1
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Zhan F, Tian W, Cao Y, Wu J, Ni R, Liu T, Yuan Y, Luan X, Cao L. Episodic Neurological Dysfunction in X-Linked Charcot-Marie-Tooth Disease: Expansion of the Phenotypic and Genetic Spectrum. J Clin Neurol 2024; 20:59-66. [PMID: 38179633 PMCID: PMC10782082 DOI: 10.3988/jcn.2023.0104] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2023] [Revised: 04/10/2023] [Accepted: 05/30/2023] [Indexed: 01/06/2024] Open
Abstract
BACKGROUND AND PURPOSE X-linked Charcot-Marie-Tooth disease type 1 (CMTX1) is characterized by peripheral neuropathy with or without episodic neurological dysfunction. We performed clinical, neuropathological, and genetic investigations of a series of patients with mutations of the gap-junction beta-1 gene (GJB1) to extend the phenotypic and genetic description of CMTX1. METHODS Detailed clinical evaluations, sural nerve biopsy, and genetic analysis were applied to patients with CMTX1. RESULTS We collected 27 patients with CMTX1 with GJB1 mutations from 14 unrelated families. The age at onset (AAO) was 20.9±12.2 years (mean±standard deviation; range, 2-45 years). Walking difficulties, weakness in the legs, and pes cavus were common initial symptoms. Compared with female patients, males tended to have a younger AAO (males vs. females=15.4±9.6 vs. 32.0±8.8 years, p=0.002), a longer disease course (16.8±16.1 vs. 5.5±3.8 years, p=0.034), and more-severe electrophysiological results. Besides peripheral neuropathy, six of the patients had special episodic central nervous system (CNS) evidence from symptoms, signs, and/or reversible white-matter lesions. Neuropathology revealed the loss of large myelinated fibers, increased number of regenerated axon clusters with abnormally thin myelin sheaths, and excessively folded myelin. Genetic analysis identified 14 GJB1 variants, 6 of which were novel. CONCLUSIONS These findings expand the phenotypic and genetic spectrum of CMTX1. Although CMTX1 was found to have high phenotypic and CNS involvement variabilities, detailed neurological examinations and nerve conduction studies will provide critical clues for accurate diagnoses. Further exploration of the underlying mechanisms of connexin 32 involvement in neuropathy or CNS dysfunction is warranted to develop promising therapies.
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Affiliation(s)
- Feixia Zhan
- Department of Neurology, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Wotu Tian
- Department of Neurology, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Yuwen Cao
- Department of Neurology, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Jingying Wu
- Department of Neurology, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Ruilong Ni
- Department of Neurology, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
- School of Medicine, Anhui University of Science and Technology, Huainan, China
| | - Taotao Liu
- Department of Neurology, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
- School of Medicine, Anhui University of Science and Technology, Huainan, China
| | - Yun Yuan
- Department of Neurology, Peking University First Hospital, Beijing, China
| | - Xinghua Luan
- Department of Neurology, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China.
| | - Li Cao
- Department of Neurology, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
- School of Medicine, Anhui University of Science and Technology, Huainan, China.
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2
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Hayes LH, Sadjadi R. Hereditary Neuropathies. Continuum (Minneap Minn) 2023; 29:1514-1537. [PMID: 37851041 DOI: 10.1212/con.0000000000001339] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2023]
Abstract
OBJECTIVE This article provides an overview of hereditary neuropathies, describes the different hereditary neuropathy subtypes and the clinical approach to differentiating between them, and summarizes their clinical management. LATEST DEVELOPMENTS Increasingly available clinical genetic testing has broadened the clinical spectrum of hereditary neuropathy subtypes and demonstrated a significant overlap of phenotypes associated with a single gene. New subtypes such as SORD -related neuropathy and CANVAS (cerebellar ataxia, neuropathy, vestibular areflexia syndrome) have emerged. The optimization of clinical management has improved gait and motor function in the adult and pediatric populations. Novel therapeutic approaches are entering clinical trials. ESSENTIAL POINTS Hereditary neuropathies constitute a spectrum of peripheral nerve disorders with variable degrees of motor and sensory symptoms, patterns of involvement, and clinical courses.
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3
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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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4
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Moss KR, Bopp TS, Johnson AE, Höke A. New evidence for secondary axonal degeneration in demyelinating neuropathies. Neurosci Lett 2021; 744:135595. [PMID: 33359733 PMCID: PMC7852893 DOI: 10.1016/j.neulet.2020.135595] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2020] [Revised: 10/31/2020] [Accepted: 12/19/2020] [Indexed: 12/28/2022]
Abstract
Development of peripheral nervous system (PNS) myelin involves a coordinated series of events between growing axons and the Schwann cell (SC) progenitors that will eventually ensheath them. Myelin sheaths have evolved out of necessity to maintain rapid impulse propagation while accounting for body space constraints. However, myelinating SCs perform additional critical functions that are required to preserve axonal integrity including mitigating energy consumption by establishing the nodal architecture, regulating axon caliber by organizing axonal cytoskeleton networks, providing trophic and potentially metabolic support, possibly supplying genetic translation materials and protecting axons from toxic insults. The intermediate steps between the loss of these functions and the initiation of axon degeneration are unknown but the importance of these processes provides insightful clues. Prevalent demyelinating diseases of the PNS include the inherited neuropathies Charcot-Marie-Tooth Disease, Type 1 (CMT1) and Hereditary Neuropathy with Liability to Pressure Palsies (HNPP) and the inflammatory diseases Acute Inflammatory Demyelinating Polyneuropathy (AIDP) and Chronic Inflammatory Demyelinating Polyneuropathy (CIDP). Secondary axon degeneration is a common feature of demyelinating neuropathies and this process is often correlated with clinical deficits and long-lasting disability in patients. There is abundant electrophysiological and histological evidence for secondary axon degeneration in patients and rodent models of PNS demyelinating diseases. Fully understanding the involvement of secondary axon degeneration in these diseases is essential for expanding our knowledge of disease pathogenesis and prognosis, which will be essential for developing novel therapeutic strategies.
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Affiliation(s)
- Kathryn R Moss
- Department of Neurology, Neuromuscular Division, Johns Hopkins School of Medicine, Baltimore, MD, United States
| | - Taylor S Bopp
- Department of Neurology, Neuromuscular Division, Johns Hopkins School of Medicine, Baltimore, MD, United States
| | - Anna E Johnson
- Department of Neurology, Neuromuscular Division, Johns Hopkins School of Medicine, Baltimore, MD, United States
| | - Ahmet Höke
- Department of Neurology, Neuromuscular Division, Johns Hopkins School of Medicine, Baltimore, MD, United States.
