1
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Naef V, Meschini MC, Tessa A, Morani F, Corsinovi D, Ogi A, Marchese M, Ori M, Santorelli FM, Doccini S. Converging Role for REEP1/SPG31 in Oxidative Stress. Int J Mol Sci 2023; 24:ijms24043527. [PMID: 36834939 PMCID: PMC9959426 DOI: 10.3390/ijms24043527] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2023] [Revised: 02/02/2023] [Accepted: 02/07/2023] [Indexed: 02/12/2023] Open
Abstract
Mutations in the receptor expression-enhancing protein 1 gene (REEP1) are associated with hereditary spastic paraplegia type 31 (SPG31), a neurological disorder characterized by length-dependent degeneration of upper motor neuron axons. Mitochondrial dysfunctions have been observed in patients harboring pathogenic variants in REEP1, suggesting a key role of bioenergetics in disease-related manifestations. Nevertheless, the regulation of mitochondrial function in SPG31 remains unclear. To elucidate the pathophysiology underlying REEP1 deficiency, we analyzed in vitro the impact of two different mutations on mitochondrial metabolism. Together with mitochondrial morphology abnormalities, loss-of-REEP1 expression highlighted a reduced ATP production with increased susceptibility to oxidative stress. Furthermore, to translate these findings from in vitro to preclinical models, we knocked down REEP1 in zebrafish. Zebrafish larvae showed a significant defect in motor axon outgrowth leading to motor impairment, mitochondrial dysfunction, and reactive oxygen species accumulation. Protective antioxidant agents such as resveratrol rescued free radical overproduction and ameliorated the SPG31 phenotype both in vitro and in vivo. Together, our findings offer new opportunities to counteract neurodegeneration in SPG31.
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Affiliation(s)
- Valentina Naef
- Molecular Medicine for Neurodegenerative and Neuromuscular Diseases Unit, IRCCS Stella Maris Foundation, 56128 Pisa, Italy
| | - Maria C. Meschini
- Molecular Medicine for Neurodegenerative and Neuromuscular Diseases Unit, IRCCS Stella Maris Foundation, 56128 Pisa, Italy
| | - Alessandra Tessa
- Molecular Medicine for Neurodegenerative and Neuromuscular Diseases Unit, IRCCS Stella Maris Foundation, 56128 Pisa, Italy
| | - Federica Morani
- Department of Biology, University of Pisa, 56126 Pisa, Italy
| | - Debora Corsinovi
- Department of Biology, University of Pisa, 56126 Pisa, Italy
- Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, 56126 Pisa, Italy
| | - Asahi Ogi
- Molecular Medicine for Neurodegenerative and Neuromuscular Diseases Unit, IRCCS Stella Maris Foundation, 56128 Pisa, Italy
| | - Maria Marchese
- Molecular Medicine for Neurodegenerative and Neuromuscular Diseases Unit, IRCCS Stella Maris Foundation, 56128 Pisa, Italy
| | - Michela Ori
- Department of Biology, University of Pisa, 56126 Pisa, Italy
| | - Filippo M. Santorelli
- Molecular Medicine for Neurodegenerative and Neuromuscular Diseases Unit, IRCCS Stella Maris Foundation, 56128 Pisa, Italy
| | - Stefano Doccini
- Molecular Medicine for Neurodegenerative and Neuromuscular Diseases Unit, IRCCS Stella Maris Foundation, 56128 Pisa, Italy
- Correspondence: ; Tel.: +39-050-886-311
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2
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Frasquet M, Sevilla T. Hereditary motor neuropathies. Curr Opin Neurol 2022; 35:562-570. [PMID: 35942667 DOI: 10.1097/wco.0000000000001087] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE OF REVIEW Distal hereditary motor neuropathies (dHMN) are a clinically and genetically diverse group of disorders that are characterized by length-dependent axonal degeneration of lower motor neurons. In this review, we will provide an overview of dHMN, and we will correlate the distinct clinical subtypes with their causative genes, focusing on the most recent advances in the field. RECENT FINDINGS Despite the massive use of new-generation sequencing (NGS) and the discovery of new genes, only a third of dHMN patients receive a molecular diagnosis. Thanks to international cooperation between researchers, new genes have been implicated in dHMN, such as SORD and VWA1 . Mutations in SORD are the most frequent cause of autosomal recessive forms of dHMN. As a result of these findings, the potential benefits of some pharmacological compounds are being studied in cell and animal models, mainly targeting axonal transport and metabolic pathways. SUMMARY Despite the wide use of NGS, the diagnosis of dHMN remains a challenge. The low prevalence of dHMN makes international cooperation necessary in order to discover new genes and causal mechanisms. Genetic diagnosis of patients and identification of new pathomechanism are essential for the development of therapeutical clinical trials.
