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Schneider V, Dupont G, Madinier G, Ramond F, Lesca G, Thauvin-Robinet C, Thomas Q. Compound Heterozygous WARS2 Variants Including a Hypomorphic Allele Cause a Milder Phenotype of Complex Dopa Responsive Dystonia: Case Report and Review of the Literature. CEREBELLUM (LONDON, ENGLAND) 2024:10.1007/s12311-024-01725-7. [PMID: 39073549 DOI: 10.1007/s12311-024-01725-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 07/24/2024] [Indexed: 07/30/2024]
Abstract
Biallelic WARS2 pathogenic variants responsible for partial defect in aminoacylation, have recently been reported in subjects presenting with late-onset phenotypes combining dopa-responsive early-onset dystonia parkinsonism with altered DaTSCAN and progressive myoclonus ataxia. Here, we present the case of a 39-year-old male with childhood-onset progressive dopa-responsive dystonia parkinsonism, prominent psychiatric features and ataxia whose genome sequencing identified a p.(Arg36Ter) nonsense variant and a hypomorphic p.(Trp13Gly) missense variant, allowing the diagnosis of WARS2-related disease. The p.(Trp13Gly) missense variant has previously been reported in individuals with less severe phenotypes than those carrying biallelic WARS2 loss-of-function variants. Among these individuals, two subjects had similar genetic backgrounds and almost identical clinical history to our patient. Our report brings additional proof that the p.(Trp13Gly) variant acts as a hypomorphic allele, offering insight on a genotype-phenotype correlation in WARS2-related disorders.
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Affiliation(s)
- Vincent Schneider
- Neurology Department, Dijon University Hospital, 14 rue Paul Gaffarel, 21000, Dijon, Burgundy, France.
- Biochemistry of the Peroxisome, Inflammation and Lipid Metabolism, EA7270/Inserm, University of Burgundy and Franche-Comté, Dijon, Burgundy, France.
| | - Gwendoline Dupont
- Neurology Department, Dijon University Hospital, 14 rue Paul Gaffarel, 21000, Dijon, Burgundy, France
| | - Guillaume Madinier
- Neurology Department, Dijon University Hospital, 14 rue Paul Gaffarel, 21000, Dijon, Burgundy, France
| | - Francis Ramond
- Department of Medical Genetics, Saint Etienne University Hospital, Saint-Etienne, France
- Auragen Multisite Laboratory, GCS Auragen, Plan France Médecine Génomique, Lyon, 2025, France
| | - Gaetan Lesca
- Auragen Multisite Laboratory, GCS Auragen, Plan France Médecine Génomique, Lyon, 2025, France
- Department of Medical Genetics, competence center for rare neurogenetic diseases, University Hospital of Lyon, Lyon, France
| | - Christel Thauvin-Robinet
- Inserm UMR1231 team GAD "genetics of developmental abnormalities", University of Burgundy, Dijon, Burgundy, France
- Reference center for rare neurogenetic diseases, Genetics Center, FHU-TRANSLAD, Dijon University Hospital, Dijon, Burgundy, France
- Functional Unity of innovative diagnosis for rare diseases, Dijon University Hospital, Dijon, Burgundy, France
| | - Quentin Thomas
- Neurology Department, Dijon University Hospital, 14 rue Paul Gaffarel, 21000, Dijon, Burgundy, France
- Inserm UMR1231 team GAD "genetics of developmental abnormalities", University of Burgundy, Dijon, Burgundy, France
- Reference center for rare neurogenetic diseases, Genetics Center, FHU-TRANSLAD, Dijon University Hospital, Dijon, Burgundy, France
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Dulic M, Godinic-Mikulcic V, Kekez M, Evic V, Rokov-Plavec J. Protein-Protein Interactions of Seryl-tRNA Synthetases with Emphasis on Human Counterparts and Their Connection to Health and Disease. Life (Basel) 2024; 14:124. [PMID: 38255739 PMCID: PMC10817482 DOI: 10.3390/life14010124] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2023] [Revised: 01/10/2024] [Accepted: 01/12/2024] [Indexed: 01/24/2024] Open
Abstract
Seryl-tRNA synthetases (SerRSs), members of the aminoacyl-tRNA synthetase family, interact with diverse proteins, enabling SerRSs to enhance their role in the translation of the genetic message or to perform alternative functions in cellular processes beyond translation. Atypical archaeal SerRS interacts with arginyl-tRNA synthetase and proteins of the ribosomal P-stalk to optimize translation through tRNA channeling. The complex between yeast SerRS and peroxin Pex21p provides a connection between translation and peroxisome function. The partnership between Arabidopsis SerRS and BEN1 indicates a link between translation and brassinosteroid metabolism and may be relevant in plant stress response mechanisms. In Drosophila, the unusual heterodimeric mitochondrial SerRS coordinates mitochondrial translation and replication via interaction with LON protease. Evolutionarily conserved interactions of yeast and human SerRSs with m3C32 tRNA methyltransferases indicate coordination between tRNA modification and aminoacylation in the cytosol and mitochondria. Human cytosolic SerRS is a cellular hub protein connecting translation to vascular development, angiogenesis, lipogenesis, and telomere maintenance. When translocated to the nucleus, SerRS acts as a master negative regulator of VEGFA gene expression. SerRS alone or in complex with YY1 and SIRT2 competes with activating transcription factors NFκB1 and c-Myc, resulting in balanced VEGFA expression important for proper vascular development and angiogenesis. In hypoxia, SerRS phosphorylation diminishes its binding to the VEGFA promoter, while the lack of nutrients triggers SerRS glycosylation, reducing its nuclear localization. Additionally, SerRS binds telomeric DNA and cooperates with the shelterin protein POT1 to regulate telomere length and cellular senescence. As an antitumor and antiangiogenic factor, human cytosolic SerRS appears to be a promising drug target and therapeutic agent for treating cancer, cardiovascular diseases, and possibly obesity and aging.
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Affiliation(s)
| | | | | | | | - Jasmina Rokov-Plavec
- Division of Biochemistry, Department of Chemistry, Faculty of Science, University of Zagreb, 10000 Zagreb, Croatia; (M.D.); (V.G.-M.); (M.K.); (V.E.)
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Mihaylova V, Herenger Y, Bethge T, Bohlhalter S. A Novel WARS2 Mutation in a Swiss Family With Predominant Generalized Dystonia Responsive to Trihexyphenidyl. J Clin Neurol 2023; 19:413-415. [PMID: 37417438 DOI: 10.3988/jcn.2022.0410] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2022] [Revised: 01/30/2023] [Accepted: 03/07/2023] [Indexed: 07/08/2023] Open
Affiliation(s)
| | - Yvan Herenger
- Genetica AG, Zurich, Human Genetics and Genetic Counselling Unit, Zurich, Switzerland
| | - Tobias Bethge
- Genetica AG, Zurich, Human Genetics and Genetic Counselling Unit, Zurich, Switzerland
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Pauly MG, Korenke GC, Diaw SH, Grözinger A, Cazurro-Gutiérrez A, Pérez-Dueñas B, González V, Macaya A, Serrano Antón AT, Peterlin B, Božović IB, Maver A, Münchau A, Lohmann K. The Expanding Phenotypical Spectrum of WARS2-Related Disorder: Four Novel Cases with a Common Recurrent Variant. Genes (Basel) 2023; 14:genes14040822. [PMID: 37107582 PMCID: PMC10137540 DOI: 10.3390/genes14040822] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2023] [Revised: 03/21/2023] [Accepted: 03/24/2023] [Indexed: 04/29/2023] Open
Abstract
Biallelic variants in the mitochondrial form of the tryptophanyl-tRNA synthetases (WARS2) can cause a neurodevelopmental disorder with movement disorders including early-onset tremor-parkinsonism syndrome. Here, we describe four new patients, who all presented at a young age with a tremor-parkinsonism syndrome and responded well to levodopa. All patients carry the same recurrent, hypomorphic missense variant (NM_015836.4: c.37T>G; p.Trp13Gly) either together with a previously described truncating variant (NM_015836.4: c.797Cdel; p.Pro266ArgfsTer10), a novel truncating variant (NM_015836.4: c.346C>T; p.Gln116Ter), a novel canonical splice site variant (NM_015836.4: c.349-1G>A), or a novel missense variant (NM_015836.4: c.475A>C, p.Thr159Pro). We investigated the mitochondrial function in patients and found increased levels of mitochondrially encoded cytochrome C Oxidase II as part of the mitochondrial respiratory chain as well as decreased mitochondrial integrity and branching. Finally, we conducted a literature review and here summarize the broad phenotypical spectrum of reported WARS2-related disorders. In conclusion, WARS2-related disorders are diagnostically challenging diseases due to the broad phenotypic spectrum and the disease relevance of a relatively common missense change that is often filtered out in a diagnostic setting since it occurs in ~0.5% of the general European population.