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5
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Niu J, Dai Y, Liu M, Li Y, Ding Q, Guan Y, Cui L, Jin L. GJB1 Mutation-A Disease Spectrum: Report of Case Series. Front Neurol 2020; 10:1406. [PMID: 32010055 PMCID: PMC6974795 DOI: 10.3389/fneur.2019.01406] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Accepted: 12/23/2019] [Indexed: 11/13/2022] Open
Abstract
Introduction: Patients with GJB1 mutations manifested as pure central nervous system (CNS) involvement without peripheral neuropathy have not been adequately reported. To expand the disease spectrum of GJB1 mutations, we report a case series. Methods: Eleven patients from 9 families with GJB1 mutations were reviewed. The clinical manifestations, electrophysiological studies, and gene tests were summarized. Results: Nine patients had peripheral neuropathy, one patient had both peripheral neuropathy and mild cognitive impairment, and one patient had recurrent episodic limbs weakness and aphasia with normal electrophysiological study, indicating CNS involvement only. Discussion: GJB1 mutations form a clinical spectrum, including most patients with peripheral nerve involvement, those with both peripheral neuropathy and CNS involvement, and patients with CNS involvement only.
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Affiliation(s)
- Jingwen Niu
- Department of Neurology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China
| | - Yi Dai
- Department of Neurology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China
| | - Mingsheng Liu
- Department of Neurology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China
| | - Yi Li
- Department of Neurology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China
| | - Qingyun Ding
- Department of Neurology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China
| | - Yuzhou Guan
- Department of Neurology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China
| | - Liying Cui
- Department of Neurology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China
| | - Liri Jin
- Department of Neurology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China
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6
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Niego A, Benítez-Burraco A. Williams Syndrome, Human Self-Domestication, and Language Evolution. Front Psychol 2019; 10:521. [PMID: 30936846 PMCID: PMC6431629 DOI: 10.3389/fpsyg.2019.00521] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2018] [Accepted: 02/22/2019] [Indexed: 01/06/2023] Open
Abstract
Language evolution resulted from changes in our biology, behavior, and culture. One source of these changes might be human self-domestication. Williams syndrome (WS) is a clinical condition with a clearly defined genetic basis which results in a distinctive behavioral and cognitive profile, including enhanced sociability. In this paper we show evidence that the WS phenotype can be satisfactorily construed as a hyper-domesticated human phenotype, plausibly resulting from the effect of the WS hemideletion on selected candidates for domestication and neural crest (NC) function. Specifically, we show that genes involved in animal domestication and NC development and function are significantly dysregulated in the blood of subjects with WS. We also discuss the consequences of this link between domestication and WS for our current understanding of language evolution.
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Affiliation(s)
- Amy Niego
- Ph.D. Program, Faculty of Humanities, University of Huelva, Huelva, Spain
| | - Antonio Benítez-Burraco
- Department of Spanish, Linguistics, and Theory of Literature, Faculty of Philology, University of Seville, Seville, Spain
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7
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Diseases of connexins expressed in myelinating glia. Neurosci Lett 2019; 695:91-99. [DOI: 10.1016/j.neulet.2017.05.037] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2017] [Revised: 05/15/2017] [Accepted: 05/19/2017] [Indexed: 11/23/2022]
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8
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Min R, van der Knaap MS. Genetic defects disrupting glial ion and water homeostasis in the brain. Brain Pathol 2019; 28:372-387. [PMID: 29740942 PMCID: PMC8028498 DOI: 10.1111/bpa.12602] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2017] [Accepted: 03/02/2018] [Indexed: 12/23/2022] Open
Abstract
Electrical activity of neurons in the brain, caused by the movement of ions between intracellular and extracellular compartments, is the basis of all our thoughts and actions. Maintaining the correct ionic concentration gradients is therefore crucial for brain functioning. Ion fluxes are accompanied by the displacement of osmotically obliged water. Since even minor brain swelling leads to severe brain damage and even death, brain ion and water movement has to be tightly regulated. Glial cells, in particular astrocytes, play a key role in ion and water homeostasis. They are endowed with specific channels, pumps and carriers to regulate ion and water flow. Glial cells form a large panglial syncytium to aid the uptake and dispersal of ions and water, and make extensive contacts with brain fluid barriers for disposal of excess ions and water. Genetic defects in glial proteins involved in ion and water homeostasis disrupt brain functioning, thereby leading to neurological diseases. Since white matter edema is often a hallmark disease feature, many of these diseases are characterized as leukodystrophies. In this review we summarize our current understanding of inherited glial diseases characterized by disturbed brain ion and water homeostasis by integrating findings from MRI, genetics, neuropathology and animal models for disease. We discuss how mutations in different glial proteins lead to disease, and highlight the similarities and differences between these diseases. To come to effective therapies for this group of diseases, a better mechanistic understanding of how glial cells shape ion and water movement in the brain is crucial.
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Affiliation(s)
- Rogier Min
- Department of Child Neurology, Amsterdam Neuroscience, VU University Medical Center, Amsterdam, The Netherlands.,Department of Integrative Neurophysiology, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, VU University, Amsterdam, The Netherlands
| | - Marjo S van der Knaap
- Department of Child Neurology, Amsterdam Neuroscience, VU University Medical Center, Amsterdam, The Netherlands.,Department of Functional Genomics, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, VU University, Amsterdam, The Netherlands
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9
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Yuan JH, Sakiyama Y, Hashiguchi A, Ando M, Okamoto Y, Yoshimura A, Higuchi Y, Takashima H. Genetic and phenotypic profile of 112 patients with X-linked Charcot-Marie-Tooth disease type 1. Eur J Neurol 2018; 25:1454-1461. [PMID: 29998508 DOI: 10.1111/ene.13750] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2018] [Accepted: 07/10/2018] [Indexed: 12/22/2022]
Abstract
BACKGROUND AND PURPOSE X-linked Charcot-Marie-Tooth disease type 1 (CMTX1), caused by mutations in gap junction protein beta 1 (GJB1), is characterized by various central nervous system symptoms and gender differences of clinical severity. The aim of this study was to identify the frequency and mutation spectrum of CMTX1 patients in Japan and to demonstrate their phenotypic diversities. METHODS Using three high-throughput sequencing systems, targeted gene panel sequencing on 1483 unrelated index patients with suspected Charcot-Marie-Tooth (CMT) disease was performed. The peripheral and central nervous system involvements of all patients with GJB1 variants were assessed retrospectively and a detailed gender comparison was conducted with the CMT examination score. RESULTS Twenty-three novel and 36 described GJB1 variants were identified from 88 pedigrees, in which 34 female and 78 male patients were enrolled. Mean age at onset of the male patients was much younger than the females, 21.56 ± 17.63 years vs. 35.53 ± 23.72 years (P = 0.007). Male patients presented with more severe phenotypes in every examination item, but statistical differences were observed only in motor dysfunctions of the lower extremities and vibration sensation. No significant sensory difference was identified between genders, either clinically or electrophysiologically. Central nervous system dysfunctions were found in 15 patients from 12 pedigrees. Therein, six patients developed stroke-like phenotypes, with dysarthria as the leading symptom. CONCLUSIONS A relatively lower frequency of CMTX1 (5.9%) was demonstrated and a broad mutation spectrum of GJB1 was described. Detailed clinical differences between genders and various central nervous system symptoms were also illustrated, even in the same pedigree.
