1
|
Parmar JM, Laing NG, Kennerson ML, Ravenscroft G. Genetics of inherited peripheral neuropathies and the next frontier: looking backwards to progress forwards. J Neurol Neurosurg Psychiatry 2024; 95:992-1001. [PMID: 38744462 DOI: 10.1136/jnnp-2024-333436] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/18/2024] [Accepted: 04/10/2024] [Indexed: 05/16/2024]
Abstract
Inherited peripheral neuropathies (IPNs) encompass a clinically and genetically heterogeneous group of disorders causing length-dependent degeneration of peripheral autonomic, motor and/or sensory nerves. Despite gold-standard diagnostic testing for pathogenic variants in over 100 known associated genes, many patients with IPN remain genetically unsolved. Providing patients with a diagnosis is critical for reducing their 'diagnostic odyssey', improving clinical care, and for informed genetic counselling. The last decade of massively parallel sequencing technologies has seen a rapid increase in the number of newly described IPN-associated gene variants contributing to IPN pathogenesis. However, the scarcity of additional families and functional data supporting variants in potential novel genes is prolonging patient diagnostic uncertainty and contributing to the missing heritability of IPNs. We review the last decade of IPN disease gene discovery to highlight novel genes, structural variation and short tandem repeat expansions contributing to IPN pathogenesis. From the lessons learnt, we provide our vision for IPN research as we anticipate the future, providing examples of emerging technologies, resources and tools that we propose that will expedite the genetic diagnosis of unsolved IPN families.
Collapse
Affiliation(s)
- Jevin M Parmar
- Rare Disease Genetics and Functional Genomics, Harry Perkins Institute of Medical Research, Perth, Western Australia, Australia
- Centre for Medical Research, Faculty of Health and Medical Sciences, The University of Western Australia, Perth, Western Australia, Australia
| | - Nigel G Laing
- Centre for Medical Research, Faculty of Health and Medical Sciences, The University of Western Australia, Perth, Western Australia, Australia
- Preventive Genetics, Harry Perkins Institute of Medical Research, Perth, Western Australia, Australia
| | - Marina L Kennerson
- Northcott Neuroscience Laboratory, ANZAC Research Institute, Concord, New South Wales, Australia
- Molecular Medicine Laboratory, Concord Hospital, Concord, New South Wales, Australia
| | - Gianina Ravenscroft
- Rare Disease Genetics and Functional Genomics, Harry Perkins Institute of Medical Research, Perth, Western Australia, Australia
- Centre for Medical Research, Faculty of Health and Medical Sciences, The University of Western Australia, Perth, Western Australia, Australia
| |
Collapse
|
2
|
Van Lent J, Prior R, Pérez Siles G, Cutrupi AN, Kennerson ML, Vangansewinkel T, Wolfs E, Mukherjee-Clavin B, Nevin Z, Judge L, Conklin B, Tyynismaa H, Clark AJ, Bennett DL, Van Den Bosch L, Saporta M, Timmerman V. Advances and challenges in modeling inherited peripheral neuropathies using iPSCs. Exp Mol Med 2024; 56:1348-1364. [PMID: 38825644 PMCID: PMC11263568 DOI: 10.1038/s12276-024-01250-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2023] [Revised: 02/21/2024] [Accepted: 03/18/2024] [Indexed: 06/04/2024] Open
Abstract
Inherited peripheral neuropathies (IPNs) are a group of diseases associated with mutations in various genes with fundamental roles in the development and function of peripheral nerves. Over the past 10 years, significant advances in identifying molecular disease mechanisms underlying axonal and myelin degeneration, acquired from cellular biology studies and transgenic fly and rodent models, have facilitated the development of promising treatment strategies. However, no clinical treatment has emerged to date. This lack of treatment highlights the urgent need for more biologically and clinically relevant models recapitulating IPNs. For both neurodevelopmental and neurodegenerative diseases, patient-specific induced pluripotent stem cells (iPSCs) are a particularly powerful platform for disease modeling and preclinical studies. In this review, we provide an update on different in vitro human cellular IPN models, including traditional two-dimensional monoculture iPSC derivatives, and recent advances in more complex human iPSC-based systems using microfluidic chips, organoids, and assembloids.