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Affiliation(s)
- Martje G Pauly
- Institute of Neurogenetics, University of Luebeck, Ratzeburger Allee 160, 23562 Luebeck, Germany
- Institute of Systems Motor Science, University of Luebeck, 23562 Luebeck, Germany
- Department of Neurology, University Hospital Schleswig Holstein, 23562 Luebeck, Germany
| | - G Christoph Korenke
- Department of Neuropediatrics, University Children's Hospital, Klinikum Oldenburg, 26133 Oldenburg, Germany
| | - Sokhna Haissatou Diaw
- Institute of Neurogenetics, University of Luebeck, Ratzeburger Allee 160, 23562 Luebeck, Germany
| | - Anne Grözinger
- Institute of Neurogenetics, University of Luebeck, Ratzeburger Allee 160, 23562 Luebeck, Germany
| | - Ana Cazurro-Gutiérrez
- Pediatric Neurology Research Group, Autonomous University of Barcelona, Hospital Universitari Vall d'Hebron, 08035 Barcelona, Spain
| | - Belén Pérez-Dueñas
- Pediatric Neurology Research Group, Autonomous University of Barcelona, Hospital Universitari Vall d'Hebron, 08035 Barcelona, Spain
- Center for Biomedical Network Research on Rare Diseases (CIBERER), 08035 Barcelona, Spain
| | - Victoria González
- Department of Neurology, Autonomous University of Barcelona, Hospital Universitari Vall d'Hebron, 08035 Barcelona, Spain
| | - Alfons Macaya
- Pediatric Neurology Research Group, Autonomous University of Barcelona, Hospital Universitari Vall d'Hebron, 08035 Barcelona, Spain
| | - Ana Teresa Serrano Antón
- Clinical Genetic Section, Pediatric Service, Hospital Clinico Universitario Virgen de la Arrixaca, 30120 Murcia, Spain
| | - Borut Peterlin
- Clinical Institute of Genomic Medicine, University Medical Centre Ljubljana, 1000 Ljubljana, Slovenia
| | - Ivana Babić Božović
- Clinical Institute of Genomic Medicine, University Medical Centre Ljubljana, 1000 Ljubljana, Slovenia
| | - Aleš Maver
- Clinical Institute of Genomic Medicine, University Medical Centre Ljubljana, 1000 Ljubljana, Slovenia
| | - Alexander Münchau
- Institute of Systems Motor Science, University of Luebeck, 23562 Luebeck, Germany
| | - Katja Lohmann
- Institute of Neurogenetics, University of Luebeck, Ratzeburger Allee 160, 23562 Luebeck, Germany
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He J, Liu XX, Ma MM, Lin JJ, Fu J, Chen YK, Xu GR, Xu LQ, Fu ZF, Xu D, Chen WF, Cao CY, Shi Y, Zeng YH, Zhang J, Chen XC, Zhang RX, Wang N, Kennerson M, Fan DS, Chen WJ. Heterozygous Seryl-tRNA Synthetase 1 Variants Cause Charcot-Marie-Tooth Disease. Ann Neurol 2023; 93:244-256. [PMID: 36088542 DOI: 10.1002/ana.26501] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Revised: 09/05/2022] [Accepted: 09/06/2022] [Indexed: 01/31/2023]
Abstract
OBJECTIVE Despite the increasing number of genes associated with Charcot-Marie-Tooth (CMT) disease, many patients currently still lack appropriate genetic diagnosis for this disease. Autosomal dominant mutations in aminoacyl-tRNA synthetases (ARSs) have been implicated in CMT. Here, we describe causal missense mutations in the gene encoding seryl-tRNA synthetase 1 (SerRS) for 3 families affected with CMT. METHODS Whole-exome sequencing was performed in 16 patients and 14 unaffected members of 3 unrelated families. The functional impact of the genetic variants identified was investigated using bioinformatic prediction tools and confirmed using cellular and biochemical assays. RESULTS Combined linkage analysis for the 3 families revealed significant linkage (Zmax LOD = 6.9) between the genomic co-ordinates on chromosome 1: 108681600-110300504. Within the linkage region, heterozygous SerRS missense variants segregated with the clinical phenotype in the 3 families. The mutant SerRS proteins exhibited reduced aminoacylation activity and abnormal SerRS dimerization, which suggests the impairment of total protein synthesis and induction of eIF2α phosphorylation. INTERPRETATION Our findings suggest the heterozygous SerRS variants identified represent a novel cause for autosomal dominant CMT. Mutant SerRS proteins are known to impact various molecular and cellular functions. Our findings provide significant advances on the current understanding of the molecular mechanisms associated with ARS-related CMT. ANN NEUROL 2023;93:244-256.
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Affiliation(s)
- Jin He
- Department of Neurology and Institute of Neurology of First Affiliated Hospital, Institute of Neuroscience, and Fujian Key Laboratory of Molecular Neurology, Fujian Medical University, Fuzhou, China
| | - Xiao-Xuan Liu
- Department of Neurology of Peking University Third Hospital, Key Laboratory for Neuroscience, National Health Commission/Ministry of Education, Peking University, Beijing, China
- Beijing Key Laboratory of Biomarker and Translational Research in Neurodegenerative Diseases, Peking University Third Hospital, Beijing, China
| | - Ming-Ming Ma
- Department of Neurology, Henan Provincial People's Hospital, Zhengzhou, China
| | - Jing-Jing Lin
- Department of Neurology and Institute of Neurology of First Affiliated Hospital, Institute of Neuroscience, and Fujian Key Laboratory of Molecular Neurology, Fujian Medical University, Fuzhou, China
| | - Jun Fu
- Department of Neurology, Henan Provincial People's Hospital, Zhengzhou, China
| | - Yi-Kun Chen
- Department of Neurology and Institute of Neurology of First Affiliated Hospital, Institute of Neuroscience, and Fujian Key Laboratory of Molecular Neurology, Fujian Medical University, Fuzhou, China
| | - Guo-Rong Xu
- Department of Neurology and Institute of Neurology of First Affiliated Hospital, Institute of Neuroscience, and Fujian Key Laboratory of Molecular Neurology, Fujian Medical University, Fuzhou, China
| | - Liu-Qing Xu
- Department of Neurology and Institute of Neurology of First Affiliated Hospital, Institute of Neuroscience, and Fujian Key Laboratory of Molecular Neurology, Fujian Medical University, Fuzhou, China
| | - Zhi-Fei Fu
- Public Technology Service Center, Fujian Medical University, Fuzhou, China
| | - Dan Xu
- Fujian Key Laboratory of Molecular Neurology, Institute of Neuroscience, Fujian Medical University, Fuzhou, China
| | - Wen-Feng Chen
- Institute of Life Sciences, College of Biological Science and Engineering, Fuzhou University, Fuzhou, China
| | - Chun-Yan Cao
- Department of Neurology and Institute of Neurology of First Affiliated Hospital, Institute of Neuroscience, and Fujian Key Laboratory of Molecular Neurology, Fujian Medical University, Fuzhou, China
| | - Yan Shi
- Fujian Key Laboratory of Molecular Neurology, Institute of Neuroscience, Fujian Medical University, Fuzhou, China
| | - Yi-Heng Zeng
- Department of Neurology and Institute of Neurology of First Affiliated Hospital, Institute of Neuroscience, and Fujian Key Laboratory of Molecular Neurology, Fujian Medical University, Fuzhou, China
| | - Jing Zhang
- Fujian Key Laboratory of Molecular Neurology, Institute of Neuroscience, Fujian Medical University, Fuzhou, China
| | - Xiao-Chun Chen
- Fujian Key Laboratory of Molecular Neurology, Institute of Neuroscience, Fujian Medical University, Fuzhou, China
| | - Ru-Xu Zhang
- Department of Neurology, Third Xiangya Hospital, Central South University, Changsha, China
| | - Ning Wang
- Department of Neurology and Institute of Neurology of First Affiliated Hospital, Institute of Neuroscience, and Fujian Key Laboratory of Molecular Neurology, Fujian Medical University, Fuzhou, China
| | - Marina Kennerson
- Northcott Neuroscience Laboratory, ANZAC Research Institute, Sydney Local Health District and Faculty of Medicine and Health, University of Sydney, Sydney, Australia
| | - Dong-Sheng Fan
- Department of Neurology of Peking University Third Hospital, Key Laboratory for Neuroscience, National Health Commission/Ministry of Education, Peking University, Beijing, China
- Beijing Key Laboratory of Biomarker and Translational Research in Neurodegenerative Diseases, Peking University Third Hospital, Beijing, China
| | - Wan-Jin Chen
- Department of Neurology and Institute of Neurology of First Affiliated Hospital, Institute of Neuroscience, and Fujian Key Laboratory of Molecular Neurology, Fujian Medical University, Fuzhou, China
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Wang Y, Li J, Zhang X, Liu M, Ji L, Yang T, Wang K, Song C, Wang P, Ye H, Shi J, Dai L. Autoantibody signatures discovered by HuProt protein microarray to enhance the diagnosis of lung cancer. Clin Immunol 2023; 246:109206. [PMID: 36528251 DOI: 10.1016/j.clim.2022.109206] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2022] [Revised: 10/27/2022] [Accepted: 11/28/2022] [Indexed: 12/23/2022]
Abstract
This study aims to discover novel autoantibodies against tumor-associated antigens (TAAs) and establish diagnostic models for assisting in the diagnosis of lung cancer and discrimination of pulmonary nodules (PNs). Ten autoantibodies to TAAbs (TAAbs) were discovered by means of protein microarray and their serum level was also higher in 212 LC patients than that in 212 NC of validation cohort 1 (P < 0.05). The model 1 comprising 4 TAAbs and CEA reached an AUC of 0.813 (95%CI: 0.762-0.864) for diagnosing LC from normal individuals. Five TAAbs existed a significant difference between 105 malignant pulmonary nodules (MPNs) and 105 benign pulmonary nodules (BPNs) patients in validation cohort 2 (P < 0.05). Model 2 could distinguish MPNs from BPNs with an AUC of 0.845. High-throughput protein microarray is an efficient approach in discovering novel TAAbs which could be used as biomarkers in lung cancer diagnosis.
