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Salpietro V, Manole A, Efthymiou S, Houlden H. A Review of Copy Number Variants in Inherited Neuropathies. Curr Genomics 2018; 19:412-419. [PMID: 30258273 PMCID: PMC6128387 DOI: 10.2174/1389202919666180330153316] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2016] [Revised: 11/23/2016] [Accepted: 03/13/2018] [Indexed: 11/22/2022] Open
Abstract
The rapid development in the last 10-15 years of microarray technologies, such as oligonucleotide array Comparative Genomic Hybridization (CGH) and Single Nucleotide Polymorphisms (SNP) genotyping array, has improved the identification of fine chromosomal structural variants, ranging in length from kilobases (kb) to megabases (Mb), as an important cause of genetic differences among healthy individuals and also as disease-susceptibility and/or disease-causing factors. Structural genomic variations due to unbalanced chromosomal rearrangements are known as Copy-Number Variants (CNVs) and these include variably sized deletions, duplications, triplications and translocations. CNVs can significantly contribute to human diseases and rearrangements in several dosage-sensitive genes have been identified as an important causative mechanism in the molecular aetiology of Charcot-Marie-Tooth (CMT) disease and of several CMT-related disorders, a group of inherited neuropathies with a broad range of clinical phenotypes, inheritance patterns and causative genes. Duplications or deletions of the dosage-sensitive gene PMP22 mapped to chromosome 17p12 represent the most frequent causes of CMT type 1A and Hereditary Neuropathy with liability to Pressure Palsies (HNPP), respectively. Additionally, CNVs have been identified in patients with other CMT types (e.g., CMT1X, CMT1B, CMT4D) and different hereditary poly- (e.g., giant axonal neuropathy) and focal- (e.g., hereditary neuralgic amyotrophy) neuropathies, supporting the notion of hereditary peripheral nerve diseases as possible genomic disorders and making crucial the identification of fine chromosomal rearrangements in the molecular assessment of such patients. Notably, the application of advanced computational tools in the analysis of Next-Generation Sequencing (NGS) data has emerged in recent years as a powerful technique for identifying a genome-wide scale complex structural variants (e.g., as the ones resulted from balanced rearrangements) and also smaller pathogenic (intragenic) CNVs that often remain beyond the detection limit of most conventional genomic microarray analyses; in the context of inherited neuropathies where more than 70 disease-causing genes have been identified to date, NGS and particularly Whole-Genome Sequencing (WGS) hold the potential to reduce the number of genomic assays required per patient to reach a diagnosis, analyzing with a single test all the Single Nucleotide Variants (SNVs) and CNVs in the genes possibly implicated in this heterogeneous group of disorders.
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Affiliation(s)
- Vincenzo Salpietro
- Department of Molecular Neuroscience, Institute of Neurology, University College London, London WC1N 3BG, UK
| | - Andreea Manole
- Department of Molecular Neuroscience, Institute of Neurology, University College London, London WC1N 3BG, UK
| | - Stephanie Efthymiou
- Department of Molecular Neuroscience, Institute of Neurology, University College London, London WC1N 3BG, UK
| | - Henry Houlden
- Department of Molecular Neuroscience, Institute of Neurology, University College London, London WC1N 3BG, UK
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Bachiller S, Roca-Ceballos MA, García-Domínguez I, Pérez-Villegas EM, Martos-Carmona D, Pérez-Castro MÁ, Real LM, Rosa JL, Tabares L, Venero JL, Armengol JÁ, Carrión ÁM, Ruiz R. HERC1 Ubiquitin Ligase Is Required for Normal Axonal Myelination in the Peripheral Nervous System. Mol Neurobiol 2018; 55:8856-8868. [PMID: 29603094 DOI: 10.1007/s12035-018-1021-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2018] [Accepted: 03/16/2018] [Indexed: 12/14/2022]
Abstract
A missense mutation in HERC1 provokes loss of cerebellar Purkinje cells, tremor, and unstable gait in tambaleante (tbl) mice. Recently, we have shown that before cerebellar degeneration takes place, the tbl mouse suffers from a reduction in the number of vesicles available for release at the neuromuscular junction (NMJ). The aim of the present work was to study to which extent the alteration in HERC1 may affect other cells in the nervous system and how this may influence the motor dysfunction observed in these mice. The functional analysis showed a consistent delay in the propagation of the action potential in mutant mice in comparison with control littermates. Morphological analyses of glial cells in motor axons revealed signs of compact myelin damage as tomacula and local hypermyelination foci. Moreover, we observed an alteration in non-myelinated terminal Schwann cells at the level of the NMJ. Additionally, we found a significant increment of phosphorylated Akt-2 in the sciatic nerve. Based on these findings, we propose a molecular model that could explain how mutated HERC1 in tbl mice affects the myelination process in the peripheral nervous system. Finally, since the myelin abnormalities found in tbl mice are histological hallmarks of neuropathic periphery diseases, tbl mutant mice could be considered as a new mouse model for this type of diseases.