Collapse
Grants
- Wellcome Trust
- R01 NS119678 NINDS NIH HHS
- U01 ES032673 NIEHS NIH HHS
- DOC-PRO4 Universiteit Antwerpen (University of Antwerp)
- This work was supported in part by the University of Antwerp (DOC-PRO4 PhD fellowship to J.V.L. and TOP-BOF research grant no. 38694 to V.T.), the Association Française contre les Myopathies (AFM research grant no. 24063 to V.T.), Association Belge contre les Maladies Neuromusculaires (ABMM research grant no. 1 to J.V.L and V.T), the interuniversity research fund (iBOF project to. L.V.D.B, E.W. and V.T.). V.T. is part of the μNEURO Research Centre of Excellence of the University of Antwerp and is an active member of the European Network for Stem Cell Core Facilities (CorEUStem, COST Action CA20140). Work in the M.L.K group was supported by the NHMRC Ideas Grant (APP1186867), CMT Australia Grant awarded to M.L.K and G.P.-S and the Australian Medical Research Future Fund (MRFF) Genomics Health Futures Mission Grant 2007681. B.M.C. is supported by the American Academy of Neurology and the Passano Foundation. L.M.J. and B.R.C. are supported by the Charcot-Marie-Tooth Association, NINDS R01 NS119678, NIEHS U01 ES032673. H.T. is supported by Academy of Finland Centre of Excellence in Stem Cell Metabolism and Sigrid Juselius Foundation. Work in the D.L.B. group is supported by a Wellcome Investigator Grant (223149/Z/21/Z), the MRC (MR/T020113/1), and with funding from the MRC and Versus Arthritis to the PAINSTORM consortium as part of the Advanced Pain Discovery Platform (MR/W002388/1).
- Australian Medical Association (Australian Medical Association Limited)
- Universiteit Hasselt (UHasselt)
- American Academy of Neurology (AAN)
- Gladstone Institutes (J. David Gladstone Institutes)
- Academy of Finland (Suomen Akatemia)
- Academy of Medical Royal Colleges (AoMRC)
- Wellcome Trust (Wellcome)
- Oxford University Hospitals NHS Trust (Oxford University Hospitals National Health Service Trust)
- KU Leuven (Katholieke Universiteit Leuven)
- Vlaams Instituut voor Biotechnologie (Flanders Institute for Biotechnology)
- Miami University | Leonard M. Miller School of Medicine (Miller School of Medicine)
Collapse
Affiliation(s)
- Jonas Van Lent
- Peripheral Neuropathy Research Group, Department of Biomedical Sciences, University of Antwerp, 2610, Antwerp, Belgium
- Laboratory of Neuromuscular Pathology, Institute Born Bunge, 2610, Antwerp, Belgium
- Institute of Oncology Research (IOR), BIOS+, 6500, Bellinzona, Switzerland
- Università della Svizzera Italiana, 6900, Lugano, Switzerland
| | - Robert Prior
- Universitätsklinikum Bonn (UKB), University of Bonn, Bonn, Germany
| | - Gonzalo Pérez Siles
- Northcott Neuroscience Laboratory, ANZAC Research Institute Sydney Local Health District and Faculty of Medicine and Health, University of Sydney, Sydney, NSW, Australia
| | - Anthony N Cutrupi
- Northcott Neuroscience Laboratory, ANZAC Research Institute Sydney Local Health District and Faculty of Medicine and Health, University of Sydney, Sydney, NSW, Australia
| | - Marina L Kennerson
- Northcott Neuroscience Laboratory, ANZAC Research Institute Sydney Local Health District and Faculty of Medicine and Health, University of Sydney, Sydney, NSW, Australia
- Molecular Medicine Laboratory, Concord Hospital, Sydney, NSW, Australia
| | - Tim Vangansewinkel
- UHasselt - Hasselt University, BIOMED, Laboratory for Functional Imaging and Research on Stem Cells (FIERCE Lab), Agoralaan, 3590, Diepenbeek, Belgium