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Affiliation(s)
- Marina Frasquet
- Department of Neurology, Hospital Universitari Doctor Peset
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER) Spain
| | - Teresa Sevilla
- Neuromuscular Diseases Unit, Department of Neurology, Hospital Universitari i Politècnic La Fe
- Neuromuscular and Ataxias Research Group, Instituto de Investigación Sanitaria La Fe
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER) Spain
- Universitat de València, Valencia, Spain
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3
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Zhu PP, Hung HF, Batchenkova N, Nixon-Abell J, Henderson J, Zheng P, Renvoisé B, Pang S, Xu CS, Saalfeld S, Funke J, Xie Y, Svara F, Hess HF, Blackstone C. Transverse endoplasmic reticulum expansion in hereditary spastic paraplegia corticospinal axons. Hum Mol Genet 2022; 31:2779-2795. [PMID: 35348668 PMCID: PMC9402237 DOI: 10.1093/hmg/ddac072] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2021] [Revised: 03/15/2022] [Accepted: 03/20/2022] [Indexed: 08/12/2023] Open
Abstract
Hereditary spastic paraplegias (HSPs) comprise a large group of inherited neurologic disorders affecting the longest corticospinal axons (SPG1-86 plus others), with shared manifestations of lower extremity spasticity and gait impairment. Common autosomal dominant HSPs are caused by mutations in genes encoding the microtubule-severing ATPase spastin (SPAST; SPG4), the membrane-bound GTPase atlastin-1 (ATL1; SPG3A) and the reticulon-like, microtubule-binding protein REEP1 (REEP1; SPG31). These proteins bind one another and function in shaping the tubular endoplasmic reticulum (ER) network. Typically, mouse models of HSPs have mild, later onset phenotypes, possibly reflecting far shorter lengths of their corticospinal axons relative to humans. Here, we have generated a robust, double mutant mouse model of HSP in which atlastin-1 is genetically modified with a K80A knock-in (KI) missense change that abolishes its GTPase activity, whereas its binding partner Reep1 is knocked out. Atl1KI/KI/Reep1-/- mice exhibit early onset and rapidly progressive declines in several motor function tests. Also, ER in mutant corticospinal axons dramatically expands transversely and periodically in a mutation dosage-dependent manner to create a ladder-like appearance, on the basis of reconstructions of focused ion beam-scanning electron microscopy datasets using machine learning-based auto-segmentation. In lockstep with changes in ER morphology, axonal mitochondria are fragmented and proportions of hypophosphorylated neurofilament H and M subunits are dramatically increased in Atl1KI/KI/Reep1-/- spinal cord. Co-occurrence of these findings links ER morphology changes to alterations in mitochondrial morphology and cytoskeletal organization. Atl1KI/KI/Reep1-/- mice represent an early onset rodent HSP model with robust behavioral and cellular readouts for testing novel therapies.
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Affiliation(s)
- Peng-Peng Zhu
- Neurogenetics Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA
| | - Hui-Fang Hung
- Neurogenetics Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA
- MassGeneral Institute for Neurodegenerative Disease, Charlestown, MA 02129, USA
- Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, USA
| | - Natalia Batchenkova
- Neurogenetics Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA
| | - Jonathon Nixon-Abell
- Neurogenetics Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA
- Howard Hughes Medical Institute, Janelia Research Campus, Ashburn, VA 20147, USA
- Cambridge Institute for Medical Research, Cambridge CB2 0XY, UK
| | - James Henderson
- Cambridge Institute for Medical Research, Cambridge CB2 0XY, UK
| | - Pengli Zheng
- Neurogenetics Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA
- MassGeneral Institute for Neurodegenerative Disease, Charlestown, MA 02129, USA
- Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, USA
| | - Benoit Renvoisé
- Neurogenetics Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA
| | - Song Pang
- Howard Hughes Medical Institute, Janelia Research Campus, Ashburn, VA 20147, USA
| | - C Shan Xu
- Howard Hughes Medical Institute, Janelia Research Campus, Ashburn, VA 20147, USA
| | - Stephan Saalfeld
- Howard Hughes Medical Institute, Janelia Research Campus, Ashburn, VA 20147, USA
| | - Jan Funke
- Howard Hughes Medical Institute, Janelia Research Campus, Ashburn, VA 20147, USA
| | - Yuxiang Xie
- Synaptic Function Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA
| | - Fabian Svara
- ariadne.ai ag, CH-6033 Buchrain, Switzerland
- Research Center Caesar, D-53175 Bonn, Germany
| | - Harald F Hess
- Howard Hughes Medical Institute, Janelia Research Campus, Ashburn, VA 20147, USA
| | - Craig Blackstone
- Neurogenetics Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA
- MassGeneral Institute for Neurodegenerative Disease, Charlestown, MA 02129, USA
- Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, USA
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4
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Ganassi M, Zammit PS. Involvement of muscle satellite cell dysfunction in neuromuscular disorders: Expanding the portfolio of satellite cell-opathies. Eur J Transl Myol 2022; 32:10064. [PMID: 35302338 PMCID: PMC8992676 DOI: 10.4081/ejtm.2022.10064] [Citation(s) in RCA: 29] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Accepted: 02/11/2022] [Indexed: 12/03/2022] Open
Abstract
Neuromuscular disorders are a heterogeneous group of acquired or hereditary conditions that affect striated muscle function. The resulting decrease in muscle strength and motility irreversibly impacts quality of life. In addition to directly affecting skeletal muscle, pathogenesis can also arise from dysfunctional crosstalk between nerves and muscles, and may include cardiac impairment. Muscular weakness is often progressive and paralleled by continuous decline in the ability of skeletal muscle to functionally adapt and regenerate. Normally, the skeletal muscle resident stem cells, named satellite cells, ensure tissue homeostasis by providing myoblasts for growth, maintenance, repair and regeneration. We recently defined 'Satellite Cell-opathies' as those inherited neuromuscular conditions presenting satellite cell dysfunction in muscular dystrophies and myopathies (doi:10.1016/j.yexcr.2021.112906). Here, we expand the portfolio of Satellite Cell-opathies by evaluating the potential impairment of satellite cell function across all 16 categories of neuromuscular disorders, including those with mainly neurogenic and cardiac involvement. We explore the expression dynamics of myopathogenes, genes whose mutation leads to skeletal muscle pathogenesis, using transcriptomic analysis. This revealed that 45% of myopathogenes are differentially expressed during early satellite cell activation (0 - 5 hours). Of these 271 myopathogenes, 83 respond to Pax7, a master regulator of satellite cells. Our analysis suggests possible perturbation of satellite cell function in many neuromuscular disorders across all categories, including those where skeletal muscle pathology is not predominant. This characterisation further aids understanding of pathomechanisms and informs on development of prognostic and diagnostic tools, and ultimately, new therapeutics.
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Affiliation(s)
- Massimo Ganassi
- King's College London, Randall Centre for Cell and Molecular Biophysics, Guy's Campus, London.
| | - Peter S Zammit
- King's College London, Randall Centre for Cell and Molecular Biophysics, Guy's Campus, London.
