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Figueiredo FB, Tomaselli PJ, Hallak J, Mattiello-Sverzut AC, Covaleski APPM, Sobreira CFDR, de Paula Gouvêa S, Marques W. Genetic diversity in hereditary axonal neuropathy: Analyzing 53 Brazilian children. J Peripher Nerv Syst 2024; 29:97-106. [PMID: 38375759 DOI: 10.1111/jns.12617] [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: 01/21/2023] [Revised: 01/24/2024] [Accepted: 01/31/2024] [Indexed: 02/21/2024]
Abstract
BACKGROUND AND AIMS The genetic epidemiology of inherited neuropathies in children remains largely unknown. In this study, we specifically investigated the genetic profile of a Brazilian cohort of pediatric patients with pure or complex axonal neuropathies, a crucial knowledge in the near future for establishing treatment priorities and perspectives for this group of patients. METHODS Fifty-three pediatric patients who were assessed prior to reaching the age of 20, and who had clinical diagnoses of axonal hereditary neuropathy or presented with axonal neuropathy as the primary clinical feature, were included in the study. The recruitment of these cases took place from January 1, 2018, to December 31, 2020. The diagnosis was based on clinical and electrophysiological data. A molecular assessment was made using target-gene panel or whole-exome sequencing. Subsequently, segregation analysis was performed on available family members, and all candidate variants found were confirmed through Sanger. RESULTS A molecular diagnosis was reached in 68% of the patients (n = 36/53), considering only pathogenic and probably pathogenic variants. Variants in MFN2 (n = 15) and GJB1 (n = 3) accounted for half of the genetically confirmed patients (50%; n = 18/36). The other 18 genetically diagnosed patients had variants in several less common genes. INTERPRETATION Apart from MFN2 and GJB1 genes, universally recognized as a frequent cause of axonal neuropathies in most studied population, our Brazilian cohort of children with axonal neuropathies showed an important genetic heterogeneity, probably reflecting the multi ethnicity of the Brazilian population. Diagnostic, counseling, and future interventions should consider this characteristic.
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Affiliation(s)
- Fernanda Barbosa Figueiredo
- Neuroscience and Behavior Sciences Department, Ribeirão Preto Medical School, University of São Paulo, São Paulo, Brazil
| | - Pedro José Tomaselli
- Neuroscience and Behavior Sciences Department, Ribeirão Preto Medical School, University of São Paulo, São Paulo, Brazil
| | - Jaime Hallak
- Neuroscience and Behavior Sciences Department, Ribeirão Preto Medical School, University of São Paulo, São Paulo, Brazil
- National Institute of Sciences and Technology-INCT-Translational Medicine-CNPq/FAPESP, Ribeirao Preto, Brazil
| | | | | | | | - Silmara de Paula Gouvêa
- Neuroscience and Behavior Sciences Department, Ribeirão Preto Medical School, University of São Paulo, São Paulo, Brazil
| | - Wilson Marques
- Neuroscience and Behavior Sciences Department, Ribeirão Preto Medical School, University of São Paulo, São Paulo, Brazil
- National Institute of Sciences and Technology-INCT-Translational Medicine-CNPq/FAPESP, Ribeirao Preto, Brazil
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2
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Kontogeorgiou Z, Kartanou C, Rentzos M, Kokotis P, Anagnostou E, Zambelis T, Chroni E, Dinopoulos A, Panas M, Koutsis G, Karadima G. Mutational screening of Greek patients with axonal Charcot-Marie-Tooth disease using targeted next-generation sequencing: Clinical and molecular spectrum delineation. J Peripher Nerv Syst 2023; 28:642-650. [PMID: 37747677 DOI: 10.1111/jns.12598] [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: 08/02/2023] [Revised: 09/04/2023] [Accepted: 09/22/2023] [Indexed: 09/26/2023]
Abstract
BACKGROUND AND AIMS Axonal forms of Charcot-Marie-Tooth disease (CMT) are classified as CMT2, distal hereditary motor neuropathy (dHMN) or hereditary sensory neuropathy (HSN) and can be caused by mutations in over 100 genes. We presently aimed to investigate for the first time the genetic landscape of axonal CMT in the Greek population. METHODS Sixty index patients with CMT2, dHMN or HSN were screened by a combination of Sanger sequencing (GJB1) and next-generation sequencing custom-made gene panel covering 24 commonly mutated genes in axonal CMT. RESULTS Overall, 20 variants classified as pathogenic or likely pathogenic were identified in heterozygous state in 20 index cases, representing 33.3% of the cohort. Of these, 14 were known pathogenic/likely pathogenic and six were designated as such according to ACMG classification, after in silico evaluation, testing for familial segregation and further literature review. The most frequently involved genes were GJB1 (11.7%), MPZ (5%) and MFN2 (5%), followed by DNM2 (3.3%) and LRSAM1 (3.3%). Single cases were identified with mutations in BSCL2, HSPB1 and GDAP1. INTERPRETATION A wide phenotypic variability in terms of severity and age of onset was noted. Given the limited number of genes tested, the diagnostic yield of the present panel compares favourably with studies in other European populations. Our study delineates the genetic and phenotypic variability of inherited axonal neuropathies in the Greek population and contributes to the pathogenicity characterization of further variants linked to axonal neuropathies.
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Affiliation(s)
- Zoi Kontogeorgiou
- Neurogenetics Unit, 1st Department of Neurology, Eginition Hospital, School of Medicine, National and Kapodistrian University of Athens, Athens, Greece
| | - Chrisoula Kartanou
- Neurogenetics Unit, 1st Department of Neurology, Eginition Hospital, School of Medicine, National and Kapodistrian University of Athens, Athens, Greece
| | - Michail Rentzos
- 1st Department of Neurology, Eginition Hospital, School of Medicine, National and Kapodistrian University of Athens, Athens, Greece
| | - Panagiotis Kokotis
- Clinical Neurophysiology Unit, 1st Department of Neurology, Eginition Hospital, School of Medicine, National and Kapodistrian University of Athens, Athens, Greece
| | - Evangelos Anagnostou
- Clinical Neurophysiology Unit, 1st Department of Neurology, Eginition Hospital, School of Medicine, National and Kapodistrian University of Athens, Athens, Greece
| | - Thomas Zambelis
- Clinical Neurophysiology Unit, 1st Department of Neurology, Eginition Hospital, School of Medicine, National and Kapodistrian University of Athens, Athens, Greece
| | - Elisabeth Chroni
- Department of Neurology, School of Medicine, University of Patras, Patras, Greece
| | - Argyris Dinopoulos
- 3rd Department of Pediatrics, General Hospital of Athens Attikon, Medical School, National and Kapodistrian University of Athens, Athens, Greece
| | - Marios Panas
- Neurogenetics Unit, 1st Department of Neurology, Eginition Hospital, School of Medicine, National and Kapodistrian University of Athens, Athens, Greece
| | - Georgios Koutsis
- Neurogenetics Unit, 1st Department of Neurology, Eginition Hospital, School of Medicine, National and Kapodistrian University of Athens, Athens, Greece
| | - Georgia Karadima
- Neurogenetics Unit, 1st Department of Neurology, Eginition Hospital, School of Medicine, National and Kapodistrian University of Athens, Athens, Greece
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Towards a Cure for HARS Disease. Genes (Basel) 2023; 14:genes14020254. [PMID: 36833180 PMCID: PMC9956352 DOI: 10.3390/genes14020254] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Revised: 01/11/2023] [Accepted: 01/13/2023] [Indexed: 01/20/2023] Open
Abstract
Histidyl-tRNA synthetase (HARS) ligates histidine to its cognate transfer RNA (tRNAHis). Mutations in HARS cause the human genetic disorders Usher syndrome type 3B (USH3B) and Charcot-Marie-Tooth syndrome type 2W (CMT2W). Treatment for these diseases remains symptomatic, and no disease specific treatments are currently available. Mutations in HARS can lead to destabilization of the enzyme, reduced aminoacylation, and decreased histidine incorporation into the proteome. Other mutations lead to a toxic gain-of-function and mistranslation of non-cognate amino acids in response to histidine codons, which can be rescued by histidine supplementation in vitro. We discuss recent advances in characterizing HARS mutations and potential applications of amino acid and tRNA therapy for future gene and allele specific therapy.
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4
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Braun JE. Extracellular chaperone networks and the export of J-domain proteins. J Biol Chem 2022; 299:102840. [PMID: 36581212 PMCID: PMC9867986 DOI: 10.1016/j.jbc.2022.102840] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2022] [Revised: 12/18/2022] [Accepted: 12/20/2022] [Indexed: 12/27/2022] Open
Abstract
An extracellular network of molecular chaperones protects a diverse array of proteins that reside in or pass through extracellular spaces. Proteins in the extracellular milieu face numerous challenges that can lead to protein misfolding and aggregation. As a checkpoint for proteins that move between cells, extracellular chaperone networks are of growing clinical relevance. J-domain proteins (JDPs) are ubiquitous molecular chaperones that are known for their essential roles in a wide array of fundamental cellular processes through their regulation of heat shock protein 70s. As the largest molecular chaperone family, JDPs have long been recognized for their diverse functions within cells. Some JDPs are elegantly selective for their "client proteins," some do not discriminate among substrates and others act cooperatively on the same target. The realization that JDPs are exported through both classical and unconventional secretory pathways has fueled investigation into the roles that JDPs play in protein quality control and intercellular communication. The proposed functions of exported JDPs are diverse. Studies suggest that export of DnaJB11 enhances extracellular proteostasis, that intercellular movement of DnaJB1 or DnaJB6 enhances the proteostasis capacity in recipient cells, whereas the import of DnaJB8 increases resistance to chemotherapy in recipient cancer cells. In addition, the export of DnaJC5 and concurrent DnaJC5-dependent ejection of dysfunctional and aggregation-prone proteins are implicated in the prevention of neurodegeneration. This review provides a brief overview of the current understanding of the extracellular chaperone networks and outlines the first wave of studies describing the cellular export of JDPs.
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Ng KWP, Chin HL, Chin AXY, Goh DLM. Using gene panels in the diagnosis of neuromuscular disorders: A mini-review. Front Neurol 2022; 13:997551. [PMID: 36313509 PMCID: PMC9602396 DOI: 10.3389/fneur.2022.997551] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2022] [Accepted: 09/21/2022] [Indexed: 09/26/2023] Open
Abstract
The diagnosis of inherited neuromuscular disorders is challenging due to their genetic and phenotypic variability. Traditionally, neurophysiology and histopathology were primarily used in the initial diagnostic approach to these conditions. Sanger sequencing for molecular diagnosis was less frequently utilized as its application was a time-consuming and cost-intensive process. The advent and accessibility of next-generation sequencing (NGS) has revolutionized the evaluation process of genetically heterogenous neuromuscular disorders. Current NGS diagnostic testing approaches include gene panels, whole exome sequencing (WES), and whole genome sequencing (WGS). Gene panels are often the most widely used, being more accessible due to availability and affordability. In this mini-review, we describe the benefits and risks of clinical genetic testing. We also discuss the utility, benefits, challenges, and limitations of using gene panels in the evaluation of neuromuscular disorders.