- VIB-Center for Brain and Disease Research, Laboratory of Neurobiology, 3000, Leuven, Belgium
| | - Esther Wolfs
- UHasselt - Hasselt University, BIOMED, Laboratory for Functional Imaging and Research on Stem Cells (FIERCE Lab), Agoralaan, 3590, Diepenbeek, Belgium
| | | | | | - Luke Judge
- Gladstone Institutes, San Francisco, CA, USA
- Department of Pediatrics, University of California, San Francisco, San Francisco, CA, USA
| | - Bruce Conklin
- Gladstone Institutes, San Francisco, CA, USA
- Department of Ophthalmology, University of California, San Francisco, San Francisco, CA, USA
- Department of Medicine, University of California, San Francisco, San Francisco, CA, USA
| | - Henna Tyynismaa
- Stem Cells and Metabolism Research Program, Faculty of Medicine, University of Helsinki, 00290, Helsinki, Finland
| | - Alex J Clark
- Blizard Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, London, UK
| | - David L Bennett
- Nuffield Department of Clinical Neuroscience, Oxford University, Oxford, UK
| | - Ludo Van Den Bosch
- VIB-Center for Brain and Disease Research, Laboratory of Neurobiology, 3000, Leuven, Belgium
- Department of Neurosciences, Experimental Neurology, and Leuven Brain Institute, KU Leuven-University of Leuven, 3000, Leuven, Belgium
| | - Mario Saporta
- Department of Neurology, Miller School of Medicine, University of Miami, Miami, FL, USA
| | - Vincent Timmerman
- Peripheral Neuropathy Research Group, Department of Biomedical Sciences, University of Antwerp, 2610, Antwerp, Belgium.
- Laboratory of Neuromuscular Pathology, Institute Born Bunge, 2610, Antwerp, Belgium.
| |
Collapse
|
3
|
Kim YG, Kwon H, Park JH, Nam SH, Ha C, Shin S, Heo WY, Kim HJ, Chung KW, Jang JH, Kim JW, Choi BO. Whole-genome sequencing in clinically diagnosed Charcot-Marie-Tooth disease undiagnosed by whole-exome sequencing. Brain Commun 2023; 5:fcad139. [PMID: 37180992 PMCID: PMC10174204 DOI: 10.1093/braincomms/fcad139] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Revised: 03/16/2023] [Accepted: 04/27/2023] [Indexed: 05/16/2023] Open
Abstract
Whole-genome sequencing is the most comprehensive form of next-generation sequencing method. We aimed to assess the additional diagnostic yield of whole-genome sequencing in patients with clinically diagnosed Charcot-Marie-Tooth disease when compared with whole-exome sequencing, which has not been reported in the literature. Whole-genome sequencing was performed on 72 families whose genetic cause of clinically diagnosed Charcot-Marie-Tooth disease was not revealed after the whole-exome sequencing and 17p12 duplication screening. Among the included families, 14 (19.4%) acquired genetic diagnoses that were compatible with their phenotypes. The most common factor that led to the additional diagnosis in the whole-genome sequencing was genotype-driven analysis (four families, 4/14), in which a wider range of genes, not limited to peripheral neuropathy-related genes, were analysed. Another four families acquired diagnosis due to the inherent advantage of whole-genome sequencing such as better coverage than the whole-exome sequencing (two families, 2/14), structural variants (one family, 1/14) and non-coding variants (one family, 1/14). In conclusion, an evident gain in diagnostic yield was obtained from whole-genome sequencing of the whole-exome sequencing-negative cases. A wide range of genes, not limited to inherited peripheral neuropathy-related genes, should be targeted during whole-genome sequencing.
