007] [Revised: 10/17/2007] [Accepted: 10/30/2007] [Indexed: 01/08/2023]
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Xin B, Puffenberger E, Nye L, Wiznitzer M, Wang H. A novel mutation in the GDAP1 gene is associated with autosomal recessive Charcot-Marie-Tooth disease in an Amish family. Clin Genet 2008; 74:274-8. [PMID: 18492089 DOI: 10.1111/j.1399-0004.2008.01018.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Charcot-Marie-Tooth disease (CMT) constitutes a large group of genetically heterogeneous disorders of the peripheral nervous system. Autosomal recessive forms of CMT are less common in the general population but account for the vast majority of CMT phenotypes in communities with a high prevalence of consanguinity. At least 10 genetic loci cause autosomal recessive forms of CMT. Mutations in the ganglioside-induced differentiation-associated protein 1 (GDAP1) gene are among the most frequent genetic causes of autosomal recessive forms of CMT. To date, 28 mutations in GDAP1 gene have been linked with the disease. Here, we report a novel GDAP1 mutation in an Old Order Amish family with CMT. To ascertain the Amish CMT locus, we performed a genome-wide single nucleotide polymorphism (SNP) analysis on one of three patients from a consanguineous pedigree. Assuming mutation homogeneity, the analysis sought large homozygous SNP blocks that also contained known CMT loci. The largest homozygous SNP block in the patient was localized to chromosome 8q13.1-21.3 and contained the GDAP1 gene. Sequence analysis revealed a novel homozygous mutation, c.692C>T, at codon 231 (p.P231L) in exon 5 of GDAP1 in all patients. Neither the unaffected individuals in the family nor the healthy control samples were homozygous for this mutation. Our findings suggested that this novel mutation in GDAP1 gene is associated with an autosomal recessive form of CMT in Ohio Old Order Amish community.
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Affiliation(s)
- B Xin
- DDC Clinic for Special Needs Children, Middlefield, OH 44062, USA.
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Pedrola L, Espert A, Valdés-Sánchez T, Sánchez-Piris M, Sirkowski EE, Scherer SS, Fariñas I, Palau F. Cell expression of GDAP1 in the nervous system and pathogenesis of Charcot-Marie-Tooth type 4A disease. J Cell Mol Med 2007; 12:679-89. [PMID: 18021315 PMCID: PMC2570022 DOI: 10.1111/j.1582-4934.2007.00158.x] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Mutations in the mitochondrial protein GDAP1 are the cause of Charcot-Marie-Tooth type 4A disease (CMT4A), a severe form of peripheral neuropathy associated with either demyelinating, axonal or intermediate pheno-types. GDAP1 is located in the outer mitochondrial membrane and it seems that may be related with the mitochondrial network dynamics. We are interested to define cell expression in the nervous system and the effect of mutations in mitochondrial morphology and pathogenesis of the disease. We investigated GDAP1 expression in the nervous system and dorsal root ganglia (DRG) neuron cultures. GDAP1 is expressed in motor and sensory neurons of the spinal cord and other large neurons such as cerebellar Purkinje neurons, hippocampal pyramidal neurons, mitral neurons of the olfactory bulb and cortical pyramidal neurons. The lack of GDAP1 staining in the white matter and nerve roots suggested that glial cells do not express GDAP1. In DRG cultures satellite cells and Schwann cells were GDAP1-negative. Overexpression of GDAP1-induced fragmentation of mitochondria suggesting a role of GDAP1 in the fission pathway of the mitochondrial dynamics. Missense mutations showed two different patterns: most of them induced mitochondrial fragmentation but the T157P mutation showed an aggregation pattern. Whereas null mutations of GDAP1 should be associated with loss of function of the protein, missense mutations may act through different pathogenic mechanisms including a dominant-negative effect, suggesting that different molecular mechanisms may underlay the pathogenesis of CMT4A.