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Affiliation(s)
- Kay W. P. Ng
- Division of Neurology, Department of Medicine, National University Hospital, Singapore, Singapore
| | - Hui-Lin Chin
- Division of Genetics and Metabolism, Department of Paediatrics, Khoo Teck Puat - National University Children's Medical Institute, National University Hospital, Singapore, Singapore
- Department of Paediatrics, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Amanda X. Y. Chin
- Division of Neurology, Department of Medicine, National University Hospital, Singapore, Singapore
| | - Denise Li-Meng Goh
- Division of Genetics and Metabolism, Department of Paediatrics, Khoo Teck Puat - National University Children's Medical Institute, National University Hospital, Singapore, Singapore
- Department of Paediatrics, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
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6
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Saveri P, Magri S, Maderna E, Balistreri F, Lombardi R, Ciano C, Moda F, Garavaglia B, Reale C, Lauria Pinter G, Taroni F, Pareyson D, Pisciotta C. DNAJB2-related CMT2: Pathomechanism insights and phenotypic spectrum widening. Eur J Neurol 2022; 29:2056-2065. [PMID: 35286755 PMCID: PMC9314055 DOI: 10.1111/ene.15326] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2021] [Revised: 02/14/2022] [Accepted: 03/09/2022] [Indexed: 11/29/2022]
Abstract
Background and purpose Mutations in DNAJB2 are associated with autosomal recessive hereditary motor neuropathies/ Charcot‐Marie‐Tooth disease type 2 (CMT2). We describe an Italian family with CMT2 due to a homozygous DNAJB2 mutation and provide insight into the pathomechanisms. Methods Patients with DNAJB2 mutations were characterized clinically, electrophysiologically and by means of skin biopsy. mRNA and protein levels were studied in lymphoblastoid cells (LCLs) from patients and controls. Results Three affected siblings were found to carry a homozygous DNAJB2 null mutation segregating with the disease. The disease manifested in the second to third decade of life. Clinical examination showed severe weakness of the thigh muscles and complete loss of movement in the foot and leg muscles. Sensation was reduced in the lower limbs. All patients had severe hearing loss and the proband also had Parkinson’s disease (PD). Nerve conduction studies showed an axonal motor and sensory length‐dependent polyneuropathy. DNAJB2 expression studies revealed reduced mRNA levels and the absence of the protein in the homozygous subject in both LCLs and skin biopsy. Interestingly, we detected phospho‐alpha‐synuclein deposits in the proband, as already seen in PD patients, and demonstrated TDP‐43 accumulation in patients’ skin. Conclusions Our results broaden the clinical spectrum of DNAJB2‐related neuropathies and provide evidence that DNAJB2 mutations should be taken into account as another causative gene of CMT2 with hearing loss and parkinsonism. The mutation likely acts through a loss‐of‐function mechanism, leading to toxic protein aggregation such as TDP‐43. The associated parkinsonism resembles the classic PD form with the addition of abnormal accumulation of phospho‐alpha‐synuclein.
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Affiliation(s)
- Paola Saveri
- Department of Clinical Neurosciences, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Stefania Magri
- Department of Diagnostics and Applied Technology, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Emanuela Maderna
- Department of Diagnostics and Applied Technology, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Francesca Balistreri
- Department of Diagnostics and Applied Technology, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Raffaella Lombardi
- Department of Clinical Neurosciences, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Claudia Ciano
- Department of Diagnostics and Applied Technology, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Fabio Moda
- Department of Diagnostics and Applied Technology, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Barbara Garavaglia
- Department of Diagnostics and Applied Technology, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Chiara Reale
- Department of Diagnostics and Applied Technology, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Giuseppe Lauria Pinter
- Department of Clinical Neurosciences, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy.,Department of Medical Biotechnology and Translational Medicine, University of Milan, Milan, Italy
| | - Franco Taroni
- Department of Diagnostics and Applied Technology, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Davide Pareyson
- Department of Clinical Neurosciences, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Chiara Pisciotta
- Department of Clinical Neurosciences, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
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7
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Genetic Workup for Charcot–Marie–Tooth Neuropathy: A Retrospective Single-Site Experience Covering 15 Years. Life (Basel) 2022; 12:life12030402. [PMID: 35330153 PMCID: PMC8948690 DOI: 10.3390/life12030402] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Revised: 03/04/2022] [Accepted: 03/07/2022] [Indexed: 11/16/2022] Open
Abstract
Charcot–Marie–Tooth (CMT) disease is the most commonly inherited neurological disorder. This study includes patients affected by CMT during regular follow-ups at the CMT clinic in Genova, a neuromuscular university center in the northwest of Italy, with the aim of describing the genetic distribution of CMT subtypes in our cohort and reporting a peculiar phenotype. Since 2004, 585 patients (447 index cases) have been evaluated at our center, 64.9% of whom have a demyelinating neuropathy and 35.1% of whom have an axonal neuropathy. A genetic diagnosis was achieved in 66% of all patients, with the following distribution: CMT1A (48%), HNPP (14%), CMT1X (13%), CMT2A (5%), and P0-related neuropathies (7%), accounting all together for 87% of all the molecularly defined neuropathies. Interestingly, we observe a peculiar phenotype with initial exclusive lower limb involvement as well as lower limb involvement that is maintained over time, which we have defined as a “strictly length-dependent” phenotype. Most patients with this clinical presentation shared variants in either HSPB1 or MPZ genes. The identification of distinctive phenotypes such as this one may help to address genetic diagnosis. In conclusion, we describe our diagnostic experiences as a multidisciplinary outpatient clinic, combining a gene-by-gene approach or targeted gene panels based on clinical presentation.
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8
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Kaida A, Iwakuma T. Regulation of p53 and Cancer Signaling by Heat Shock Protein 40/J-Domain Protein Family Members. Int J Mol Sci 2021; 22:13527. [PMID: 34948322 PMCID: PMC8706882 DOI: 10.3390/ijms222413527] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2021] [Revised: 12/13/2021] [Accepted: 12/14/2021] [Indexed: 12/27/2022] Open
Abstract
Heat shock proteins (HSPs) are molecular chaperones that assist diverse cellular activities including protein folding, intracellular transportation, assembly or disassembly of protein complexes, and stabilization or degradation of misfolded or aggregated proteins. HSP40, also known as J-domain proteins (JDPs), is the largest family with over fifty members and contains highly conserved J domains responsible for binding to HSP70 and stimulation of the ATPase activity as a co-chaperone. Tumor suppressor p53 (p53), the most frequently mutated gene in human cancers, is one of the proteins that functionally interact with HSP40/JDPs. The majority of p53 mutations are missense mutations, resulting in acquirement of unexpected oncogenic activities, referred to as gain of function (GOF), in addition to loss of the tumor suppressive function. Moreover, stability and levels of wild-type p53 (wtp53) and mutant p53 (mutp53) are crucial for their tumor suppressive and oncogenic activities, respectively. However, the regulatory mechanisms of wtp53 and mutp53 are not fully understood. Accumulating reports demonstrate regulation of wtp53 and mutp53 levels and/or activities by HSP40/JDPs. Here, we summarize updated knowledge related to the link of HSP40/JDPs with p53 and cancer signaling to improve our understanding of the regulation of tumor suppressive wtp53 and oncogenic mutp53 GOF activities.
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Affiliation(s)
- Atsushi Kaida
- Department of Oral Radiation Oncology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo 113-8510, Japan;
- Department of Cancer Biology, University of Kansas Medical Center, Kansas City, KS 66160, USA
| | - Tomoo Iwakuma
- Department of Cancer Biology, University of Kansas Medical Center, Kansas City, KS 66160, USA
- Department of Pediatrics, Children’s Mercy Research Institute, Kansas City, MO 64108, USA
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9
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Ferese R, Campopiano R, Scala S, D'Alessio C, Storto M, Buttari F, Centonze D, Logroscino G, Zecca C, Zampatti S, Fornai F, Cianci V, Manfroi E, Giardina E, Magnani M, Suppa A, Novelli G, Gambardella S. Cohort Analysis of 67 Charcot-Marie-Tooth Italian Patients: Identification of New Mutations and Broadening of Phenotype Expression Produced by Rare Variants. Front Genet 2021; 12:682050. [PMID: 34354735 PMCID: PMC8329958 DOI: 10.3389/fgene.2021.682050] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Accepted: 06/17/2021] [Indexed: 11/13/2022] Open
Abstract
Charcot-Marie-Tooth (CMT) disease is the most prevalent inherited motor sensory neuropathy, which clusters a clinically and genetically heterogeneous group of disorders with more than 90 genes associated with different phenotypes. The goal of this study is to identify the genetic features in the recruited cohort of patients, highlighting the role of rare variants in the genotype-phenotype correlation. We enrolled 67 patients and applied a diagnostic protocol including multiple ligation-dependent probe amplification for copy number variation (CNV) detection of PMP22 locus, and next-generation sequencing (NGS) for sequencing of 47 genes known to be associated with CMT and routinely screened in medical genetics. This approach allowed the identification of 26 patients carrying a whole gene CNV of PMP22. In the remaining 41 patients, NGS identified the causative variants in eight patients in the genes HSPB1, MFN2, KIF1A, GDAP1, MTMR2, SH3TC2, KIF5A, and MPZ (five new vs. three previously reported variants; three sporadic vs. five familial variants). Familial segregation analysis allowed to correctly interpret two variants, initially reported as "variants of uncertain significance" but re-classified as pathological. In this cohort is reported a patient carrying a novel familial mutation in the tail domain of KIF5A [a protein domain previously associated with familial amyotrophic lateral sclerosis (ALS)], and a CMT patient carrying a HSPB1 mutation, previously reported in ALS. These data indicate that combined tools for gene association in medical genetics allow dissecting unexpected phenotypes associated with previously known or unknown genotypes, thus broadening the phenotype expression produced by either pathogenic or undefined variants. Clinical trial registration: ClinicalTrials.gov (NCT03084224).
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Affiliation(s)
| | | | | | | | | | | | - Diego Centonze
- IRCCS Neuromed, Pozzilli, Italy.,Laboratory of Synaptic Immunopathology, Department of Systems Medicine, Tor Vergata University, Rome, Italy
| | - Giancarlo Logroscino
- Center for Neurodegenerative Diseases and the Aging Brain, Department of Clinical Research in Neurology, The University of Bari "Aldo Moro," "Pia Fondazione Card G. Panico" Hospital Tricase, Lecce, Italy.,Department of Basic Medicine Neuroscience and Sense Organs, University "Aldo Moro" Bari, Bari, Italy
| | - Chiara Zecca
- Center for Neurodegenerative Diseases and the Aging Brain, Department of Clinical Research in Neurology, The University of Bari "Aldo Moro," "Pia Fondazione Card G. Panico" Hospital Tricase, Lecce, Italy
| | - Stefania Zampatti
- IRCCS Neuromed, Pozzilli, Italy.,Genomic Medicine Laboratory, IRCCS Fondazione Santa Lucia, Rome, Italy
| | - Francesco Fornai
- IRCCS Neuromed, Pozzilli, Italy.,Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Pisa, Italy
| | - Vittoria Cianci
- Regional Epilepsy Centre, Great Metropolitan Hospital Bianchi-Melacrino-Morelli, Reggio Calabria, Italy
| | - Elisabetta Manfroi
- Department of Neuroscience- Neurogenetics, Santa Maria Hospital, Terni, Italy
| | - Emiliano Giardina
- Genomic Medicine Laboratory, IRCCS Fondazione Santa Lucia, Rome, Italy.,Department of Biomedicine and Prevention, University of Rome "Tor Vergata," Rome, Italy
| | - Mauro Magnani
- Department of Biomolecular Sciences, University of Urbino "Carlo Bo," Urbino, Italy
| | - Antonio Suppa
- IRCCS Neuromed, Pozzilli, Italy.,Department of Human Neurosciences, Sapienza University of Rome, Rome, Italy
| | - Giuseppe Novelli
- IRCCS Neuromed, Pozzilli, Italy.,Department of Biomedicine and Prevention, University of Rome "Tor Vergata," Rome, Italy
| | - Stefano Gambardella
- IRCCS Neuromed, Pozzilli, Italy.,Department of Biomolecular Sciences, University of Urbino "Carlo Bo," Urbino, Italy
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Felice KJ, Whitaker CH, Khorasanizadeh S. Diagnostic yield of advanced genetic testing in patients with hereditary neuropathies: A retrospective single-site study. Muscle Nerve 2021; 64:454-461. [PMID: 34232518 DOI: 10.1002/mus.27368] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Revised: 06/29/2021] [Accepted: 07/04/2021] [Indexed: 11/09/2022]
Abstract
INTRODUCTION/AIMS Advanced genetic testing including next-generation sequencing (AGT/NGS) has facilitated DNA testing in the clinical setting and greatly expanded new gene discovery for the Charcot-Marie-Tooth neuropathies and other hereditary neuropathies (CMT/HN). Herein, we report AGT/NGS results, clinical findings, and diagnostic yield in a cohort of CMT/HN patients evaluated at our neuropathy care center. METHODS We reviewed the medical records of all patients with suspected CMT/HN who underwent AGT/NGS at the Hospital for Special Care from January 2017 through January 2020. Patients with variants reported as pathogenic or likely pathogenic were included for further clinical review. RESULTS We ordered AGT/NGS on 108 patients with suspected CMT/HN. Of these, pathogenic or likely pathogenic variants were identified in 17 patients (diagnostic yield, 15.7%), including 6 (35%) with PMP22 duplications; 3 (18%) with MPZ variants; 2 (12%) with MFN2 variants; and 1 each with NEFL, IGHMBP2, GJB1, BSCL2, DNM2, and TTR variants. Diagnostic yield increased to 31.0% for patients with a positive family history. DISCUSSION AGT/NGS panels can provide specific genetic diagnoses for a subset of patients with CMT/HN disorders, which improves disease and genetic counseling and prepares patients for disease-focused therapies. Despite these advancements, many patients with known or suspected CMT/HN disorders remain without a specific genetic diagnosis. Continued advancements in genetic testing, such as multiomic technology and better understanding of genotype-phenotype correlation, will further improve detection rates for patients with suspected CMT/HN disorders.