Collapse
Affiliation(s)
- Young-gon Kim
- Correspondence to: Jong-Won Kim, MD, PhD Department of Laboratory Medicine and Genetics, Samsung Medical Center 81 Irwon-ro, Gangnam-gu, Seoul 06351, South Korea E-mail:
| | | | - Jong-ho Park
- Clinical Genomics Center, Samsung Medical Center, Seoul 06351, Republic of Korea
| | - Soo Hyun Nam
- Cell and Gene Therapy Institute (CGTI), Samsung Medical Center, Seoul 06351, Republic of Korea
| | - Changhee Ha
- Department of Laboratory Medicine and Genetics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul 06351, Republic of Korea
| | - Sunghwan Shin
- Department of Laboratory Medicine and Genetics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul 06351, Republic of Korea
| | - Won Young Heo
- Department of Laboratory Medicine and Genetics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul 06351, Republic of Korea
| | - Hye Jin Kim
- Department of Neurology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul 06351, Republic of Korea
| | - Ki Wha Chung
- Department of Biological Sciences, Kongju National University, Gongju 32588, South Korea
| | - Ja-Hyun Jang
- Department of Laboratory Medicine and Genetics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul 06351, Republic of Korea
| | - Jong-Won Kim
- Department of Laboratory Medicine and Genetics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul 06351, Republic of Korea
- Clinical Genomics Center, Samsung Medical Center, Seoul 06351, Republic of Korea
| | - Byung-Ok Choi
- Correspondence may also be sent to: Byung-Ok Choi, MD, PhD Department of Neurology, Samsung Medical Center 81 Irwon-ro, Gangnam-gu, Seoul 06351, South Korea E-mail:
| |
Collapse
|
4
|
Perez-Siles G, Ellis M, Ashe A, Grosz B, Vucic S, Kiernan MC, Morris KA, Reddel SW, Kennerson ML. A Compound Heterozygous Mutation in Calpain 1 Identifies a New Genetic Cause for Spinal Muscular Atrophy Type 4 (SMA4). Front Genet 2022; 12:801253. [PMID: 35126465 PMCID: PMC8807693 DOI: 10.3389/fgene.2021.801253] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Accepted: 12/21/2021] [Indexed: 12/27/2022] Open
Abstract
Spinal Muscular Atrophy (SMA) is a heterogeneous group of neuromuscular diseases characterized by degeneration of anterior horn cells of the spinal cord, leading to muscular atrophy and weakness. Although the major cause of SMA is autosomal recessive exon deletions or loss-of-function mutations of survival motor neuron 1 (SMN1) gene, next generation sequencing technologies are increasing the genetic heterogeneity of SMA. SMA type 4 (SMA4) is an adult onset, less severe form of SMA for which genetic and pathogenic causes remain elusive.Whole exome sequencing in a 30-year-old brother and sister with SMA4 identified a compound heterozygous mutation (p. G492R/p. F610C) in calpain-1 (CAPN1). Mutations in CAPN1 have been previously associated with cerebellar ataxia and hereditary spastic paraplegia. Using skin fibroblasts from a patient bearing the p. G492R/p. F610C mutation, we demonstrate reduced levels of CAPN1 protein and protease activity. Functional characterization of the SMA4 fibroblasts revealed no changes in SMN protein levels and subcellular distribution. Additional cellular pathways associated with SMA remain unaffected in the patient fibroblasts, highlighting the tissue specificity of CAPN1 dysfunction in SMA4 pathophysiology. This study provides genetic and functional evidence of CAPN1 as a novel gene for the SMA4 phenotype and expands the phenotype of CAPN1 mutation disorders.