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5
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Darios F, Coarelli G, Durr A. Genetics in hereditary spastic paraplegias: Essential but not enough. Curr Opin Neurobiol 2021; 72:8-14. [PMID: 34403957 DOI: 10.1016/j.conb.2021.07.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2021] [Revised: 06/04/2021] [Accepted: 07/14/2021] [Indexed: 12/01/2022]
Abstract
Hereditary spastic paraplegias consist of a group of rare neurodegenerative diseases characterized by lower limb spasticity. These inherited Mendelian disorders show high genetic variability associated with wide clinical diversity. Pathophysiological investigations have suggested that mutations in genes affecting the same cellular pathway generally lead to similar clinical symptoms, highlighting the importance of genetic mutation in these diseases. However, phenotype-genotype correlations have failed to explain the observed large inter-individual variability linked to mutations in a single gene, suggesting that genetics alone is not sufficient to explain symptom diversity. The identification of biomarkers, such as neurofilament light chain, could fill the gap and predict disease evolution.
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Affiliation(s)
- Frédéric Darios
- Sorbonne Université, Institut du Cerveau - Paris Brain Institute - ICM, Inserm U1127, CNRS UMR7225, Paris, 75013, France.
| | - Giulia Coarelli
- Sorbonne Université, Institut du Cerveau - Paris Brain Institute - ICM, Inserm U1127, CNRS UMR7225, Paris, 75013, France; AP-HP, Hôpital de la Pitié Salpêtrière, Paris, 75013, France
| | - Alexandra Durr
- Sorbonne Université, Institut du Cerveau - Paris Brain Institute - ICM, Inserm U1127, CNRS UMR7225, Paris, 75013, France; AP-HP, Hôpital de la Pitié Salpêtrière, Paris, 75013, France.
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6
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Rudenskaya GE, Kadnikova VA, Bessonova LA, Sparber PA, Kurbatov SA, Mironovich OL, Konovalov FA, Ryzhkova OP. [Autosomal dominant spastic paraplegias]. Zh Nevrol Psikhiatr Im S S Korsakova 2021; 121:75-87. [PMID: 34184482 DOI: 10.17116/jnevro202112105175] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
OBJECTIVE To estimate the proportion and spectrum of infrequent autosomal dominant spastic paraplegias in a group of families with DNA-confirmed diagnosis and to investigate their molecular and clinical characteristics. MATERIAL AND METHODS Ten families with 6 AD-SPG: SPG6 (n=1), SPG8 (n=2), SPG9A (n=1), SPG12 (n=1), SPG17 (n=3), SPG31 (n=2) were studied using clinical, genealogical, molecular-genetic (massive parallel sequencing, spastic paraplegia panel, whole-exome sequencing, multiplex ligation-dependent amplification, Sanger sequencing) and bioinformatic methods. RESULTS AND CONCLUSION Nine heterozygous mutations were detected in 6 genes, including the common de novo mutation p.Gly106Arg in NIPA1 (SPG6), the earlier reported mutation p.Val626Phe in WASHC5 (SPG8) in isolated case and the novel p.Val695Ala in WASHC5 (SPG8) in a family with 4 patients, the novel mutation p.Thr301Arg in RTN2 (SPG12) in a family with 2 patients, the novel mutation c.105+4A>G in REEP1 (SPG31) in a family with 4 patients and the reported earlier p.Lys101Lys in REEP1 (SPG31) in a family with 3 patients, the known de novo mutation p.Arg252Gln in ALDH18A1 (SPG9A) in two monozygous twins; the common mutation p.Ser90Leu in BSCL2 (SPG17) in a family with 3 patients and in isolated case, reported mutation p.Leu363Pro in a family with 2 patients. SPG6, SPG8, SPG12 and SPG31 presented 'pure' phenotypes, SPG31 had most benign course. Age of onset varied in SPG31 family and was atypically early in SPG6 case. Patients with SPG9A and SPG17 had 'complicated' paraplegias; amyotrophy of hands typical for SPG17 was absent in a child and in an adolescent from 2 families, but may develop later.
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Affiliation(s)
- G E Rudenskaya
- Bochkov Research Center for Medical Genetics, Moscow, Russia
| | - V A Kadnikova
- Bochkov Research Center for Medical Genetics, Moscow, Russia
| | - L A Bessonova
- Bochkov Research Center for Medical Genetics, Moscow, Russia
| | - P A Sparber
- Bochkov Research Center for Medical Genetics, Moscow, Russia
| | - S A Kurbatov
- Voronezh Regional Clinical Consultative and Diagnostic Center, Vodonezh, Russia
| | - O L Mironovich
- Bochkov Research Center for Medical Genetics, Moscow, Russia
| | - F A Konovalov
- Genomed LLC, Laboratory of Clinical Bioinformatics, Moscow, Russia
| | - O P Ryzhkova
- Bochkov Research Center for Medical Genetics, Moscow, Russia
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7
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Kanwal S, Choi YJI, Lim SO, Choi HJ, Park JH, Nuzhat R, Khan A, Perveen S, Choi BO, Chung KW. Novel homozygous mutations in Pakistani families with Charcot-Marie-Tooth disease. BMC Med Genomics 2021; 14:174. [PMID: 34193129 PMCID: PMC8247155 DOI: 10.1186/s12920-021-01019-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2021] [Accepted: 06/18/2021] [Indexed: 11/10/2022] Open
Abstract
Background Charcot–Marie–Tooth disease (CMT) is a group of genetically and clinically heterogeneous peripheral nervous system disorders. Few studies have identified genetic causes of CMT in the Pakistani patients. Methods This study was performed to identify pathogenic mutations in five consanguineous Pakistani CMT families negative for PMP22 duplication. Genomic screening was performed by application of whole exome sequencing. Results We identified five pathogenic or likely pathogenic homozygous mutations in four genes: c.2599C > T (p.Gln867*) and c.3650G > A (p.Gly1217Asp) in SH3TC2, c.19C > T (p.Arg7*) in HK1, c.247delG (p.Gly83Alafs*44) in REEP1, and c.334G > A (p.Val112Met) in MFN2. These mutations have not been reported in CMT patients. Mutations in SH3TC2, HK1, REEP1, and MFN2 have been reported to be associated with CMT4C, CMT4G, dHMN5B (DSMA5B), and CMT2A, respectively. The genotype–phenotype correlations were confirmed in all the examined families. We also confirmed that both alleles from the homozygous variants originated from a single ancestor using homozygosity mapping. Conclusions This study found five novel mutations as the underlying causes of CMT. Pathogenic mutations in SH3TC2, HK1, and REEP1 have been reported rarely in other populations, suggesting ethnic-specific distribution. This study would be useful for the exact molecular diagnosis and treatment of CMT in Pakistani patients.
