1
|
Arumugam SK, Subbarayan S. A Neonate with Recurrent Extubation Failure. Neoreviews 2024; 25:e163-e165. [PMID: 38425199 DOI: 10.1542/neo.25-3-e163] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/02/2024]
|
2
|
Kanduc D. Molecular Mimicry between Meningococcal B Factor H-Binding Protein and Human Proteins. Glob Med Genet 2023; 10:311-314. [PMID: 38025196 PMCID: PMC10653992 DOI: 10.1055/s-0043-1776985] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2023] Open
Abstract
This study calls attention on molecular mimicry and the consequent autoimmune cross reactivity as the molecular mechanism that can cause adverse events following meningococcal B vaccination and warns against active immunizations based on entire antigen.
Collapse
Affiliation(s)
- Darja Kanduc
- Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari, Bari, Italy
| |
Collapse
|
3
|
Chang C, Sell LB, Shi Q, Bhat MA. Mouse models of human CNTNAP1-associated congenital hypomyelinating neuropathy and genetic restoration of murine neurological deficits. Cell Rep 2023; 42:113274. [PMID: 37862170 PMCID: PMC10873044 DOI: 10.1016/j.celrep.2023.113274] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2023] [Revised: 08/14/2023] [Accepted: 09/28/2023] [Indexed: 10/22/2023] Open
Abstract
The Contactin-associated protein 1 (Cntnap1) mouse mutants fail to establish proper axonal domains in myelinated axons. Human CNTNAP1 mutations are linked to hypomyelinating neuropathy-3, which causes severe neurological deficits. To understand the human neuropathology and to model human CNTNAP1C323R and CNTNAP1R764C mutations, we generated Cntnap1C324R and Cntnap1R765C mouse mutants, respectively. Both Cntnap1 mutants show weight loss, reduced nerve conduction, and progressive motor dysfunction. The paranodal ultrastructure shows everted myelin loops and the absence of axo-glial junctions. Biochemical analysis reveals that these Cntnap1 mutant proteins are nearly undetectable in the paranodes, have reduced surface expression and stability, and are retained in the neuronal soma. Postnatal transgenic expression of Cntnap1 in the mutant backgrounds rescues the phenotypes and restores the organization of axonal domains with improved motor function. This study uncovers the mechanistic impact of two human CNTNAP1 mutations in a mouse model and provides proof of concept for gene therapy for CNTNAP1 patients.
Collapse
Affiliation(s)
- Cheng Chang
- Department of Cellular and Integrative Physiology University of Texas Health Science Center San Antonio, 7703 Floyd Curl Drive, San Antonio, TX 78229, USA; The Second Xiangya Hospital of Central South University, Changsha 410011, Hunan, China
| | - Lacey B Sell
- Department of Cellular and Integrative Physiology University of Texas Health Science Center San Antonio, 7703 Floyd Curl Drive, San Antonio, TX 78229, USA; IBMS Neuroscience Graduate Program, Joe R. and Teresa Lozano Long School of Medicine, University of Texas Health Science Center San Antonio, 7703 Floyd Curl Drive, San Antonio, TX 78229, USA
| | - Qian Shi
- Department of Cellular and Integrative Physiology University of Texas Health Science Center San Antonio, 7703 Floyd Curl Drive, San Antonio, TX 78229, USA; IBMS Neuroscience Graduate Program, Joe R. and Teresa Lozano Long School of Medicine, University of Texas Health Science Center San Antonio, 7703 Floyd Curl Drive, San Antonio, TX 78229, USA
| | - Manzoor A Bhat
- Department of Cellular and Integrative Physiology University of Texas Health Science Center San Antonio, 7703 Floyd Curl Drive, San Antonio, TX 78229, USA; IBMS Neuroscience Graduate Program, Joe R. and Teresa Lozano Long School of Medicine, University of Texas Health Science Center San Antonio, 7703 Floyd Curl Drive, San Antonio, TX 78229, USA.
| |
Collapse
|
4
|
Khadilkar SV, Kamat S, Patel R. Nodo-paranodopathies: Concepts, Clinical Implications, and Management. Ann Indian Acad Neurol 2022; 25:1001-1008. [PMID: 36911467 PMCID: PMC9996523 DOI: 10.4103/aian.aian_382_22] [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: 04/27/2022] [Revised: 04/27/2022] [Accepted: 04/28/2022] [Indexed: 11/04/2022] Open
Abstract
Peripheral neuropathies are traditionally categorized into demyelinating or axonal. It has been proposed that dysfunction at nodal/paranodal region may be a key for better understanding of pathophysiology in patients with immune mediated neuropathies. In last few years, antibodies targeting node and paranode of myelinated nerves have been increasingly detected in patients with immune mediated neuropathies. These patients have clinical phenotype similar common inflammatory neuropathies like Guillain Barre syndrome and chronic inflammatory demyelinating polyradiculoneuropathy with some additional atypical neurological and systemic features, and they respond poorly to conventional first line immunotherapies like IVIG. This review summarizes the structure of the node, concept and pathophysiology of nodopathies. We provide an overview of clinical phenotypes in patients with specific nodal/paranodal antibodies, along with electrophysiological and other diagnostic features and suggest therapeutic line of management based on current evidence.