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Affiliation(s)
- Yulin Wang
- Henan Institute of Medical and Pharmaceutical Sciences, Academy of Medical Science, Zhengzhou University, Zhengzhou 450052, Henan, China
| | - Jiaqi Li
- Henan Institute of Medical and Pharmaceutical Sciences, Academy of Medical Science, Zhengzhou University, Zhengzhou 450052, Henan, China; Henan Key Laboratory of Tumor Molecular Biomarkers, Zhengzhou University, Zhengzhou 450052, Henan, China; Henan Key Laboratory of Tumor Epidemiology & State Key Laboratory of Esophageal Cancer Prevention, Zhengzhou University, Zhengzhou 450052, Henan, China
| | - Xue Zhang
- Henan Institute of Medical and Pharmaceutical Sciences, Academy of Medical Science, Zhengzhou University, Zhengzhou 450052, Henan, China; Henan Key Laboratory of Tumor Molecular Biomarkers, Zhengzhou University, Zhengzhou 450052, Henan, China; Henan Key Laboratory of Tumor Epidemiology & State Key Laboratory of Esophageal Cancer Prevention, Zhengzhou University, Zhengzhou 450052, Henan, China
| | - Man Liu
- Henan Institute of Medical and Pharmaceutical Sciences, Academy of Medical Science, Zhengzhou University, Zhengzhou 450052, Henan, China; Henan Key Laboratory of Tumor Molecular Biomarkers, Zhengzhou University, Zhengzhou 450052, Henan, China; Henan Key Laboratory of Tumor Epidemiology & State Key Laboratory of Esophageal Cancer Prevention, Zhengzhou University, Zhengzhou 450052, Henan, China; Laboratory of Molecular Biology, Henan Luoyang Orthopedic Hospital (Henan Provincial Orthopedic Hospital), Zhengzhou, China
| | - Longtao Ji
- Henan Institute of Medical and Pharmaceutical Sciences, Academy of Medical Science, Zhengzhou University, Zhengzhou 450052, Henan, China; Henan Key Laboratory of Tumor Molecular Biomarkers, Zhengzhou University, Zhengzhou 450052, Henan, China; BGI College, Zhengzhou University, Zhengzhou 450052, Henan, China
| | - Ting Yang
- Henan Institute of Medical and Pharmaceutical Sciences, Academy of Medical Science, Zhengzhou University, Zhengzhou 450052, Henan, China; Henan Key Laboratory of Tumor Molecular Biomarkers, Zhengzhou University, Zhengzhou 450052, Henan, China; BGI College, Zhengzhou University, Zhengzhou 450052, Henan, China
| | - Kaijuan Wang
- Henan Key Laboratory of Tumor Epidemiology & State Key Laboratory of Esophageal Cancer Prevention, Zhengzhou University, Zhengzhou 450052, Henan, China
| | - Chunhua Song
- Henan Key Laboratory of Tumor Epidemiology & State Key Laboratory of Esophageal Cancer Prevention, Zhengzhou University, Zhengzhou 450052, Henan, China
| | - Peng Wang
- Henan Key Laboratory of Tumor Epidemiology & State Key Laboratory of Esophageal Cancer Prevention, Zhengzhou University, Zhengzhou 450052, Henan, China
| | - Hua Ye
- Henan Key Laboratory of Tumor Epidemiology & State Key Laboratory of Esophageal Cancer Prevention, Zhengzhou University, Zhengzhou 450052, Henan, China
| | - Jianxiang Shi
- Henan Institute of Medical and Pharmaceutical Sciences, Academy of Medical Science, Zhengzhou University, Zhengzhou 450052, Henan, China; Henan Key Laboratory of Tumor Molecular Biomarkers, Zhengzhou University, Zhengzhou 450052, Henan, China; Henan Key Laboratory of Tumor Epidemiology & State Key Laboratory of Esophageal Cancer Prevention, Zhengzhou University, Zhengzhou 450052, Henan, China
| | - Liping Dai
- Henan Institute of Medical and Pharmaceutical Sciences, Academy of Medical Science, Zhengzhou University, Zhengzhou 450052, Henan, China; Henan Key Laboratory of Tumor Molecular Biomarkers, Zhengzhou University, Zhengzhou 450052, Henan, China; Henan Key Laboratory of Tumor Epidemiology & State Key Laboratory of Esophageal Cancer Prevention, Zhengzhou University, Zhengzhou 450052, Henan, China; BGI College, Zhengzhou University, Zhengzhou 450052, Henan, China.
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Del Greco C, Antonellis A. The Role of Nuclear-Encoded Mitochondrial tRNA Charging Enzymes in Human Inherited Disease. Genes (Basel) 2022; 13:2319. [PMID: 36553587 PMCID: PMC9777667 DOI: 10.3390/genes13122319] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2022] [Revised: 11/30/2022] [Accepted: 12/02/2022] [Indexed: 12/13/2022] Open
Abstract
Aminoacyl-tRNA synthetases (ARSs) are highly conserved essential enzymes that charge tRNA with cognate amino acids-the first step of protein synthesis. Of the 37 nuclear-encoded human ARS genes, 17 encode enzymes are exclusively targeted to the mitochondria (mt-ARSs). Mutations in nuclear mt-ARS genes are associated with rare, recessive human diseases with a broad range of clinical phenotypes. While the hypothesized disease mechanism is a loss-of-function effect, there is significant clinical heterogeneity among patients that have mutations in different mt-ARS genes and also among patients that have mutations in the same mt-ARS gene. This observation suggests that additional factors are involved in disease etiology. In this review, we present our current understanding of diseases caused by mutations in the genes encoding mt-ARSs and propose explanations for the observed clinical heterogeneity.
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Affiliation(s)
- Christina Del Greco
- Department of Human Genetics, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | - Anthony Antonellis
- Department of Human Genetics, University of Michigan Medical School, Ann Arbor, MI 48109, USA
- Department of Neurology, University of Michigan Medical School, Ann Arbor, MI 48109, USA
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Verdura E, Senger B, Raspall-Chaure M, Schlüter A, Launay N, Ruiz M, Casasnovas C, Rodriguez-Palmero A, Macaya A, Becker HD, Pujol A. Loss of seryl-tRNA synthetase ( SARS1) causes complex spastic paraplegia and cellular senescence. J Med Genet 2022; 59:1227-1233. [PMID: 36041817 PMCID: PMC9691831 DOI: 10.1136/jmg-2022-108529] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Accepted: 07/25/2022] [Indexed: 01/12/2023]
Abstract
BACKGROUND Aminoacyl-tRNA synthetases (ARS) are key enzymes catalysing the first reactions in protein synthesis, with increasingly recognised pleiotropic roles in tumourgenesis, angiogenesis, immune response and lifespan. Germline mutations in several ARS genes have been associated with both recessive and dominant neurological diseases. Recently, patients affected with microcephaly, intellectual disability and ataxia harbouring biallelic variants in the seryl-tRNA synthetase encoded by seryl-tRNA synthetase 1 (SARS1) were reported. METHODS We used exome sequencing to identify the causal variant in a patient affected by complex spastic paraplegia with ataxia, intellectual disability, developmental delay and seizures, but without microcephaly. Complementation and serylation assays using patient's fibroblasts and an Saccharomyces cerevisiae model were performed to examine this variant's pathogenicity. RESULTS A de novo splice site deletion in SARS1 was identified in our patient, resulting in a 5-amino acid in-frame insertion near its active site. Complementation assays in S. cerevisiae and serylation assays in both yeast strains and patient fibroblasts proved a loss-of-function, dominant negative effect. Fibroblasts showed an abnormal cell shape, arrested division and increased beta-galactosidase staining along with a senescence-associated secretory phenotype (raised interleukin-6, p21, p16 and p53 levels). CONCLUSION We refine the phenotypic spectrum and modes of inheritance of a newly described, ultrarare neurodevelopmental disorder, while unveiling the role of SARS1 as a regulator of cell growth, division and senescence.
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Affiliation(s)
- Edgard Verdura
- Neurometabolic Diseases Laboratory, Bellvitge Biomedical Research Institute (IDIBELL), L'Hospitalet de Llobregat, 08908, Barcelona, Catalonia, Spain,Centre for Biomedical Research on Rare Diseases (CIBERER), Instituto de Salud Carlos III, Madrid, Spain
| | | | - Miquel Raspall-Chaure
- Pediatric Neurology Research Group, Vall d’Hebron University Hospital, Universitat Autònoma de Barcelona, 08035, Barcelona, Catalonia, Spain,Department of Paediatric Neurology, Vall d’Hebron University Hospital, 08035, Barcelona, Catalonia, Spain
| | - Agatha Schlüter
- Neurometabolic Diseases Laboratory, Bellvitge Biomedical Research Institute (IDIBELL), L'Hospitalet de Llobregat, 08908, Barcelona, Catalonia, Spain,Centre for Biomedical Research on Rare Diseases (CIBERER), Instituto de Salud Carlos III, Madrid, Spain
| | - Nathalie Launay
- Neurometabolic Diseases Laboratory, Bellvitge Biomedical Research Institute (IDIBELL), L'Hospitalet de Llobregat, 08908, Barcelona, Catalonia, Spain,Centre for Biomedical Research on Rare Diseases (CIBERER), Instituto de Salud Carlos III, Madrid, Spain
| | - Montserrat Ruiz
- Neurometabolic Diseases Laboratory, Bellvitge Biomedical Research Institute (IDIBELL), L'Hospitalet de Llobregat, 08908, Barcelona, Catalonia, Spain,Centre for Biomedical Research on Rare Diseases (CIBERER), Instituto de Salud Carlos III, Madrid, Spain
| | - Carlos Casasnovas
- Neurometabolic Diseases Laboratory, Bellvitge Biomedical Research Institute (IDIBELL), L'Hospitalet de Llobregat, 08908, Barcelona, Catalonia, Spain,Centre for Biomedical Research on Rare Diseases (CIBERER), Instituto de Salud Carlos III, Madrid, Spain,Hospital Universitari de Bellvitge, Barcelona, Spain
| | - Agustí Rodriguez-Palmero
- Neurometabolic Diseases Laboratory, Bellvitge Biomedical Research Institute (IDIBELL), L'Hospitalet de Llobregat, 08908, Barcelona, Catalonia, Spain,Pediatrics, Hospital Germans Trias i Pujol, Barcelona, Spain
| | - Alfons Macaya
- Pediatric Neurology Research Group, Vall d’Hebron University Hospital, Universitat Autònoma de Barcelona, 08035, Barcelona, Catalonia, Spain,Department of Paediatric Neurology, Vall d’Hebron University Hospital, 08035, Barcelona, Catalonia, Spain,Institut de Neurociències, Universitat Autònoma de Barcelona, 08193, Barcelona, Catalonia, Spain
| | | | - Aurora Pujol
- Neurometabolic Diseases Laboratory, Bellvitge Biomedical Research Institute (IDIBELL), L'Hospitalet de Llobregat, 08908, Barcelona, Catalonia, Spain,Centre for Biomedical Research on Rare Diseases (CIBERER), Instituto de Salud Carlos III, Madrid, Spain,Catalan Institution of Research and Advanced Studies (ICREA), 08010, Barcelona, Catalonia, Spain
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9
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Turvey AK, Horvath GA, Cavalcanti ARO. Aminoacyl-tRNA synthetases in human health and disease. Front Physiol 2022; 13:1029218. [PMID: 36330207 PMCID: PMC9623071 DOI: 10.3389/fphys.2022.1029218] [Citation(s) in RCA: 27] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2022] [Accepted: 10/04/2022] [Indexed: 11/29/2022] Open
Abstract
The Aminoacyl-tRNA Synthetases (aaRSs) are an evolutionarily ancient family of enzymes that catalyze the esterification reaction linking a transfer RNA (tRNA) with its cognate amino acid matching the anticodon triplet of the tRNA. Proper functioning of the aaRSs to create aminoacylated (or “charged”) tRNAs is required for efficient and accurate protein synthesis. Beyond their basic canonical function in protein biosynthesis, aaRSs have a surprisingly diverse array of non-canonical functions that are actively being defined. The human genome contains 37 genes that encode unique aaRS proteins. To date, 56 human genetic diseases caused by damaging variants in aaRS genes have been described: 46 are autosomal recessive biallelic disorders and 10 are autosomal dominant monoallelic disorders. Our appreciation of human diseases caused by damaging genetic variants in the aaRSs has been greatly accelerated by the advent of next-generation sequencing, with 89% of these gene discoveries made since 2010. In addition to these genetic disorders of the aaRSs, anti-synthetase syndrome (ASSD) is a rare autoimmune inflammatory myopathy that involves the production of autoantibodies that disrupt aaRS proteins. This review provides an overview of the basic biology of aaRS proteins and describes the rapidly growing list of human diseases known to be caused by genetic variants or autoimmune targeting that affect both the canonical and non-canonical functions of these essential proteins.