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Affiliation(s)
- Kevin J Felice
- Department of Neuromuscular Medicine, Hospital for Special Care, New Britain, Connecticut, USA
| | - Charles H Whitaker
- Department of Neuromuscular Medicine, Hospital for Special Care, New Britain, Connecticut, USA
| | - Sadaf Khorasanizadeh
- Department of Neuromuscular Medicine, Hospital for Special Care, New Britain, Connecticut, USA
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11
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Schiavon CR, Shadel GS, Manor U. Impaired Mitochondrial Mobility in Charcot-Marie-Tooth Disease. Front Cell Dev Biol 2021; 9:624823. [PMID: 33598463 PMCID: PMC7882694 DOI: 10.3389/fcell.2021.624823] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2020] [Accepted: 01/05/2021] [Indexed: 12/13/2022] Open
Abstract
Charcot-Marie-Tooth (CMT) disease is a progressive, peripheral neuropathy and the most commonly inherited neurological disorder. Clinical manifestations of CMT mutations are typically limited to peripheral neurons, the longest cells in the body. Currently, mutations in at least 80 different genes are associated with CMT and new mutations are regularly being discovered. A large portion of the proteins mutated in axonal CMT have documented roles in mitochondrial mobility, suggesting that organelle trafficking defects may be a common underlying disease mechanism. This review will focus on the potential role of altered mitochondrial mobility in the pathogenesis of axonal CMT, highlighting the conceptional challenges and potential experimental and therapeutic opportunities presented by this "impaired mobility" model of the disease.
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Affiliation(s)
- Cara R. Schiavon
- Waitt Advanced Biophotonics Center, Salk Institute for Biological Studies, La Jolla, CA, United States
- Molecular and Cell Biology Laboratory, Salk Institute for Biological Studies, La Jolla, CA, United States
| | - Gerald S. Shadel
- Molecular and Cell Biology Laboratory, Salk Institute for Biological Studies, La Jolla, CA, United States
| | - Uri Manor
- Waitt Advanced Biophotonics Center, Salk Institute for Biological Studies, La Jolla, CA, United States
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Frasquet M, Rojas-García R, Argente-Escrig H, Vázquez-Costa JF, Muelas N, Vílchez JJ, Sivera R, Millet E, Barreiro M, Díaz-Manera J, Turon-Sans J, Cortés-Vicente E, Querol L, Ramírez-Jiménez L, Martínez-Rubio D, Sánchez-Monteagudo A, Espinós C, Sevilla T, Lupo V. Distal hereditary motor neuropathies: Mutation spectrum and genotype-phenotype correlation. Eur J Neurol 2021; 28:1334-1343. [PMID: 33369814 DOI: 10.1111/ene.14700] [Citation(s) in RCA: 41] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Revised: 11/28/2020] [Accepted: 12/17/2020] [Indexed: 01/12/2023]
Abstract
BACKGROUND AND PURPOSE Distal hereditary motor neuropathies (dHMNs) are a heterogeneous group of disorders characterized by degeneration of the motor component of peripheral nerves. Currently, only 15% to 32.5% of patients with dHMN are characterized genetically. Additionally, the prevalence of these genetic disorders is not well known. Recently, biallelic mutations in the sorbitol dehydrogenase gene (SORD) have been identified as a cause of dHMN, with an estimated frequency in undiagnosed cases of up to 10%. METHODS In the present study, we included 163 patients belonging to 108 different families who were diagnosed with a dHMN and who underwent a thorough genetic screening that included next-generation sequencing and subsequent Sanger sequencing of SORD. RESULTS Most probands were sporadic cases (62.3%), and the most frequent age of onset of symptoms was 2 to 10 years (28.8%). A genetic diagnosis was achieved in 37/108 (34.2%) families and 78/163 (47.8%) of all patients. The most frequent cause of distal hereditary motor neuropathies were mutations in HSPB1 (10.4%), GARS1 (9.8%), BICD2 (8.0%), and DNAJB2 (6.7%) genes. In addition, 3.1% of patients were found to be carriers of biallelic mutations in SORD. Mutations in another seven genes were also identified, although they were much less frequent. Eight new pathogenic mutations were detected, and 17 patients without a definite genetic diagnosis carried variants of uncertain significance. The calculated minimum prevalence of dHMN was 2.3 per 100,000 individuals. CONCLUSIONS This study confirms the genetic heterogeneity of dHMN and that biallelic SORD mutations are a cause of dHMN in different populations.
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Affiliation(s)
- Marina Frasquet
- Neuromuscular Diseases Unit, Department of Neurology, Hospital Universitari i Politècnic La Fe, Valencia, Spain.,Neuromuscular and Ataxias Research Group, Instituto de Investigación Sanitaria La Fe, Valencia, Spain.,Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER) Spain, Valencia, Spain
| | - Ricard Rojas-García
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER) Spain, Valencia, Spain.,Neuromuscular Diseases Unit, Department of Neurology, Hospital de la Santa Creu i Sant Pau, Barcelona, Spain.,Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Herminia Argente-Escrig
- Neuromuscular and Ataxias Research Group, Instituto de Investigación Sanitaria La Fe, Valencia, Spain.,Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER) Spain, Valencia, Spain
| | - Juan Francisco Vázquez-Costa
- Neuromuscular Diseases Unit, Department of Neurology, Hospital Universitari i Politècnic La Fe, Valencia, Spain.,Neuromuscular and Ataxias Research Group, Instituto de Investigación Sanitaria La Fe, Valencia, Spain.,Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER) Spain, Valencia, Spain.,Department of Medicine, Universitat de València, Valencia, Spain
| | - Nuria Muelas
- Neuromuscular Diseases Unit, Department of Neurology, Hospital Universitari i Politècnic La Fe, Valencia, Spain.,Neuromuscular and Ataxias Research Group, Instituto de Investigación Sanitaria La Fe, Valencia, Spain.,Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER) Spain, Valencia, Spain
| | - Juan Jesús Vílchez
- Neuromuscular and Ataxias Research Group, Instituto de Investigación Sanitaria La Fe, Valencia, Spain.,Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER) Spain, Valencia, Spain
| | - Rafael Sivera
- Department of Neurology, Hospital Francesc de Borja, Gandía, Spain
| | - Elvira Millet
- Department of Clinical Neurophysiology, Hospital Universitari i Politècnic La Fe, Valencia, Spain
| | - Marisa Barreiro
- Neuromuscular and Ataxias Research Group, Instituto de Investigación Sanitaria La Fe, Valencia, Spain
| | - Jordi Díaz-Manera
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER) Spain, Valencia, Spain.,Neuromuscular Diseases Unit, Department of Neurology, Hospital de la Santa Creu i Sant Pau, Barcelona, Spain.,Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Janina Turon-Sans
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER) Spain, Valencia, Spain.,Neuromuscular Diseases Unit, Department of Neurology, Hospital de la Santa Creu i Sant Pau, Barcelona, Spain.,Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Elena Cortés-Vicente
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER) Spain, Valencia, Spain.,Neuromuscular Diseases Unit, Department of Neurology, Hospital de la Santa Creu i Sant Pau, Barcelona, Spain.,Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Luis Querol
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER) Spain, Valencia, Spain.,Neuromuscular Diseases Unit, Department of Neurology, Hospital de la Santa Creu i Sant Pau, Barcelona, Spain.,Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Laura Ramírez-Jiménez
- Department of Genomics and Translational Genetics, Centro de Investigación Príncipe Felipe (CIPF), Valencia, Spain
| | - Dolores Martínez-Rubio
- Unit of Genetics and Genomics of Neuromuscular and Neurodegenerative Disorders, Centro de Investigación Príncipe Felipe (CIPF), Valencia, Spain.,Rare Diseases Joint Units, INCLIVA and IIS La Fe-CIPF, Valencia, Spain
| | - Ana Sánchez-Monteagudo
- Unit of Genetics and Genomics of Neuromuscular and Neurodegenerative Disorders, Centro de Investigación Príncipe Felipe (CIPF), Valencia, Spain.,Rare Diseases Joint Units, INCLIVA and IIS La Fe-CIPF, Valencia, Spain
| | - Carmen Espinós
- Unit of Genetics and Genomics of Neuromuscular and Neurodegenerative Disorders, Centro de Investigación Príncipe Felipe (CIPF), Valencia, Spain.,Rare Diseases Joint Units, INCLIVA and IIS La Fe-CIPF, Valencia, Spain
| | - Teresa Sevilla
- Neuromuscular Diseases Unit, Department of Neurology, Hospital Universitari i Politècnic La Fe, Valencia, Spain.,Neuromuscular and Ataxias Research Group, Instituto de Investigación Sanitaria La Fe, Valencia, Spain.,Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER) Spain, Valencia, Spain.,Department of Medicine, Universitat de València, Valencia, Spain
| | - Vincenzo Lupo
- Unit of Genetics and Genomics of Neuromuscular and Neurodegenerative Disorders, Centro de Investigación Príncipe Felipe (CIPF), Valencia, Spain.,Rare Diseases Joint Units, INCLIVA and IIS La Fe-CIPF, Valencia, Spain
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Reilich P, Schlotter B, Montagnese F, Jordan B, Stock F, Schäff-Vogelsang M, Hotter B, Eger K, Diebold I, Erdmann H, Becker K, Schön U, Abicht A. Location matters - Genotype-phenotype correlation in LRSAM1 mutations associated with rare Charcot-Marie-Tooth neuropathy CMT2P. Neuromuscul Disord 2021; 31:123-133. [PMID: 33414056 DOI: 10.1016/j.nmd.2020.11.011] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Revised: 11/16/2020] [Accepted: 11/23/2020] [Indexed: 01/01/2023]
Abstract
More than 80 genes are known to be associated with Charcot-Marie-Tooth disease (CMT). Mutations of LRSAM1 were identified as a rare cause and define the subgroup of axonal neuropathy CMT2P. We identified additional 14 patients out of 12 families. Clinical and electrophysiological data confirm a late-onset axonal neuropathy with a predominance of sensorimotor impairment. The patients harbored ten different variants in LRSAM1, seven of which were novel. Due to variable inheritance patterns and clustering of pathogenic variants in 3´-prime exons, interpretation of genetic variants in LRSAM1 is challenging. The majority follows dominant inheritance, whereas recessive inheritance has been described for one variant. Variants at the 3`end may or may not escape from nonsense-mediated decay, thereby defining the pattern of inheritance. Our data emphasize the importance of the C-terminal RING domain, which exerts a dominant-negative effect on protein function, whenever affected by an altered or truncated protein. In conclusion, CMT2P is a rare, but nevertheless relevant cause of adult-onset axonal and painful neuropathy. ACMG (American College of Medical Genetics and genomics) criteria should be carefully applied in variant interpretation, with special attention to premature termination codon-introducing variants and their location within the gene.