Collapse
Affiliation(s)
- Satish V. Khadilkar
- Departments of Neurology, Bombay Hospital Institute of Medical Sciences, Seth GS Medical College and KEM Hospital, Mumbai, Maharashtra, India
| | - Saurabh Kamat
- Departments of Neurology, Bombay Hospital Institute of Medical Sciences, Seth GS Medical College and KEM Hospital, Mumbai, Maharashtra, India
| | - Riddhi Patel
- Departments of Neurology, Bombay Hospital Institute of Medical Sciences, Seth GS Medical College and KEM Hospital, Mumbai, Maharashtra, India
| |
Collapse
|
5
|
Vallat JM, Deschamps N, Taithe F, Richard L, Duchesne M, Magy L, Mathis S. Are Miller Fisher syndrome and CANDA due to a paranodopathy? J Neurol Sci 2022; 438:120279. [DOI: 10.1016/j.jns.2022.120279] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Revised: 05/04/2022] [Accepted: 05/06/2022] [Indexed: 01/06/2023]
|
6
|
Tracking the Molecular Scenarios for Tumorigenic Remodeling of Extracellular Matrix Based on Gene Expression Profiling in Equine Skin Neoplasia Models. Int J Mol Sci 2022; 23:ijms23126506. [PMID: 35742950 PMCID: PMC9223705 DOI: 10.3390/ijms23126506] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2022] [Revised: 06/05/2022] [Accepted: 06/09/2022] [Indexed: 11/17/2022] Open
Abstract
An important component of tissues is the extracellular matrix (ECM), which not only forms a tissue scaffold, but also provides the environment for numerous biochemical reactions. Its composition is strictly regulated, and any irregularities can result in the development of many diseases, including cancer. Sarcoid is the most common skin cancer in equids. Its formation results from the presence of the genetic material of the bovine papillomavirus (BPV). In addition, it is assumed that sarcoid-dependent oncogenic transformation arises from a disturbed wound healing process, which may be due to the incorrect functioning of the ECM. Moreover, sarcoid is characterized by a failure to metastasize. Therefore, in this study we decided to investigate the differences in the expression profiles of genes related not only to ECM remodeling, but also to the cell adhesion pathway, in order to estimate the influence of disturbances within the ECM on the sarcoid formation process. Furthermore, we conducted comparative research not only between equine sarcoid tissue bioptates and healthy skin-derived explants, but also between dermal fibroblast cell lines transfected and non-transfected with a construct encoding the E4 protein of the BP virus, in order to determine its effect on ECM disorders. The obtained results strongly support the hypothesis that ECM-related genes are correlated with sarcoid formation. The deregulated expression of selected genes was shown in both equine sarcoid tissue bioptates and adult cutaneous fibroblast cell (ACFC) lines neoplastically transformed by nucleofection with gene constructs encoding BPV1-E1^E4 protein. The identified genes (CD99, ITGB1, JAM3 and CADM1) were up- or down-regulated, which pinpointed the phenotypic differences from the backgrounds noticed for adequate expression profiles in other cancerous or noncancerous tumors as reported in the available literature data. Unravelling the molecular pathways of ECM remodeling and cell adhesion in the in vivo and ex vivo models of epidermal/dermal sarcoid-related cancerogenesis might provide powerful tools for further investigations of genetic and epigenetic biomarkers for both silencing and re-initiating the processes of sarcoid-dependent neoplasia. Recognizing those biomarkers might insightfully explain the relatively high capacity of sarcoid-descended cancerous cell derivatives to epigenomically reprogram their nonmalignant neoplastic status in domestic horse cloned embryos produced by somatic cell nuclear transfer (SCNT).
Collapse
|
7
|
Garel P, Lesca G, Ville D, Poulat AL, Chatron N, Sanlaville D, Des Portes V, Arzimanoglou A, Lion-François L. CNTNAP1-encephalopathy: Six novel patients surviving the neonatal period. Eur J Paediatr Neurol 2022; 37:98-104. [PMID: 35182943 DOI: 10.1016/j.ejpn.2022.01.015] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Revised: 12/29/2021] [Accepted: 01/26/2022] [Indexed: 11/29/2022]
Abstract
CNTNAP1 encodes CASPR1, involved in the paranodal junction. Thirty-three patients, with CNTNAP1 biallelic mutations have been described previously. Most of them had a very severe neurological impairment and passed away in the first months of life. We identified four patients, from two unrelated families, who survived over the neonatal period. Exome sequencing showed compound heterozygous or homozygous variants. Severe hypotonia was a constant feature. When compared to previous reports, the most important clinical differences observed in our patients were the absence of antenatal problems and, in two of them, the lack of respiratory distress. Less commonly reported characteristics such as epileptic seizures, dystonia, and impaired communication skills were also observed. MRIs revealed hypomyelination or abnormal white matter signal, cerebral or cerebellar atrophy. The present observations support a wider than initially reported clinical spectrum, including survival after the neonatal period and additional neurological features. They contribute to better delineate the phenotype-genotype correlations for CNTNAP1. In addition, we report one more family with two sibs who carry a missense variant of uncertain significance which we propose could be associated with a milder phenotype.
Collapse
Affiliation(s)
- Pauline Garel
- Department of Pediatrics, Centre Hospitalier Universitaire de Saint Etienne, Saint-Priest-en-Jarez, France.
| | - Gaetan Lesca
- Genetics Department, Member of the ERN EpiCARE, HFME, University Hospitals of Lyon (HCL), Lyon, France; INMG (Institut Neuromyogene), Faculté de Médecine Lyon Est, Université Claude Bernard Lyon 1, Lyon, France
| | - Dorothée Ville
- Pediatric Neurology Department, Member of the ERN EpiCARE, University Hospitals of Lyon (HCL), Lyon, France
| | - Anne-Lise Poulat
- Pediatric Neurology Department, Member of the ERN EpiCARE, University Hospitals of Lyon (HCL), Lyon, France
| | - Nicolas Chatron
- Department of Biology and Pathology, University Hospitals of Lyon (HCL), Lyon, France; INMG (Institut Neuromyogene), Faculté de Médecine Lyon Est, Université Claude Bernard Lyon 1, Lyon, France
| | - Damien Sanlaville
- Department of Biology and Pathology, University Hospitals of Lyon (HCL), Lyon, France; INMG (Institut Neuromyogene), Faculté de Médecine Lyon Est, Université Claude Bernard Lyon 1, Lyon, France
| | - Vincent Des Portes
- Pediatric Neurology Department, Member of the ERN EpiCARE, University Hospitals of Lyon (HCL), Lyon, France
| | - Alexis Arzimanoglou
- Department of Paediatric Clinical Epileptology, Sleep Disorders and Functional Neurology, Member of the ERN EpiCARE, University Hospitals of Lyon (HCL), Lyon, France
| | - Laurence Lion-François
- Pediatric Neurology Department, Member of the ERN EpiCARE, University Hospitals of Lyon (HCL), Lyon, France
| |
Collapse
|
8
|
Cavallaro T, Tagliapietra M, Fabrizi GM, Bai Y, Shy ME, Vallat JM. Hereditary neuropathies: A pathological perspective. J Peripher Nerv Syst 2021; 26 Suppl 2:S42-S60. [PMID: 34499384 DOI: 10.1111/jns.12467] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Revised: 03/30/2021] [Accepted: 08/24/2021] [Indexed: 12/29/2022]
Abstract
Hereditary neuropathies may result from mutations in genes expressed by Schwann cells or neurons that affect selectively the peripheral nervous system (PNS) or may represent a minor or major component of complex inherited diseases that involve also the central nervous system and/or other organs and tissues. The chapter is constantly expanding and reworking, thanks to advances of molecular genetics; next-generation sequencing is identifying a plethora of new genes and is revolutionizing the diagnostic approach. In the past, diagnostic sural nerve biopsies paved the way to the discovery and elucidation of major genes and molecular pathways associated to most frequent hereditary motor-sensory neuropathies. Nowadays, a sural nerve biopsy may prove useful in selected cases for the differential diagnosis of an acquired neuropathy when clinical examination, nerve conduction studies, and molecular tests are not sufficiently informative. Skin biopsy has emerged as a minimally invasive window on the PNS, which may provide biomarkers of progression and clues to the physiopathology and molecular pathology of inherited neuropathies. The aim of our review is to illustrate the pathological features of more frequent and paradigmatic hereditary neuropathies and to highlight their correlations with the roles of the involved genes and functional consequences of related molecular defects.