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Affiliation(s)
- Laia Pedrola
- Department of Genomics and Proteomics, Instituto de Biomedicina, CSIC, Valencia, Spain
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Newman CJ, Walsh M, O'Sullivan R, Jenkinson A, Bennett D, Lynch B, O'Brien T. The characteristics of gait in Charcot-Marie-Tooth disease types I and II. Gait Posture 2007; 26:120-7. [PMID: 17010610 DOI: 10.1016/j.gaitpost.2006.08.006] [Citation(s) in RCA: 87] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/10/2005] [Revised: 07/30/2006] [Accepted: 08/13/2006] [Indexed: 02/02/2023]
Abstract
Certain typical gait characteristics such as foot-drop and foot supination are well described in Charcot-Marie-Tooth disease. These are directly related to the primary disease and due to the weakness of ankle dorsiflexors and everters characteristic of this hereditary neuropathy. We analysed 16 subjects aged 8-52 years old (11 with type I, 5 with type II Charcot-Marie-Tooth disease) using three-dimensional gait analysis and identified kinematic features previously unreported. These patients showed a combination of tight tendo achillei, foot-drop, failure of plantar flexion and increased foot supination, but also presented with excessive internal rotation of the knee and/or tibia, knee hyperextension in stance, excessive external rotation at the hips and decreased hip adduction in stance (typical of a broad based gait). These proximal features could have been an adaptation to or consequence of the disrupted ankle and foot biomechanics, however a direct relation to the neuropathy is also possible since sub-normal muscle power was observed at the proximal levels in most subjects on both manual testing and kinetic analysis. Gait analysis is a useful tool in defining the characteristic gait of patients with Charcot-Marie-Tooth disease.
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Claramunt R, Sevilla T, Lupo V, Cuesta A, Millán JM, Vílchez JJ, Palau F, Espinós C. The p.R1109X mutation in SH3TC2 gene is predominant in Spanish Gypsies with Charcot-Marie-Tooth disease type 4. Clin Genet 2007; 71:343-9. [PMID: 17470135 DOI: 10.1111/j.1399-0004.2007.00774.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Charcot-Marie-Tooth (CMT) disease type 4 (CMT4) is the name given to autosomal recessive forms of hereditary motor and sensory neuropathy (HMSN). When we began this study, three genes or loci associated with inherited peripheral neuropathies had already been identified in the European Gypsy population: HMSN-Lom (MIM 601455), HMSN-Russe (MIM 605285) and the congenital cataracts facial dysmorphism neuropathy syndrome (MIM 604168). We have carried out genetic analyses in a series of 20 Spanish Gypsy families diagnosed with a demyelinating CMT disease compatible with an autosomal recessive trait. We found the p.R148X mutation in the N-myc downstream-regulated gene 1 gene to be responsible for the HMSN-Lom in four families and also possible linkage to the HMSN-Russe locus in three others. We have also studied the CMT4C locus because of the clinical similarities and showed that in 10 families, the disease is caused by mutations located on the SH3 domain and tetratricopeptide repeats 2 (SH3TC2) gene: p.R1109X in 20 out of 21 chromosomes and p.C737_P738delinsX in only one chromosome. Moreover, the SH3TC2 p.R1109X mutation is associated with a conserved haplotype and, therefore, may be a private founder mutation for the Gypsy population. Estimation of the allelic age revealed that the SH3TC2 p.R1109X mutation may have arisen about 225 years ago, probably as the consequence of a bottleneck.
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Affiliation(s)
- R Claramunt
- Instituto de Biomedicina, Consejo Superior de Investigaciones Científicas, Valencia, Spain
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Palau F, Espinós C. Autosomal recessive cerebellar ataxias. Orphanet J Rare Dis 2006; 1:47. [PMID: 17112370 PMCID: PMC1664553 DOI: 10.1186/1750-1172-1-47] [Citation(s) in RCA: 115] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2006] [Accepted: 11/17/2006] [Indexed: 02/06/2023] Open
Abstract
Autosomal recessive cerebellar ataxias (ARCA) are a heterogeneous group of rare neurological disorders involving both central and peripheral nervous system, and in some case other systems and organs, and characterized by degeneration or abnormal development of cerebellum and spinal cord, autosomal recessive inheritance and, in most cases, early onset occurring before the age of 20 years. This group encompasses a large number of rare diseases, the most frequent in Caucasian population being Friedreich ataxia (estimated prevalence 2–4/100,000), ataxia-telangiectasia (1–2.5/100,000) and early onset cerebellar ataxia with retained tendon reflexes (1/100,000). Other forms ARCA are much less common. Based on clinicogenetic criteria, five main types ARCA can be distinguished: congenital ataxias (developmental disorder), ataxias associated with metabolic disorders, ataxias with a DNA repair defect, degenerative ataxias, and ataxia associated with other features. These diseases are due to mutations in specific genes, some of which have been identified, such as frataxin in Friedreich ataxia, α-tocopherol transfer protein in ataxia with vitamin E deficiency (AVED), aprataxin in ataxia with oculomotor apraxia (AOA1), and senataxin in ataxia with oculomotor apraxia (AOA2). Clinical diagnosis is confirmed by ancillary tests such as neuroimaging (magnetic resonance imaging, scanning), electrophysiological examination, and mutation analysis when the causative gene is identified. Correct clinical and genetic diagnosis is important for appropriate genetic counseling and prognosis and, in some instances, pharmacological treatment. Due to autosomal recessive inheritance, previous familial history of affected individuals is unlikely. For most ARCA there is no specific drug treatment except for coenzyme Q10 deficiency and abetalipoproteinemia.