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Affiliation(s)
- J-H Yuan
- Department of Neurology and Geriatrics, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima, Japan
| | - Y Sakiyama
- Department of Neurology and Geriatrics, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima, Japan
| | - A Hashiguchi
- Department of Neurology and Geriatrics, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima, Japan
| | - M Ando
- Department of Neurology and Geriatrics, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima, Japan
| | - Y Okamoto
- Department of Neurology and Geriatrics, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima, Japan
| | - A Yoshimura
- Department of Neurology and Geriatrics, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima, Japan
| | - Y Higuchi
- Department of Neurology and Geriatrics, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima, Japan
| | - H Takashima
- Department of Neurology and Geriatrics, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima, Japan
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10
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Shimizu C, Kasahara H, Furuta N, Shibata M, Nagashima K, Hashiguchi A, Takashima H, Ikeda Y. [Charcot-Marie-Tooth disease showing transient central nervous system lesions after a large amount of alcohol intake: A case report]. Rinsho Shinkeigaku 2018; 58:479-484. [PMID: 30068806 DOI: 10.5692/clinicalneurol.cn-001130] [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] [Indexed: 06/08/2023]
Abstract
A 23-year-old man experienced numbness in the perioral region and right arm, and right leg weakness on the second day after drinking a large amount of alcohol during foreign travel. His symptoms disappeared but then reappeared repetitively. Cerebral MRI performed on the third day after onset showed multiple white matter lesions; however, these lesions disappeared 26 days after onset. Neurological examination and nerve conduction studies revealed demyelinating polyneuropathy. Genetic testing for Charcot-Marie-Tooth disease, X-linked dominant 1 (CMTX1) due to GJB1 mutation was conducted based on the symptoms of transient central nervous system lesions and polyneuropathy exhibited by the patient and his mother. As a result, a c.530T>C (p.V177A) substitution in exon 2 of GJB1 was identified. CMTX1 patients should be advised to avoid excessive drinking because this could induce central nervous system lesions.
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Affiliation(s)
- Chisato Shimizu
- Department of Neurology, Gunma University Graduate School of Medicine
| | - Hiroo Kasahara
- Department of Neurology, Gunma University Graduate School of Medicine
| | - Natsumi Furuta
- Department of Neurology, Gunma University Graduate School of Medicine
| | - Makoto Shibata
- Department of Neurology, Gunma University Graduate School of Medicine
- Department of Neurology, National Hospital Organization Takasaki General Medical Center
| | - Kazuaki Nagashima
- Department of Neurology, Gunma University Graduate School of Medicine
| | - Akihiro Hashiguchi
- Department of Neurology and Geriatrics, Kagoshima University Graduate School of Medical and Dental Sciences
| | - Hiroshi Takashima
- Department of Neurology and Geriatrics, Kagoshima University Graduate School of Medical and Dental Sciences
| | - Yoshio Ikeda
- Department of Neurology, Gunma University Graduate School of Medicine
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11
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Le Bras A, Proisy M, Kuchenbuch M, Gomes C, Tréguier C, Napuri S, Quehen E, Bruneau B. Reversible lesions of the corpus callosum with initially restricted diffusion in a series of Caucasian children. Pediatr Radiol 2018; 48:999-1007. [PMID: 29666887 DOI: 10.1007/s00247-018-4124-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/28/2017] [Revised: 02/10/2018] [Accepted: 03/22/2018] [Indexed: 10/17/2022]
Abstract
BACKGROUND Reversible lesions of the corpus callosum with initial restricted diffusion on diffusion-weighted imaging (DWI) are rare and mainly described in the south Asiatic population. OBJECTIVE The purpose of this study was to describe the clinical presentation, imaging findings, prognosis and etiology of transient restricted diffusion lesions of the corpus callosum in a series of Caucasian children. MATERIALS AND METHODS Seven children presenting with a transient restricted DWI lesion of the corpus callosum were included. Their clinical presentations and paraclinical examinations were investigated in addition to their MRI findings during the acute phase and at follow-up. RESULTS Five patients initially presenting with prodromal flu-like symptoms were diagnosed with mild encephalopathy with reversible corpus callosum lesions, three of which were due to the influenza virus. For two patients (twins) with a stroke-like presentation and without febrile illness, a central nervous system manifestation of X-linked Charcot-Marie-Tooth disease with connexin 32 mutation was diagnosed. All patients had a good clinical prognosis without clinical sequelae or residual MRI lesion for all patients at follow-up. CONCLUSION A transient lesion of the corpus callosum with restricted diffusion should prompt the radiologist to suggest an infectious trigger in children. The prognosis of these patients was good with normalization of clinical symptoms and MRI without any specific treatment.
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Affiliation(s)
- Anthony Le Bras
- Department of Medical Imaging, Hôpital Sud, CHU de Rennes, Rennes, France.