Collapse
Affiliation(s)
- Tiziana Cavallaro
- Department of Neurosciences, Biomedicine, and Movement Sciences, University of Verona, Verona, VR, Italy
| | - Matteo Tagliapietra
- Department of Neurosciences, Biomedicine, and Movement Sciences, University of Verona, Verona, VR, Italy
| | - Gian Maria Fabrizi
- Department of Neurosciences, Biomedicine, and Movement Sciences, University of Verona, Verona, VR, Italy
| | - Yunhong Bai
- Department of Neurology, Carver College of Medicine, University of Iowa, Iowa City, Iowa, USA
| | - Michael E Shy
- Department of Neurology, Carver College of Medicine, University of Iowa, Iowa City, Iowa, USA
| | - Jean-Michel Vallat
- Department of Neurology, National Reference Center for "Rare Peripheral Neuropathies", CHU Dupuytren, Limoges, France
| |
Collapse
|
9
|
Abstract
Myelination of axons provides the structural basis for rapid saltatory impulse propagation along vertebrate fiber tracts, a well-established neurophysiological concept. However, myelinating oligodendrocytes and Schwann cells serve additional functions in neuronal energy metabolism that are remarkably similar to those of axon-ensheathing glial cells in unmyelinated invertebrates. Here we discuss myelin evolution and physiological glial functions, beginning with the role of ensheathing glia in preventing ephaptic coupling, axoglial metabolic support, and eliminating oxidative radicals. In both vertebrates and invertebrates, axoglial interactions are bidirectional, serving to regulate cell fate, nerve conduction, and behavioral performance. One key step in the evolution of compact myelin in the vertebrate lineage was the emergence of the open reading frame for myelin basic protein within another gene. Several other proteins were neofunctionalized as myelin constituents and help maintain a healthy nervous system. Myelination in vertebrates became a major prerequisite of inhabiting new ecological niches.
Collapse
Affiliation(s)
- Klaus-Armin Nave
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, D-37075 Göttingen, Germany; ,
| | - Hauke B Werner
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, D-37075 Göttingen, Germany; ,
| |
Collapse
|
10
|
Kalafatakis I, Savvaki M, Velona T, Karagogeos D. Implication of Contactins in Demyelinating Pathologies. Life (Basel) 2021; 11:life11010051. [PMID: 33451101 PMCID: PMC7828632 DOI: 10.3390/life11010051] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Revised: 01/09/2021] [Accepted: 01/11/2021] [Indexed: 12/19/2022] Open
Abstract
Demyelinating pathologies comprise of a variety of conditions where either central or peripheral myelin is attacked, resulting in white matter lesions and neurodegeneration. Myelinated axons are organized into molecularly distinct domains, and this segregation is crucial for their proper function. These defined domains are differentially affected at the different stages of demyelination as well as at the lesion and perilesion sites. Among the main players in myelinated axon organization are proteins of the contactin (CNTN) group of the immunoglobulin superfamily (IgSF) of cell adhesion molecules, namely Contactin-1 and Contactin-2 (CNTN1, CNTN2). The two contactins perform their functions through intermolecular interactions, which are crucial for myelinated axon integrity and functionality. In this review, we focus on the implication of these two molecules as well as their interactors in demyelinating pathologies in humans. At first, we describe the organization and function of myelinated axons in the central (CNS) and the peripheral (PNS) nervous system, further analyzing the role of CNTN1 and CNTN2 as well as their interactors in myelination. In the last section, studies showing the correlation of the two contactins with demyelinating pathologies are reviewed, highlighting the importance of these recognition molecules in shaping the function of the nervous system in multiple ways.
Collapse
|
11
|
Letko A, Minor KM, Friedenberg SG, Shelton GD, Salvador JP, Mandigers PJJ, Leegwater PAJ, Winkler PA, Petersen-Jones SM, Stanley BJ, Ekenstedt KJ, Johnson GS, Hansen L, Jagannathan V, Mickelson JR, Drögemüller C. A CNTNAP1 Missense Variant Is Associated with Canine Laryngeal Paralysis and Polyneuropathy. Genes (Basel) 2020; 11:E1426. [PMID: 33261176 PMCID: PMC7761076 DOI: 10.3390/genes11121426] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Revised: 11/25/2020] [Accepted: 11/26/2020] [Indexed: 02/06/2023] Open
Abstract
Laryngeal paralysis associated with a generalized polyneuropathy (LPPN) most commonly exists in geriatric dogs from a variety of large and giant breeds. The purpose of this study was to discover the underlying genetic and molecular mechanisms in a younger-onset form of this neurodegenerative disease seen in two closely related giant dog breeds, the Leonberger and Saint Bernard. Neuropathology of an affected dog from each breed showed variable nerve fiber loss and scattered inappropriately thin myelinated fibers. Using across-breed genome-wide association, haplotype analysis, and whole-genome sequencing, we identified a missense variant in the CNTNAP1 gene (c.2810G>A; p.Gly937Glu) in which homozygotes in both studied breeds are affected. CNTNAP1 encodes a contactin-associated protein important for organization of myelinated axons. The herein described likely pathogenic CNTNAP1 variant occurs in unrelated breeds at variable frequencies. Individual homozygous mutant LPPN-affected Labrador retrievers that were on average four years younger than dogs affected by geriatric onset laryngeal paralysis polyneuropathy could be explained by this variant. Pathologic changes in a Labrador retriever nerve biopsy from a homozygous mutant dog were similar to those of the Leonberger and Saint Bernard. The impact of this variant on health in English bulldogs and Irish terriers, two breeds with higher CNTNAP1 variant allele frequencies, remains unclear. Pathogenic variants in CNTNAP1 have previously been reported in human patients with lethal congenital contracture syndrome and hypomyelinating neuropathy, including vocal cord palsy and severe respiratory distress. This is the first report of contactin-associated LPPN in dogs characterized by a deleterious variant that most likely predates modern breed establishment.