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Affiliation(s)
- Francesc Palau
- Genetics and Molecular Medicine Unit, Instituto de Biomedicina, CSIC, Jaume Roig, 11 46010 Valencia, Spain
- Centre for Biomedical Research on Rare Diseases (CIBERER), Instituto de Salud Carlos III, Valencia, Spain
| | - Carmen Espinós
- Genetics and Molecular Medicine Unit, Instituto de Biomedicina, CSIC, Jaume Roig, 11 46010 Valencia, Spain
- Centre for Biomedical Research on Rare Diseases (CIBERER), Instituto de Salud Carlos III, Valencia, Spain
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SHY MICHAELE, KAMHOLZ JOHN, LOVELACE ROBERTE. Introduction to the Third International Symposium on Charcot-Marie-Tooth Disorders. Ann N Y Acad Sci 2006; 883:xiii-xviii. [DOI: 10.1111/j.1749-6632.1999.tb08559.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
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Pedrola L, Espert A, Wu X, Claramunt R, Shy ME, Palau F. GDAP1, the protein causing Charcot–Marie–Tooth disease type 4A, is expressed in neurons and is associated with mitochondria. Hum Mol Genet 2005; 14:1087-94. [PMID: 15772096 DOI: 10.1093/hmg/ddi121] [Citation(s) in RCA: 143] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Mutations in GDAP1, the ganglioside-induced differentiation-associated protein 1 gene, cause Charcot-Marie-Tooth (CMT) type 4A, a severe autosomal recessive form of neuropathy associated with either demyelinating or axonal phenotypes. Here, we demonstrate that GDAP1 has far greater expression in neurons than in myelinating Schwann cells. We investigated cell localization of GDAP1 in a human neuroblastoma cell line by means of transient overexpression and co-localization with organelle markers in COS-7 cells and by western blot analysis of subcell fractions with anti-GDAP1 polyclonal antibodies. We observed that GDAP1 is localized in mitochondria. We also show that C-terminal transmembrane domains are necessary for the correct localization in mitochondria; however, missense mutations do not change the mitochondrial pattern of the wild-type protein. Our findings suggest that CMT4A disease is in fact a mitochondrial neuropathy mainly involving axons and represents a disease belonging to the new category of mitochondrial disorders caused by mutations in nuclear genes. We postulate that GDAP1 may be related to the maintenance of the mitochondrial network.
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Affiliation(s)
- Laia Pedrola
- Laboratory of Genetics and Molecular Medicine, Department of Genomics and Proteomics, Instituto de Biomedicina, CSIC, Valencia, Spain
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Berciano J, García A, Combarros O. Initial semeiology in children with Charcot-Marie-Tooth disease 1A duplication. Muscle Nerve 2003; 27:34-9. [PMID: 12508292 DOI: 10.1002/mus.10299] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The aim of this study was to describe the initial signs and symptoms in Charcot-Marie-Tooth disease type 1A (CMT-1A). Twelve secondary cases with CMT-1A were serially evaluated. Ages at initial clinical examination ranged between 1 month and 5 years (mean, 2 years) and final ages between 6 and 23 years (mean, 13 years). First signs of the disease were detected at initial or upon serial examinations in all 12 patients at ages ranging between 1 and 10 years (median, 4 years). The most frequent signs were lower limb areflexia in 12, difficulty in heel walking in 8, nerve enlargement in 6, atrophy of intrinsic foot muscles in 6, clawing of toes in 5, pes cavus or cavus varus in 4, shortening of Achilles tendon in 3, peroneal weakness in 1, and stocking hypoesthesia in 1. Only three patients were symptomatic at the initial evaluation. We conclude that initial CMT-1A signs usually appear in early childhood, although they may be quite subtle and require serial examinations for detection. Lower limb areflexia is the only constant early sign.