| | - Maia Proisy
- Department of Medical Imaging, Hôpital Sud, CHU de Rennes, Rennes, France
| | - Mathieu Kuchenbuch
- Department of Pediatric Neurology, Hôpital sud, CHU Rennes, Rennes, France
| | - Constantin Gomes
- Department of Pediatric Neurology, Hôpital sud, CHU Rennes, Rennes, France
| | - Catherine Tréguier
- Department of Medical Imaging, Hôpital Sud, CHU de Rennes, Rennes, France
| | - Sylvia Napuri
- Department of Pediatric Neurology, Hôpital sud, CHU Rennes, Rennes, France
| | - Emmanuel Quehen
- Department of Medical Imaging, CHU Pontchaillou, Rennes, France
| | - Bertrand Bruneau
- Department of Medical Imaging, Hôpital Sud, CHU de Rennes, Rennes, France
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12
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Zeydan B, Uygunoglu U, Altintas A, Saip S, Siva A, Abbink TEM, van der Knaap MS, Yalcinkaya C. Identification of 3 Novel Patients with CLCN2-Related Leukoencephalopathy due to CLCN2 Mutations. Eur Neurol 2017; 78:125-127. [PMID: 28746943 DOI: 10.1159/000478089] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2017] [Accepted: 06/07/2017] [Indexed: 11/19/2022]
Affiliation(s)
- Burcu Zeydan
- Department of Neurology, Cerrahpaşa School of Medicine, Istanbul University, Istanbul, Turkey.,Department of Radiology, Mayo Clinic College of Medicine, Rochester, Minnesota, USA
| | - Ugur Uygunoglu
- Department of Neurology, Cerrahpaşa School of Medicine, Istanbul University, Istanbul, Turkey
| | - Ayse Altintas
- Department of Neurology, Cerrahpaşa School of Medicine, Istanbul University, Istanbul, Turkey
| | - Sabahattin Saip
- Department of Neurology, Cerrahpaşa School of Medicine, Istanbul University, Istanbul, Turkey
| | - Aksel Siva
- Department of Neurology, Cerrahpaşa School of Medicine, Istanbul University, Istanbul, Turkey
| | - Truus E M Abbink
- Department of Child Neurology, VU University Medical Centre, Amsterdam, the Netherlands
| | - Marjo S van der Knaap
- Department of Child Neurology, VU University Medical Centre, Amsterdam, the Netherlands
| | - Cengiz Yalcinkaya
- Department of Neurology, Cerrahpaşa School of Medicine, Istanbul University, Istanbul, Turkey
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13
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Xie C, Zhou X, Zhu D, Liu W, Wang X, Yang H, Li Z, Hao Y, Zhang GX, Guan Y. CNS involvement in CMTX1 caused by a novel connexin 32 mutation: a 6-year follow-up in neuroimaging and nerve conduction. Neurol Sci 2016; 37:1063-70. [PMID: 27098243 DOI: 10.1007/s10072-016-2537-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2015] [Accepted: 02/24/2016] [Indexed: 12/29/2022]
Abstract
X-linked Charcot-Marie-Tooth disease, type 1 (CMTX1) is one of the most common inherited neurological disorders. Obvious CNS involvement is relatively rare in CMTX1 patients. A 24-year-old male with CMTX1 presented with three transient stroke-like attacks, and was followed up regularly for 6 years with brain MRI and electrophysiological examination. Transient symmetrical high signals on T2 imaging and restricted diffusion were found in bilateral deep white matter. Electrophysiological measurement revealed a sensorimotor peripheral neuropathy with slightly reduced nerve conduction velocities. A novel thymine to cytosine mutation at nucleotide position 445 in the connexin 32 allele of the GJB1 gene was identified. During the 6-year longitudinal study, patient's motor and sensory function did not worsen; radiological abnormalities correlated with episodes of CNS dysfunction and resolved after clinical recovery; electrophysiological records showed no obvious change. Little change in the patient's clinical, radiological and electrophysiological results over the follow-up reflected a slow disease progression.
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Affiliation(s)
- Chong Xie
- Department of Neurology, Changhai Hospital, Second Military Medical University, Shanghai, 200433, China
| | - Xiajun Zhou
- Department of Neurology, Renji Hospital, Shanghai Jiaotong University, 160 Pujian Road, Shanghai, China
| | - Desheng Zhu
- Department of Neurology, Huashan Hospital, Fudan University, Shanghai, China
| | - Wei Liu
- Department of Neurology, Changhai Hospital, Second Military Medical University, Shanghai, 200433, China
| | - Xiaoqing Wang
- Department of Neurology, Changhai Hospital, Second Military Medical University, Shanghai, 200433, China
| | - Hong Yang
- Department of Neurology, Shanghai Yangpu Geriatric Hospital, Shanghai, China
| | - Zezhi Li
- Department of Neurology, Renji Hospital, Shanghai Jiaotong University, 160 Pujian Road, Shanghai, China
| | - Yong Hao
- Department of Neurology, Renji Hospital, Shanghai Jiaotong University, 160 Pujian Road, Shanghai, China
| | - Guang-Xian Zhang
- Department of Neurology, Thomas Jefferson University, 900 Walnut Street, Suite 300, Philadelphia, PA, 19107, USA.
| | - Yangtai Guan
- Department of Neurology, Changhai Hospital, Second Military Medical University, Shanghai, 200433, China
- Department of Neurology, Renji Hospital, Shanghai Jiaotong University, 160 Pujian Road, Shanghai, China
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14
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Wang Y, Yin F. A Review of X-linked Charcot-Marie-Tooth Disease. J Child Neurol 2016; 31:761-72. [PMID: 26385972 DOI: 10.1177/0883073815604227] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/26/2015] [Accepted: 08/06/2015] [Indexed: 01/25/2023]
Abstract
X-linked Charcot-Marie-Tooth disease (CMTX) is the second common genetic variant of CMT. CMTX type 1 causes 90% of CMTX. The most important clinical features of CMTX are similar with other types of CMT; however, a few patients get the central nervous system involved with or without white matter lesions; males are more severely and earlier affected than females. In this review, the authors focus on the origin and classification of CMTX, the central nervous system manifestations of CMTX1, the possible mechanism by which GJB1 mutations cause CMT1X, and the emerging therapeutic strategies for CMTX. Moreover, several cases are presented to illustrate the central nervous system manifestations.
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Affiliation(s)
- Ying Wang
- Department of Pediatrics, Xiangya Hospital of Central South University, Changsha, Hunan, China
| | - Fei Yin
- Department of Pediatrics, Xiangya Hospital of Central South University, Changsha, Hunan, China Hunan Intellectual and Developmental Disabilities Research Center, Hunan, China
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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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Demyelinating CMT–what’s known, what’s new and what’s in store? Neurosci Lett 2015; 596:14-26. [DOI: 10.1016/j.neulet.2015.01.059] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2014] [Accepted: 01/23/2015] [Indexed: 02/06/2023]
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Kulkarni GB, Mailankody P, Isnwara PP, Prasad C, Mustare V. Episodic neurological dysfunction in hereditary peripheral neuropathy. Ann Indian Acad Neurol 2015; 18:111-4. [PMID: 25745327 PMCID: PMC4350196 DOI: 10.4103/0972-2327.144314] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2014] [Revised: 09/05/2014] [Accepted: 09/07/2014] [Indexed: 11/04/2022] Open
Abstract
Episodic transient neurological symptoms are an important set of problems presenting to a neurologist in his routine practice. Occasionally, detailed clinical history including past and family history supplemented with focused examination can bring out a rare cause for such symptoms. We describe in this report in a young male presenting with episodic focal neurological dysfunction, with family history of similar episodes in mother and brother. Examination showed features of pes cavus and peripheral neuropathy for which patient was asymptomatic. Mother and brother were established cases of hereditary neuropathy. Imaging on multiple occasions showed reversible white matter abnormalities. Clinical suspicion of X-linked Charcot-Marie-Tooth disease type 1 (CMT1X) was confirmed with detection of mutation in Gap Junction B1 (GJB1) gene, which codes for connexin 32 protein (c.425G>A; p.R142Q hemizygous mutation). Though this mutation has been already reported in CMTX patients, it has not been associated with transient neurological dysfunctions. This is probably the first reported case of CMTX patient with transient neurological dysfunction from India, whose family members had similar episodes.