Collapse
Affiliation(s)
- Anna Letko
- Institute of Genetics, Vetsuisse Faculty, University of Bern, 3012 Bern, Switzerland; (V.J.); (C.D.)
| | - Katie M. Minor
- Department of Veterinary and Biomedical Sciences, College of Veterinary Medicine, University of Minnesota, Saint Paul, MN 55108, USA; (K.M.M.); (J.R.M.)
| | - Steven G. Friedenberg
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine, University of Minnesota, Saint Paul, MN 55108, USA;
| | - G. Diane Shelton
- Department of Pathology, School of Medicine, University of California San Diego, La Jolla, CA 92093-0709, USA; (G.D.S.); (J.P.S.)
| | - Jill Pesayco Salvador
- Department of Pathology, School of Medicine, University of California San Diego, La Jolla, CA 92093-0709, USA; (G.D.S.); (J.P.S.)
| | - Paul J. J. Mandigers
- Department of Clinical Sciences, Utrecht University, 3584 CM Utrecht, The Netherlands; (P.J.J.M.); (P.A.J.L.)
| | - Peter A. J. Leegwater
- Department of Clinical Sciences, Utrecht University, 3584 CM Utrecht, The Netherlands; (P.J.J.M.); (P.A.J.L.)
| | - Paige A. Winkler
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, East Lansing, MI 48824, USA; (P.A.W.); (S.M.P.-J.); (B.J.S.)
| | - Simon M. Petersen-Jones
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, East Lansing, MI 48824, USA; (P.A.W.); (S.M.P.-J.); (B.J.S.)
| | - Bryden J. Stanley
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, East Lansing, MI 48824, USA; (P.A.W.); (S.M.P.-J.); (B.J.S.)
| | - Kari J. Ekenstedt
- Department of Basic Medical Sciences, College of Veterinary Medicine, Purdue University, West Lafayette, IN 47907, USA;
| | - Gary S. Johnson
- Department of Veterinary Pathobiology, University of Missouri, Columbia, MO 65211, USA; (G.S.J.); (L.H.)
| | - Liz Hansen
- Department of Veterinary Pathobiology, University of Missouri, Columbia, MO 65211, USA; (G.S.J.); (L.H.)
| | - Vidhya Jagannathan
- Institute of Genetics, Vetsuisse Faculty, University of Bern, 3012 Bern, Switzerland; (V.J.); (C.D.)
| | - James R. Mickelson
- Department of Veterinary and Biomedical Sciences, College of Veterinary Medicine, University of Minnesota, Saint Paul, MN 55108, USA; (K.M.M.); (J.R.M.)
| | - Cord Drögemüller
- Institute of Genetics, Vetsuisse Faculty, University of Bern, 3012 Bern, Switzerland; (V.J.); (C.D.)
| |
Collapse
|
12
|
Abstract
The nodes of Ranvier have clustered Na+ and K+ channels necessary for rapid and efficient axonal action potential conduction. However, detailed mechanisms of channel clustering have only recently been identified: they include two independent axon-glia interactions that converge on distinct axonal cytoskeletons. Here, we discuss how glial cell adhesion molecules and the extracellular matrix molecules that bind them assemble combinations of ankyrins, spectrins and other cytoskeletal scaffolding proteins, which cluster ion channels. We present a detailed molecular model, incorporating these overlapping mechanisms, to explain how the nodes of Ranvier are assembled in both the peripheral and central nervous systems.
Collapse
|
13
|
Li W, Yang L, Tang C, Liu K, Lu Y, Wang H, Yan K, Qiu Z, Zhou W. Mutations of CNTNAP1 led to defects in neuronal development. JCI Insight 2020; 5:135697. [PMID: 33148880 PMCID: PMC7710280 DOI: 10.1172/jci.insight.135697] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2019] [Accepted: 09/30/2020] [Indexed: 12/20/2022] Open
Abstract
Mutations of CNTNAP1 were associated with myelination disorders, suggesting the role of CNTNAP1 in myelination processes. Whether CNTNAP1 may have a role in early cortical neuronal development is largely unknown. In this study, we identified 4 compound heterozygous mutations of CNTNAP1 in 2 Chinese families. Using mouse models, we found that CNTNAP1 is highly expressed in neurons and is located predominantly in MAP2+ neurons during the early developmental stage. Importantly, Cntnap1 deficiency results in aberrant dendritic growth and spine development in vitro and in vivo, and it delayed migration of cortical neurons during early development. Finally, we found that the number of parvalbumin+ neurons in the cortex and hippocampus of Cntnap1–/– mice is strikingly increased by P15, suggesting that excitation/inhibition balance is impaired. Together, this evidence elucidates a critical function of CNTNAP1 in cortical development, providing insights underlying molecular and circuit mechanisms of CNTNAP1-related disease. Deficiency of CNTNAP1 causes severe cortical developmental deficits, leading to human lethal perinatal symptoms.