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Affiliation(s)
- Sumaira Kanwal
- Department of Biosciences, COMSATS University Islamabad, Sahiwal, Pakistan
| | - Yu JIn Choi
- Department of Biological Sciences, Kongju National University, 56 Gongjudaehakro, Gongju, 32588, Korea
| | - Si On Lim
- Department of Biological Sciences, Kongju National University, 56 Gongjudaehakro, Gongju, 32588, Korea
| | - Hee Ji Choi
- Department of Biological Sciences, Kongju National University, 56 Gongjudaehakro, Gongju, 32588, Korea
| | - Jin Hee Park
- Department of Biological Sciences, Kongju National University, 56 Gongjudaehakro, Gongju, 32588, Korea
| | - Rana Nuzhat
- Department of Pediatric Neurology, The Children Hospital and Institute of Child Health, Multan, Pakistan
| | - Aneela Khan
- Department of Pediatric Neurology, The Children Hospital and Institute of Child Health, Multan, Pakistan
| | - Shazia Perveen
- Department of Zoology, The Women University, Multan, Pakistan
| | - Byung-Ok Choi
- Department of Neurology, Samsung Medical Center, Sungkyunkwan University School of Medicine, 81 Irwon-ro, Gangnam-gu, Seoul, 06351, Korea.
| | - Ki Wha Chung
- Department of Biological Sciences, Kongju National University, 56 Gongjudaehakro, Gongju, 32588, Korea.
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8
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Thomas Q, Vitobello A, Tran Mau-Them F, Duffourd Y, Fromont A, Giroud M, Daubail B, Jacquin-Piques A, Hervieu-Begue M, Moreau T, Osseby GV, Garret P, Nambot S, Delanne J, Bruel AL, Sorlin A, Callier P, Denomme-Pichon AS, Faivre L, Béjot Y, Philippe C, Thauvin-Robinet C, Moutton S. High efficiency and clinical relevance of exome sequencing in the daily practice of neurogenetics. J Med Genet 2021; 59:445-452. [PMID: 34085946 DOI: 10.1136/jmedgenet-2020-107369] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Revised: 02/08/2021] [Accepted: 02/19/2021] [Indexed: 01/13/2023]
Abstract
OBJECTIVE To assess the efficiency and relevance of clinical exome sequencing (cES) as a first-tier or second-tier test for the diagnosis of progressive neurological disorders in the daily practice of Neurology and Genetic Departments. METHODS Sixty-seven probands with various progressive neurological disorders (cerebellar ataxias, neuromuscular disorders, spastic paraplegias, movement disorders and individuals with complex phenotypes labelled 'other') were recruited over a 4-year period regardless of their age, gender, familial history and clinical framework. Individuals could have had prior genetic tests as long as it was not cES. cES was performed in a proband-only (60/67) or trio (7/67) strategy depending on available samples and was analysed with an in-house pipeline including software for CNV and mitochondrial-DNA variant detection. RESULTS In 29/67 individuals, cES identified clearly pathogenic variants leading to a 43% positive yield. When performed as a first-tier test, cES identified pathogenic variants for 53% of individuals (10/19). Difficult cases were solved including double diagnoses within a kindred or identification of a neurodegeneration with brain iron accumulation in a patient with encephalopathy of suspected mitochondrial origin. CONCLUSION This study shows that cES is a powerful tool for the daily practice of neurogenetics offering an efficient (43%) and appropriate approach for clinically and genetically complex and heterogeneous disorders.
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Affiliation(s)
- Quentin Thomas
- Inserm UMR1231 team GAD, University of Burgundy and Franche-Comté, Dijon, France .,Genetics Center, FHU-TRANSLAD, Dijon University Hospital, Dijon, Burgundy, France.,Neurology Department, Dijon University Hospital, Dijon, Burgundy, France
| | - Antonio Vitobello
- Inserm UMR1231 team GAD, University of Burgundy and Franche-Comté, Dijon, France.,Functional Unity of innovative diagnosis for rare diseases, Dijon Bourgogne University Hospital, Dijon, Burgundy, France
| | - Frederic Tran Mau-Them
- Inserm UMR1231 team GAD, University of Burgundy and Franche-Comté, Dijon, France.,Functional Unity of innovative diagnosis for rare diseases, Dijon Bourgogne University Hospital, Dijon, Burgundy, France
| | - Yannis Duffourd
- Inserm UMR1231 team GAD, University of Burgundy and Franche-Comté, Dijon, France.,Functional Unity of innovative diagnosis for rare diseases, Dijon Bourgogne University Hospital, Dijon, Burgundy, France
| | - Agnès Fromont
- Neurology Department, Dijon University Hospital, Dijon, Burgundy, France
| | - Maurice Giroud
- Neurology Department, Dijon University Hospital, Dijon, Burgundy, France.,Dijon Stroke Registry, EA7460, Pathophysiology and Epidemiology of Cerebro-Cardiovascular Diseases (PEC2), University of Burgundy and Franche-Comté, Dijon, Burgundy, France
| | - Benoit Daubail
- Department of Adult Neurophysiology, Dijon University Hospital, Dijon, Burgundy, France
| | - Agnès Jacquin-Piques
- Department of Adult Neurophysiology, Dijon University Hospital, Dijon, Burgundy, France
| | | | - Thibault Moreau
- Neurology Department, Dijon University Hospital, Dijon, Burgundy, France
| | - Guy-Victor Osseby
- Neurology Department, Dijon University Hospital, Dijon, Burgundy, France
| | - Philippine Garret
- Inserm UMR1231 team GAD, University of Burgundy and Franche-Comté, Dijon, France.,Functional Unity of innovative diagnosis for rare diseases, Dijon Bourgogne University Hospital, Dijon, Burgundy, France
| | - Sophie Nambot
- Inserm UMR1231 team GAD, University of Burgundy and Franche-Comté, Dijon, France.,Genetics Center, FHU-TRANSLAD, Dijon University Hospital, Dijon, Burgundy, France
| | - Julian Delanne
- Inserm UMR1231 team GAD, University of Burgundy and Franche-Comté, Dijon, France.,Genetics Center, FHU-TRANSLAD, Dijon University Hospital, Dijon, Burgundy, France
| | - Ange-Line Bruel