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Affiliation(s)
- Girish Baburao Kulkarni
- Department of Neurology, National Institute of Mental Health and Neurosciences, Bengaluru, Karnataka, India
| | - Pooja Mailankody
- Department of Neurology, National Institute of Mental Health and Neurosciences, Bengaluru, Karnataka, India
| | - Pawanraj Palu Isnwara
- Department of Neurology, National Institute of Mental Health and Neurosciences, Bengaluru, Karnataka, India
| | - Chandrajit Prasad
- Department of Neuroradiology, National Institute of Mental Health and Neurosciences, Bengaluru, Karnataka, India
| | - Veerendrakumar Mustare
- Department of Neurology, National Institute of Mental Health and Neurosciences, Bengaluru, Karnataka, India
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A new mutation in GJC2 associated with subclinical leukodystrophy. J Neurol 2014; 261:1929-38. [PMID: 25059390 DOI: 10.1007/s00415-014-7429-1] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2014] [Revised: 06/27/2014] [Accepted: 06/28/2014] [Indexed: 12/13/2022]
Abstract
Recessive mutations in GJC2, the gene-encoding connexin 47 (Cx47), cause Pelizaeus-Merzbacher-like disease type 1, a severe dysmyelinating disorder. One recessive mutation (p.Ile33Met) has been associated with a much milder phenotype--hereditary spastic paraplegia type 44. Here, we present evidence that a novel Arg98Leu mutation causes an even milder phenotype--a subclinical leukodystrophy. The Arg98Leu mutant forms gap junction plaques in HeLa cells comparable to wild-type Cx47, but electrical coupling was 20-fold lower in cell pairs expressing Arg98Leu than for cell pairs expressing wild-type Cx47. On the other hand, coupling between Cx47Arg98Leu and Cx43WT expressing cells did not show such reductions. Single channel conductance and normalized steady-state junctional conductance-junctional voltage (G(j)-V(j)) relations differed only slightly from those for wild-type Cx47. Our data suggest that the minimal phenotype in this patient results from a reduced efficiency of opening of Cx47 channels between oligodendrocyte and oligodendrocyte with preserved coupling between oligodendrocyte and astrocyte, and support a partial loss of function model for the mild Cx47 associated disease phenotypes.
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McKinney JL, De Los Reyes EC, Lo WD, Flanigan KM. Recurrent central nervous system white matter changes in charcot-Marie-tooth type X disease. Muscle Nerve 2014; 49:451-4. [PMID: 24170412 DOI: 10.1002/mus.24108] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/17/2013] [Indexed: 11/10/2022]
Abstract
INTRODUCTION X-linked Charcot-Marie-Tooth (CMT1X) disease is caused by mutations in the GJB1 gene. We describe a young man who presented with recurrent central nervous symptoms and transient white matter changes in the setting of a novel mutation in the GJB1 gene. METHODS Evaluation included clinical examination, neuroimaging, electrophysiological, and molecular genetic studies. RESULTS Clinical examination on 2 admissions 5 years apart demonstrated hemiparesis with findings of underlying peripheral neuropathy. Electrophysiologic studies revealed a sensorimotor polyneuropathy. MRI studies from both admissions revealed white matter changes, with improvement on an intervening study. Mutation analysis showed a novel mutation (c.98T>A; p.Ile33Asn) in the GJB1 gene. CONCLUSIONS Mutations in GJB1 can result in recurrent central nervous system symptoms with transient white matter signal changes on MRI. In patients presenting with hemiparesis, the presence of signs of a peripheral neuropathy may facilitate identification of CMT1X, and is likely to affect clinical management.
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Affiliation(s)
- Jennifer L McKinney
- Division of Child Neurology, Nationwide Children's Hospital, 700 Children's Drive, Columbus, Ohio, 43205, USA; Department of Pediatrics, Ohio State University, Columbus, Ohio, USA
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Caramins M, Colebatch JG, Bainbridge MN, Scherer SS, Abrams CK, Hackett EL, Freidin MM, Jhangiani SN, Wang M, Wu Y, Muzny DM, Lindeman R, Gibbs RA. Exome sequencing identification of a GJB1 missense mutation in a kindred with X-linked spinocerebellar ataxia (SCA-X1). Hum Mol Genet 2013; 22:4329-38. [PMID: 23773993 PMCID: PMC3792691 DOI: 10.1093/hmg/ddt282] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2013] [Accepted: 06/11/2013] [Indexed: 12/21/2022] Open
Abstract
We undertook a gene identification and molecular characterization project in a large kindred originally clinically diagnosed with SCA-X1. While presenting with ataxia, this kindred also had some unique peripheral nervous system features. The implicated region on the X chromosome was delineated using haplotyping. Large deletions and duplications were excluded by array comparative genomic hybridization. Exome sequencing was undertaken in two affected subjects. The single identified X chromosome candidate variant was then confirmed to co-segregate appropriately in all affected, carrier and unaffected family members by Sanger sequencing. The variant was confirmed to be novel by comparison with dbSNP, and filtering for a minor allele frequency of <1% in 1000 Genomes project, and was not present in the NHLBI Exome Sequencing Project or a local database at the BCM HGSC. Functional experiments on transfected cells were subsequently undertaken to assess the biological effect of the variant in vitro. The variant identified consisted of a previously unidentified non-synonymous variant, GJB1 p.P58S, in the Connexin 32/Gap Junction Beta 1 gene. Segregation studies with Sanger sequencing confirmed the presence of the variant in all affected individuals and one known carrier, and the absence of the variant in unaffected members. Functional studies confirmed that the p.P58S variant reduced the number and size of gap junction plaques, but the conductance of the gap junctions was unaffected. Two X-linked ataxias have been associated with genetic loci, with the first of these recently characterized at the molecular level. This represents the second kindred with molecular characterization of X-linked ataxia, and is the first instance of a previously unreported GJB1 mutation with a dominant and permanent ataxia phenotype, although different CNS deficits have previously been reported. This pedigree has also been relatively unique in its phenotype due to the presence of central and peripheral neural abnormalities. Other X-linked SCAs with unique features might therefore also potentially represent variable phenotypic expression of other known neurological entities.