Collapse
Affiliation(s)
| | - Lin Yang
- Key Laboratory of Birth Defects.,Division of Endocrinology, Genetics and Metabolic Disease, and
| | - Chuanqing Tang
- Stem Cell Research Center, Institute of Pediatrics, Children's Hospital, Fudan University, Shanghai, China
| | | | | | | | | | - Zilong Qiu
- Institute of Neuroscience, State Key Laboratory of Neuroscience.,CAS Center for Excellence in Brain Science and Intelligence Technology.,Shanghai Center for Brain Science and Brain-Inspired Intelligence Technology.,Chinese Academy of Sciences, and.,National Clinical Research Center for Aging and Medicine, Huashan Hospital, Fudan University, Shanghai, China
| | - Wenhao Zhou
- Division of Neonatology.,Key Laboratory of Birth Defects.,Key Laboratory of Neonatal Diseases, Ministry of Health, Children's Hospital of Fudan University, Shanghai, China
| |
Collapse
|
14
|
Vallat JM, Magy L, Corcia P, Boulesteix JM, Uncini A, Mathis S. Ultrastructural Lesions of Nodo-Paranodopathies in Peripheral Neuropathies. J Neuropathol Exp Neurol 2020; 79:247-255. [PMID: 31923310 DOI: 10.1093/jnen/nlz134] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2019] [Revised: 11/05/2019] [Accepted: 12/05/2019] [Indexed: 01/06/2023] Open
Abstract
Whatever the cause of myelin damage of the peripheral nervous system, the initial attack on myelin by a dysimmune process may begin either at the internodal area or in the paranodal and nodal regions. The term "nodo-paranodopathy" was first applied to some "axonal Guillain-Barré syndrome" subtypes, then extended to cases classified as chronic inflammatory demyelinating polyradiculoneuropathy bearing IgG4 antibodies against paranodal axoglial proteins. In these cases, paranodal dissection develops in the absence of macrophage-induced demyelination. In contrast, the mechanisms of demyelination of other dysimmune neuropathies induced by macrophages are unexplained, as no antibodies have been identified in such cases. Electron microscopy of longitudinal sections of nerve biopsies is useful to visualize and authenticate the characteristic lesions of paranodes/nodes. However, it should be borne in mind that identical ultrastructural aspects are seen in other types of polyneuropathies: Genetic, experimental, and in a few polyneuropathies for which there is no obvious etiology. Ultrastructural nerve studies confirm the initial involvement of nodes/paranodes in various types of acquired and genetic neuropathies. For some of them, the antibodies or the proteins involved by mutations are clearly identified such as Caspr-1, Contactin-1, NFasc155, and NFasc186; other unidentified proteins are likely to be involved as well.
Collapse
Affiliation(s)
- Jean-Michel Vallat
- From the Department of Neurology, National Reference Center for 'Rare Peripheral Neuropathies', University Hospital, Limoges, France
| | - Laurent Magy
- From the Department of Neurology, National Reference Center for 'Rare Peripheral Neuropathies', University Hospital, Limoges, France
| | - Philippe Corcia
- Department of Neurology, ALS Reference Center, CHU Tours (Bretonneau Hospital), Tours, France
| | | | - Antonino Uncini
- Department of Neurosciences, Imaging and Clinical Sciences, University "G. d'Annunzio", Chieti-Pescara, Italy
| | - Stéphane Mathis
- Department of Neurology, Nerve-Muscle Unit, CHU Bordeaux (Pellegrin University Hospital), Bordeaux, France
| |
Collapse
|
15
|
CNTNAP1 Mutations and Their Clinical Presentations: New Case Report and Systematic Review. Case Rep Med 2020; 2020:8795607. [PMID: 32328110 PMCID: PMC7174947 DOI: 10.1155/2020/8795607] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Revised: 03/23/2020] [Accepted: 03/27/2020] [Indexed: 01/11/2023] Open
Abstract
Lethal congenital contracture syndrome type 7 (LCCS7) and congenital hypomyelinating neuropathy type 3 (CHN3) are rare autosomal recessive diseases, characterized by severe neonatal hypotonia, polyhydramnios, arthrogryposis, facial diplegia, and severe motor paralysis, leading to death in early infancy. They are related to mutations in the CNTNAP1 (contactin associated protein 1) gene, playing an important role in myelination. Recent studies have shown that both diseases could present with a wide phenotypic spectrum, with promising survival up to early childhood. We report on a 7-year-old boy from a nonconsanguineous Lebanese family presenting with neonatal hypotonia, respiratory distress, and arthrogryposis. Molecular analysis revealed the presence of a pathogenic variant in the CNTNAP1 gene leading to a premature stop codon: NM_003632.2:c.3361C>T p.(Arg1121∗). A review of the literature is discussed.
Collapse
|
16
|
Molecular organization and function of vertebrate septate-like junctions. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2020; 1862:183211. [PMID: 32032590 DOI: 10.1016/j.bbamem.2020.183211] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2019] [Revised: 01/22/2020] [Accepted: 01/26/2020] [Indexed: 12/21/2022]
Abstract
Septate-like junctions display characteristic ladder-like ultrastructure reminiscent of the invertebrate epithelial septate junctions and are present at the paranodes of myelinated axons. The paranodal junctions where the myelin loops attach to the axon at the borders of the node of Ranvier provide both a paracellular barrier to ion diffusion and a lateral fence along the axonal membrane. The septate-like junctions constrain the proper distribution of nodal Na+ channels and juxtaparanodal K+ channels, which are required for the safe propagation of the nerve influx and rapid saltatory conduction. The paranodal cell adhesion molecules have been identified as target antigens in peripheral demyelinating autoimmune diseases and the pathogenic mechanisms described. This review aims at presenting the recent knowledge on the molecular and structural organization of septate-like junctions, their formation and stabilization during development, and how they are involved in demyelinating diseases.