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Affiliation(s)
- Alexandra K. Turvey
- Department of Biology, Pomona College, Claremont, CA, United States
- *Correspondence: Alexandra K. Turvey,
| | - Gabriella A. Horvath
- Division of Biochemical Genetics, Department of Pediatrics, University of British Columbia, BC Children’s Hospital, Vancouver, BC, Canada
- Adult Metabolic Diseases Clinic, Vancouver General Hospital, Vancouver, BC, Canada
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10
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Karaer K, Karaer D, Yüksel Z, Işikay S. Neurodevelopmental disorder with microcephaly, ataxia, and seizures syndrome: expansion of the clinical spectrum. Clin Dysmorphol 2022; 31:167-173. [PMID: 36004946 DOI: 10.1097/mcd.0000000000000426] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Neurodevelopmental disorder with microcephaly, ataxia, and seizures (NEDMAS) syndrome is a rare neurodevelopmental disorder characterized by moderate intellectual disability (ID), thin body habitus, microcephaly, seizures, ataxia, muscle weakness, and speech impairment. So far, only two families with NEDMAS have been reported. We report the clinical and molecular characteristics of three unrelated Turkish families with four NEDMAS patients. Whole-exome sequencing was used to search for the disease-causing variant. The main manifestations of the probands are severe developmental delay and ID, thin body habitus, and severe hypotonia. Brain imaging revealed bilateral cerebral and cerebellar diffuse atrophy. Sequencing results showed that both patients carried a novel missense variant c.1196C>T (p.Thr399Met) in the seryl-tRNA synthetase gene. Our findings help expand the variant spectrum of NEDMAS and provide additional information for diagnosing cases with atypical features.
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Affiliation(s)
- Kadri Karaer
- Department of Medical Genetics, Pamukkale University Faculty of Medicine, Denizli, Turkiye
| | - Derya Karaer
- Department of Medical Genetics, Pamukkale University Faculty of Medicine, Denizli, Turkiye
| | - Zafer Yüksel
- Human Genetics, Bioscientia GmbH, Ingelheim, Germany
| | - Sedat Işikay
- Department of Pediatric Neurology, Gaziantep University Faculty of Medicine, Gaziantep, Turkey
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11
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Bögershausen N, Krawczyk HE, Jamra RA, Lin SJ, Yigit G, Hüning I, Polo AM, Vona B, Huang K, Schmidt J, Altmüller J, Luppe J, Platzer K, Dörgeloh BB, Busche A, Biskup S, Mendes MI, Smith DEC, Salomons GS, Zibat A, Bültmann E, Nürnberg P, Spielmann M, Lemke JR, Li Y, Zenker M, Varshney GK, Hillen HS, Kratz CP, Wollnik B. WARS1 and SARS1: Two tRNA synthetases implicated in autosomal recessive microcephaly. Hum Mutat 2022; 43:1454-1471. [PMID: 35790048 DOI: 10.1002/humu.24430] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2021] [Revised: 06/10/2022] [Accepted: 07/01/2022] [Indexed: 02/04/2023]
Abstract
Aminoacylation of transfer RNA (tRNA) is a key step in protein biosynthesis, carried out by highly specific aminoacyl-tRNA synthetases (ARSs). ARSs have been implicated in autosomal dominant and autosomal recessive human disorders. Autosomal dominant variants in tryptophanyl-tRNA synthetase 1 (WARS1) are known to cause distal hereditary motor neuropathy and Charcot-Marie-Tooth disease, but a recessively inherited phenotype is yet to be clearly defined. Seryl-tRNA synthetase 1 (SARS1) has rarely been implicated in an autosomal recessive developmental disorder. Here, we report five individuals with biallelic missense variants in WARS1 or SARS1, who presented with an overlapping phenotype of microcephaly, developmental delay, intellectual disability, and brain anomalies. Structural mapping showed that the SARS1 variant is located directly within the enzyme's active site, most likely diminishing activity, while the WARS1 variant is located in the N-terminal domain. We further characterize the identified WARS1 variant by showing that it negatively impacts protein abundance and is unable to rescue the phenotype of a CRISPR/Cas9 wars1 knockout zebrafish model. In summary, we describe two overlapping autosomal recessive syndromes caused by variants in WARS1 and SARS1, present functional insights into the pathogenesis of the WARS1-related syndrome and define an emerging disease spectrum: ARS-related developmental disorders with or without microcephaly.
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Affiliation(s)
- Nina Bögershausen
- Institute of Human Genetics, University Medical Center Göttingen, Göttingen, Germany
| | - Hannah E Krawczyk
- Institute of Human Genetics, University Medical Center Göttingen, Göttingen, Germany
| | - Rami A Jamra
- Institute of Human Genetics, University of Leipzig Medical Center, Leipzig, Germany
| | - Sheng-Jia Lin
- Genes & Human Disease Research Program, Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma, USA
| | - Gökhan Yigit
- Institute of Human Genetics, University Medical Center Göttingen, Göttingen, Germany
| | - Irina Hüning
- Institut für Humangenetik, Universitätsklinikum Schleswig-Holstein, Lübeck, Germany
| | - Anna M Polo
- MVZ Labor Krone, Filialpraxis für Humangenetik, Bielefeld, Germany
| | - Barbara Vona
- Institute of Human Genetics, University Medical Center Göttingen, Göttingen, Germany.,Institute for Auditory Neuroscience and InnerEarLab, University Medical Center Göttingen, Göttingen, Germany
| | - Kevin Huang
- Genes & Human Disease Research Program, Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma, USA
| | - Julia Schmidt
- Institute of Human Genetics, University Medical Center Göttingen, Göttingen, Germany
| | - Janine Altmüller
- Cologne Center for Genomics (CCG), Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany.,Core Facility Genomics, Berlin Institute of Health at Charité - Universitätsmedizin Berlin, Berlin, Germany.,Max Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC), Berlin, Germany
| | - Johannes Luppe
- Institute of Human Genetics, University of Leipzig Medical Center, Leipzig, Germany
| | - Konrad Platzer
- Institute of Human Genetics, University of Leipzig Medical Center, Leipzig, Germany
| | - Beate B Dörgeloh
- Department of Pediatric Hematology and Oncology, Hannover Medical School, Hannover, Germany
| | - Andreas Busche
- Institut für Humangenetik, Westfälische Wilhelms-Universität Münster, Münster, Germany
| | - Saskia Biskup
- CeGaT GmbH, Center for Genomics and Transcriptomics, Tübingen, Germany
| | - Marisa I Mendes
- Laboratory Genetic Metabolic Diseases, Amsterdam Gastroenterology and Metabolism, Amsterdam Neuroscience, Amsterdam UMC, Amsterdam, Netherlands
| | - Desiree E C Smith
- Laboratory Genetic Metabolic Diseases, Amsterdam Gastroenterology and Metabolism, Amsterdam Neuroscience, Amsterdam UMC, Amsterdam, Netherlands
| | - Gajja S Salomons
- Laboratory Genetic Metabolic Diseases, Amsterdam Gastroenterology and Metabolism, Amsterdam Neuroscience, Amsterdam UMC, Amsterdam, Netherlands
| | - Arne Zibat
- Institute of Human Genetics, University Medical Center Göttingen, Göttingen, Germany
| | - Eva Bültmann
- Institute of Diagnostic and Interventional Neuroradiology, Hannover Medical School, Hannover, Germany
| | - Peter Nürnberg
- Cologne Center for Genomics (CCG), Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany.,Center for Molecular Medicine Cologne (CMMC), Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
| | - Malte Spielmann
- Institut für Humangenetik, Universitätsklinikum Schleswig-Holstein, Lübeck, Germany
| | - Johannes R Lemke
- Institute of Human Genetics, University of Leipzig Medical Center, Leipzig, Germany
| | - Yun Li
- Institute of Human Genetics, University Medical Center Göttingen, Göttingen, Germany
| | - Martin Zenker
- Institute of Human Genetics, Otto-von-Guericke University Magdeburg, Magdeburg, Germany
| | - Gaurav K Varshney
- Genes & Human Disease Research Program, Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma, USA
| | - Hauke S Hillen
- Research Group Structure and Function of Molecular Machines, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany.,Department of Cellular Biochemistry, University Medical Center Göttingen, Göttingen, Germany.,Cluster of Excellence "Multiscale Bioimaging: From Molecular Machines to Networks of Excitable cells" (MBExC), University of Göttingen, Göttingen, Germany
| | - Christian P Kratz
- Department of Pediatric Hematology and Oncology, Hannover Medical School, Hannover, Germany
| | - Bernd Wollnik
- Institute of Human Genetics, University Medical Center Göttingen, Göttingen, Germany.,Cluster of Excellence "Multiscale Bioimaging: From Molecular Machines to Networks of Excitable cells" (MBExC), University of Göttingen, Göttingen, Germany.,DZHK (German Centre for Cardiovascular Research), Partner Site Göttingen, Göttingen, Germany
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12
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Abstract
The human brain consumes five orders of magnitude more energy than the sun by unit of mass and time. This staggering bioenergetic cost serves mostly synaptic transmission and actin cytoskeleton dynamics. The peak of both brain bioenergetic demands and the age of onset for neurodevelopmental disorders is approximately 5 years of age. This correlation suggests that defects in the machinery that provides cellular energy would be causative and/or consequence of neurodevelopmental disorders. We explore this hypothesis from the perspective of the machinery required for the synthesis of the electron transport chain, an ATP-producing and NADH-consuming enzymatic cascade. The electron transport chain is constituted by nuclear- and mitochondrial-genome-encoded subunits. These subunits are synthesized by the 80S and the 55S ribosomes, which are segregated to the cytoplasm and the mitochondrial matrix, correspondingly. Mitochondrial protein synthesis by the 55S ribosome is the rate-limiting step in the synthesis of electron transport chain components, suggesting that mitochondrial protein synthesis is a bottleneck for tissues with high bionergetic demands. We discuss genetic defects in the human nuclear and mitochondrial genomes that affect these protein synthesis machineries and cause a phenotypic spectrum spanning autism spectrum disorders to neurodegeneration during neurodevelopment. We propose that dysregulated mitochondrial protein synthesis is a chief, yet understudied, causative mechanism of neurodevelopmental and behavioral disorders.