- Inserm UMR1231 team GAD, University of Burgundy and Franche-Comté, Dijon, France.,Functional Unity of innovative diagnosis for rare diseases, Dijon Bourgogne University Hospital, Dijon, Burgundy, France
| | - Arthur Sorlin
- Inserm UMR1231 team GAD, University of Burgundy and Franche-Comté, Dijon, France.,Functional Unity of innovative diagnosis for rare diseases, Dijon Bourgogne University Hospital, Dijon, Burgundy, France
| | - Patrick Callier
- Functional Unity of innovative diagnosis for rare diseases, Dijon Bourgogne University Hospital, Dijon, Burgundy, France
| | - Anne-Sophie Denomme-Pichon
- Inserm UMR1231 team GAD, University of Burgundy and Franche-Comté, Dijon, France.,Functional Unity of innovative diagnosis for rare diseases, Dijon Bourgogne University Hospital, Dijon, Burgundy, France
| | - Laurence Faivre
- Genetics Center, FHU-TRANSLAD, Dijon University Hospital, Dijon, Burgundy, France
| | - Yannick Béjot
- Neurology Department, Dijon University Hospital, Dijon, Burgundy, France.,Dijon Stroke Registry, EA7460, Pathophysiology and Epidemiology of Cerebro-Cardiovascular Diseases (PEC2), University of Burgundy and Franche-Comté, Dijon, Burgundy, France
| | - Christophe Philippe
- Functional Unity of innovative diagnosis for rare diseases, Dijon Bourgogne University Hospital, Dijon, Burgundy, France
| | - Christel Thauvin-Robinet
- Genetics Center, FHU-TRANSLAD, Dijon University Hospital, Dijon, Burgundy, France.,Functional Unity of innovative diagnosis for rare diseases, Dijon Bourgogne University Hospital, Dijon, Burgundy, France
| | - Sébastien Moutton
- Inserm UMR1231 team GAD, University of Burgundy and Franche-Comté, Dijon, France.,Genetics Center, FHU-TRANSLAD, Dijon University Hospital, Dijon, Burgundy, France
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9
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Beijer D, Baets J. The expanding genetic landscape of hereditary motor neuropathies. Brain 2021; 143:3540-3563. [PMID: 33210134 DOI: 10.1093/brain/awaa311] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Revised: 07/15/2020] [Accepted: 07/27/2020] [Indexed: 12/12/2022] Open
Abstract
Hereditary motor neuropathies are clinically and genetically diverse disorders characterized by length-dependent axonal degeneration of lower motor neurons. Although currently as many as 26 causal genes are known, there is considerable missing heritability compared to other inherited neuropathies such as Charcot-Marie-Tooth disease. Intriguingly, this genetic landscape spans a discrete number of key biological processes within the peripheral nerve. Also, in terms of underlying pathophysiology, hereditary motor neuropathies show striking overlap with several other neuromuscular and neurological disorders. In this review, we provide a current overview of the genetic spectrum of hereditary motor neuropathies highlighting recent reports of novel genes and mutations or recent discoveries in the underlying disease mechanisms. In addition, we link hereditary motor neuropathies with various related disorders by addressing the main affected pathways of disease divided into five major processes: axonal transport, tRNA aminoacylation, RNA metabolism and DNA integrity, ion channels and transporters and endoplasmic reticulum.
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Affiliation(s)
- Danique Beijer
- Translational Neurosciences, Faculty of Medicine and Health Sciences, University of Antwerp, Belgium.,Laboratory of Neuromuscular Pathology, Institute Born-Bunge, University of Antwerp, Belgium
| | - Jonathan Baets
- Translational Neurosciences, Faculty of Medicine and Health Sciences, University of Antwerp, Belgium.,Laboratory of Neuromuscular Pathology, Institute Born-Bunge, University of Antwerp, Belgium.,Neuromuscular Reference Centre, Department of Neurology, Antwerp University Hospital, Belgium
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Guglielmi A. A complete overview of REEP1: old and new insights on its role in hereditary spastic paraplegia and neurodegeneration. Rev Neurosci 2020; 31:351-362. [PMID: 31913854 DOI: 10.1515/revneuro-2019-0083] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2019] [Accepted: 11/08/2019] [Indexed: 01/09/2023]
Abstract
At the end of 19th century, Adolf von Strümpell and Sigmund Freud independently described the symptoms of a new pathology now known as hereditary spastic paraplegia (HSP). HSP is part of the group of genetic neurodegenerative diseases usually associated with slow progressive pyramidal syndrome, spasticity, weakness of the lower limbs, and distal-end degeneration of motor neuron long axons. Patients are typically characterized by gait symptoms (with or without other neurological disorders), which can appear both in young and adult ages depending on the different HSP forms. The disease prevalence is at 1.3-9.6 in 100 000 individuals in different areas of the world, making HSP part of the group of rare neurodegenerative diseases. Thus far, there are no specific clinical and paraclinical tests, and DNA analysis is still the only strategy to obtain a certain diagnosis. For these reasons, it is mandatory to extend the knowledge on genetic causes, pathology mechanism, and disease progression to give clinicians more tools to obtain early diagnosis, better therapeutic strategies, and examination tests. This review gives an overview of HSP pathologies and general insights to a specific HSP subtype called spastic paraplegia 31 (SPG31), which rises after mutation of REEP1 gene. In fact, recent findings discovered an interesting endoplasmic reticulum antistress function of REEP1 and a role of this protein in preventing τ accumulation in animal models. For this reason, this work tries to elucidate the main aspects of REEP1, which are described in the literature, to better understand its role in SPG31 HSP and other pathologies.