Collapse
|
17
|
Morelli KH, Hatton CL, Harper SQ, Burgess RW. Gene therapies for axonal neuropathies: Available strategies, successes to date, and what to target next. Brain Res 2020; 1732:146683. [PMID: 32001243 DOI: 10.1016/j.brainres.2020.146683] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2019] [Revised: 01/23/2020] [Accepted: 01/24/2020] [Indexed: 12/20/2022]
Abstract
Nearly one-hundred loci in the human genome have been associated with different forms of Charcot-Marie-Tooth disease (CMT) and related inherited neuropathies. Despite this wealth of gene targets, treatment options are still extremely limited, and clear "druggable" pathways are not obvious for many of these mutations. However, recent advances in gene therapies are beginning to circumvent this challenge. Each type of CMT is a monogenic disorder, and the cellular targets are usually well-defined and typically include peripheral neurons or Schwann cells. In addition, the genetic mechanism is often also clear, with loss-of-function mutations requiring restoration of gene expression, and gain-of-function or dominant-negative mutations requiring silencing of the mutant allele. These factors combine to make CMT a good target for developing genetic therapies. Here we will review the state of relatively established gene therapy approaches, including viral vector-mediated gene replacement and antisense oligonucleotides for exon skipping, altering splicing, and gene knockdown. We will also describe earlier stage approaches for allele-specific knockdown and CRIPSR/Cas9 gene editing. We will next describe how these various approaches have been deployed in clinical and preclinical studies. Finally, we will evaluate various forms of CMT as candidates for gene therapy based on the current understanding of their genetics, cellular/tissue targets, validated animal models, and availability of patient populations and natural history data.
Collapse
Affiliation(s)
- Kathryn H Morelli
- The Jackson Laboratory, Bar Harbor, ME 04609, USA; The Graduate School of Biomedical Science and Engineering, University of Maine, Orono, ME 04469, USA
| | | | - Scott Q Harper
- Center for Gene Therapy, The Research Institute at Nationwide Children's Hospital, Columbus, OH, USA; Department of Pediatrics, The Ohio State University College of Medicine, Columbus, OH, USA
| | - Robert W Burgess
- The Jackson Laboratory, Bar Harbor, ME 04609, USA; The Graduate School of Biomedical Science and Engineering, University of Maine, Orono, ME 04469, USA.
| |
Collapse
|
18
|
Wu R, Fu J, Meng L, Lv H, Wang Z, Zhirong J, Yuan Y. Homozygous splice‐site mutation c.78 + 5G>A in
PMP22
causes congenital hypomyelinating neuropathy. Neuropathology 2019; 39:441-446. [PMID: 31777123 DOI: 10.1111/neup.12604] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2019] [Revised: 08/24/2019] [Accepted: 08/25/2019] [Indexed: 01/10/2023]
Affiliation(s)
- Rui Wu
- Department of NeurologyPeking University First Hospital Beijing China
| | - Jun Fu
- Department of NeurologyPeking University First Hospital Beijing China
| | - Lingchao Meng
- Department of NeurologyPeking University First Hospital Beijing China
| | - He Lv
- Department of NeurologyPeking University First Hospital Beijing China
| | - Zhaoxia Wang
- Department of NeurologyPeking University First Hospital Beijing China
| | - Jia Zhirong
- Department of NeurologyPeking University First Hospital Beijing China
| | - Yun Yuan
- Department of NeurologyPeking University First Hospital Beijing China
| |
Collapse
|
19
|
Freed AS, Weiss MD, Malouf EA, Hisama FM. CNTNAP1 mutations in an adult with Charcot Marie Tooth disease. Muscle Nerve 2019; 60:E28-E30. [PMID: 31397905 DOI: 10.1002/mus.26658] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2018] [Revised: 07/25/2019] [Accepted: 08/06/2019] [Indexed: 01/16/2023]
Affiliation(s)
- Amanda S Freed
- Medical Genetics and Genomics Residency Program, Washington School of Medicine, University of Washington, Seattle, Washington
| | - Michael D Weiss
- Professor of Neurology and Adjunct Professor of Rehabilitation Medicine, Washington School of Medicine, University of Washington School of Medicine, Seattle, Washington
| | - Emily A Malouf
- Division of Medical Genetics, Washington School of Medicine, University of Washington Medical Center, Seattle, Washington
| | - Fuki M Hisama
- Professor of Medical Genetics and Adjunct Professor of Neurology, Washington School of Medicine, University of Washington School of Medicine, Seattle, Washington
| |
Collapse
|
20
|
Kim MJ, Petratos S. Oligodendroglial Lineage Cells in Thyroid Hormone-Deprived Conditions. Stem Cells Int 2019; 2019:5496891. [PMID: 31182964 PMCID: PMC6515029 DOI: 10.1155/2019/5496891] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2019] [Accepted: 03/20/2019] [Indexed: 01/06/2023] Open
Abstract
Oligodendrocytes are supporting glial cells that ensure the metabolism and homeostasis of neurons with specific synaptic axoglial interactions in the central nervous system. These require key myelinating glial trophic signals important for growth and metabolism. Thyroid hormone (TH) is one such trophic signal that regulates oligodendrocyte maturation, myelination, and oligodendroglial synaptic dynamics via either genomic or nongenomic pathways. The intracellular and extracellular transport of TH is facilitated by a specific transmembrane transporter known as the monocarboxylate transporter 8 (MCT8). Dysfunction of the MCT8 due to mutation, inhibition, or downregulation during brain development leads to inherited hypomyelination, which manifests as psychomotor retardation in the X-linked inherited Allan-Herndon-Dudley syndrome (AHDS). In particular, oligodendroglial-specific MCT8 deficiency may restrict the intracellular T3 availability, culminating in deficient metabolic communication between the oligodendrocytes and the neurons they ensheath, potentially promulgating neurodegenerative adult diseases such as multiple sclerosis (MS). Based on the therapeutic effects exhibited by TH in various preclinical studies, particularly related to its remyelinating potential, TH has now entered the initial stages of a clinical trial to test the therapeutic efficacy in relapsing-remitting MS patients (NCT02506751). However, TH analogs, such as DITPA or Triac, may well serve as future therapeutic options to rescue mature oligodendrocytes and/or promote oligodendrocyte precursor cell differentiation in an environment of MCT8 deficiency within the CNS. This review outlines the therapeutic strategies to overcome the differentiation blockade of oligodendrocyte precursors and maintain mature axoglial interactions in TH-deprived conditions.