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Affiliation(s)
- Peter Reilich
- Department of Neurology, Friedrich-Baur-Institute, Ludwig-Maximilians-University Munich, Munich, Germany
| | - Beate Schlotter
- Department of Neurology, Friedrich-Baur-Institute, Ludwig-Maximilians-University Munich, Munich, Germany
| | - Federica Montagnese
- Department of Neurology, Friedrich-Baur-Institute, Ludwig-Maximilians-University Munich, Munich, Germany
| | - Berit Jordan
- Department of Neurology, University Hospital of Halle, Halle, Germany; Department of Neurology, University Hospital of Heidelberg, Heidelberg, Germany
| | - Friedrich Stock
- Institute of Human Genetics, Universitätsklinikum Münster, Münster, Germany
| | | | - Benjamin Hotter
- Department of Neurology, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt- Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Katherina Eger
- Gemeinschaftspraxis für Neurologie und Psychiatrie, Leipzig, Germany
| | - Isabel Diebold
- Department of Pediatrics, Technical University of Munich School of Medicine, Munich, Germany; Medical Genetics Centre, Bayerstr. 3-5, 80335 Munich, Germany
| | - Hannes Erdmann
- Medical Genetics Centre, Bayerstr. 3-5, 80335 Munich, Germany
| | - Kerstin Becker
- Medical Genetics Centre, Bayerstr. 3-5, 80335 Munich, Germany
| | - Ulrike Schön
- Medical Genetics Centre, Bayerstr. 3-5, 80335 Munich, Germany
| | - Angela Abicht
- Department of Neurology, Friedrich-Baur-Institute, Ludwig-Maximilians-University Munich, Munich, Germany; Medical Genetics Centre, Bayerstr. 3-5, 80335 Munich, Germany.
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Hsp40 proteins phase separate to chaperone the assembly and maintenance of membraneless organelles. Proc Natl Acad Sci U S A 2020; 117:31123-31133. [PMID: 33229560 DOI: 10.1073/pnas.2002437117] [Citation(s) in RCA: 50] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Membraneless organelles contain a wide spectrum of molecular chaperones, indicating their important roles in modulating the metastable conformation and biological function of membraneless organelles. Here we report that class I and II Hsp40 (DNAJ) proteins possess a high ability of phase separation rendered by the flexible G/F-rich region. Different Hsp40 proteins localize in different membraneless organelles. Specifically, human Hdj1 (DNAJB1), a class II Hsp40 protein, condenses in ubiquitin (Ub)-rich nuclear bodies, while Hdj2 (DNAJA1), a class I Hsp40 protein, condenses in nucleoli. Upon stress, both Hsp40 proteins incorporate into stress granules (SGs). Mutations of the G/F-rich region not only markedly impaired Hdj1 phase separation and SG involvement and disrupted the synergistic phase separation and colocalization of Hdj1 and fused in sarcoma (FUS) in cells. Being cophase separated with FUS, Hdj1 stabilized the liquid phase of FUS against proceeding into amyloid aggregation in vitro and alleviated abnormal FUS aggregation in cells. Moreover, Hdj1 uses different domains to chaperone FUS phase separation and amyloid aggregation. This paper suggests that phase separation is an intrinsic property of Hsp40 proteins, which enables efficient incorporation and function of Hsp40 in membraneless organelles and may further mediate the buildup of chaperone network in membraneless organelles.
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Abstract
PURPOSE OF REVIEW Charcot-Marie-Tooth (CMT) disease and related disorders are the commonest group of inherited neuromuscular diseases and represent a heterogeneous group of disorders. This review will cover recent advances in genetic diagnosis and the evolving genetic and phenotype landscape of this disease group. We will review recent evidence of the increasingly recognized phenotypic overlap with other neurodegenerative conditions including hereditary spastic paraplegia, hereditary ataxias and mitochondrial diseases and highlight the importance of deep phenotyping to inform genetic diagnosis and prognosis. RECENT FINDINGS Through whole exome sequencing and multicentre collaboration new genes are being identified as causal for CMT expanding the genetic heterogeneity of this condition. In addition, an increasing number of variants have been identified in genes known to cause complex inherited diseases in which the peripheral neuropathy is part of the disorder and may be the presenting feature. The recent discovery of a repeat expansion in the RFC1 gene in cerebellar ataxia, neuropathy, vestibular areflexia syndrome highlights the prevalence of late-onset recessive conditions which have historically been considered to cause early-onset disease. SUMMARY CMT is an evolving field with considerable phenotypic and genetic heterogeneity and deep phenotyping remains a cornerstone in contemporary CMT diagnostics.
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16
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Neuromuscular Diseases Due to Chaperone Mutations: A Review and Some New Results. Int J Mol Sci 2020; 21:ijms21041409. [PMID: 32093037 PMCID: PMC7073051 DOI: 10.3390/ijms21041409] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2020] [Revised: 02/12/2020] [Accepted: 02/13/2020] [Indexed: 12/12/2022] Open
Abstract
Skeletal muscle and the nervous system depend on efficient protein quality control, and they express chaperones and cochaperones at high levels to maintain protein homeostasis. Mutations in many of these proteins cause neuromuscular diseases, myopathies, and hereditary motor and sensorimotor neuropathies. In this review, we cover mutations in DNAJB6, DNAJB2, αB-crystallin (CRYAB, HSPB5), HSPB1, HSPB3, HSPB8, and BAG3, and discuss the molecular mechanisms by which they cause neuromuscular disease. In addition, previously unpublished results are presented, showing downstream effects of BAG3 p.P209L on DNAJB6 turnover and localization.
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17
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Cortese A, Wilcox JE, Polke JM, Poh R, Skorupinska M, Rossor AM, Laura M, Tomaselli PJ, Houlden H, Shy ME, Reilly MM. Targeted next-generation sequencing panels in the diagnosis of Charcot-Marie-Tooth disease. Neurology 2019; 94:e51-e61. [PMID: 31827005 PMCID: PMC7011687 DOI: 10.1212/wnl.0000000000008672] [Citation(s) in RCA: 67] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2019] [Accepted: 06/24/2019] [Indexed: 12/22/2022] Open
Abstract
OBJECTIVE To investigate the effectiveness of targeted next-generation sequencing (NGS) panels in achieving a molecular diagnosis in Charcot-Marie-Tooth disease (CMT) and related disorders in a clinical setting. METHODS We prospectively enrolled 220 patients from 2 tertiary referral centers, one in London, United Kingdom (n = 120), and one in Iowa (n = 100), in whom a targeted CMT NGS panel had been requested as a diagnostic test. PMP22 duplication/deletion was previously excluded in demyelinating cases. We reviewed the genetic and clinical data upon completion of the diagnostic process. RESULTS After targeted NGS sequencing, a definite molecular diagnosis, defined as a pathogenic or likely pathogenic variant, was reached in 30% of cases (n = 67). The diagnostic rate was similar in London (32%) and Iowa (29%). Variants of unknown significance were found in an additional 33% of cases. Mutations in GJB1, MFN2, and MPZ accounted for 39% of cases that received genetic confirmation, while the remainder of positive cases had mutations in diverse genes, including SH3TC2, GDAP1, IGHMBP2, LRSAM1, FDG4, and GARS, and another 12 less common genes. Copy number changes in PMP22, MPZ, MFN2, SH3TC2, and FDG4 were also accurately detected. A definite genetic diagnosis was more likely in cases with an early onset, a positive family history of neuropathy or consanguinity, and a demyelinating neuropathy. CONCLUSIONS NGS panels are effective tools in the diagnosis of CMT, leading to genetic confirmation in one-third of cases negative for PMP22 duplication/deletion, thus highlighting how rarer and previously undiagnosed subtypes represent a relevant part of the genetic landscape of CMT.