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Affiliation(s)
- Alessio Guglielmi
- Neurobiology Laboratory, International Centre of Genetic Engineering and Biotechnology, I-34149 Trieste, Italy
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11
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Srivastava S, D'Amore A, Cohen JS, Swanson LC, Ricca I, Pini A, Fatemi A, Ebrahimi-Fakhari D, Santorelli FM. Expansion of the genetic landscape of ERLIN2-related disorders. Ann Clin Transl Neurol 2020; 7:573-578. [PMID: 32147972 PMCID: PMC7187699 DOI: 10.1002/acn3.51007] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2019] [Revised: 02/19/2020] [Accepted: 02/19/2020] [Indexed: 12/11/2022] Open
Abstract
ERLIN2‐related disorders are rare conditions of the motor system and clinical details are limited to a small number of prior descriptions. We here presented clinical and genetic details in five individuals (four different families) where three subjects carried a common homozygous p.Asn292ArgfsX26, associated also with sensorineural hearing loss in one child. One further subject had a de novo p.Gln63Lys and one harbors the homozygous p.Val136Gly because of maternal isodisomy of chromosome 8. Overall, we expanded the clinical and genetic spectrum of ERLIN2‐related disorders and we reiterate that autosomal‐dominant transmission is a potential mode of inheritance. Future research will elucidate disease mechanisms.
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Affiliation(s)
- Siddharth Srivastava
- Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Angelica D'Amore
- Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts.,Molecular Medicine, IRCCS Fondazione Stella Maris, Pisa, Italy
| | - Julie S Cohen
- Department of Neurology and Developmental Medicine, Kennedy Krieger Institute, Baltimore, Maryland
| | - Lindsay C Swanson
- Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Ivana Ricca
- Molecular Medicine, IRCCS Fondazione Stella Maris, Pisa, Italy
| | - Antonella Pini
- IRCCS Istituto delleScienzeNeurologiche di Bologna-UOC Neuropsichiatria Infantile, Bologna, Italy
| | - Ali Fatemi
- Department of Neurology and Developmental Medicine, Kennedy Krieger Institute, Baltimore, Maryland
| | - Darius Ebrahimi-Fakhari
- Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts
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12
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Gusic M, Schottmann G, Feichtinger RG, Du C, Scholz C, Wagner M, Mayr JA, Lee CY, Yépez VA, Lorenz N, Morales-Gonzalez S, Panneman DM, Rötig A, Rodenburg RJT, Wortmann SB, Prokisch H, Schuelke M. Bi-Allelic UQCRFS1 Variants Are Associated with Mitochondrial Complex III Deficiency, Cardiomyopathy, and Alopecia Totalis. Am J Hum Genet 2020; 106:102-111. [PMID: 31883641 DOI: 10.1016/j.ajhg.2019.12.005] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2019] [Accepted: 12/05/2019] [Indexed: 01/15/2023] Open
Abstract
Isolated complex III (CIII) deficiencies are among the least frequently diagnosed mitochondrial disorders. Clinical symptoms range from isolated myopathy to severe multi-systemic disorders with early death and disability. To date, we know of pathogenic variants in genes encoding five out of 10 subunits and five out of 13 assembly factors of CIII. Here we describe rare bi-allelic variants in the gene of a catalytic subunit of CIII, UQCRFS1, which encodes the Rieske iron-sulfur protein, in two unrelated individuals. Affected children presented with low CIII activity in fibroblasts, lactic acidosis, fetal bradycardia, hypertrophic cardiomyopathy, and alopecia totalis. Studies in proband-derived fibroblasts showed a deleterious effect of the variants on UQCRFS1 protein abundance, mitochondrial import, CIII assembly, and cellular respiration. Complementation studies via lentiviral transduction and overexpression of wild-type UQCRFS1 restored mitochondrial function and rescued the cellular phenotype, confirming UQCRFS1 variants as causative for CIII deficiency. We demonstrate that mutations in UQCRFS1 can cause mitochondrial disease, and our results thereby expand the clinical and mutational spectrum of CIII deficiencies.
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Affiliation(s)
- Mirjana Gusic
- Institute of Human Genetics, Helmholtz Zentrum München, 85764 Neuherberg, Germany; Institute of Human Genetics, Technical University Munich, 81675 Munich, Germany
| | - Gudrun Schottmann
- Charité-Universitätsmedizin Berlin, corporate member of the Freie Universität Berlin and Humboldt-Universität zu Berlin, and Berlin Institute of Health: NeuroCure Cluster of Excellence, 10117 Berlin, Germany; Charité-Universitätsmedizin Berlin, corporate member of the Freie Universität Berlin and Humboldt-Universität zu Berlin, and Berlin Institute of Health: Department of Neuropediatrics, 13353 Berlin, Germany
| | - René G Feichtinger
- University Children's Hospital, Salzburger Landeskliniken (SALK) and Paracelsus Medical University (PMU), 5020 Salzburg, Austria
| | - Chen Du
- Institute of Human Genetics, Medizinische Hochschule Hannover, 30625 Hannover, Germany
| | - Caroline Scholz
- Institute of Human Genetics, Medizinische Hochschule Hannover, 30625 Hannover, Germany
| | - Matias Wagner