Collapse
Affiliation(s)
- Min Joung Kim
- Department of Neuroscience, Central Clinical School, Monash University, Prahran, Victoria 3004, Australia
| | - Steven Petratos
- Department of Neuroscience, Central Clinical School, Monash University, Prahran, Victoria 3004, Australia
| |
Collapse
|
21
|
Yermakov LM, Hong LA, Drouet DE, Griggs RB, Susuki K. Functional Domains in Myelinated Axons. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1190:65-83. [PMID: 31760639 DOI: 10.1007/978-981-32-9636-7_6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Propagation of action potentials along axons is optimized through interactions between neurons and myelinating glial cells. Myelination drives division of the axons into distinct molecular domains including nodes of Ranvier. The high density of voltage-gated sodium channels at nodes generates action potentials allowing for rapid and efficient saltatory nerve conduction. At paranodes flanking both sides of the nodes, myelinating glial cells interact with axons, forming junctions that are essential for node formation and maintenance. Recent studies indicate that the disruption of these specialized axonal domains is involved in the pathophysiology of various neurological diseases. Loss of paranodal axoglial junctions due to genetic mutations or autoimmune attack against the paranodal proteins leads to nerve conduction failure and neurological symptoms. Breakdown of nodal and paranodal proteins by calpains, the calcium-dependent cysteine proteases, may be a common mechanism involved in various nervous system diseases and injuries. This chapter reviews recent progress in neurobiology and pathophysiology of specialized axonal domains along myelinated nerve fibers.
Collapse
Affiliation(s)
- Leonid M Yermakov
- Department of Neuroscience, Cell Biology, and Physiology, Boonshoft School of Medicine, Wright State University, Dayton, OH, USA
| | - Lulu A Hong
- Department of Neuroscience, Cell Biology, and Physiology, Boonshoft School of Medicine, Wright State University, Dayton, OH, USA
| | - Domenica E Drouet
- Department of Neuroscience, Cell Biology, and Physiology, Boonshoft School of Medicine, Wright State University, Dayton, OH, USA
| | - Ryan B Griggs
- Department of Neuroscience, Cell Biology, and Physiology, Boonshoft School of Medicine, Wright State University, Dayton, OH, USA
| | - Keiichiro Susuki
- Department of Neuroscience, Cell Biology, and Physiology, Boonshoft School of Medicine, Wright State University, Dayton, OH, USA.
| |
Collapse
|
22
|
Conant A, Curiel J, Pizzino A, Sabetrasekh P, Murphy J, Bloom M, Evans SH, Helman G, Taft RJ, Simons C, Whitehead MT, Moore SA, Vanderver A. Absence of Axoglial Paranodal Junctions in a Child With CNTNAP1 Mutations, Hypomyelination, and Arthrogryposis. J Child Neurol 2018; 33:642-650. [PMID: 29882456 PMCID: PMC6800098 DOI: 10.1177/0883073818776157] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Leukodystrophies and genetic leukoencephalopathies are a heterogeneous group of heritable disorders that affect the glial-axonal unit. As more patients with unsolved leukodystrophies and genetic leukoencephalopathies undergo next generation sequencing, causative mutations in genes leading to central hypomyelination are being identified. Two such individuals presented with arthrogryposis multiplex congenita, congenital hypomyelinating neuropathy, and central hypomyelination with early respiratory failure. Whole exome sequencing identified biallelic mutations in the CNTNAP1 gene: homozygous c.1163G>C (p.Arg388Pro) and compound heterozygous c.967T>C (p.Cys323Arg) and c.319C>T (p.Arg107*). Sural nerve and quadriceps muscle biopsies demonstrated progressive, severe onion bulb and axonal pathology. By ultrastructural evaluation, septate axoglial paranodal junctions were absent from nodes of Ranvier. Serial brain magnetic resonance images revealed hypomyelination, progressive atrophy, and reduced diffusion in the globus pallidus in both patients. These 2 families illustrate severe progressive peripheral demyelinating neuropathy due to the absence of septate paranodal junctions and central hypomyelination with neurodegeneration in CNTNAP1-associated arthrogryposis multiplex congenita.
Collapse
Affiliation(s)
- Alexander Conant
- 1 Department of Neurology, Children's National Health System, Washington, DC, USA
| | - Julian Curiel
- 2 Department of Neurology, Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Amy Pizzino
- 1 Department of Neurology, Children's National Health System, Washington, DC, USA
| | - Parisa Sabetrasekh
- 1 Department of Neurology, Children's National Health System, Washington, DC, USA
| | - Jennifer Murphy
- 3 National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA
| | - Miriam Bloom
- 4 Department of Pediatric Hospitalist Medicine, Children's National Health System, Washington, DC, USA
| | - Sarah H Evans
- 5 Department of Physical Medicine and Rehabilitation, Children's National Health System, Washington, DC, USA
| | - Guy Helman
- 1 Department of Neurology, Children's National Health System, Washington, DC, USA.,6 Center for Genetic Medicine, Children's National Health System, Washington DC, USA.,7 Murdoch Children's Research Institute, Parkville, Melbourne, Australia
| | - Ryan J Taft
- 8 Illumina, San Diego, CA, USA.,9 Institute for Molecular Bioscience, University of Queensland, St. Lucia, Queensland, Australia
| | - Cas Simons
- 7 Murdoch Children's Research Institute, Parkville, Melbourne, Australia.,9 Institute for Molecular Bioscience, University of Queensland, St. Lucia, Queensland, Australia
| | - Matthew T Whitehead
- 10 Neuroradiology Department, Children's National Health System, Washington, DC, USA.,11 George Washington University School of Medicine, Washington, DC, USA
| | - Steven A Moore
- 12 Department of Pathology, University of Iowa Carver College of Medicine and Paul D. Wellstone Muscular Dystrophy Cooperative Research Center, Iowa City, IA, USA
| | - Adeline Vanderver
- 1 Department of Neurology, Children's National Health System, Washington, DC, USA.,2 Department of Neurology, Children's Hospital of Philadelphia, Philadelphia, PA, USA.,3 National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA.,11 George Washington University School of Medicine, Washington, DC, USA
| |
Collapse
|
23
|