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13
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Dzinovic I, Winkelmann J, Zech M. Genetic intersection between dystonia and neurodevelopmental disorders: Insights from genomic sequencing. Parkinsonism Relat Disord 2022; 102:131-140. [DOI: 10.1016/j.parkreldis.2022.08.019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/03/2022] [Revised: 08/12/2022] [Accepted: 08/18/2022] [Indexed: 10/15/2022]
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14
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Galindo-Feria AS, Notarnicola A, Lundberg IE, Horuluoglu B. Aminoacyl-tRNA Synthetases: On Anti-Synthetase Syndrome and Beyond. Front Immunol 2022; 13:866087. [PMID: 35634293 PMCID: PMC9136399 DOI: 10.3389/fimmu.2022.866087] [Citation(s) in RCA: 33] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2022] [Accepted: 03/28/2022] [Indexed: 12/20/2022] Open
Abstract
Anti-synthetase syndrome (ASSD) is an autoimmune disease characterized by the presence of autoantibodies targeting one of several aminoacyl t-RNA synthetases (aaRSs) along with clinical features including interstitial lung disease, myositis, Raynaud’s phenomenon, arthritis, mechanic’s hands, and fever. The family of aaRSs consists of highly conserved cytoplasmic and mitochondrial enzymes, one for each amino acid, which are essential for the RNA translation machinery and protein synthesis. Along with their main functions, aaRSs are involved in the development of immune responses, regulation of transcription, and gene-specific silencing of translation. During the last decade, these proteins have been associated with cancer, neurological disorders, infectious responses, and autoimmune diseases including ASSD. To date, several aaRSs have been described to be possible autoantigens in different diseases. The most commonly described are histidyl (HisRS), threonyl (ThrRS), alanyl (AlaRS), glycyl (GlyRS), isoleucyl (IleRS), asparaginyl (AsnRS), phenylalanyl (PheRS), tyrosyl (TyrRS), lysyl (LysRS), glutaminyl (GlnRS), tryptophanyl (TrpRS), and seryl (SerRS) tRNA synthetases. Autoantibodies against the first eight autoantigens listed above have been associated with ASSD while the rest have been associated with other diseases. This review will address what is known about the function of the aaRSs with a focus on their autoantigenic properties. We will also describe the anti-aaRSs autoantibodies and their association to specific clinical manifestations, and discuss their potential contribution to the pathogenesis of ASSD.
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Affiliation(s)
- Angeles S. Galindo-Feria
- Division of Rheumatology, Department of Medicine, Solna, Karolinska Institutet, Stockholm, Sweden
- Center for Molecular Medicine, Karolinska Institutet, and Karolinska University Hospital Solna, Stockholm, Sweden
| | - Antonella Notarnicola
- Center for Molecular Medicine, Karolinska Institutet, and Karolinska University Hospital Solna, Stockholm, Sweden
| | - Ingrid E. Lundberg
- Division of Rheumatology, Department of Medicine, Solna, Karolinska Institutet, Stockholm, Sweden
- Center for Molecular Medicine, Karolinska Institutet, and Karolinska University Hospital Solna, Stockholm, Sweden
| | - Begum Horuluoglu
- Division of Rheumatology, Department of Medicine, Solna, Karolinska Institutet, Stockholm, Sweden
- Center for Molecular Medicine, Karolinska Institutet, and Karolinska University Hospital Solna, Stockholm, Sweden
- *Correspondence: Begum Horuluoglu,
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15
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WARS2 mutations cause dopa-responsive early-onset parkinsonism and progressive myoclonus ataxia. Parkinsonism Relat Disord 2021; 94:54-61. [PMID: 34890876 DOI: 10.1016/j.parkreldis.2021.11.030] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Revised: 10/12/2021] [Accepted: 11/28/2021] [Indexed: 11/22/2022]
Abstract
INTRODUCTION Sixteen subjects with biallelic WARS2 variants encoding the tryptophanyl mitochondrial aminoacyl-tRNA synthetase, presenting with a neonatal- or infantile-onset mitochondrial disease, have been reported to date. Here we present six novel cases with WARS2-related diseases and expand the spectrum to later onset phenotypes including dopa-responsive early-onset parkinsonism and progressive myoclonus-ataxia. METHODS Six individuals from four families underwent whole-exome sequencing within research and diagnostic settings. Following the identification of a genetic defect, in-depth phenotyping and protein expression studies were performed. RESULTS A relatively common (gnomAD MAF = 0.0033) pathogenic p.(Trp13Gly) missense variant in WARS2 was detected in trans in all six affected individuals in combination with different pathogenic alleles (exon 2 deletion in family 1; p.(Leu100del) in family 2; p.(Gly50Asp) in family 3; and p.(Glu208*) in family 4). Two subjects presented with action tremor around age 10-12 years and developed tremor-dominant parkinsonism with prominent neuropsychiatric features later in their 20s. Two subjects presented with a progressive myoclonus-ataxia dominant phenotype. One subject presented with spasticity, choreo-dystonia, myoclonus, and speech problems. One subject presented with speech problems, ataxia, and tremor. Western blotting analyses in patient-derived fibroblasts showed a markedly decreased expression of the full-length WARS2 protein in both subjects carrying p.(Trp13Gly) and an exon-2 deletion in compound heterozygosity. CONCLUSIONS This study expands the spectrum of the disease to later onset phenotypes of early-onset tremor-dominant parkinsonism and progressive myoclonus-ataxia phenotypes.
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16
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Ravel JM, Dreumont N, Mosca P, Smith DEC, Mendes MI, Wiedemann A, Coelho D, Schmitt E, Rivière JB, Tran Mau-Them F, Thevenon J, Kuentz P, Polivka M, Fuchs SA, Kok G, Thauvin-Robinet C, Guéant JL, Salomons GS, Faivre L, Feillet F. A bi-allelic loss-of-function SARS1 variant in children with neurodevelopmental delay, deafness, cardiomyopathy, and decompensation during fever. Hum Mutat 2021; 42:1576-1583. [PMID: 34570399 DOI: 10.1002/humu.24285] [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: 01/28/2021] [Revised: 09/01/2021] [Accepted: 09/23/2021] [Indexed: 11/08/2022]
Abstract
Aminoacyl-tRNA synthetases (aaRS) are ubiquitously expressed enzymes responsible for ligating amino acids to their cognate tRNA molecules through an aminoacylation reaction. The resulting aminoacyl-tRNA is delivered to ribosome elongation factors to participate in protein synthesis. Seryl-tRNA synthetase (SARS1) is one of the cytosolic aaRSs and catalyzes serine attachment to tRNASer . SARS1 deficiency has already been associated with moderate intellectual disability, ataxia, muscle weakness, and seizure in one family. We describe here a new clinical presentation including developmental delay, central deafness, cardiomyopathy, and metabolic decompensation during fever leading to death, in a consanguineous Turkish family, with biallelic variants (c.638G>T, p.(Arg213Leu)) in SARS1. This missense variant was shown to lead to protein instability, resulting in reduced protein level and enzymatic activity. Our results describe a new clinical entity and expand the clinical and mutational spectrum of SARS1 and aaRS deficiencies.