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Affiliation(s)
- José Berciano
- Service of Neurology, University Hospital "Marqués de Valdecilla," University of Cantabria, Santander 39008, Spain.
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Benstead TJ, Grant IA. Progress in clinical neurosciences: Charcot-Marie-Tooth disease and related inherited peripheral neuropathies. Can J Neurol Sci 2001; 28:199-214. [PMID: 11513338 DOI: 10.1017/s0317167100001347] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The classification of Charcot-Marie-Tooth disease and related hereditary motor and sensory neuropathies has evolved to incorporate clinical, electrophysiological and burgeoning molecular genetic information that characterize the many disorders. For several inherited neuropathies, the gene product abnormality is known and for others, candidate genes have been identified. Genetic testing can pinpoint a specific inherited neuropathy for many patients. However, clinical and electrophysiological assessments continue to be essential tools for diagnosis and management of this disease group. This article reviews clinical, electrophysiological, pathological and molecular aspects of hereditary motor and sensory neuropathies.
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Affiliation(s)
- T J Benstead
- Division of Neurology, QEII Health Sciences Centre and Dalhousie University Medical School, Halifax, Nova Scotia, Canada
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Gemignani F, Marbini A. Charcot-Marie-Tooth disease (CMT): distinctive phenotypic and genotypic features in CMT type 2. J Neurol Sci 2001; 184:1-9. [PMID: 11231025 DOI: 10.1016/s0022-510x(00)00497-4] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Charcot-Marie-Tooth disease (CMT), or hereditary motor and sensory neuropathy (HMSN), includes two main subtypes of CMT1/HMSN I (demyelinating), and CMT2/HMSN II (axonal). Further heterogeneity has been demonstrated by genetic molecular studies, with at least four responsible genes for CMT1. As for CMT2, a mutation in the neurofilament-light (NF-L) gene has been identified in a single family, and other CMT2 loci have been mapped. We propose a clinical classification of the CMT2 phenotypes, and review the features of the identified CMT2 genotypes. The following main subtypes of CMT2 are considered in the phenotype classification: classical CMT2, the variants of CMT2 showing atypical features that may represent either variance in the classical CMT2 phenotype or separate entities; CMT2 plus, i.e. complex forms with involvement of additional neural structures. The recognized CMT2 genotypes include: CMT2A (mapped to chromosome 1p35-36); CMT2B (3q13-22); CMT2C (with vocal cord paresis); CMT2D (7p14); CMT2E, related to a mutation in the NF-L gene on chromosome 8p21; proximal CMT2, or HMSN P (3q13.1); CMT2 with MPZ mutations; autosomal recessive CMT2 (1q21.2-q21.3); agenesis of the corpus callosum with sensorimotor neuronopathy (15q13-q15); CMT2 X-linked with deafness and mental retardation (Xq24-q26). The identified genotypes may correspond to previously described clinical subtypes of CMT2. In particular, classical CMT2 presents in association with NF-L gene mutation, in the only CMT2 family with known gene mutation, and in CMT2A patients. However, the features of classical CMT2 have been paradoxically reported also in families with MPZ mutation, and conversely several CMT2 families are not linked to the known CMT2 loci. Further cloning of the CMT2 genes will ultimately shed light on the pathogenic mechanism(s) implicated in the process of axonal degeneration, shared by the different CMT2 genotypes.
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Affiliation(s)
- F Gemignani
- Institute of Neurology, University of Parma, via del Quartiere 4, I-43100 Parma, Italy.