Collapse
Affiliation(s)
- G. Perez-Siles
- Northcott Neuroscience Laboratory, ANZAC Research Institute, Sydney, NSW, Australia
- Sydney Medical School, University of Sydney, Sydney, NSW, Australia
- *Correspondence: G. Perez-Siles , ; M. L. Kennerson,
| | - M. Ellis
- Northcott Neuroscience Laboratory, ANZAC Research Institute, Sydney, NSW, Australia
| | - A. Ashe
- Brain and Mind Centre, The University of Sydney, Sydney, NSW, Australia
| | - B. Grosz
- Northcott Neuroscience Laboratory, ANZAC Research Institute, Sydney, NSW, Australia
- Sydney Medical School, University of Sydney, Sydney, NSW, Australia
| | - S. Vucic
- Brain and Nerve Research Center, Concord Clinical School, University of Sydney, Sydney, NSW, Australia
| | - M. C. Kiernan
- Brain and Mind Centre, The University of Sydney, Sydney, NSW, Australia
- Department of Neurology, Royal Prince Alfred Hospital, Sydney, NSW, Australia
| | - K. A. Morris
- Department of Neurology, Concord Repatriation General Hospital, Sydney, Sydney, NSW, Australia
| | - S. W. Reddel
- Brain and Mind Centre, The University of Sydney, Sydney, NSW, Australia
| | - M. L. Kennerson
- Northcott Neuroscience Laboratory, ANZAC Research Institute, Sydney, NSW, Australia
- Sydney Medical School, University of Sydney, Sydney, NSW, Australia
- Molecular Medicine Laboratory, Concord Repatriation General Hospital, Sydney, NSW, Australia
- *Correspondence: G. Perez-Siles , ; M. L. Kennerson,
| |
Collapse
|
5
|
Rossor AM. Broadening the genetic spectrum of distal hereditary motor neuropathy. Eur J Neurol 2021; 28:1104-1105. [PMID: 33449405 DOI: 10.1111/ene.14734] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Accepted: 01/09/2021] [Indexed: 11/29/2022]
Affiliation(s)
- Alexander M Rossor
- Queen Square Centre for Neuromuscular Diseases, UCL Institute of Neurology and National Hospital for Neurology and Neurosurgery, London, UK
| |
Collapse
|
6
|
Mortreux J, Bacquet J, Boyer A, Alazard E, Bellance R, Giguet-Valard AG, Cerino M, Krahn M, Audic F, Chabrol B, Laugel V, Desvignes JP, Béroud C, Nguyen K, Verschueren A, Lévy N, Attarian S, Delague V, Missirian C, Bonello-Palot N. Identification of novel pathogenic copy number variations in Charcot-Marie-Tooth disease. J Hum Genet 2019; 65:313-323. [PMID: 31852984 DOI: 10.1038/s10038-019-0710-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2019] [Revised: 12/03/2019] [Accepted: 12/08/2019] [Indexed: 12/13/2022]
Abstract
Charcot-Marie-Tooth disease (CMT) is a hereditary sensory-motor neuropathy characterized by a strong clinical and genetic heterogeneity. Over the past few years, with the occurrence of whole-exome sequencing (WES) or whole-genome sequencing (WGS), the molecular diagnosis rate has been improved by allowing the screening of more than 80 genes at one time. In CMT, except the recurrent PMP22 duplication accounting for about 60% of pathogenic variations, pathogenic copy number variations (CNVs) are rarely reported and only a few studies screening specifically CNVs have been performed. The aim of the present study was to screen for CNVs in the most prevalent genes associated with CMT in a cohort of 200 patients negative for the PMP22 duplication. CNVs were screened using the Exome Depth software on next generation sequencing (NGS) data obtained by targeted capture and sequencing of a panel of 81 CMT associated genes. Deleterious CNVs were identified in four patients (2%), in four genes: GDAP1, LRSAM1, GAN, and FGD4. All CNVs were confirmed by high-resolution oligonucleotide array Comparative Genomic Hybridization (aCGH) and/or quantitative PCR. By identifying four new CNVs in four different genes, we demonstrate that, although they are rare mutational events in CMT, CNVs might contribute significantly to mutational spectrum of Charcot-Marie-Tooth disease and should be searched in routine NGS diagnosis. This strategy increases the molecular diagnosis rate of patients with neuropathy.