Low KJ, Stals K, Caswell R, Wakeling M, Clayton-Smith J, Donaldson A, Foulds N, Norman A, Splitt M, Urankar K, Vijayakumar K, Majumdar A, Study D, Ellard S, Smithson SF. Phenotype of CNTNAP1: a study of patients demonstrating a specific severe congenital hypomyelinating neuropathy with survival beyond infancy. Eur J Hum Genet 2018; 26:796-807. [PMID: 29511323 PMCID: PMC5974240 DOI: 10.1038/s41431-018-0110-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2017] [Revised: 01/10/2018] [Accepted: 01/16/2018] [Indexed: 11/18/2022] Open
Abstract
CHN is genetically heterogeneous and its genetic basis is difficult to determine on features alone. CNTNAP1 encodes CASPR, integral in the paranodal junction high molecular mass complex. Nineteen individuals with biallelic variants have been described in association with severe congenital hypomyelinating neuropathy, respiratory compromise, profound intellectual disability and death within the first year. We report 7 additional patients ascertained through exome sequencing. We identified 9 novel CNTNAP1 variants in 6 families: three missense variants, four nonsense variants, one frameshift variant and one splice site variant. Significant polyhydramnios occurred in 6/7 pregnancies. Severe respiratory compromise was seen in 6/7 (tracheostomy in 5). A complex neurological phenotype was seen in all patients who had marked brain hypomyelination/demyelination and profound developmental delay. Additional neurological findings included cranial nerve compromise: orobulbar dysfunction in 5/7, facial nerve weakness in 4/7 and vocal cord paresis in 5/7. Dystonia occurred in 2/7 patients and limb contractures in 5/7. All had severe gastroesophageal reflux, and a gastrostomy was required in 5/7. In contrast to most previous reports, only one patient died in the first year of life. Protein modelling was performed for all detected CNTNAP1 variants. We propose a genotype-phenotype correlation, whereby hypomorphic missense variants partially ameliorate the phenotype, prolonging survival. This study suggests that biallelic variants in CNTNAP1 cause a distinct recognisable syndrome, which is not caused by other genes associated with CHN. Neonates presenting with this phenotype will benefit from early genetic definition to inform clinical management and enable essential genetic counselling for their families.
Collapse
Affiliation(s)
- K J Low
- Department of Clinical Genetics, St Michaels Hospital, Bristol, UK
- School of Clinical Sciences, University of Bristol, Bristol, UK
| | - K Stals
- Department of Molecular Genetics, Royal Devon & Exeter NHS Foundation Trust, Exeter, UK
| | - R Caswell
- Institute for Biomedical and Clinical Science, University of Exeter Medical School, Exeter, UK
| | - M Wakeling
- Institute for Biomedical and Clinical Science, University of Exeter Medical School, Exeter, UK
| | - J Clayton-Smith
- Manchester Centre for Genomic Medicine, St Marys' Hospital, Manchester, UK
- Institute of Human Development, University of Manchester, Manchester, UK
| | - A Donaldson
- Department of Clinical Genetics, St Michaels Hospital, Bristol, UK
| | - N Foulds
- Wessex Clinical Genetics Service, Southampton, UK
| | - A Norman
- Department of Clinical Genetics, St Michaels Hospital, Bristol, UK
| | - M Splitt
- Northern Genetics Service, Institute of Genetics Medicine, Newcastle upon Tyne, UK
| | - K Urankar
- Department of Neuropathology, North Bristol NHS Trust, Bristol, UK
| | - K Vijayakumar
- Paediatric Neuromuscular Service, Bristol Royal Hospital for Children, Bristol, UK
| | - A Majumdar
- Paediatric Neuromuscular Service, Bristol Royal Hospital for Children, Bristol, UK
| | - Ddd Study
- Wellcome Trust Sanger Institute, Cambridge, UK
| | - S Ellard
- Department of Molecular Genetics, Royal Devon & Exeter NHS Foundation Trust, Exeter, UK
- Institute for Biomedical and Clinical Science, University of Exeter Medical School, Exeter, UK
| | - S F Smithson
- Department of Clinical Genetics, St Michaels Hospital, Bristol, UK.
- School of Clinical Sciences, University of Bristol, Bristol, UK.
| |
Collapse
|
24
|
Fehmi J, Scherer SS, Willison HJ, Rinaldi S. Nodes, paranodes and neuropathies. J Neurol Neurosurg Psychiatry 2018; 89:61-71. [PMID: 28819062 DOI: 10.1136/jnnp-2016-315480] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/03/2017] [Revised: 06/28/2017] [Accepted: 06/29/2017] [Indexed: 12/13/2022]
Abstract
This review summarises recent evidence supporting the involvement of the specialised nodal and perinodal domains (the paranode and juxtaparanode) of myelinated axons in the pathology of acquired, inflammatory, peripheral neuropathies.The identification of new target antigens in the inflammatory neuropathies heralds a revolution in diagnosis, and has already begun to inform increasingly targeted and individualised therapies. Rapid progress in our basic understanding of the highly specialised nodal regions of peripheral nerves serves to strengthen the links between their unique microstructural identities, functions and pathologies. In this context, the detection of autoantibodies directed against nodal and perinodal targets is likely to be of increasing clinical importance. Antiganglioside antibodies have long been used in clinical practice as diagnostic serum biomarkers, and associate with specific clinical variants but not to the common forms of either acute or chronic demyelinating autoimmune neuropathy. It is now apparent that antibodies directed against several region-specific cell adhesion molecules, including neurofascin, contactin and contactin-associated protein, can be linked to phenotypically distinct peripheral neuropathies. Importantly, the immunological characteristics of these antibodies facilitate the prediction of treatment responsiveness.
Collapse
Affiliation(s)
- Janev Fehmi
- Department of Neurology, Southmead Hospital, Bristol, UK
| | - Steven S Scherer
- Department of Neurology, The Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Hugh J Willison
- Department of Neuroimmunology, Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - Simon Rinaldi
- Department of Clinical Neurosciences, West Wing, John Radcliffe Hospital, Oxford, UK
| |
Collapse
|
25
|
Duchesne M, Mathis S, Richard L, Magdelaine C, Corcia P, Nouioua S, Tazir M, Magy L, Vallat JM. Nerve Biopsy Is Still Useful in Some Inherited Neuropathies. J Neuropathol Exp Neurol 2017; 77:88-99. [DOI: 10.1093/jnen/nlx111] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
|