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Dupré N, Cossette L, Hand CK, Bouchard JP, Rouleau GA, Puymirat J. A founder mutation in French-Canadian families with X-linked hereditary neuropathy. Can J Neurol Sci 2001; 28:51-5. [PMID: 11252295 DOI: 10.1017/s0317167100052550] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
BACKGROUND The aim of the present study was to identify the mutations in the connexin 32 gene in French-Canadian families with X-linked Charcot-Marie-Tooth disease (CMTX). METHODS Molecular analysis was performed by nonisotopic single strand conformation polymorphism (SSCP) analysis and sequencing. Clinical evaluation was carried out according to the scale defined by the European Hereditary Motor and Sensory Neuropathy Consortium. RESULTS In one family, the mutation Arg142Trp was located in the transmembrane domain III whereas, in four other families we identified a novel mutation (Ser26Trp) located in the transmembrane domain I of the connexin 32 gene. Haplotype analysis revealed that these four families are related and suggests a founder mutation. Sixteen patients from these four families were studied. As expected, all the affected males were more clinically affected than the females and all affected patients exhibited some electrophysiological characteristics of demyelination. CONCLUSION Our study suggests that the Ser26Trp mutation may cause a primary demyelinating neuropathy that is not associated with a specific clinical phenotype. We also find evidence that the majority of kindreds share a common ancestor.
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Affiliation(s)
- N Dupré
- Laboratoire de Recherche en Génétique Humaine, CHU Laval, Ste-Foy, Québec, Canada
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Lewis RA, Sumner AJ, Shy ME. Electrophysiological features of inherited demyelinating neuropathies: A reappraisal in the era of molecular diagnosis. Muscle Nerve 2000; 23:1472-87. [PMID: 11003782 DOI: 10.1002/1097-4598(200010)23:10<1472::aid-mus3>3.0.co;2-#] [Citation(s) in RCA: 111] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The observation that inherited demyelinating neuropathies have uniform conduction slowing and that acquired disorders have nonuniform or multifocal slowing was made prior to the identification of mutations in myelin-specific genes which cause many of the inherited disorders involving peripheral nerve myelin. It is now clear that the electrophysiological aspects of these disorders are more complex than previously realized. Specifically, certain mutations appear to induce nonuniform slowing of conduction which resemble the findings in acquired demyelinating neuropathies. It is clinically important to recognize the different electrodiagnostic patterns of the various inherited demyelinating neuropathies. In addition, an understanding of the relationship between mutations of specific genes and their associated neurophysiological findings is likely to facilitate understanding of the role of these myelin proteins in peripheral nerve function and of how abnormalities in myelin proteins lead to neuropathy. We therefore review the current information on the electrophysiological features of the inherited demyelinating neuropathies in hopes of clarifying their electrodiagnostic features and to shed light on the physiological consequences of the different genetic mutations.
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Affiliation(s)
- R A Lewis
- Department of Neurology, Wayne State University School of Medicine, UHC 8D, 4201 St. Antoine, Detroit, Michigan, USA.
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Berciano J, García A, Calleja J, Combarros O. Clinico-electrophysiological correlation of extensor digitorum brevis muscle atrophy in children with charcot-marie-tooth disease 1A duplication. Neuromuscul Disord 2000; 10:419-24. [PMID: 10899448 DOI: 10.1016/s0960-8966(99)00114-5] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
The purpose of the study is to describe the electrophysiologic abnormalities accounting for the appearance and progression of extensor digitorum brevis (EDB) muscle atrophy in Charcot-Marie-Tooth-disease type 1A (CMT-1A) children. Twelve children with CMT-1A duplication were serially evaluated. Initial ages of clinico-electrophysiological exams ranged from 1 month to 4 years (mean: 2 years) and final ages from 6 to 23 years (mean: 13). All subjects had two or more electrophysiological studies of the peroneal nerve. EDB atrophy was observed in two out of 12 (17%) patients by the age of 5, in eight out of ten (80%) examined between 5 and 9 years, and in all eight (100%) patients who had reached the second decade at the end. Nerve conduction maturation was systematically abnormal, but by age of 5 the mean values of nerve conduction parameters of peroneal nerve did not significantly differ from those in older patients. Compound muscle action potential (CMAP) amplitudes of EDB were reduced in 42% of cases initially and 100% upon last exam. Furthermore, a constant finding throughout the study was progressive attenuation of CMAPs, these becoming unobtainable in four cases. EDB muscle atrophy in CMT-1A children is an age-dependent sign which is accounted for by gradual reduction of the distal peroneal nerve CMAP amplitudes.