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Affiliation(s)
- Melody Caramins
- Department of Haematology and
- Department of Genetics, South Eastern Area Laboratory Services, Randwick, NSW 2031, Australia
| | - James G. Colebatch
- Department of Neurology, Prince of Wales Hospital
- Neuroscience Research Australia, Randwick, NSW 2031, Australia
| | | | - Steven S. Scherer
- Department of Neurology, The Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Charles K. Abrams
- Department of Neurology and
- Department of Physiology and Pharmacology, State University of New York, Downstate Medical Center, Brooklyn, NY 11203, USA
| | - Emma L. Hackett
- Department of Haematology and
- Department of Genetics, South Eastern Area Laboratory Services, Randwick, NSW 2031, Australia
| | | | - Shalini N. Jhangiani
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX 77030, USA
| | - Min Wang
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX 77030, USA
| | - Yuanqing Wu
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX 77030, USA
| | - Donna M. Muzny
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX 77030, USA
| | - Robert Lindeman
- Department of Haematology and
- Department of Genetics, South Eastern Area Laboratory Services, Randwick, NSW 2031, Australia
| | - Richard A. Gibbs
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX 77030, USA
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Depienne C, Bugiani M, Dupuits C, Galanaud D, Touitou V, Postma N, van Berkel C, Polder E, Tollard E, Darios F, Brice A, de Die-Smulders CE, Vles JS, Vanderver A, Uziel G, Yalcinkaya C, Frints SG, Kalscheuer VM, Klooster J, Kamermans M, Abbink TE, Wolf NI, Sedel F, van der Knaap MS. Brain white matter oedema due to ClC-2 chloride channel deficiency: an observational analytical study. Lancet Neurol 2013; 12:659-68. [PMID: 23707145 DOI: 10.1016/s1474-4422(13)70053-x] [Citation(s) in RCA: 128] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
BACKGROUND Mutant mouse models suggest that the chloride channel ClC-2 has functions in ion and water homoeostasis, but this has not been confirmed in human beings. We aimed to define novel disorders characterised by distinct patterns of MRI abnormalities in patients with leukoencephalopathies of unknown origin, and to identify the genes mutated in these disorders. We were specifically interested in leukoencephalopathies characterised by white matter oedema, suggesting a defect in ion and water homoeostasis. METHODS In this observational analytical study, we recruited patients with leukoencephalopathies characterised by MRI signal abnormalities in the posterior limbs of the internal capsules, midbrain cerebral peduncles, and middle cerebellar peduncles from our databases of patients with leukoencephalopathies of unknown origin. We used exome sequencing to identify the gene involved. We screened the candidate gene in additional patients by Sanger sequencing and mRNA analysis, and investigated the functional effects of the mutations. We assessed the localisation of ClC-2 with immunohistochemistry and electron microscopy in post-mortem human brains of individuals without neurological disorders. FINDINGS Seven patients met our inclusion criteria, three with adult-onset disease and four with childhood-onset disease. We identified homozygous or compound-heterozygous mutations in CLCN2 in three adult and three paediatric patients. We found evidence that the CLCN2 mutations result in loss of function of ClC-2. The remaining paediatric patient had an X-linked family history and a mutation in GJB1, encoding connexin 32. Clinical features were variable and included cerebellar ataxia, spasticity, chorioretinopathy with visual field defects, optic neuropathy, cognitive defects, and headaches. MRI showed restricted diffusion suggesting myelin vacuolation that was confined to the specified white matter structures in adult patients, and more diffusely involved the brain white matter in paediatric patients. We detected ClC-2 in all components of the panglial syncytium, enriched in astrocytic endfeet at the perivascular basal lamina, in the glia limitans, and in ependymal cells. INTERPRETATION Our observations substantiate the concept that ClC-2 is involved in brain ion and water homoeostasis. Autosomal-recessive CLCN2 mutations cause a leukoencephalopathy that belongs to an emerging group of disorders affecting brain ion and water homoeostasis and characterised by intramyelinic oedema. FUNDING European Leukodystrophies Association, INSERM and Assistance Publique-Hôpitaux de Paris, Dutch Organisation for Scientific Research (ZonMw), E-Rare, Hersenstichting, Optimix Foundation for Scientific Research, Myelin Disorders Bioregistry Project, National Institute of Neurological Disorders and Stroke, and Genetic and Epigenetic Networks in Cognitive Dysfunction (GENCODYS) Project (funded by the European Union Framework Programme 7).
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Siskind CE, Panchal S, Smith CO, Feely SME, Dalton JC, Schindler AB, Krajewski KM. A review of genetic counseling for Charcot Marie Tooth disease (CMT). J Genet Couns 2013; 22:422-36. [PMID: 23604902 DOI: 10.1007/s10897-013-9584-4] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2012] [Accepted: 03/20/2013] [Indexed: 02/07/2023]
Abstract
Charcot Marie Tooth disease (CMT) encompasses the inherited peripheral neuropathies. While four genes have been found to cause over 90 % of genetically identifiable causes of CMT (PMP22, GJB1, MPZ, MFN2), at least 51 genes and loci have been found to cause CMT when mutated, creating difficulties for clinicians to find a genetic subtype for families. Here, the classic features of CMT as well as characteristic features of the most common subtypes of CMT are described, as well as methods for narrowing down the possible subtypes. Psychosocial concerns particular to the CMT population are identified. This is the most inclusive publication for CMT-specific genetic counseling.
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Affiliation(s)
- Carly E Siskind
- Neurosciences Department, Stanford Hospital and Clinics, 300 Pasteur Dr., Stanford, CA 94305, USA.
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Abstract
Charcot-Marie-Tooth (CMT) disease is a heterogeneous group of inherited peripheral neuropathies in which the neuropathy is the sole or primary component of the disorder, as opposed to diseases in which the neuropathy is part of a more generalized neurologic or multisystem syndrome. Because of the great genetic heterogeneity of this condition, it can be challenging for the general neurologist to diagnose patients with specific types of CMT. This article reviews the biology of the inherited peripheral neuropathies, delineates major phenotypic features of the CMT subtypes, and suggest strategies for focusing genetic testing.
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Affiliation(s)
- Mario A Saporta
- National Laboratory of Embryonic Stem Cells, Biomedical Sciences Department, Federal University of Rio de Janeiro, Rua Republica do Peru 362/602, Rio de Janeiro 22021-040, Brazil.