- Institute of Human Genetics, Helmholtz Zentrum München, 85764 Neuherberg, Germany; Institute of Human Genetics, Technical University Munich, 81675 Munich, Germany; Institute of Neurogenomics, Helmholtz Zentrum München, 85764 Neuherberg, Germany
| | - Johannes A Mayr
- University Children's Hospital, Salzburger Landeskliniken (SALK) and Paracelsus Medical University (PMU), 5020 Salzburg, Austria
| | - Chae-Young Lee
- Charité-Universitätsmedizin Berlin, corporate member of the Freie Universität Berlin and Humboldt-Universität zu Berlin, and Berlin Institute of Health: NeuroCure Cluster of Excellence, 10117 Berlin, Germany; Charité-Universitätsmedizin Berlin, corporate member of the Freie Universität Berlin and Humboldt-Universität zu Berlin, and Berlin Institute of Health: Department of Neuropediatrics, 13353 Berlin, Germany
| | - Vicente A Yépez
- Department of Informatics, Technical University of Munich, 81371 Garching, Germany
| | - Norbert Lorenz
- Department of Pediatric Cardiology, Municipal Hospital Dresden, 01307 Dresden, Germany
| | - Susanne Morales-Gonzalez
- Charité-Universitätsmedizin Berlin, corporate member of the Freie Universität Berlin and Humboldt-Universität zu Berlin, and Berlin Institute of Health: NeuroCure Cluster of Excellence, 10117 Berlin, Germany; Charité-Universitätsmedizin Berlin, corporate member of the Freie Universität Berlin and Humboldt-Universität zu Berlin, and Berlin Institute of Health: Department of Neuropediatrics, 13353 Berlin, Germany
| | - Daan M Panneman
- Radboud Center for Mitochondrial Disorders, Department of Pediatrics, Radboud UMC, Nijmegen 6525, the Netherlands
| | - Agnès Rötig
- UMR 1163, Université Paris Descartes, Sorbonne Paris Cité, Institut IMAGINE, 24 Boulevard du Montparnasse, 75015 Paris, France
| | - Richard J T Rodenburg
- Radboud Center for Mitochondrial Disorders, Department of Pediatrics, Radboud UMC, Nijmegen 6525, the Netherlands
| | - Saskia B Wortmann
- Institute of Human Genetics, Helmholtz Zentrum München, 85764 Neuherberg, Germany; Institute of Human Genetics, Technical University Munich, 81675 Munich, Germany; University Children's Hospital, Salzburger Landeskliniken (SALK) and Paracelsus Medical University (PMU), 5020 Salzburg, Austria
| | - Holger Prokisch
- Institute of Human Genetics, Helmholtz Zentrum München, 85764 Neuherberg, Germany; Institute of Human Genetics, Technical University Munich, 81675 Munich, Germany
| | - Markus Schuelke
- Charité-Universitätsmedizin Berlin, corporate member of the Freie Universität Berlin and Humboldt-Universität zu Berlin, and Berlin Institute of Health: NeuroCure Cluster of Excellence, 10117 Berlin, Germany; Charité-Universitätsmedizin Berlin, corporate member of the Freie Universität Berlin and Humboldt-Universität zu Berlin, and Berlin Institute of Health: Department of Neuropediatrics, 13353 Berlin, Germany.
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Maroofian R, Behnam M, Kaiyrzhanov R, Salpietro V, Salehi M, Houlden H. Further supporting evidence for REEP1 phenotypic and allelic heterogeneity. NEUROLOGY-GENETICS 2019; 5:e379. [PMID: 31872057 PMCID: PMC6878944 DOI: 10.1212/nxg.0000000000000379] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/08/2019] [Accepted: 10/15/2019] [Indexed: 11/15/2022]
Affiliation(s)
- Reza Maroofian
- Department of Neuromuscular Disorders Institute of Neurology (R.M., R.K., V.S., H.H.), University College London, Queen Square; and Medical Genetics Laboratory of Genome (M.B., M.S.), Isfahan, Iran
| | - Mahdiyeh Behnam
- Department of Neuromuscular Disorders Institute of Neurology (R.M., R.K., V.S., H.H.), University College London, Queen Square; and Medical Genetics Laboratory of Genome (M.B., M.S.), Isfahan, Iran
| | - Rauan Kaiyrzhanov
- Department of Neuromuscular Disorders Institute of Neurology (R.M., R.K., V.S., H.H.), University College London, Queen Square; and Medical Genetics Laboratory of Genome (M.B., M.S.), Isfahan, Iran
| | - Vincenzo Salpietro
- Department of Neuromuscular Disorders Institute of Neurology (R.M., R.K., V.S., H.H.), University College London, Queen Square; and Medical Genetics Laboratory of Genome (M.B., M.S.), Isfahan, Iran
| | - Mansour Salehi
- Department of Neuromuscular Disorders Institute of Neurology (R.M., R.K., V.S., H.H.), University College London, Queen Square; and Medical Genetics Laboratory of Genome (M.B., M.S.), Isfahan, Iran
| | - Henry Houlden
- Department of Neuromuscular Disorders Institute of Neurology (R.M., R.K., V.S., H.H.), University College London, Queen Square; and Medical Genetics Laboratory of Genome (M.B., M.S.), Isfahan, Iran
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Rudenskaya GE, Kadnikova VA, Ryzhkova OP. [Common forms of hereditary spastic paraplegias]. Zh Nevrol Psikhiatr Im S S Korsakova 2019; 119:94-104. [PMID: 30874534 DOI: 10.17116/jnevro201911902194] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
A group of hereditary spastic paraplegias includes about 80 spastic paraplegia genes (SPG): forms with identified (almost 70) or only mapped (about 10) genes. Methods of next generation sequencing (NGS), along with new SPG discovering, modify knowledge about earlier delineated SPG. Clinical and genetic characteristics of common autosomal dominant (SPG4, SPG3, SPG31) and autosomal recessive (SPG11, SPG7, SPG15) forms are presented.