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Affiliation(s)
- Andrea Cortese
- From the MRC Centre for Neuromuscular Diseases (A.C., J.M.P., R.P., M.S., A.M.R., M.L., P.J.T., H.H., M.M.R.), Department of Neuromuscular Diseases, National Hospital for Neurology and Neurosurgery, UCL Queen Square Institute of Neurology, London, UK; Department of Brain and Behavioral Sciences (A.C.), University of Pavia, Italy; and the Department of Neurology (J.E.W., M.E.S.), University of Iowa Carver College of Medicine, Iowa City
| | - Janel E Wilcox
- From the MRC Centre for Neuromuscular Diseases (A.C., J.M.P., R.P., M.S., A.M.R., M.L., P.J.T., H.H., M.M.R.), Department of Neuromuscular Diseases, National Hospital for Neurology and Neurosurgery, UCL Queen Square Institute of Neurology, London, UK; Department of Brain and Behavioral Sciences (A.C.), University of Pavia, Italy; and the Department of Neurology (J.E.W., M.E.S.), University of Iowa Carver College of Medicine, Iowa City
| | - James M Polke
- From the MRC Centre for Neuromuscular Diseases (A.C., J.M.P., R.P., M.S., A.M.R., M.L., P.J.T., H.H., M.M.R.), Department of Neuromuscular Diseases, National Hospital for Neurology and Neurosurgery, UCL Queen Square Institute of Neurology, London, UK; Department of Brain and Behavioral Sciences (A.C.), University of Pavia, Italy; and the Department of Neurology (J.E.W., M.E.S.), University of Iowa Carver College of Medicine, Iowa City
| | - Roy Poh
- From the MRC Centre for Neuromuscular Diseases (A.C., J.M.P., R.P., M.S., A.M.R., M.L., P.J.T., H.H., M.M.R.), Department of Neuromuscular Diseases, National Hospital for Neurology and Neurosurgery, UCL Queen Square Institute of Neurology, London, UK; Department of Brain and Behavioral Sciences (A.C.), University of Pavia, Italy; and the Department of Neurology (J.E.W., M.E.S.), University of Iowa Carver College of Medicine, Iowa City
| | - Mariola Skorupinska
- From the MRC Centre for Neuromuscular Diseases (A.C., J.M.P., R.P., M.S., A.M.R., M.L., P.J.T., H.H., M.M.R.), Department of Neuromuscular Diseases, National Hospital for Neurology and Neurosurgery, UCL Queen Square Institute of Neurology, London, UK; Department of Brain and Behavioral Sciences (A.C.), University of Pavia, Italy; and the Department of Neurology (J.E.W., M.E.S.), University of Iowa Carver College of Medicine, Iowa City
| | - Alexander M Rossor
- From the MRC Centre for Neuromuscular Diseases (A.C., J.M.P., R.P., M.S., A.M.R., M.L., P.J.T., H.H., M.M.R.), Department of Neuromuscular Diseases, National Hospital for Neurology and Neurosurgery, UCL Queen Square Institute of Neurology, London, UK; Department of Brain and Behavioral Sciences (A.C.), University of Pavia, Italy; and the Department of Neurology (J.E.W., M.E.S.), University of Iowa Carver College of Medicine, Iowa City
| | - Matilde Laura
- From the MRC Centre for Neuromuscular Diseases (A.C., J.M.P., R.P., M.S., A.M.R., M.L., P.J.T., H.H., M.M.R.), Department of Neuromuscular Diseases, National Hospital for Neurology and Neurosurgery, UCL Queen Square Institute of Neurology, London, UK; Department of Brain and Behavioral Sciences (A.C.), University of Pavia, Italy; and the Department of Neurology (J.E.W., M.E.S.), University of Iowa Carver College of Medicine, Iowa City
| | - Pedro J Tomaselli
- From the MRC Centre for Neuromuscular Diseases (A.C., J.M.P., R.P., M.S., A.M.R., M.L., P.J.T., H.H., M.M.R.), Department of Neuromuscular Diseases, National Hospital for Neurology and Neurosurgery, UCL Queen Square Institute of Neurology, London, UK; Department of Brain and Behavioral Sciences (A.C.), University of Pavia, Italy; and the Department of Neurology (J.E.W., M.E.S.), University of Iowa Carver College of Medicine, Iowa City
| | - Henry Houlden
- From the MRC Centre for Neuromuscular Diseases (A.C., J.M.P., R.P., M.S., A.M.R., M.L., P.J.T., H.H., M.M.R.), Department of Neuromuscular Diseases, National Hospital for Neurology and Neurosurgery, UCL Queen Square Institute of Neurology, London, UK; Department of Brain and Behavioral Sciences (A.C.), University of Pavia, Italy; and the Department of Neurology (J.E.W., M.E.S.), University of Iowa Carver College of Medicine, Iowa City
| | - Michael E Shy
- From the MRC Centre for Neuromuscular Diseases (A.C., J.M.P., R.P., M.S., A.M.R., M.L., P.J.T., H.H., M.M.R.), Department of Neuromuscular Diseases, National Hospital for Neurology and Neurosurgery, UCL Queen Square Institute of Neurology, London, UK; Department of Brain and Behavioral Sciences (A.C.), University of Pavia, Italy; and the Department of Neurology (J.E.W., M.E.S.), University of Iowa Carver College of Medicine, Iowa City
| | - Mary M Reilly
- From the MRC Centre for Neuromuscular Diseases (A.C., J.M.P., R.P., M.S., A.M.R., M.L., P.J.T., H.H., M.M.R.), Department of Neuromuscular Diseases, National Hospital for Neurology and Neurosurgery, UCL Queen Square Institute of Neurology, London, UK; Department of Brain and Behavioral Sciences (A.C.), University of Pavia, Italy; and the Department of Neurology (J.E.W., M.E.S.), University of Iowa Carver College of Medicine, Iowa City.
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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.
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He J, Guo L, Xu G, Xu L, Lin S, Chen W, Wang N. Clinical and genetic investigation in Chinese patients with demyelinating Charcot-Marie-Tooth disease. J Peripher Nerv Syst 2018; 23:216-226. [PMID: 29896895 DOI: 10.1111/jns.12277] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2018] [Revised: 06/06/2018] [Accepted: 06/11/2018] [Indexed: 11/29/2022]
Abstract
Demyelinating Charcot-Marie-Tooth disease (CMT) is the most common subtype of CMT. It is caused mainly by 17p11.2 heterozygous duplication, but also by mutations in more than 20 genes which affect development and function of Schwann cells. To investigate the profile of genes mutated and clinical features in demyelinating CMT of Chinese descent, we collected a cohort of 44 demyelinating CMT patients and screened them using multiplex ligation-dependent probe amplification (MLPA) and targeted next-generation sequencing (NGS) technology. The MLPA technology revealed that 77.3% demyelinating CMT patients harbored 17p11.2 heterozygous duplication and 6.8% patients harbored heterozygous deletion of exon 6 of MPZ gene, that was further confirmed a novel c.674_675insA mutation in MPZ gene. In the patients with 17p12 heterozygous duplication, 3 sets of independent families were discordant for the CMT phenotype within the same family. The targeted NGS technology revealed that 6 candidate mutations including 1 previously reported mutation (GDAP1: c.571C>T) and 5 novel mutations (SBF2: c.415T>C, c.619G>T, c.1258A>G; GDAP1: c.589delC; PMP22: c.318delT) were found. In conclusion, combined MLPA technique with targeted NGS, the demyelinating CMT genetic diagnostic success rate was increased.
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Affiliation(s)
- Jin He
- Department of Neurology and Institute of Neurology, First Affiliated Hospital, Fujian Medical University, Fuzhou, China.,Fujian Key Laboratory of Molecular Neurology, Fuzhou, China
| | - Lingling Guo
- Department of Neurology and Institute of Neurology, First Affiliated Hospital, Fujian Medical University, Fuzhou, China
| | - Guorong Xu
- Department of Neurology and Institute of Neurology, First Affiliated Hospital, Fujian Medical University, Fuzhou, China
| | - Liuqing Xu
- Department of Neurology and Institute of Neurology, First Affiliated Hospital, Fujian Medical University, Fuzhou, China
| | - Shan Lin
- Department of Neurology and Institute of Neurology, First Affiliated Hospital, Fujian Medical University, Fuzhou, China
| | - Wanjin Chen
- Department of Neurology and Institute of Neurology, First Affiliated Hospital, Fujian Medical University, Fuzhou, China.,Fujian Key Laboratory of Molecular Neurology, Fuzhou, China
| | - Ning Wang
- Department of Neurology and Institute of Neurology, First Affiliated Hospital, Fujian Medical University, Fuzhou, China.,Fujian Key Laboratory of Molecular Neurology, Fuzhou, China
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Quadros Santos Monteiro Fonseca AT, Zanoteli E. Charcot-Marie-Tooth disease. REVISTA MÉDICA CLÍNICA LAS CONDES 2018. [DOI: 10.1016/j.rmclc.2018.06.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022] Open
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21
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Karakaya M, Storbeck M, Strathmann EA, Delle Vedove A, Hölker I, Altmueller J, Naghiyeva L, Schmitz-Steinkrüger L, Vezyroglou K, Motameny S, Alawbathani S, Thiele H, Polat AI, Okur D, Boostani R, Karimiani EG, Wunderlich G, Ardicli D, Topaloglu H, Kirschner J, Schrank B, Maroofian R, Magnusson O, Yis U, Nürnberg P, Heller R, Wirth B. Targeted sequencing with expanded gene profile enables high diagnostic yield in non-5q-spinal muscular atrophies. Hum Mutat 2018; 39:1284-1298. [PMID: 29858556 DOI: 10.1002/humu.23560] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2018] [Revised: 05/14/2018] [Accepted: 05/30/2018] [Indexed: 11/08/2022]
Abstract
Spinal muscular atrophies (SMAs) are a heterogeneous group of disorders characterized by muscular atrophy, weakness, and hypotonia due to suspected lower motor neuron degeneration (LMND). In a large cohort of 3,465 individuals suspected with SMA submitted for SMN1 testing to our routine diagnostic laboratory, 48.8% carried a homozygous SMN1 deletion, 2.8% a subtle mutation, and an SMN1 deletion, whereas 48.4% remained undiagnosed. Recently, several other genes implicated in SMA/LMND have been reported. Despite several efforts to establish a diagnostic algorithm for non-5q-SMA (SMA without deletion or point mutations in SMN1 [5q13.2]), data from large-scale studies are not available. We tested the clinical utility of targeted sequencing in non-5q-SMA by developing two different gene panels. We first analyzed 30 individuals with a small panel including 62 genes associated with LMND using IonTorrent-AmpliSeq target enrichment. Then, additional 65 individuals were tested with a broader panel encompassing up to 479 genes implicated in neuromuscular diseases (NMDs) with Agilent-SureSelect target enrichment. The NMD panel provided a higher diagnostic yield (33%) than the restricted LMND panel (13%). Nondiagnosed cases were further subjected to exome or genome sequencing. Our experience supports the use of gene panels covering a broad disease spectrum for diseases that are highly heterogeneous and clinically difficult to differentiate.
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Affiliation(s)
- Mert Karakaya
- Institute of Human Genetics, Center for Molecular Medicine Cologne, Institute of Genetics, and Center for Rare Diseases Cologne, University of Cologne, Cologne, Germany
| | - Markus Storbeck
- Institute of Human Genetics, Center for Molecular Medicine Cologne, Institute of Genetics, and Center for Rare Diseases Cologne, University of Cologne, Cologne, Germany
| | - Eike A Strathmann
- Institute of Human Genetics, Center for Molecular Medicine Cologne, Institute of Genetics, and Center for Rare Diseases Cologne, University of Cologne, Cologne, Germany
| | - Andrea Delle Vedove
- Institute of Human Genetics, Center for Molecular Medicine Cologne, Institute of Genetics, and Center for Rare Diseases Cologne, University of Cologne, Cologne, Germany
| | - Irmgard Hölker
- Institute of Human Genetics, Center for Molecular Medicine Cologne, Institute of Genetics, and Center for Rare Diseases Cologne, University of Cologne, Cologne, Germany
| | - Janine Altmueller
- Institute of Human Genetics, Center for Molecular Medicine Cologne, Institute of Genetics, and Center for Rare Diseases Cologne, University of Cologne, Cologne, Germany.,Cologne Center for Genomics (CCG), University of Cologne, Cologne, Germany
| | - Leyla Naghiyeva
- Institute of Human Genetics, Center for Molecular Medicine Cologne, Institute of Genetics, and Center for Rare Diseases Cologne, University of Cologne, Cologne, Germany
| | - Lea Schmitz-Steinkrüger
- Institute of Human Genetics, Center for Molecular Medicine Cologne, Institute of Genetics, and Center for Rare Diseases Cologne, University of Cologne, Cologne, Germany
| | - Katharina Vezyroglou
- Institute of Human Genetics, Center for Molecular Medicine Cologne, Institute of Genetics, and Center for Rare Diseases Cologne, University of Cologne, Cologne, Germany
| | - Susanne Motameny
- Cologne Center for Genomics (CCG), University of Cologne, Cologne, Germany
| | - Salem Alawbathani
- Cologne Center for Genomics (CCG), University of Cologne, Cologne, Germany
| | - Holger Thiele
- Cologne Center for Genomics (CCG), University of Cologne, Cologne, Germany
| | - Ayse Ipek Polat
- Dokuz Eylül University, Department of Pediatric Neurology, Izmir, Turkey
| | - Derya Okur
- Dokuz Eylül University, Department of Pediatric Neurology, Izmir, Turkey
| | - Reza Boostani
- Mashhad University of Medical Sciences, Department of Neurology, Mashhad, Iran
| | - Ehsan Ghayoor Karimiani
- Next Generation Genetic Polyclinic, Mashhad, Iran.,Razavi Cancer Research Center, Razavi Hospital, Imam Reza International University, Mashhad, Iran
| | | | - Didem Ardicli
- Hacettepe University, Department of Pediatric Neurology, Ankara, Turkey
| | - Haluk Topaloglu
- Hacettepe University, Department of Pediatric Neurology, Ankara, Turkey
| | - Janbernd Kirschner
- Department of Neuropediatrics and Muscle Disorders, Faculty of Medicine, Medical Center, University of Freiburg, Freiburg, Germany
| | - Bertold Schrank
- DKD HELIOS Kliniken, Department of Neurology, Wiesbaden, Germany
| | - Reza Maroofian
- Genetics and Molecular Cell Sciences Research Centre, St George's University of London, London, UK
| | | | - Uluc Yis
- Dokuz Eylül University, Department of Pediatric Neurology, Izmir, Turkey
| | - Peter Nürnberg
- Cologne Center for Genomics (CCG), University of Cologne, Cologne, Germany
| | - Raoul Heller
- Institute of Human Genetics, Center for Molecular Medicine Cologne, Institute of Genetics, and Center for Rare Diseases Cologne, University of Cologne, Cologne, Germany
| | - Brunhilde Wirth
- Institute of Human Genetics, Center for Molecular Medicine Cologne, Institute of Genetics, and Center for Rare Diseases Cologne, University of Cologne, Cologne, Germany
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22
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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.