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Pareyson D, Marchesi C, Salsano E. Dominant Charcot-Marie-Tooth syndrome and cognate disorders. HANDBOOK OF CLINICAL NEUROLOGY 2013; 115:817-845. [PMID: 23931817 DOI: 10.1016/b978-0-444-52902-2.00047-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Charcot-Marie-Tooth neuropathy (CMT) is a group of genetically heterogeneous disorders sharing a similar phenotype, characterized by wasting and weakness mainly involving the distal muscles of lower and upper limbs, variably associated with distal sensory loss and skeletal deformities. This chapter deals with dominantly transmitted CMT and related disorders, namely hereditary neuropathy with liability to pressure palsies (HNPP) and hereditary neuralgic amyotrophy (HNA). During the last 20 years, several genes have been uncovered associated with CMT and our understanding of the underlying molecular mechanisms has greatly improved. Consequently, a precise genetic diagnosis is now possible in the majority of cases, thus allowing proper genetic counseling. Although, unfortunately, treatment is still unavailable for all types of CMT, several cellular and animal models have been developed and some compounds have proved effective in these models. The first trials with ascorbic acid in CMT type 1A have been completed and, although negative, are providing relevant information on disease course and on how to prepare for future trials.
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Affiliation(s)
- Davide Pareyson
- Clinics of Central and Peripheral Degenerative Neuropathies Unit, Department of Clinical Neurosciences, IRCCS Foundation, C. Besta Neurological Institute, Milan, Italy.
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Kleopa KA, Abrams CK, Scherer SS. How do mutations in GJB1 cause X-linked Charcot-Marie-Tooth disease? Brain Res 2012; 1487:198-205. [PMID: 22771394 PMCID: PMC3488165 DOI: 10.1016/j.brainres.2012.03.068] [Citation(s) in RCA: 76] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2011] [Accepted: 03/24/2012] [Indexed: 11/26/2022]
Abstract
The X-linked form of Charcot-Marie-Tooth disease (CMT1X) is the second most common form of hereditary motor and sensory neuropathy. The clinical phenotype is characterized by progressive weakness, atrophy, and sensory abnormalities that are most pronounced in the distal extremities. Some patients have CNS manifestations. Affected males have moderate to severe symptoms, whereas heterozygous females are usually less affected. Neurophysiology shows intermediate slowing of conduction and length-dependent axonal loss. Nerve biopsies show more prominent axonal degeneration than de/remyelination. Mutations in GJB1, the gene that encodes the gap junction (GJ) protein connexin32 (Cx32) cause CMT1X; more than 400 different mutations have been described. Many Cx32 mutants fail to form functional GJs, or form GJs with abnormal biophysical properties. Schwann cells and oligodendrocytes express Cx32, and the GJs formed by Cx32 play an important role in the homeostasis of myelinated axons. Animal models of CMT1X demonstrate that loss of Cx32 in myelinating Schwann cells causes a demyelinating neuropathy. Effective therapies remain to be developed. This article is part of a Special Issue entitled Electrical Synapses.
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Affiliation(s)
- Kleopas A Kleopa
- Neurology Clinics and Neuroscience Laboratory, The Cyprus Institute of Neurology and Genetics, Nicosia, Cyprus
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Abrams CK, Scherer SS. Gap junctions in inherited human disorders of the central nervous system. BIOCHIMICA ET BIOPHYSICA ACTA 2012; 1818:2030-47. [PMID: 21871435 PMCID: PMC3771870 DOI: 10.1016/j.bbamem.2011.08.015] [Citation(s) in RCA: 86] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2011] [Revised: 08/04/2011] [Accepted: 08/10/2011] [Indexed: 12/15/2022]
Abstract
CNS glia and neurons express connexins, the proteins that form gap junctions in vertebrates. We review the connexins expressed by oligodendrocytes and astrocytes, and discuss their proposed physiologic roles. Of the 21 members of the human connexin family, mutations in three are associated with significant central nervous system manifestations. For each, we review the phenotype and discuss possible mechanisms of disease. Mutations in GJB1, the gene for connexin 32 (Cx32) cause the second most common form of Charcot-Marie-Tooth disease (CMT1X). Though the only consistent phenotype in CMT1X patients is a peripheral demyelinating neuropathy, CNS signs and symptoms have been found in some patients. Recessive mutations in GJC2, the gene for Cx47, are one cause of Pelizaeus-Merzbacher-like disease (PMLD), which is characterized by nystagmus within the first 6 months of life, cerebellar ataxia by 4 years, and spasticity by 6 years of age. MRI imaging shows abnormal myelination. A different recessive GJC2 mutation causes a form of hereditary spastic paraparesis, which is a milder phenotype than PMLD. Dominant mutations in GJA1, the gene for Cx43, cause oculodentodigital dysplasia (ODDD), a pleitropic disorder characterized by oculo-facial abnormalities including micropthalmia, microcornia and hypoplastic nares, syndactyly of the fourth to fifth fingers and dental abnormalities. Neurologic manifestations, including spasticity and gait difficulties, are often but not universally seen. Recessive GJA1 mutations cause Hallermann-Streiff syndrome, a disorder showing substantial overlap with ODDD. This article is part of a Special Issue entitled: The Communicating junctions, composition, structure and functions.
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Affiliation(s)
- Charles K. Abrams
- Department of Neurology and Physiology & Pharmacology, SUNY Downstate Medical Center, 450 Clarkson Avenue, Brooklyn, NY 11203, 1-718-270-1270 Phone, 1-718-270-8944 Fax,
| | - Steven S. Scherer
- Department of Neurology, The University of Pennsylvania School of Medicine, Room 450 Stemmler Hall, 36th Street and Hamilton Walk, Philadelphia, PA 19104-6077, 215-573-3198,
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Liégeois FJ, Morgan AT. Neural bases of childhood speech disorders: lateralization and plasticity for speech functions during development. Neurosci Biobehav Rev 2011; 36:439-58. [PMID: 21827785 DOI: 10.1016/j.neubiorev.2011.07.011] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2011] [Revised: 07/07/2011] [Accepted: 07/23/2011] [Indexed: 11/27/2022]
Abstract
Current models of speech production in adults emphasize the crucial role played by the left perisylvian cortex, primary and pre-motor cortices, the basal ganglia, and the cerebellum for normal speech production. Whether similar brain-behaviour relationships and leftward cortical dominance are found in childhood remains unclear. Here we reviewed recent evidence linking motor speech disorders (apraxia of speech and dysarthria) and brain abnormalities in children and adolescents with developmental, progressive, or childhood-acquired conditions. We found no evidence that unilateral damage can result in apraxia of speech, or that left hemisphere lesions are more likely to result in dysarthria than lesion to the right. The few studies reporting on childhood apraxia of speech converged towards morphological, structural, metabolic or epileptic anomalies affecting the basal ganglia, perisylvian and rolandic cortices bilaterally. Persistent dysarthria, similarly, was commonly reported in individuals with syndromes and conditions affecting these same structures bilaterally. In conclusion, for the first time we provide evidence that longterm and severe childhood speech disorders result predominantly from bilateral disruption of the neural networks involved in speech production.