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Affiliation(s)
| | - V A Kadnikova
- Research Centre for Medical Genetics, Moscow, Russia
| | - O P Ryzhkova
- Research Centre for Medical Genetics, Moscow, Russia
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15
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Peripheral neuropathy in hereditary spastic paraplegia caused by REEP1 variants. J Neurol 2019; 266:735-744. [DOI: 10.1007/s00415-019-09196-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2018] [Revised: 01/07/2019] [Accepted: 01/08/2019] [Indexed: 12/15/2022]
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16
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Exome sequencing in adult neurology practice: Challenges and rewards in a mixed resource setting. Clin Neurol Neurosurg 2018; 174:48-56. [DOI: 10.1016/j.clineuro.2018.09.012] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2017] [Revised: 08/28/2018] [Accepted: 09/05/2018] [Indexed: 12/17/2022]
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18
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Kamada M, Kawarai T, Miyamoto R, Kawakita R, Tojima Y, Montecchiani C, D'Onofrio L, Caltagirone C, Orlacchio A, Kaji R. Spastic paraplegia type 31: A novel REEP1 splice site donor variant and expansion of the phenotype variability. Parkinsonism Relat Disord 2018; 46:79-83. [DOI: 10.1016/j.parkreldis.2017.10.012] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/18/2017] [Revised: 09/28/2017] [Accepted: 10/18/2017] [Indexed: 11/26/2022]
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Renvoisé B, Malone B, Falgairolle M, Munasinghe J, Stadler J, Sibilla C, Park SH, Blackstone C. Reep1 null mice reveal a converging role for hereditary spastic paraplegia proteins in lipid droplet regulation. Hum Mol Genet 2017; 25:5111-5125. [PMID: 27638887 DOI: 10.1093/hmg/ddw315] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2016] [Accepted: 09/12/2016] [Indexed: 12/21/2022] Open
Abstract
Hereditary spastic paraplegias (HSPs; SPG1-76 plus others) are length-dependent disorders affecting long corticospinal axons, and the most common autosomal dominant forms are caused by mutations in genes that encode the spastin (SPG4), atlastin-1 (SPG3A) and REEP1 (SPG31) proteins. These proteins bind one another and shape the tubular endoplasmic reticulum (ER) network throughout cells. They also are involved in lipid droplet formation, enlargement, or both in cells, though mechanisms remain unclear. Here we have identified evidence of partial lipoatrophy in Reep1 null mice in addition to prominent spastic paraparesis. Furthermore, Reep1-/- embryonic fibroblasts and neurons in the cerebral cortex both show lipid droplet abnormalities. The apparent partial lipodystrophy in Reep1 null mice, although less severe, is reminiscent of the lipoatrophy phenotype observed in the most common form of autosomal recessive lipodystrophy, Berardinelli-Seip congenital lipodystrophy. Berardinelli-Seip lipodystrophy is caused by autosomal recessive mutations in the BSCL2 gene that encodes an ER protein, seipin, that is also mutated in the autosomal dominant HSP SPG17 (Silver syndrome). Furthermore, REEP1 co-immunoprecipitates with seipin in cells. This strengthens the link between alterations in ER morphogenesis and lipid abnormalities, with important pathogenic implications for the most common forms of HSP.
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Affiliation(s)
| | | | | | - Jeeva Munasinghe
- Laboratory of Functional and Molecular Imaging, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, USA
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Schottmann G, Picker-Minh S, Schwarz JM, Gill E, Rodenburg RJT, Stenzel W, Kaindl AM, Schuelke M. Recessive mutation in EXOSC3 associates with mitochondrial dysfunction and pontocerebellar hypoplasia. Mitochondrion 2017; 37:46-54. [PMID: 28687512 DOI: 10.1016/j.mito.2017.06.007] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2016] [Revised: 06/06/2017] [Accepted: 06/21/2017] [Indexed: 12/13/2022]
Abstract
Recessive mutations in EXOSC3, encoding a subunit of the human RNA exosome complex, cause pontocerebellar hypoplasia type 1b (PCH1B). We report a boy with severe muscular hypotonia, psychomotor retardation, progressive microcephaly, and cerebellar atrophy. Biochemical abnormalities comprised mitochondrial complex I and pyruvate dehydrogenase complex (PDHc) deficiency. Whole exome sequencing uncovered a known EXOSC3 mutation p.(D132A) as the underlying cause. In patient fibroblasts, a large portion of the EXOSC3 protein was trapped in the cytosol. MtDNA copy numbers in muscle were reduced to 35%, but mutations in the mtDNA and in nuclear mitochondrial genes were ruled out. RNA-Seq of patient muscle showed highly increased mRNA copy numbers, especially for genes encoding structural subunits of OXPHOS complexes I, III, and IV, possibly due to reduced degradation by a dysfunctional exosome complex. This is the first case of mitochondrial dysfunction associated with an EXOSC3 mutation, which expands the phenotypic spectrum of PCH1B. We discuss the links between exosome and mitochondrial dysfunction.
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Affiliation(s)
- Gudrun Schottmann
- NeuroCure Clinical Research Center (NCRC), Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Germany; Department of Neuropediatrics, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Germany
| | - Sylvie Picker-Minh
- Department of Neuropediatrics, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Germany; Center for Chronically Sick Children, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Germany; Institute of Cell Biology and Neurobiology, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Germany; Berlin Institute of Health (BIH), Berlin, Germany
| | - Jana Marie Schwarz
- NeuroCure Clinical Research Center (NCRC), Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Germany
| | - Esther Gill
- NeuroCure Clinical Research Center (NCRC), Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Germany
| | - Richard J T Rodenburg
- Radboud Center for Mitochondrial Disorders, Department of Pediatrics, Translational Metabolic Laboratory, Radboudumc, Nijmegen, The Netherlands
| | - Werner Stenzel
- Institute of Neuropathology, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Germany
| | - Angela M Kaindl
- Department of Neuropediatrics, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Germany; Center for Chronically Sick Children, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Germany; Institute of Cell Biology and Neurobiology, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Germany; Berlin Institute of Health (BIH), Berlin, Germany.
| | - Markus Schuelke
- NeuroCure Clinical Research Center (NCRC), Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Germany; Department of Neuropediatrics, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Germany.
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Abstract
The current issue of Neurology® Genetics emphasizes the unparalleled role of next-generation sequencing (NGS) in defining an expanding spectrum of genetic neurologic disorders. Clinically, NGS encompasses the use of large gene panels, whole-exome sequencing (WES), or whole-genome sequencing (WGS). The impact of NGS technology is twofold. First, researchers have discovered novel genes as the cause of neurologic disorders. This research includes the efforts of Martikainen et al.(1) to define further the phenotype of a previously reported SNCA mutation that is associated with autosomal dominant Parkinson disease. Second and more common is the connection of novel phenotypes with previously described genes. Several articles in the current issue highlight the role of NGS in this effort. For example, Schottman et al.(2) identified REEP1 mutations as the cause of a severe axonal neuropathy with a spinal muscular atrophy with respiratory distress (SMARD) phenotype. This gene was previously associated with a hereditary spastic paraplegia phenotype. Similarly, Shieh et al.(3) expand the phenotype associated with mutations in L1CAM to a neuronal migration phenotype.
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