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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
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23
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Abbott JA, Meyer-Schuman R, Lupo V, Feely S, Mademan I, Oprescu SN, Griffin LB, Alberti MA, Casasnovas C, Aharoni S, Basel-Vanagaite L, Züchner S, De Jonghe P, Baets J, Shy ME, Espinós C, Demeler B, Antonellis A, Francklyn C. Substrate interaction defects in histidyl-tRNA synthetase linked to dominant axonal peripheral neuropathy. Hum Mutat 2018; 39:415-432. [PMID: 29235198 PMCID: PMC5983030 DOI: 10.1002/humu.23380] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2017] [Revised: 12/01/2017] [Accepted: 12/07/2017] [Indexed: 11/09/2022]
Abstract
Histidyl-tRNA synthetase (HARS) ligates histidine to cognate tRNA molecules, which is required for protein translation. Mutations in HARS cause the dominant axonal peripheral neuropathy Charcot-Marie-Tooth disease type 2W (CMT2W); however, the precise molecular mechanism remains undefined. Here, we investigated three HARS missense mutations associated with CMT2W (p.Tyr330Cys, p.Ser356Asn, and p.Val155Gly). The three mutations localize to the HARS catalytic domain and failed to complement deletion of the yeast ortholog (HTS1). Enzyme kinetics, differential scanning fluorimetry (DSF), and analytical ultracentrifugation (AUC) were employed to assess the effect of these substitutions on primary aminoacylation function and overall dimeric structure. Notably, the p.Tyr330Cys, p.Ser356Asn, and p.Val155Gly HARS substitutions all led to reduced aminoacylation, providing a direct connection between CMT2W-linked HARS mutations and loss of canonical ARS function. While DSF assays revealed that only one of the variants (p.Val155Gly) was less thermally stable relative to wild-type, all three HARS mutants formed stable dimers, as measured by AUC. Our work represents the first biochemical analysis of CMT-associated HARS mutations and underscores how loss of the primary aminoacylation function can contribute to disease pathology.
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Affiliation(s)
- Jamie A. Abbott
- Department of Biochemistry, University of Vermont, College of Medicine, Burlington, Vermont
| | - Rebecca Meyer-Schuman
- Department of Human Genetics, University of Michigan Medical School, Ann Arbor, Michigan
| | - Vincenzo Lupo
- Unit of Genetics and Genomics of Neuromuscular Disorders, Centro de Investigación Príncipe Felipe (CIPF), Valencia, Spain
| | - Shawna Feely
- Department of Neurology, University of Iowa Hospitals and Clinics, Iowa City, Iowa
| | - Inès Mademan
- Neurogenetics Group, Center for Molecular Neurology, VIB, Antwerp, Belgium
- Laboratory of Neuromuscular Pathology, Institute Born-Bunge, University of Antwerp, Antwerpen, Belgium
| | - Stephanie N. Oprescu
- Department of Human Genetics, University of Michigan Medical School, Ann Arbor, Michigan
| | - Laurie B. Griffin
- Cellular and Molecular Biology Program, University of Michigan Medical School, Ann Arbor, Michigan
- Medical Scientist Training Program, University of Michigan Medical School, Ann Arbor, Michigan
| | - M. Antonia Alberti
- Department of Neurology, Hospital Universitario de Bellvitge, Barcelona, Spain
| | - Carlos Casasnovas
- Department of Neurology, Hospital Universitario de Bellvitge, Barcelona, Spain
| | - Sharon Aharoni
- Institute of Child Neurology, Schneider Children’s Medical Center of Israel, Petah Tikva, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Lina Basel-Vanagaite
- Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
- Raphael Recanati Genetic Institute, Rabin Medical Center, Beilinson Campus, Petah Tikva, Israel
- Pediatric Genetics Unit, Schneider Children’s Medical Center, Petah Tikva, Israel
- Felsenstein Medical Research Center, Rabin Medical Center, Petah Tikva, Israel
| | - Stephan Züchner
- Dr John T McDonald Foundation Department of Human Genetics & John P Hussman Institute for Human Genomics, University of Miami Miller School of Medicine, Miami, Florida
| | - Peter De Jonghe
- Neurogenetics Group, Center for Molecular Neurology, VIB, Antwerp, Belgium
- Laboratory of Neuromuscular Pathology, Institute Born-Bunge, University of Antwerp, Antwerpen, Belgium
- Department of Neurology, Antwerp University Hospital, Antwerpen, Belgium
| | - Jonathan Baets
- Neurogenetics Group, Center for Molecular Neurology, VIB, Antwerp, Belgium
- Laboratory of Neuromuscular Pathology, Institute Born-Bunge, University of Antwerp, Antwerpen, Belgium
- Department of Neurology, Antwerp University Hospital, Antwerpen, Belgium
| | - Michael E. Shy
- Department of Neurology, University of Iowa Hospitals and Clinics, Iowa City, Iowa
| | - Carmen Espinós
- Unit of Genetics and Genomics of Neuromuscular Disorders, Centro de Investigación Príncipe Felipe (CIPF), Valencia, Spain
| | - Borries Demeler
- Department of Biochemistry, The University of Texas Health Sciences at San Antonio, San Antonio, Texas
| | - Anthony Antonellis
- Department of Human Genetics, University of Michigan Medical School, Ann Arbor, Michigan
- Cellular and Molecular Biology Program, University of Michigan Medical School, Ann Arbor, Michigan
| | - Christopher Francklyn
- Department of Biochemistry, University of Vermont, College of Medicine, Burlington, Vermont
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24
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Fernández-Marmiesse A, Gouveia S, Couce ML. NGS Technologies as a Turning Point in Rare Disease Research , Diagnosis and Treatment. Curr Med Chem 2018; 25:404-432. [PMID: 28721829 PMCID: PMC5815091 DOI: 10.2174/0929867324666170718101946] [Citation(s) in RCA: 92] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2017] [Revised: 06/19/2017] [Accepted: 07/14/2017] [Indexed: 01/17/2023]
Abstract
Approximately 25-50 million Americans, 30 million Europeans, and 8% of the Australian population have a rare disease. Rare diseases are thus a common problem for clinicians and account for enormous healthcare costs worldwide due to the difficulty of establishing a specific diagnosis. In this article, we review the milestones achieved in our understanding of rare diseases since the emergence of next-generation sequencing (NGS) technologies and analyze how these advances have influenced research and diagnosis. The first half of this review describes how NGS has changed diagnostic workflows and provided an unprecedented, simple way of discovering novel disease-associated genes. We focus particularly on metabolic and neurodevelopmental disorders. NGS has enabled cheap and rapid genetic diagnosis, highlighted the relevance of mosaic and de novo mutations, brought to light the wide phenotypic spectrum of most genes, detected digenic inheritance or the presence of more than one rare disease in the same patient, and paved the way for promising new therapies. In the second part of the review, we look at the limitations and challenges of NGS, including determination of variant causality, the loss of variants in coding and non-coding regions, and the detection of somatic mosaicism variants and epigenetic mutations, and discuss how these can be overcome in the near future.
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Affiliation(s)
- Ana Fernández-Marmiesse
- Unit of Diagnosis and Treatment of Congenital Metabolic Diseases, Department of Pediatrics, Hospital Clínico Universitario de Santiago de Compostela, Santiago de Compostela, Spain
| | - Sofía Gouveia
- Unit of Diagnosis and Treatment of Congenital Metabolic Diseases, Department of Pediatrics, Hospital Clínico Universitario de Santiago de Compostela, Santiago de Compostela, Spain
| | - María L. Couce
- Unit of Diagnosis and Treatment of Congenital Metabolic Diseases, Department of Pediatrics, Hospital Clínico Universitario de Santiago de Compostela, Santiago de Compostela, Spain
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25
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Zarouchlioti C, Parfitt DA, Li W, Gittings LM, Cheetham ME. DNAJ Proteins in neurodegeneration: essential and protective factors. Philos Trans R Soc Lond B Biol Sci 2018; 373:20160534. [PMID: 29203718 PMCID: PMC5717533 DOI: 10.1098/rstb.2016.0534] [Citation(s) in RCA: 88] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/08/2017] [Indexed: 12/16/2022] Open
Abstract
Maintenance of protein homeostasis is vitally important in post-mitotic cells, particularly neurons. Neurodegenerative diseases such as polyglutamine expansion disorders-like Huntington's disease or spinocerebellar ataxia (SCA), Alzheimer's disease, fronto-temporal dementia (FTD), amyotrophic lateral sclerosis (ALS) and Parkinson's disease-are often characterized by the presence of inclusions of aggregated protein. Neurons contain complex protein networks dedicated to protein quality control and maintaining protein homeostasis, or proteostasis. Molecular chaperones are a class of proteins with prominent roles in maintaining proteostasis, which act to bind and shield hydrophobic regions of nascent or misfolded proteins while allowing correct folding, conformational changes and enabling quality control. There are many different families of molecular chaperones with multiple functions in proteostasis. The DNAJ family of molecular chaperones is the largest chaperone family and is defined by the J-domain, which regulates the function of HSP70 chaperones. DNAJ proteins can also have multiple other protein domains such as ubiquitin-interacting motifs or clathrin-binding domains leading to diverse and specific roles in the cell, including targeting client proteins for degradation via the proteasome, chaperone-mediated autophagy and uncoating clathrin-coated vesicles. DNAJ proteins can also contain ER-signal peptides or mitochondrial leader sequences, targeting them to specific organelles in the cell. In this review, we discuss the multiple roles of DNAJ proteins and in particular focus on the role of DNAJ proteins in protecting against neurodegenerative diseases caused by misfolded proteins. We also discuss the role of DNAJ proteins as direct causes of inherited neurodegeneration via mutations in DNAJ family genes.This article is part of the theme issue 'Heat shock proteins as modulators and therapeutic targets of chronic disease: an integrated perspective'.
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Affiliation(s)
| | - David A Parfitt
- UCL Institute of Ophthalmology, 11-43 Bath Street, London EC1 V 9EL, UK
| | - Wenwen Li
- UCL Institute of Ophthalmology, 11-43 Bath Street, London EC1 V 9EL, UK
| | - Lauren M Gittings
- UCL Institute of Ophthalmology, 11-43 Bath Street, London EC1 V 9EL, UK
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26
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Li LX, Zhao SY, Liu ZJ, Ni W, Li HF, Xiao BG, Wu ZY. Improving molecular diagnosis of Chinese patients with Charcot-Marie-Tooth by targeted next-generation sequencing and functional analysis. Oncotarget 2018; 7:27655-64. [PMID: 27027447 PMCID: PMC5053678 DOI: 10.18632/oncotarget.8377] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2016] [Accepted: 03/16/2016] [Indexed: 12/19/2022] Open
Abstract
Charcot-Marie-Tooth (CMT) disease is the most common hereditary peripheral neuropathy. More than 50 causative genes have been identified. The lack of genotype-phenotype correlations in many CMT patients make it difficult to decide which genes are affected. Recently, targeted next-generation sequencing (NGS) has been introduced as an alternative approach for diagnosis of genetic disorders. Here, we applied targeted NGS in combination with PMP22 duplication/deletion analysis to screen causative genes in 22 Chinese CMT families. The novel variants detected by targeted NGS were then further studied in cultured cells. Of the 22 unrelated patients, 8 had PMP22 duplication. The targeted NGS revealed 10 possible pathogenic variants in 11 patients, including 7 previously reported variants and 3 novel heterozygous variants (GJB1: p.Y157H; MFN2: p.G127S; YARS: p.V293M). Further classification of the novel variants according to American College of Medical Genetics and Genomics (ACMG) standards and guidelines and functional analysis in cultured cells indicated that p.Y157H in GJB1 was pathogenic, p.G127S in MFN2 was likely pathogenic, while p.V293M in YARS was likely benign. Our results suggest the potential for targeted NGS to make a more rapid and precise diagnosis in CMT patients. Moreover, the functional analysis is required when the novel variants are indistinct.