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Affiliation(s)
- Frédérique J Liégeois
- Developmental Cognitive Neuroscience Unit, UCL Institute of Child Health, 30 Guilford Street, London WC1N 1EH, UK.
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Wasseff SK, Scherer SS. Cx32 and Cx47 mediate oligodendrocyte:astrocyte and oligodendrocyte:oligodendrocyte gap junction coupling. Neurobiol Dis 2011; 42:506-13. [PMID: 21396451 PMCID: PMC3773476 DOI: 10.1016/j.nbd.2011.03.003] [Citation(s) in RCA: 83] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2011] [Accepted: 03/02/2011] [Indexed: 12/24/2022] Open
Abstract
In addition to the extensive gap junction coupling between astrocytes themselves, oligodendrocytes are thought to be exclusively coupled to astrocytes (O:A coupling) via heterotypic gap junctions composed of Cx47:Cx43 and Cx32:Cx30. We used fluorescent dyes to examine functional coupling in acute slices from the cerebra of mice lacking Cx32 and/or Cx47. In the corpus callosum, unexpectedly, oligodendrocytes appeared to be directly and exclusively coupled to other oligodendrocytes (O:O coupling), and electron microscopy revealed gap junctions between adjacent oligodendrocytes. O:O coupling was more affected in mice lacking Cx32 than in mice lacking Cx47. In the neocortex, oligodendrocytes appeared to be directly and exclusively coupled to astrocytes; Cx47, but not Cx32, was required for O:A coupling.
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Affiliation(s)
- Sameh K. Wasseff
- Department of Neurology, University of Pennsylvania School of Medicine, Philadelphia, PA, USA
| | - Steven S. Scherer
- Department of Neurology, University of Pennsylvania School of Medicine, Philadelphia, PA, USA
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Absoud M, Brueton L, Gupta R, Quinlivan R, Wassmer E. Hereditary motor sensory neuropathy (type 1) presenting with transient and persistent central nervous system manifestations: a novel genetic mutation. Dev Med Child Neurol 2011; 53:381-2. [PMID: 21309765 DOI: 10.1111/j.1469-8749.2010.03901.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Rosser T, Muir J, Panigrahy A, Baldwin EE, Boles RG. Transient leukoencephalopathy associated with X-linked Charcot-Marie-Tooth disease. J Child Neurol 2010; 25:1013-6. [PMID: 20472869 DOI: 10.1177/0883073809352378] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
X-linked hereditary demyelinating neuropathy (Charcot-Marie-Tooth 1X) accounts for 10% to 20% of all hereditary demyelinating neuropathies and is caused by mutations in the GJB1 gene, which codes for connexin 32. Connexin 32 is a gap junction protein widely expressed in Schwann cells as well as oligodendrocytes. Transient leukoencephalopathy has been reported in children and adults with Charcot-Marie-Tooth 1X. The case of a previously healthy 10-year-old boy who presented with fluctuating neurological deficits is reviewed. His brain magnetic resonance imaging scans showed abnormal restricted diffusion and mild hyperintense T2-weighted and fluid attenuation inversion recovery abnormalities in the splenium of the corpus callosum and the posterior cerebral white matter in a bilaterally symmetric distribution. A family history of Charcot-Marie-Tooth disease was revealed late in his presentation, and genetic testing identified a mutation in the GJB1 gene that has not previously been associated with central nervous system involvement.
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Affiliation(s)
- Tena Rosser
- Division of Neurology, Childrens Hospital Los Angeles, and Department of Pediatrics, University of Southern California Keck School of Medicine, Los Angeles, California 90027, USA.
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Anand G, Maheshwari N, Roberts D, Padeniya A, Hamilton-Ayers M, van der Knaap M, Fratter C, Jayawant S. X-linked hereditary motor sensory neuropathy (type 1) presenting with a stroke-like episode. Dev Med Child Neurol 2010; 52:677-9. [PMID: 20491857 DOI: 10.1111/j.1469-8749.2010.03674.x] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
X-linked hereditary motor sensory neuropathy type 1 (CMTX 1) is caused by mutation in the GJB1 gene that codes for the connexin 32 protein. Central nervous system involvement with or without white matter changes on magnetic resonance imaging (MRI) has rarely been reported in this condition. We report the case of a 7-year-old, previously well male who presented with a stroke-like episode that manifested as left hemiparesis and dysphasia. An initial brain MRI showed white matter signal changes affecting the corpus callosum and periventricular areas with a posterior predominance. Our patient made a complete clinical recovery in 36 hours. Clinical examination at this stage showed no evidence of a peripheral neuropathy. A repeat brain MRI 6 weeks later showed almost complete resolution of the changes seen initially. Subsequent investigations showed a Val177Ala mutation in the GJB1 gene. This mutation has so far not been described in the Caucasian population and has been only described once before. Electrophysiological studies showed a mixed demyelinating and axonal sensorimotor neuropathy in keeping with CMTX 1. Five months after the initial presentation our patient developed clinical evidence of a peripheral neuropathy in the form of absent ankle reflexes, weak dorsiflexors, and evertors of both feet.
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Affiliation(s)
- Geetha Anand
- Paediatric Neurology, Oxford Radcliffe NHS Trust, Oxford, UK.
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Abstract
PURPOSE OF REVIEW We review recent advances in Charcot-Marie-Tooth disease (CMT), the most frequent inherited neuromuscular disorder. RECENT FINDINGS During the last year further progresses have occurred in this field and concerned identification of novel mutations in recently identified genes, allowing better definition of associated phenotypes; increased knowledge on pathophysiologic mechanisms of the different CMT types, with the contribution of cellular and animal model studies; studies on the natural history of CMT and attempts at developing appropriate outcome measures to assess disease course and intervention efficacy; trials with ascorbic acid in CMT type 1A; and studies on new possible therapeutic strategies. SUMMARY Such advances have implications on clinical management of CMT and are modifying the clinical approach to CMT, by improving diagnostic tools, allowing better definition of prognosis, and increasing the hope for future effective treatments. Research on CMT is important as is shedding light on important pathways that regulates the normal function of axonal transport, vesicular trafficking, and also revealing new aspects of intracellular organelles' function and interactions.
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