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Affiliation(s)
- Jean-Marie Ravel
- Reference Centre of Inborn Metabolism Diseases, Université de Lorraine, CHRU-Nancy, Nancy, France.,NGERE, Université de Lorraine, Inserm, Nancy, France
| | | | - Pauline Mosca
- NGERE, Université de Lorraine, Inserm, Nancy, France
| | - Desiree E C Smith
- Metabolic Unit, Department of Clinical Chemistry, Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| | - Marisa I Mendes
- Metabolic Unit, Department of Clinical Chemistry, Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| | | | - David Coelho
- NGERE, Université de Lorraine, Inserm, Nancy, France
| | | | - Jean-Baptiste Rivière
- Unité Fonctionnelle Innovation en Diagnostic génomique des maladies rares, CHU Dijon Bourgogne, Dijon, France.,Centre de Génétique, Centre de Référence Anomalies du Développement et Syndromes Malformatifs, Centre de Compétence Maladies Mitochondriales, FHU TRANSLAD, Hôpital d'Enfants, CHU de Dijon, France.,INSERM UMR1231, Equipe Génétique des Anomalies du Développement, Université de Bourgogne, Dijon, France
| | - Frédéric Tran Mau-Them
- Unité Fonctionnelle Innovation en Diagnostic génomique des maladies rares, CHU Dijon Bourgogne, Dijon, France.,Centre de Génétique, Centre de Référence Anomalies du Développement et Syndromes Malformatifs, Centre de Compétence Maladies Mitochondriales, FHU TRANSLAD, Hôpital d'Enfants, CHU de Dijon, France.,INSERM UMR1231, Equipe Génétique des Anomalies du Développement, Université de Bourgogne, Dijon, France
| | - Julien Thevenon
- Unité Fonctionnelle Innovation en Diagnostic génomique des maladies rares, CHU Dijon Bourgogne, Dijon, France.,Centre de Génétique, Centre de Référence Anomalies du Développement et Syndromes Malformatifs, Centre de Compétence Maladies Mitochondriales, FHU TRANSLAD, Hôpital d'Enfants, CHU de Dijon, France.,INSERM UMR1231, Equipe Génétique des Anomalies du Développement, Université de Bourgogne, Dijon, France
| | - Paul Kuentz
- Centre de Génétique, Centre de Référence Anomalies du Développement et Syndromes Malformatifs, Centre de Compétence Maladies Mitochondriales, FHU TRANSLAD, Hôpital d'Enfants, CHU de Dijon, France.,INSERM UMR1231, Equipe Génétique des Anomalies du Développement, Université de Bourgogne, Dijon, France
| | - Marc Polivka
- Department of Pathology, Hôpital Lariboisière, Paris, France
| | - Sabine A Fuchs
- Department of Metabolic Diseases, Wilhelmina Children's Hospital, University Medical Center Utrecht, Utrecht, The Netherlands.,Regenerative Medicine Center Utrecht, Regenerative Medicine Utrecht, Utrecht, The Netherlands.,On behalf of "United for Metabolic Diseases,", Amsterdam, the Netherlands
| | - Gautam Kok
- Department of Pathology, Hôpital Lariboisière, Paris, France
| | - Christel Thauvin-Robinet
- Unité Fonctionnelle Innovation en Diagnostic génomique des maladies rares, CHU Dijon Bourgogne, Dijon, France.,Centre de Génétique, Centre de Référence Anomalies du Développement et Syndromes Malformatifs, Centre de Compétence Maladies Mitochondriales, FHU TRANSLAD, Hôpital d'Enfants, CHU de Dijon, France.,INSERM UMR1231, Equipe Génétique des Anomalies du Développement, Université de Bourgogne, Dijon, France
| | - Jean-Louis Guéant
- Reference Centre of Inborn Metabolism Diseases, Université de Lorraine, CHRU-Nancy, Nancy, France.,NGERE, Université de Lorraine, Inserm, Nancy, France
| | - Gajja S Salomons
- Metabolic Unit, Department of Clinical Chemistry, Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| | - Laurence Faivre
- Centre de Génétique, Centre de Référence Anomalies du Développement et Syndromes Malformatifs, Centre de Compétence Maladies Mitochondriales, FHU TRANSLAD, Hôpital d'Enfants, CHU de Dijon, France.,INSERM UMR1231, Equipe Génétique des Anomalies du Développement, Université de Bourgogne, Dijon, France
| | - François Feillet
- Reference Centre of Inborn Metabolism Diseases, Université de Lorraine, CHRU-Nancy, Nancy, France.,NGERE, Université de Lorraine, Inserm, Nancy, France
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17
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Treatment of ARS deficiencies with specific amino acids. Genet Med 2021; 23:2202-2207. [PMID: 34194004 PMCID: PMC8244667 DOI: 10.1038/s41436-021-01249-z] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2021] [Revised: 06/07/2021] [Accepted: 06/08/2021] [Indexed: 02/01/2023] Open
Abstract
Purpose Recessive cytosolic aminoacyl-tRNA synthetase (ARS) deficiencies are severe multiorgan diseases, with limited treatment options. By loading transfer RNAs (tRNAs) with their cognate amino acids, ARS are essential for protein translation. However, it remains unknown why ARS deficiencies lead to specific symptoms, especially early life and during infections. We set out to increase pathophysiological insight and improve therapeutic possibilities. Methods In fibroblasts from patients with isoleucyl-RS (IARS), leucyl-RS (LARS), phenylalanyl-RS-beta-subunit (FARSB), and seryl-RS (SARS) deficiencies, we investigated aminoacylation activity, thermostability, and sensitivity to ARS-specific amino acid concentrations, and developed personalized treatments. Results Aminoacylation activity was reduced in all patients, and further diminished at 38.5/40 °C (PLARS and PFARSB), consistent with infectious deteriorations. With lower cognate amino acid concentrations, patient fibroblast growth was severely affected. To prevent local and/or temporal deficiencies, we treated patients with corresponding amino acids (follow-up: 1/2–2 2/3rd years), and intensified treatment during infections. All patients showed beneficial treatment effects, most strikingly in growth (without tube feeding), head circumference, development, coping with infections, and oxygen dependency. Conclusion For these four ARS deficiencies, we observed a common disease mechanism of episodic insufficient aminoacylation to meet translational demands and illustrate the power of amino acid supplementation for the expanding ARS patient group. Moreover, we provide a strategy for personalized preclinical functional evaluation. ![]()
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18
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Graille M. Division of labor in epitranscriptomics: What have we learnt from the structures of eukaryotic and viral multimeric RNA methyltransferases? WILEY INTERDISCIPLINARY REVIEWS-RNA 2021; 13:e1673. [PMID: 34044474 DOI: 10.1002/wrna.1673] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2021] [Revised: 04/30/2021] [Accepted: 05/04/2021] [Indexed: 02/06/2023]
Abstract
The translation of an mRNA template into the corresponding protein is a highly complex and regulated choreography performed by ribosomes, tRNAs, and translation factors. Most RNAs involved in this process are decorated by multiple chemical modifications (known as epitranscriptomic marks) contributing to the efficiency, the fidelity, and the regulation of the mRNA translation process. Many of these epitranscriptomic marks are written by holoenzymes made of a catalytic subunit associated with an activating subunit. These holoenzymes play critical roles in cell development. Indeed, several mutations being identified in the genes encoding for those proteins are linked to human pathologies such as cancers and intellectual disorders for instance. This review describes the structural and functional properties of RNA methyltransferase holoenzymes, which when mutated often result in brain development pathologies. It illustrates how structurally different activating subunits contribute to the catalytic activity of these holoenzymes through common mechanistic trends that most likely apply to other classes of holoenzymes. This article is categorized under: RNA Processing > RNA Editing and Modification RNA Processing > Capping and 5' End Modifications.
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Affiliation(s)
- Marc Graille
- Laboratoire de Biologie Structurale de la Cellule (BIOC), CNRS, Ecole Polytechnique, IP Paris, Palaiseau Cedex, France
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19
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Co-occurring WARS2 and CHRNA6 mutations in a child with a severe form of infantile parkinsonism. Parkinsonism Relat Disord 2020; 72:75-79. [PMID: 32120303 DOI: 10.1016/j.parkreldis.2020.02.003] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/27/2019] [Revised: 02/10/2020] [Accepted: 02/11/2020] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To investigate the molecular cause(s) underlying a severe form of infantile-onset parkinsonism and characterize functionally the identified variants. METHODS A trio-based whole exome sequencing (WES) approach was used to identify the candidate variants underlying the disorder. In silico modeling, and in vitro and in vivo studies were performed to explore the impact of these variants on protein function and relevant cellular processes. RESULTS WES analysis identified biallelic variants in WARS2, encoding the mitochondrial tryptophanyl tRNA synthetase (mtTrpRS), a gene whose mutations have recently been associated with multiple neurological phenotypes, including childhood-onset, levodopa-responsive or unresponsive parkinsonism in a few patients. A substantial reduction of mtTrpRS levels in mitochondria and reduced OXPHOS function was demonstrated, supporting their pathogenicity. Based on the infantile-onset and severity of the phenotype, additional variants were considered as possible genetic modifiers. Functional assessment of a selected panel of candidates pointed to a de novo missense mutation in CHRNA6, encoding the α6 subunit of neuronal nicotinic receptors, which are involved in the cholinergic modulation of dopamine release in the striatum, as a second event likely contributing to the phenotype. In silico, in vitro (Xenopus oocytes and GH4C1 cells) and in vivo (C. elegans) analyses demonstrated the disruptive effects of the mutation on acetylcholine receptor structure and function. CONCLUSION Our findings consolidate the association between biallelic WARS2 mutations and movement disorders, and suggest CHRNA6 as a genetic modifier of the phenotype.