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Affiliation(s)
- Li-Xi Li
- Department of Neurology and Institute of Neurology, Huashan Hospital, Institutes of Brain Science and State Key Laboratory of Medical Neurobiology, Shanghai Medical College, Fudan University, Shanghai, 200040, China
| | - Shao-Yun Zhao
- Department of Neurology and Research Center of Neurology in Second Affiliated Hospital, and The Collaborative Innovation Center for Brain Science, Zhejiang University School of Medicine, Hangzhou, 310009, China
| | - Zhi-Jun Liu
- Department of Neurology and Institute of Neurology, Huashan Hospital, Institutes of Brain Science and State Key Laboratory of Medical Neurobiology, Shanghai Medical College, Fudan University, Shanghai, 200040, China
| | - Wang Ni
- Department of Neurology and Research Center of Neurology in Second Affiliated Hospital, and The Collaborative Innovation Center for Brain Science, Zhejiang University School of Medicine, Hangzhou, 310009, China
| | - Hong-Fu Li
- Department of Neurology and Research Center of Neurology in Second Affiliated Hospital, and The Collaborative Innovation Center for Brain Science, Zhejiang University School of Medicine, Hangzhou, 310009, China
| | - Bao-Guo Xiao
- Department of Neurology and Institute of Neurology, Huashan Hospital, Institutes of Brain Science and State Key Laboratory of Medical Neurobiology, Shanghai Medical College, Fudan University, Shanghai, 200040, China
| | - Zhi-Ying Wu
- Department of Neurology and Institute of Neurology, Huashan Hospital, Institutes of Brain Science and State Key Laboratory of Medical Neurobiology, Shanghai Medical College, Fudan University, Shanghai, 200040, China.,Department of Neurology and Research Center of Neurology in Second Affiliated Hospital, and The Collaborative Innovation Center for Brain Science, Zhejiang University School of Medicine, Hangzhou, 310009, China
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27
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Abstract
PURPOSE OF REVIEW Charcot-Marie-Tooth disease (CMT) is one of the commonest inherited neuromuscular diseases with a population prevalence of 1 in 2500. This review will cover recent advances in the genetics and pathomechanisms of CMT and how these are leading to the development of rational therapies. RECENT FINDINGS Pathomechanistic and therapeutic target advances in CMT include the identification of the ErbB receptor signalling pathway as a therapeutic target in CMT1A and pharmacological modification of the unfolded protein response in CMT1B. In CMT2D, due to mutations in glycyl-tRNA synthetase, vascular endothelial growth factor-mediated stimulation of the Nrp1 receptor has been identified as a therapeutic target. Preclinical advances have been accompanied by the publication of large natural history cohorts and the identification of a sensitive biomarker of disease (muscle MRI) that is able to detect disease progression in CMT1A over 1 year. SUMMARY Advances in next-generation sequencing technology, cell biology and animal models of CMT are paving the way for rational treatments. The combination of robust natural history data and the identification of sensitive biomarkers mean that we are now entering an exciting therapeutic era in the field of the genetic neuropathies.
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28
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A newly distal hereditary motor neuropathy caused by a rare AIFM1 mutation. Neurogenetics 2017; 18:245-250. [DOI: 10.1007/s10048-017-0524-6] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2017] [Accepted: 09/14/2017] [Indexed: 11/25/2022]
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29
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Li LX, Liu GL, Liu ZJ, Lu C, Wu ZY. Identification and functional characterization of two missense mutations in NDRG1 associated with Charcot-Marie-Tooth disease type 4D. Hum Mutat 2017; 38:1569-1578. [PMID: 28776325 DOI: 10.1002/humu.23309] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2016] [Revised: 06/27/2017] [Accepted: 07/30/2017] [Indexed: 11/10/2022]
Abstract
Charcot-Marie-Tooth disease type 4D (CMT4D) is an autosomal-recessive demyelinating form of CMT characterized by a severe distal motor and sensory neuropathy. NDRG1 is the causative gene for CMT4D. To date, only four mutations in NDRG1 -c.442C>T (p.Arg148*), c.739delC (p.His247Thrfs*74), c.538-1G>A, and duplication of exons 6-8-have been described in CMT4D patients. Here, using targeted next-generation sequencing examination, we identified for the first time two homozygous missense variants in NDRG1, c.437T>C (p.Leu146Pro) and c.701G>A (p.Arg234Gln), in two Chinese CMT families with consanguineous histories. Further functional studies were performed to characterize the biological effects of these variants. Cell culture transfection studies showed that mutant NDRG1 carrying p.Leu146Pro, p.Arg148*, or p.Arg234Gln variant degraded faster than wild-type NDRG1, resulting in lower protein levels. Live cell confocal microscopy and coimmunoprecipitation analysis indicated that these variants did not disrupt the interaction between NDRG1 and Rab4a protein. However, NDRG1-knockdown cells expressing mutant NDRG1 displayed enlarged Rab4a-positive compartments. Moreover, mutant NDRG1 could not enhance the uptake of DiI-LDL or increase the fraction of low-density lipoprotein receptor on the cell surface. Taken together, our study described two missense mutations in NDRG1 and emphasized the important role of NDRG1 in intracellular protein trafficking.
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Affiliation(s)
- Li-Xi Li
- Department of Neurology and Research Center of Neurology in Second Affiliated Hospital, and the Collaborative Innovation Center for Brain Science, Zhejiang University School of Medicine, Hangzhou, China.,Department of Neurology and Institute of Neurology, Huashan Hospital, Shanghai Medical College, Fudan University, Shanghai, China
| | - Gong-Lu Liu
- Department of Neurology and Research Center of Neurology in Second Affiliated Hospital, and the Collaborative Innovation Center for Brain Science, Zhejiang University School of Medicine, Hangzhou, China
| | - Zhi-Jun Liu
- Department of Neurology and Research Center of Neurology in Second Affiliated Hospital, and the Collaborative Innovation Center for Brain Science, Zhejiang University School of Medicine, Hangzhou, China.,Department of Neurology and Institute of Neurology, Huashan Hospital, Shanghai Medical College, Fudan University, Shanghai, China
| | - Cong Lu
- Department of Neurology and Research Center of Neurology in Second Affiliated Hospital, and the Collaborative Innovation Center for Brain Science, Zhejiang University School of Medicine, Hangzhou, China
| | - Zhi-Ying Wu
- Department of Neurology and Research Center of Neurology in Second Affiliated Hospital, and the Collaborative Innovation Center for Brain Science, Zhejiang University School of Medicine, Hangzhou, China
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30
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Walsh M, Bell KM, Chong B, Creed E, Brett GR, Pope K, Thorne NP, Sadedin S, Georgeson P, Phelan DG, Day T, Taylor JA, Sexton A, Lockhart PJ, Kiers L, Fahey M, Macciocca I, Gaff CL, Oshlack A, Yiu EM, James PA, Stark Z, Ryan MM. Diagnostic and cost utility of whole exome sequencing in peripheral neuropathy. Ann Clin Transl Neurol 2017; 4:318-325. [PMID: 28491899 PMCID: PMC5420808 DOI: 10.1002/acn3.409] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2016] [Revised: 03/07/2017] [Accepted: 03/15/2017] [Indexed: 12/15/2022] Open
Abstract
Objective To explore the diagnostic utility and cost effectiveness of whole exome sequencing (WES) in a cohort of individuals with peripheral neuropathy. Methods Singleton WES was performed in individuals recruited though one pediatric and one adult tertiary center between February 2014 and December 2015. Initial analysis was restricted to a virtual panel of 55 genes associated with peripheral neuropathies. Patients with uninformative results underwent expanded analysis of the WES data. Data on the cost of prior investigations and assessments performed for diagnostic purposes in each patient was collected. Results Fifty patients with a peripheral neuropathy were recruited (median age 18 years; range 2–68 years). The median time from initial presentation to study enrollment was 6 years 9 months (range 2 months–62 years), and the average cost of prior investigations and assessments for diagnostic purposes AU$4013 per patient. Eleven individuals received a diagnosis from the virtual panel. Eight individuals received a diagnosis following expanded analysis of the WES data, increasing the overall diagnostic yield to 38%. Two additional individuals were diagnosed with pathogenic copy number variants through SNP microarray. Conclusions This study provides evidence that WES has a high diagnostic utility and is cost effective in patients with a peripheral neuropathy. Expanded analysis of WES data significantly improves the diagnostic yield in patients in whom a diagnosis is not found on the initial targeted analysis. This is primarily due to diagnosis of conditions caused by newly discovered genes and the resolution of complex and atypical phenotypes.