Collapse
Affiliation(s)
- J Mortreux
- Département de génétique médicale, Hôpital Timone enfants, Assistance-Publique Hôpitaux de Marseille, Marseille, France.,Aix Marseille Univ, INSERM, MMG, U1251, Marseille, France
| | - J Bacquet
- Département de génétique médicale, Hôpital Timone enfants, Assistance-Publique Hôpitaux de Marseille, Marseille, France.,Aix Marseille Univ, INSERM, MMG, U1251, Marseille, France
| | - A Boyer
- Département de génétique médicale, Hôpital Timone enfants, Assistance-Publique Hôpitaux de Marseille, Marseille, France
| | - E Alazard
- Département de génétique médicale, Hôpital Timone enfants, Assistance-Publique Hôpitaux de Marseille, Marseille, France
| | - R Bellance
- Centre de référence Caribéen pour les maladies neuromusculaires, CeRCa, Hôpital Pierre-Zobda-Quitman, CHU de Martinique, France
| | - A G Giguet-Valard
- Centre de référence Caribéen pour les maladies neuromusculaires, CeRCa, Hôpital Pierre-Zobda-Quitman, CHU de Martinique, France
| | - M Cerino
- Département de génétique médicale, Hôpital Timone enfants, Assistance-Publique Hôpitaux de Marseille, Marseille, France.,Aix Marseille Univ, INSERM, MMG, U1251, Marseille, France
| | - M Krahn
- Département de génétique médicale, Hôpital Timone enfants, Assistance-Publique Hôpitaux de Marseille, Marseille, France.,Aix Marseille Univ, INSERM, MMG, U1251, Marseille, France
| | - F Audic
- Centre de référence des maladies neuromusculaires, Hôpital de la Timone enfant, Assistance-Publique Hôpitaux de Marseille, Marseille, France
| | - B Chabrol
- Centre de référence des maladies neuromusculaires, Hôpital de la Timone enfant, Assistance-Publique Hôpitaux de Marseille, Marseille, France
| | - V Laugel
- Centre de référence des maladies neuromusculaires, Service de pédiatrie, CHU Strasbourg, France
| | - J P Desvignes
- Aix Marseille Univ, INSERM, MMG, U1251, Marseille, France
| | - C Béroud
- Département de génétique médicale, Hôpital Timone enfants, Assistance-Publique Hôpitaux de Marseille, Marseille, France.,Aix Marseille Univ, INSERM, MMG, U1251, Marseille, France
| | - K Nguyen
- Département de génétique médicale, Hôpital Timone enfants, Assistance-Publique Hôpitaux de Marseille, Marseille, France.,Aix Marseille Univ, INSERM, MMG, U1251, Marseille, France
| | - A Verschueren
- Centre de référence des maladies neuromusculaires, Hôpital de la Timone Adulte, Assistance-Publique Hôpitaux de Marseille, Marseille, France
| | - N Lévy
- Département de génétique médicale, Hôpital Timone enfants, Assistance-Publique Hôpitaux de Marseille, Marseille, France.,Aix Marseille Univ, INSERM, MMG, U1251, Marseille, France
| | - S Attarian
- Centre de référence des maladies neuromusculaires, Hôpital de la Timone Adulte, Assistance-Publique Hôpitaux de Marseille, Marseille, France
| | - V Delague
- Aix Marseille Univ, INSERM, MMG, U1251, Marseille, France
| | - C Missirian
- Département de génétique médicale, Hôpital Timone enfants, Assistance-Publique Hôpitaux de Marseille, Marseille, France.,Aix Marseille Univ, INSERM, MMG, U1251, Marseille, France
| | - N Bonello-Palot
- Département de génétique médicale, Hôpital Timone enfants, Assistance-Publique Hôpitaux de Marseille, Marseille, France. .,Aix Marseille Univ, INSERM, MMG, U1251, Marseille, France.