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Abstract
Aminoacyl-tRNA synthetases (ARSs) are essential enzymes for protein synthesis with evolutionarily conserved enzymatic mechanisms. Despite their similarity across organisms, scientists have been able to generate effective anti-infective agents based on the structural differences in the catalytic clefts of ARSs from pathogens and humans. However, recent genomic, proteomic and functionomic advances have unveiled unexpected disease-associated mutations and altered expression, secretion and interactions in human ARSs, revealing hidden biological functions beyond their catalytic roles in protein synthesis. These studies have also brought to light their potential as a rich and unexplored source for new therapeutic targets and agents through multiple avenues, including direct targeting of the catalytic sites, controlling disease-associated protein-protein interactions and developing novel biologics from the secreted ARS proteins or their parts. This Review addresses the emerging biology and therapeutic applications of human ARSs in diseases including autoimmune and rare diseases, and cancer.
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Hübers A, Huppertz HJ, Wortmann SB, Kassubek J. Mutation of the WARS2 Gene as the Cause of a Severe Hyperkinetic Movement Disorder. Mov Disord Clin Pract 2020; 7:88-90. [PMID: 31970218 DOI: 10.1002/mdc3.12855] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2019] [Revised: 10/04/2019] [Accepted: 10/10/2019] [Indexed: 12/29/2022] Open
Affiliation(s)
| | | | - Saskia B Wortmann
- University Children's Hospital Salzburg Austria.,Institute of Human Genetics, Technische Universität München München Germany.,Institute of Human Genetics, Helmholtz Zentrum München Neuherberg Germany
| | - Jan Kassubek
- Department of Neurology University of Ulm Ulm Germany
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22
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Human diseases linked to cytoplasmic aminoacyl-tRNA synthetases. BIOLOGY OF AMINOACYL-TRNA SYNTHETASES 2020; 48:277-319. [DOI: 10.1016/bs.enz.2020.06.009] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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23
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Thompson K, Collier JJ, Glasgow RIC, Robertson FM, Pyle A, Blakely EL, Alston CL, Oláhová M, McFarland R, Taylor RW. Recent advances in understanding the molecular genetic basis of mitochondrial disease. J Inherit Metab Dis 2020; 43:36-50. [PMID: 31021000 PMCID: PMC7041634 DOI: 10.1002/jimd.12104] [Citation(s) in RCA: 94] [Impact Index Per Article: 23.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/21/2019] [Revised: 04/03/2019] [Accepted: 04/24/2019] [Indexed: 12/22/2022]
Abstract
Mitochondrial disease is hugely diverse with respect to associated clinical presentations and underlying genetic causes, with pathogenic variants in over 300 disease genes currently described. Approximately half of these have been discovered in the last decade due to the increasingly widespread application of next generation sequencing technologies, in particular unbiased, whole exome-and latterly, whole genome sequencing. These technologies allow more genetic data to be collected from patients with mitochondrial disorders, continually improving the diagnostic success rate in a clinical setting. Despite these significant advances, some patients still remain without a definitive genetic diagnosis. Large datasets containing many variants of unknown significance have become a major challenge with next generation sequencing strategies and these require significant functional validation to confirm pathogenicity. This interface between diagnostics and research is critical in continuing to expand the list of known pathogenic variants and concomitantly enhance our knowledge of mitochondrial biology. The increasing use of whole exome sequencing, whole genome sequencing and other "omics" techniques such as transcriptomics and proteomics will generate even more data and allow further interrogation and validation of genetic causes, including those outside of coding regions. This will improve diagnostic yields still further and emphasizes the integral role that functional assessment of variant causality plays in this process-the overarching focus of this review.
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Affiliation(s)
- Kyle Thompson
- Wellcome Centre for Mitochondrial Research, Institute of NeuroscienceNewcastle UniversityNewcastle upon TyneUK
| | - Jack J. Collier
- Wellcome Centre for Mitochondrial Research, Institute of NeuroscienceNewcastle UniversityNewcastle upon TyneUK
| | - Ruth I. C. Glasgow
- Wellcome Centre for Mitochondrial Research, Institute of NeuroscienceNewcastle UniversityNewcastle upon TyneUK
| | - Fiona M. Robertson
- Wellcome Centre for Mitochondrial Research, Institute of NeuroscienceNewcastle UniversityNewcastle upon TyneUK
| | - Angela Pyle
- Wellcome Centre for Mitochondrial Research, Institute of Genetic MedicineNewcastle UniversityNewcastle upon TyneUK
| | - Emma L. Blakely
- Wellcome Centre for Mitochondrial Research, Institute of NeuroscienceNewcastle UniversityNewcastle upon TyneUK
- NHS Highly Specialised Mitochondrial Diagnostic LaboratoryNewcastle upon Tyne Hospitals NHS Foundation TrustNewcastle upon TyneUK
| | - Charlotte L. Alston
- Wellcome Centre for Mitochondrial Research, Institute of NeuroscienceNewcastle UniversityNewcastle upon TyneUK
- NHS Highly Specialised Mitochondrial Diagnostic LaboratoryNewcastle upon Tyne Hospitals NHS Foundation TrustNewcastle upon TyneUK
| | - Monika Oláhová
- Wellcome Centre for Mitochondrial Research, Institute of NeuroscienceNewcastle UniversityNewcastle upon TyneUK
| | - Robert McFarland
- Wellcome Centre for Mitochondrial Research, Institute of NeuroscienceNewcastle UniversityNewcastle upon TyneUK
| | - Robert W. Taylor
- Wellcome Centre for Mitochondrial Research, Institute of NeuroscienceNewcastle UniversityNewcastle upon TyneUK
- NHS Highly Specialised Mitochondrial Diagnostic LaboratoryNewcastle upon Tyne Hospitals NHS Foundation TrustNewcastle upon TyneUK
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24
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Agnew T, Goldsworthy M, Aguilar C, Morgan A, Simon M, Hilton H, Esapa C, Wu Y, Cater H, Bentley L, Scudamore C, Poulton J, Morten KJ, Thompson K, He L, Brown SDM, Taylor RW, Bowl MR, Cox RD. A Wars2 Mutant Mouse Model Displays OXPHOS Deficiencies and Activation of Tissue-Specific Stress Response Pathways. Cell Rep 2019; 25:3315-3328.e6. [PMID: 30566859 PMCID: PMC6315286 DOI: 10.1016/j.celrep.2018.11.080] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2018] [Revised: 07/06/2018] [Accepted: 11/21/2018] [Indexed: 01/02/2023] Open
Abstract
Mutations in genes essential for mitochondrial function have pleiotropic effects. The mechanisms underlying these traits yield insights into metabolic homeostasis and potential therapies. Here we report the characterization of a mouse model harboring a mutation in the tryptophanyl-tRNA synthetase 2 (Wars2) gene, encoding the mitochondrial-localized WARS2 protein. This hypomorphic allele causes progressive tissue-specific pathologies, including hearing loss, reduced adiposity, adipose tissue dysfunction, and hypertrophic cardiomyopathy. We demonstrate the tissue heterogeneity arises as a result of variable activation of the integrated stress response (ISR) pathway and the ability of certain tissues to respond to impaired mitochondrial translation. Many of the systemic metabolic effects are likely mediated through elevated fibroblast growth factor 21 (FGF21) following activation of the ISR in certain tissues. These findings demonstrate the potential pleiotropy associated with Wars2 mutations in patients. A hypomorphic point mutation in the Wars2 gene was identified Mutant mice exhibit progressive tissue-specific pathologies Variable activation of stress response pathways Demonstrating pleiotropic effects
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Affiliation(s)
- Thomas Agnew
- MRC Harwell Institute, Mammalian Genetics Unit and Mary Lyon Centre, Harwell Campus, Oxfordshire OX11 0RD, UK
| | - Michelle Goldsworthy
- MRC Harwell Institute, Mammalian Genetics Unit and Mary Lyon Centre, Harwell Campus, Oxfordshire OX11 0RD, UK
| | - Carlos Aguilar
- MRC Harwell Institute, Mammalian Genetics Unit and Mary Lyon Centre, Harwell Campus, Oxfordshire OX11 0RD, UK
| | - Anna Morgan
- MRC Harwell Institute, Mammalian Genetics Unit and Mary Lyon Centre, Harwell Campus, Oxfordshire OX11 0RD, UK
| | - Michelle Simon
- MRC Harwell Institute, Mammalian Genetics Unit and Mary Lyon Centre, Harwell Campus, Oxfordshire OX11 0RD, UK
| | - Helen Hilton
- MRC Harwell Institute, Mammalian Genetics Unit and Mary Lyon Centre, Harwell Campus, Oxfordshire OX11 0RD, UK
| | - Chris Esapa
- MRC Harwell Institute, Mammalian Genetics Unit and Mary Lyon Centre, Harwell Campus, Oxfordshire OX11 0RD, UK
| | - Yixing Wu
- MRC Harwell Institute, Mammalian Genetics Unit and Mary Lyon Centre, Harwell Campus, Oxfordshire OX11 0RD, UK
| | - Heather Cater
- MRC Harwell Institute, Mammalian Genetics Unit and Mary Lyon Centre, Harwell Campus, Oxfordshire OX11 0RD, UK
| | - Liz Bentley
- MRC Harwell Institute, Mammalian Genetics Unit and Mary Lyon Centre, Harwell Campus, Oxfordshire OX11 0RD, UK
| | - Cheryl Scudamore
- MRC Harwell Institute, Mammalian Genetics Unit and Mary Lyon Centre, Harwell Campus, Oxfordshire OX11 0RD, UK
| | - Joanna Poulton
- Nuffield Department of Obstetrics and Gynaecology, University of Oxford, Level 3 The Women's Centre, John Radcliffe Hospital, Headington, Oxford OX3 9DU, UK
| | - Karl J Morten
- Nuffield Department of Obstetrics and Gynaecology, University of Oxford, Level 3 The Women's Centre, John Radcliffe Hospital, Headington, Oxford OX3 9DU, UK
| | - Kyle Thompson
- Wellcome Centre for Mitochondrial Research, Institute of Neuroscience, The Medical School, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
| | - Langping He
- Wellcome Centre for Mitochondrial Research, Institute of Neuroscience, The Medical School, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
| | - Steve D M Brown
- MRC Harwell Institute, Mammalian Genetics Unit and Mary Lyon Centre, Harwell Campus, Oxfordshire OX11 0RD, UK
| | - Robert W Taylor
- Wellcome Centre for Mitochondrial Research, Institute of Neuroscience, The Medical School, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
| | - Michael R Bowl
- MRC Harwell Institute, Mammalian Genetics Unit and Mary Lyon Centre, Harwell Campus, Oxfordshire OX11 0RD, UK.
| | - Roger D Cox
- MRC Harwell Institute, Mammalian Genetics Unit and Mary Lyon Centre, Harwell Campus, Oxfordshire OX11 0RD, UK.