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Affiliation(s)
- J Berciano
- Service of Neurology, University Hospital 'Marqués de Valdecilla', 39008, Santander, Spain.
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Combarros O, Oterino A, Berciano J, Benito A, Fernández-Luna JL. Diagnosis of the CMT1A duplication by PCR based detection of a novel junction fragment. J Med Genet 1998; 35:962-3. [PMID: 9832048 PMCID: PMC1051497 DOI: 10.1136/jmg.35.11.962] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
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Bell C, Haites N. The peripheral neuropathies and their molecular genetics. ADVANCES IN GENETICS 1998; 36:1-44. [PMID: 9348652 DOI: 10.1016/s0065-2660(08)60306-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Affiliation(s)
- C Bell
- Department of Medicine and Therapeutics, University of Aberdeen Medical School, Scotland
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47
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Affiliation(s)
- C N Martyn
- MRC Environmental Epidemiology Unit, Southampton University, Southampton General Hospital, UK
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48
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Abstract
Although the prevalence of the hereditary motor and sensory neuropathies in childhood is not clearly established and the age of presentation may overlap the arbitrary boundary between pediatric and adult neurology, the recent explosion of genetic information regarding these conditions has completely altered our understanding and classification of these diseases. The current status of our understanding of the molecular basis of the hereditary neuropathies which might present in childhood is reviewed. The impact of this information on our concepts of the mechanisms operative in the production of the clinical signs and symptoms in these diseases is discussed.
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Affiliation(s)
- R A Ouvrier
- Department of Neurology, New Children's Hospital, Westmead, NSW Australia
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49
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Oterino A, Montón FI, Cabrera VM, Pinto F, Gonzalez A, Lavilla NR. Arginine-164-tryptophan substitution in connexin32 associated with X linked dominant Charcot-Marie-Tooth disease. J Med Genet 1996; 33:413-5. [PMID: 8733054 PMCID: PMC1050613 DOI: 10.1136/jmg.33.5.413] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
A Spanish family with X linked dominant Charcot-Marie-Tooth (CMTX1) neuropathy was screened for point mutations in the connexin32 gene (GJ beta 1). The patients showed a C-T transition at position 552 which predicts arginine to tryptophan substitution at amino acid 164 (R164K). This mutation destroys an AciI restriction site at position 552 and creates a PflMI restriction site.
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Affiliation(s)
- A Oterino
- Hospital Nuestra Señora La Candelaria, Santa Cruz de Tenerife, Spain
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50
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de Freitas MR, Nascimento OJ, de Freitas GR. [Charcot-Marie-Tooth disease. Clinical study in 45 patients]. ARQUIVOS DE NEURO-PSIQUIATRIA 1995; 53:545-51. [PMID: 8585809 DOI: 10.1590/s0004-282x1995000400001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Charcot-Marie-Tooth (CMT) disease is the commonest inherited peripheral neuropathy. The clinical study of 45 patients with CMT is presented. They were derived from Antonio Pedro Hospital of Universidade Federal Fluminense in Niteroi, RJ, Brazil. Such patients could be divided by the motor conduction velocity in two types: a demyelinating form or type I (11 cases) and an axonal form or type II (34 cases). The disease was inherited as an autosomal dominant trait in 23 patients and as an autosomal recessive trait in 7 cases. In 15 patients the disorder was sporadic. The age of onset was in most of our cases before the 20 years. All of them had distal weakness in lower limbs. 38.2% had also distal weakness in upper limbs. 80% had distal wasting of the lower limbs and 50% had distal wasting of upper limbs. The tendon reflexes were absent in 64% in lower limbs and in 28% in upper limbs. The sensitive impairment in the distal regions of the extremities was mild in most patients. We found enlargement of peripheral nerves in 7 patients of type I. Pes cavus was present in 21 cases and scoliosis in 7. We found postural tremor of hands in 6 patients. In 9 cases there were rare features as mental retardation, trigeminal nevralgia, optic atrophy, deafness and calf enlargement. In most of our cases the clinical course was very slow progressive. A greater severity was seen in our sporadic cases.
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Affiliation(s)
- M R de Freitas
- Serviço de Neurologia, Faculdade de Medicina, Universidade Federal Fluminense, Niterói RJ, Brasil
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