| |
Collapse
|
7
|
Next-generation sequencing in Charcot-Marie-Tooth disease: opportunities and challenges. Nat Rev Neurol 2019; 15:644-656. [PMID: 31582811 DOI: 10.1038/s41582-019-0254-5] [Citation(s) in RCA: 120] [Impact Index Per Article: 24.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/12/2019] [Indexed: 01/08/2023]
Abstract
Charcot-Marie-Tooth disease and the related disorders hereditary motor neuropathy and hereditary sensory neuropathy, collectively termed CMT, are the commonest group of inherited neuromuscular diseases, and they exhibit wide phenotypic and genetic heterogeneity. CMT is usually characterized by distal muscle atrophy, often with foot deformity, weakness and sensory loss. In the past decade, next-generation sequencing (NGS) technologies have revolutionized genomic medicine and, as these technologies are being applied to clinical practice, they are changing our diagnostic approach to CMT. In this Review, we discuss the application of NGS technologies, including disease-specific gene panels, whole-exome sequencing, whole-genome sequencing (WGS), mitochondrial sequencing and high-throughput transcriptome sequencing, to the diagnosis of CMT. We discuss the growing challenge of variant interpretation and consider how the clinical phenotype can be combined with genetic, bioinformatic and functional evidence to assess the pathogenicity of genetic variants in patients with CMT. WGS has several advantages over the other techniques that we discuss, which include unparalleled coverage of coding, non-coding and intergenic areas of both nuclear and mitochondrial genomes, the ability to identify structural variants and the opportunity to perform genome-wide dense homozygosity mapping. We propose an algorithm for incorporating WGS into the CMT diagnostic pathway.
Collapse
|
8
|
Cutrupi AN, Brewer MH, Nicholson GA, Kennerson M. Structural variations causing inherited peripheral neuropathies: A paradigm for understanding genomic organization, chromatin interactions, and gene dysregulation. Mol Genet Genomic Med 2018; 6:422-433. [PMID: 29573232 PMCID: PMC6014456 DOI: 10.1002/mgg3.390] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2017] [Revised: 02/09/2018] [Accepted: 03/01/2018] [Indexed: 11/16/2022] Open
Abstract
Inherited peripheral neuropathies (IPNs) are a clinically and genetically heterogeneous group of diseases affecting the motor and sensory peripheral nerves. IPNs have benefited from gene discovery and genetic diagnosis using next-generation sequencing with over 80 causative genes available for testing. Despite this success, up to 50% of cases remain genetically unsolved. In the absence of protein coding mutations, noncoding DNA or structural variation (SV) mutations are a possible explanation. The most common IPN, Charcot-Marie-Tooth neuropathy type 1A (CMT1A), is caused by a 1.5 Mb duplication causing trisomy of the dosage sensitive gene PMP22. Using genome sequencing, we recently identified two large genomic rearrangements causing IPN subtypes X-linked CMT (CMTX3) and distal hereditary motor neuropathy (DHMN1), thereby expanding the spectrum of SV mutations causing IPN. Understanding how newly discovered SVs can cause IPN may serve as a useful paradigm to examine the role of topologically associated domains (TADs), chromatin interactions, and gene dysregulation in disease. This review will describe the growing role of SV in the pathogenesis of IPN and the importance of considering this type of mutation in Mendelian diseases where protein coding mutations cannot be identified.
Collapse
Affiliation(s)
- Anthony N. Cutrupi
- Northcott Neuroscience LaboratoryANZAC Research InstituteSydneyNSWAustralia
- Sydney Medical SchoolUniversity of SydneySydneyNSWAustralia
| | - Megan H. Brewer
- Northcott Neuroscience LaboratoryANZAC Research InstituteSydneyNSWAustralia
- Sydney Medical SchoolUniversity of SydneySydneyNSWAustralia
| | - Garth A. Nicholson
- Northcott Neuroscience LaboratoryANZAC Research InstituteSydneyNSWAustralia
- Sydney Medical SchoolUniversity of SydneySydneyNSWAustralia
- Molecular Medicine LaboratoryConcord HospitalSydneyNSWAustralia
| | - Marina L. Kennerson
- Northcott Neuroscience LaboratoryANZAC Research InstituteSydneyNSWAustralia
- Sydney Medical SchoolUniversity of SydneySydneyNSWAustralia
- Molecular Medicine LaboratoryConcord HospitalSydneyNSWAustralia
| |
Collapse
|