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Affiliation(s)
- Maie Walsh
- Murdoch Childrens Research Institute Melbourne Australia.,Royal Melbourne Hospital Melbourne Australia
| | - Katrina M Bell
- Murdoch Childrens Research Institute Melbourne Australia
| | - Belinda Chong
- Murdoch Childrens Research Institute Melbourne Australia
| | - Emma Creed
- Royal Melbourne Hospital Melbourne Australia.,Melbourne Genomics Health Alliance Melbourne Australia
| | - Gemma R Brett
- Murdoch Childrens Research Institute Melbourne Australia.,Melbourne Genomics Health Alliance Melbourne Australia
| | - Kate Pope
- Murdoch Childrens Research Institute Melbourne Australia
| | - Natalie P Thorne
- Melbourne Genomics Health Alliance Melbourne Australia.,Murdoch Childrens Research Institute Melbourne Australia.,University of Melbourne Melbourne Australia
| | - Simon Sadedin
- Murdoch Childrens Research Institute Melbourne Australia
| | | | - Dean G Phelan
- Murdoch Childrens Research Institute Melbourne Australia
| | - Timothy Day
- Royal Melbourne Hospital Melbourne Australia
| | | | | | - Paul J Lockhart
- Murdoch Childrens Research Institute Melbourne Australia.,Bruce Lefroy Centre Murdoch Childrens Research Institute Parkville Australia.,Department of Paediatrics The University of Melbourne Melbourne Australia
| | | | | | - Ivan Macciocca
- Murdoch Childrens Research Institute Melbourne Australia.,Melbourne Genomics Health Alliance Melbourne Australia
| | - Clara L Gaff
- Melbourne Genomics Health Alliance Melbourne Australia.,University of Melbourne Melbourne Australia
| | - Alicia Oshlack
- Murdoch Childrens Research Institute Melbourne Australia.,University of Melbourne Melbourne Australia
| | - Eppie M Yiu
- Bruce Lefroy Centre Murdoch Childrens Research Institute Parkville Australia.,Department of Paediatrics The University of Melbourne Melbourne Australia.,Royal Children's Hospital Melbourne Australia
| | - Paul A James
- Royal Melbourne Hospital Melbourne Australia.,University of Melbourne Melbourne Australia
| | - Zornitza Stark
- Murdoch Childrens Research Institute Melbourne Australia
| | - Monique M Ryan
- Murdoch Childrens Research Institute Melbourne Australia.,Melbourne Genomics Health Alliance Melbourne Australia.,Department of Paediatrics The University of Melbourne Melbourne Australia.,Royal Children's Hospital Melbourne Australia
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31
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Ho CC, Tai SM, Lee ECN, Mak TSH, Liu TKT, Tang VWL, Poon WT. Rapid Identification of Pathogenic Variants in Two Cases of Charcot-Marie-Tooth Disease by Gene-Panel Sequencing. Int J Mol Sci 2017; 18:ijms18040770. [PMID: 28379183 PMCID: PMC5412354 DOI: 10.3390/ijms18040770] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2017] [Revised: 03/28/2017] [Accepted: 03/31/2017] [Indexed: 12/14/2022] Open
Abstract
Charcot-Marie-Tooth disease (CMT) is a common inherited peripheral neuropathy affecting up to 1 in 1214 of the general population with more than 60 nuclear genes implicated in its pathogenesis. Traditional molecular diagnostic pathways based on relative prevalence and clinical phenotyping are limited by long turnaround time, population-specific prevalence of causative variants and inability to assess multiple co-existing variants. In this study, a CMT gene panel comprising 27 genes was used to uncover the pathogenic mutations in two index patients. The first patient is a 15-year-old boy, born of consanguineous parents, who has had frequent trips and falls since infancy, and was later found to have inverted champagne bottle appearance of bilateral legs and foot drop. His elder sister is similarly affected. The second patient is a 37-year-old woman referred for pre-pregnancy genetic diagnosis. During early adulthood, she developed progressive lower limb weakness, difficulties in tip-toe walking and thinning of calf muscles. Both patients are clinically compatible with CMT, have undergone multiple genetic testings and have not previously received a definitive genetic diagnosis. Patients 1 and 2 were found to have pathogenic homozygous HSPB1:NM_001540:c.250G>A (p.G84R) variant and heterozygous GDAP1:NM_018972:c.358C>T (p.R120W) variant, respectively. Advantages and limitations of the current approach are discussed.
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Affiliation(s)
- Chi-Chun Ho
- Department of Clinical Pathology, Pamela Youde Nethersole Eastern Hospital, Chai Wan, Hong Kong, China.
| | - Shuk-Mui Tai
- Department of Paediatrics & Adolescent Medicine, Pamela Youde Nethersole Eastern Hospital, Chai Wan, Hong Kong, China.
| | - Edmond Chi-Nam Lee
- Department of Medicine, Pamela Youde Nethersole Eastern Hospital, Chai Wan, Hong Kong, China.
| | - Timothy Shin-Heng Mak
- Centre for Genomic Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong, China.
| | - Timothy Kam-Tim Liu
- Department of Paediatrics & Adolescent Medicine, Pamela Youde Nethersole Eastern Hospital, Chai Wan, Hong Kong, China.
| | - Victor Wai-Lun Tang
- Department of Clinical Pathology, Pamela Youde Nethersole Eastern Hospital, Chai Wan, Hong Kong, China.
| | - Wing-Tat Poon
- Department of Clinical Pathology, Pamela Youde Nethersole Eastern Hospital, Chai Wan, Hong Kong, China.
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32
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Iqbal Z, Rydning SL, Wedding IM, Koht J, Pihlstrøm L, Rengmark AH, Henriksen SP, Tallaksen CME, Toft M. Targeted high throughput sequencing in hereditary ataxia and spastic paraplegia. PLoS One 2017; 12:e0174667. [PMID: 28362824 PMCID: PMC5375131 DOI: 10.1371/journal.pone.0174667] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2016] [Accepted: 03/13/2017] [Indexed: 12/24/2022] Open
Abstract
Hereditary ataxia and spastic paraplegia are heterogeneous monogenic neurodegenerative disorders. To date, a large number of individuals with such disorders remain undiagnosed. Here, we have assessed molecular diagnosis by gene panel sequencing in 105 early and late-onset hereditary ataxia and spastic paraplegia probands, in whom extensive previous investigations had failed to identify the genetic cause of disease. Pathogenic and likely-pathogenic variants were identified in 20 probands (19%) and variants of uncertain significance in ten probands (10%). Together these accounted for 30 probands (29%) and involved 18 different genes. Among several interesting findings, dominantly inherited KIF1A variants, p.(Val8Met) and p.(Ile27Thr) segregated in two independent families, both presenting with a pure spastic paraplegia phenotype. Two homozygous missense variants, p.(Gly4230Ser) and p.(Leu4221Val) were found in SACS in one consanguineous family, presenting with spastic ataxia and isolated cerebellar atrophy. The average disease duration in probands with pathogenic and likely-pathogenic variants was 31 years, ranging from 4 to 51 years. In conclusion, this study confirmed and expanded the clinical phenotypes associated with known disease genes. The results demonstrate that gene panel sequencing and similar sequencing approaches can serve as efficient diagnostic tools for different heterogeneous disorders. Early use of such strategies may help to reduce both costs and time of the diagnostic process.
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Affiliation(s)
- Zafar Iqbal
- Department of Neurology, Oslo University Hospital, Oslo, Norway
- * E-mail:
| | - Siri L. Rydning
- Department of Neurology, Oslo University Hospital, Oslo, Norway
- Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, Oslo, Norway
| | - Iselin M. Wedding
- Department of Neurology, Oslo University Hospital, Oslo, Norway
- Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, Oslo, Norway
| | - Jeanette Koht
- Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, Oslo, Norway
- Department of Neurology, Drammen Hospital, Vestre Viken Hospital Trust, Drammen, Norway
| | - Lasse Pihlstrøm
- Department of Neurology, Oslo University Hospital, Oslo, Norway
- Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, Oslo, Norway
| | | | | | - Chantal M. E. Tallaksen
- Department of Neurology, Oslo University Hospital, Oslo, Norway
- Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, Oslo, Norway
| | - Mathias Toft
- Department of Neurology, Oslo University Hospital, Oslo, Norway
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33
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Lupo V, Aguado C, Knecht E, Espinós C. Chaperonopathies: Spotlight on Hereditary Motor Neuropathies. Front Mol Biosci 2016; 3:81. [PMID: 28018906 PMCID: PMC5155517 DOI: 10.3389/fmolb.2016.00081] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2016] [Accepted: 11/29/2016] [Indexed: 12/18/2022] Open
Abstract
Distal hereditary motor neuropathies (dHMN) are a group of rare hereditary neuromuscular disorders characterized by an atrophy that affects peroneal muscles in the absence of sensory symptoms. To date, 23 genes are thought to be responsible for dHMN, four of which encode chaperones: DNAJB2, which encodes a member of the HSP40/DNAJ co-chaperone family; and HSPB1, HSPB3, and HSPB8, encoding three members of the small heat shock protein family. While around 30 different mutations in HSPB1 have been identified, the remaining three genes are altered in many fewer cases. Indeed, a mutation of HSPB3 has only been described in one case, whereas a few cases have been reported carrying mutations in DNAJB2 and HSPB8, most of them caused by a founder c.352+1G>A mutation in DNAJB2 and by mutations affecting the K141 residue in the HSPB8 chaperone. Hence, their rare occurrence makes it difficult to understand the pathological mechanisms driven by such mutations in this neuropathy. Chaperones can assemble into multi-chaperone complexes that form an integrated chaperone network within the cell. Such complexes fulfill relevant roles in a variety of processes, such as the correct folding of newly synthesized proteins, in which chaperones escort them to precise cellular locations, and as a response to protein misfolding, which includes the degradation of proteins that fail to refold properly. Despite this range of functions, mutations in some of these chaperones lead to diseases with a similar clinical profile, suggesting common pathways. This review provides an overview of the genetics of those dHMNs that share a common disease mechanism and that are caused by mutations in four genes encoding chaperones: DNAJB2, HSPB1, HSPB3, and HSPB8.
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Affiliation(s)
- Vincenzo Lupo
- Molecular Basis of Human Diseases Program, Centro de Investigación Príncipe FelipeValencia, Spain; INCLIVA & IIS La Fe Rare Diseases Joint UnitsValencia, Spain
| | - Carmen Aguado
- Molecular Basis of Human Diseases Program, Centro de Investigación Príncipe FelipeValencia, Spain; INCLIVA & IIS La Fe Rare Diseases Joint UnitsValencia, Spain; Centro de Investigación Biomédica en RedValencia, Spain
| | - Erwin Knecht
- Molecular Basis of Human Diseases Program, Centro de Investigación Príncipe FelipeValencia, Spain; INCLIVA & IIS La Fe Rare Diseases Joint UnitsValencia, Spain; Centro de Investigación Biomédica en RedValencia, Spain
| | - Carmen Espinós
- Molecular Basis of Human Diseases Program, Centro de Investigación Príncipe FelipeValencia, Spain; INCLIVA & IIS La Fe Rare Diseases Joint UnitsValencia, Spain
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34
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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] [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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35
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Sanchez E, Darvish H, Mesias R, Taghavi S, Firouzabadi SG, Walker RH, Tafakhori A, Paisán-Ruiz C. Identification of a Large DNAJB2 Deletion in a Family with Spinal Muscular Atrophy and Parkinsonism. Hum Mutat 2016; 37:1180-1189. [PMID: 27449489 DOI: 10.1002/humu.23055] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2016] [Accepted: 07/20/2016] [Indexed: 01/10/2023]
Abstract
In this study, we described the identification of a large DNAJB2 (HSJ1) deletion in a family with recessive spinal muscular atrophy and Parkinsonism. After performing homozygosity mapping and whole genome sequencing, we identified a 3.8 kb deletion, spanning the entire DnaJ domain of the HSJ1 protein, as the disease-segregating mutation. By performing functional assays, we showed that HSJ1b-related DnaJ domain deletion leads to loss of HSJ1b mRNA and protein levels, increased HSJ1a mRNA and protein expressions, increased cell death, protein aggregation, and enhanced autophagy. Given the role of HSJ1 proteins in the degradation of misfolded proteins, we speculated that enhanced autophagy might be promoted by the elevated HSJ1a expression seen in HSJ1b-deficient cells. We also observed a significant reduction in both tau and brain-derived neurotrophic factor levels, which may explain the dopaminergic deficits seen in one of the affected siblings. We concluded that HSJ1b deficiency leads to a complex neurological phenotype, possibly due to the accumulation of misfolded proteins, caused by the lack of the DnaJ domain activity. We thus expand the phenotypic and genotypic spectrums associated with DNAJB2 disease and suggest relevant disease-associated mechanisms.
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Affiliation(s)
- Elena Sanchez
- Department of Neurology, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York City, New York
| | - Hossein Darvish
- Department of Medical Genetics, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Roxana Mesias
- Department of Neurology, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York City, New York.,The Graduate School of Biomedical Sciences, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York City, New York
| | - Shaghyegh Taghavi
- Department of Medical Genetics, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | | | - Ruth H Walker
- Department of Neurology, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York City, New York.,Department of Neurology, James J. Peters Veterans Affairs Medical Center, Bronx, New York City, New York
| | - Abbas Tafakhori
- Department of Neurology, School of Medicine, Imam Khomeini Hospital and Iranian Center of Neurological Research, Tehran University of Medical Sciences, Tehran, Iran
| | - Coro Paisán-Ruiz
- Department of Neurology, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York City, New York. .,Department of Psychiatry, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York City, New York. .,Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York City, New York. .,Mindich Child Health and Development Institute, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York City, New York. .,Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York City, New York.
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