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Affiliation(s)
- Sara Bachiller
- Department of Physiology, Anatomy and Cellular Biology, University of Pablo de Olavide, Seville, Spain
| | - María Angustias Roca-Ceballos
- Department of Biochemistry and Molecular Biology, School of Pharmacy, University of Seville, and Instituto de Biomedicina de Sevilla-Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, Calle Profesor García González 2, 41012, Sevilla, Spain
| | - Irene García-Domínguez
- Department of Biochemistry and Molecular Biology, School of Pharmacy, University of Seville, and Instituto de Biomedicina de Sevilla-Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, Calle Profesor García González 2, 41012, Sevilla, Spain
| | - Eva María Pérez-Villegas
- Department of Physiology, Anatomy and Cellular Biology, University of Pablo de Olavide, Seville, Spain
| | - David Martos-Carmona
- Department of Physiology, Anatomy and Cellular Biology, University of Pablo de Olavide, Seville, Spain
| | - Miguel Ángel Pérez-Castro
- Department of Biochemistry and Molecular Biology, School of Pharmacy, University of Seville, and Instituto de Biomedicina de Sevilla-Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, Calle Profesor García González 2, 41012, Sevilla, Spain
| | - Luis Miguel Real
- Unit of Infectious Diseases and Microbiology, Valme University Hospital, Seville, Spain
| | - José Luis Rosa
- Departament de Ciències Fisiològiques II, IDIBELL, Campus de Bellvitge, Universitat de Barcelona, L'Hospitalet de Llobregat, E-08907, Barcelona, Spain
| | - Lucía Tabares
- Department of Medical Physiology and Biophysics, School of Medicine, University of Seville, Seville, Spain
| | - José Luis Venero
- Department of Biochemistry and Molecular Biology, School of Pharmacy, University of Seville, and Instituto de Biomedicina de Sevilla-Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, Calle Profesor García González 2, 41012, Sevilla, Spain
| | - José Ángel Armengol
- Department of Physiology, Anatomy and Cellular Biology, University of Pablo de Olavide, Seville, Spain
| | - Ángel Manuel Carrión
- Department of Physiology, Anatomy and Cellular Biology, University of Pablo de Olavide, Seville, Spain
| | - Rocío Ruiz
- Department of Physiology, Anatomy and Cellular Biology, University of Pablo de Olavide, Seville, Spain. .,Department of Biochemistry and Molecular Biology, School of Pharmacy, University of Seville, and Instituto de Biomedicina de Sevilla-Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, Calle Profesor García González 2, 41012, Sevilla, Spain.
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Laššuthová P, Šafka Brožková D, Krůtová M, Neupauerová J, Haberlová J, Mazanec R, Dřímal P, Seeman P. Improving diagnosis of inherited peripheral neuropathies through gene panel analysis. Orphanet J Rare Dis 2016; 11:118. [PMID: 27549087 PMCID: PMC4994270 DOI: 10.1186/s13023-016-0500-5] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2016] [Accepted: 08/09/2016] [Indexed: 12/30/2022] Open
Abstract
BACKGROUND Inherited peripheral neuropathies (IPN) are the most common inherited neurological condition. It represents a highly heterogeneous group, both clinically and genetically. Targeted disease specific gene panel massively parallel sequencing (MPS) seems to be a useful tool in diagnosis of disorders with high genetic heterogeneity. METHODS In our study, we have designed, validated and updated our own custom gene panel of all known genes associated with IPN. One hundred and ninety-eight patients have been tested so far. Only patients in whom mutations in more common causes or relevant genes have already been excluded were enrolled. Five consecutive panel designs were prepared according to recent literature search, the last one covering ninety-three genes. Each patient was tested only once. All data were evaluated with at least two different pipelines. RESULTS In summary, causative mutation has been found in fifty-one patients (26 %). The results were inconclusive in thirty-one (16 %) patients. No variants of likely significance to IPN were found in one hundred and sixteen (58 %) patients. CONCLUSION MPS gene panel enables testing of all known IPN causes at once with high coverage and at an affordable cost making it truly a method of choice also in IPN. Gene panel testing results in several interesting results and findings.
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Affiliation(s)
- Petra Laššuthová
- Department of Paediatric Neurology, DNA Laboratory, 2nd Faculty of Medicine, Charles University in Prague and University Hospital Motol, Prague, Czech Republic
| | - Dana Šafka Brožková
- Department of Paediatric Neurology, DNA Laboratory, 2nd Faculty of Medicine, Charles University in Prague and University Hospital Motol, Prague, Czech Republic
| | - Marcela Krůtová
- Department of Paediatric Neurology, DNA Laboratory, 2nd Faculty of Medicine, Charles University in Prague and University Hospital Motol, Prague, Czech Republic
| | - Jana Neupauerová
- Department of Paediatric Neurology, DNA Laboratory, 2nd Faculty of Medicine, Charles University in Prague and University Hospital Motol, Prague, Czech Republic
| | - Jana Haberlová
- Department of Paediatric Neurology, 2nd Faculty of Medicine, Charles University in Prague and University Hospital Motol, Prague, Czech Republic
| | - Radim Mazanec
- Department of Neurology, 2nd Faculty of Medicine, Charles University in Prague and University Hospital Motol, Prague, Czech Republic
| | - Pavel Dřímal
- Department of Paediatric Neurology, DNA Laboratory, 2nd Faculty of Medicine, Charles University in Prague and University Hospital Motol, Prague, Czech Republic
| | - Pavel Seeman
- Department of Paediatric Neurology, DNA Laboratory, 2nd Faculty of Medicine, Charles University in Prague and University Hospital Motol, Prague, Czech Republic
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