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Virdee M, Swarnalingam E, Kozenko M, Tarnopolsky M, Jones K. Expanding the Phenotype: Neurodevelopmental Disorder, Mitochondrial, With Abnormal Movements and Lactic Acidosis, With or Without Seizures (NEMMLAS) due to WARS2 Biallelic Variants, Encoding Mitochondrial Tryptophanyl-tRNA Synthase. J Child Neurol 2019; 34:778-781. [PMID: 31282308 DOI: 10.1177/0883073819854604] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
BACKGROUND WARS2 encodes a tryptophanyl tRNA synthetase, which is involved in mitochondrial protein synthesis. Biallelic mutations in WARS2 are rare and have been associated with a spectrum of clinical presentations, including neurodevelopmental disorder with abnormal movements, lactic acidosis with or without seizures (NEMMLAS). CASE PRESENTATION Here we present the case of an 8-year-old girl with ataxia and parkinsonism with periventricular white matter abnormalities on magnetic resonance imaging (MRI) and global developmental delay. The initial investigations revealed an elevated lactate level. Extensive metabolic testing, including a muscle biopsy, was inconclusive. Cerebrospinal fluid (CSF) neurotransmitter levels were low; however, a trial of levodopa was unremarkable. The chromosomal microarray and initial ataxia gene panel was normal. Zinc supplementation for a heterozygous variant of unknown significance in the CP gene on the ataxia exome panel was not effective in treating her symptoms. Reanalysis of the ataxia exome panel highlighted biallelic mutations in WARS2, which lead to the diagnosis of neurodevelopmental disorder, mitochondrial, with abnormal movements and lactic acidosis, with or without seizures (NEMMLAS). This lead to parental genetic testing, redirected therapy, and helped to expand the symptomology of this rare condition. CONCLUSION Here we emphasize the importance of imminent and repeat expanded genetic testing to ensure early diagnosis and treatment for rare pediatric disorders. The patient is being trialed on a mitochondrial cocktail in an attempt to compensate for defects in mitochondrial protein synthesis associated with this variant. Longitudinal monitoring of disease manifestation will help establish the currently unknown natural history of this condition.
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Affiliation(s)
- Manveen Virdee
- 1 Neurology Division, Department of Pediatrics, McMaster University, Hamilton, Ontario, Canada
| | - Eroshini Swarnalingam
- 2 Genetics Division, Department of Pediatrics, McMaster University, Hamilton, Ontario, Canada
| | - Mariya Kozenko
- 2 Genetics Division, Department of Pediatrics, McMaster University, Hamilton, Ontario, Canada
| | - Mark Tarnopolsky
- 3 Neuromuscular and Neurometabolics Division, Department of Pediatrics, McMaster University, Hamilton, Ontario, Canada
| | - Kevin Jones
- 1 Neurology Division, Department of Pediatrics, McMaster University, Hamilton, Ontario, Canada
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26
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Jensen LR, Garrett L, Hölter SM, Rathkolb B, Rácz I, Adler T, Prehn C, Hans W, Rozman J, Becker L, Aguilar-Pimentel JA, Puk O, Moreth K, Dopatka M, Walther DJ, von Bohlen und Halbach V, Rath M, Delatycki M, Bert B, Fink H, Blümlein K, Ralser M, Van Dijck A, Kooy F, Stark Z, Müller S, Scherthan H, Gecz J, Wurst W, Wolf E, Zimmer A, Klingenspor M, Graw J, Klopstock T, Busch D, Adamski J, Fuchs H, Gailus-Durner V, de Angelis MH, von Bohlen und Halbach O, Ropers HH, Kuss AW. A mouse model for intellectual disability caused by mutations in the X-linked 2′‑O‑methyltransferase Ftsj1 gene. Biochim Biophys Acta Mol Basis Dis 2019; 1865:2083-2093. [DOI: 10.1016/j.bbadis.2018.12.011] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2018] [Revised: 12/06/2018] [Accepted: 12/10/2018] [Indexed: 01/13/2023]
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27
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Royer‐Bertrand B, Tsouni P, Mullen P, Campos Xavier B, Mittaz Crettol L, Lobrinus AJ, Ghika J, Baumgartner MR, Rivolta C, Superti‐Furga A, Kuntzer T, Francklyn C, Tran C. Peripheral neuropathy and cognitive impairment associated with a novel monoallelic HARS variant. Ann Clin Transl Neurol 2019; 6:1072-1080. [PMID: 31211171 PMCID: PMC6562026 DOI: 10.1002/acn3.791] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Revised: 03/20/2019] [Accepted: 04/05/2019] [Indexed: 12/31/2022] Open
Abstract
Background A 49‐year‐old male presented with late‐onset demyelinating peripheral neuropathy, cerebellar atrophy, and cognitive deficit. Nerve biopsy revealed intra‐axonal inclusions suggestive of polyglucosan bodies, raising the suspicion of adult polyglucosan bodies disease (OMIM 263570). Methods and Results While known genes associated with polyglucosan bodies storage were negative, whole‐exome sequencing identified an unreported monoallelic variant, c.397G>T (p.Val133Phe), in the histidyl‐tRNA synthetase (HARS) gene. While we did not identify mutations in genes known to be associated with polygucosan body disease, whole‐exome sequencing revealed an unreported monoallelic variant, c.397G>T in the histidyl‐tRNA synthetase (HARS) gene, encoding a substitution (Val133Phe) in the catalytic domain. Expression of this variant in patient cells resulted in reduced aminoacylation activity in extracts obtained from dermal fibroblasts, without compromising overall protein synthesis. Interpretation Genetic variants in the genes coding for the different aminoacyl‐tRNA synthases are associated with various clinical conditions. To date, a number of HARS variant have been associated with peripheral neuropathy, but not cognitive deficits. Further studies are needed to explore why HARS mutations confer a neuronal‐specific phenotype.
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Affiliation(s)
- Béryl Royer‐Bertrand
- Division of Genetic MedicineLausanne University Hospital (CHUV)LausanneSwitzerland
- Department of Computational BiologyUnit of Medical GeneticsUniversity of LausanneLausanneSwitzerland
| | - Pinelopi Tsouni
- Nerve‐Muscle UnitDepartment of Clinical NeurosciencesLausanne University Hospital (CHUV)LausanneSwitzerland
- Leenaards Memory CentreDepartment of Clinical NeurosciencesLausanne University Hospital (CHUV)LausanneSwitzerland
| | - Patrick Mullen
- Department of BiochemistryLarner College of MedicineUniversity of VermontBurlingtonVermont
| | | | | | | | - Joseph Ghika
- Leenaards Memory CentreDepartment of Clinical NeurosciencesLausanne University Hospital (CHUV)LausanneSwitzerland
| | - Matthias R. Baumgartner
- Division of Metabolism and Children's Research Center (CRC)University Children's HospitalZurichSwitzerland
- radiz ‐ Rare Disease Initiative ZurichClinical Research Priority Program for Rare DiseasesUniversity of ZurichZurichSwitzerland
| | - Carlo Rivolta
- Department of Computational BiologyUnit of Medical GeneticsUniversity of LausanneLausanneSwitzerland
- Department of Genetics and Genome BiologyUniversity of LeicesterLeicesterUnited Kingdom
| | - Andrea Superti‐Furga
- Division of Genetic MedicineLausanne University Hospital (CHUV)LausanneSwitzerland
| | - Thierry Kuntzer
- Nerve‐Muscle UnitDepartment of Clinical NeurosciencesLausanne University Hospital (CHUV)LausanneSwitzerland
| | - Christopher Francklyn
- Department of BiochemistryLarner College of MedicineUniversity of VermontBurlingtonVermont
| | - Christel Tran
- Division of Genetic MedicineLausanne University Hospital (CHUV)LausanneSwitzerland
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28
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Schaffer AE, Pinkard O, Coller JM. tRNA Metabolism and Neurodevelopmental Disorders. Annu Rev Genomics Hum Genet 2019; 20:359-387. [PMID: 31082281 DOI: 10.1146/annurev-genom-083118-015334] [Citation(s) in RCA: 57] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
tRNAs are short noncoding RNAs required for protein translation. The human genome includes more than 600 putative tRNA genes, many of which are considered redundant. tRNA transcripts are subject to tightly controlled, multistep maturation processes that lead to the removal of flanking sequences and the addition of nontemplated nucleotides. Furthermore, tRNAs are highly structured and posttranscriptionally modified. Together, these unique features have impeded the adoption of modern genomics and transcriptomics technologies for tRNA studies. Nevertheless, it has become apparent from human neurogenetic research that many tRNA biogenesis proteins cause brain abnormalities and other neurological disorders when mutated. The cerebral cortex, cerebellum, and peripheral nervous system show defects, impairment, and degeneration upon tRNA misregulation, suggesting that they are particularly sensitive to changes in tRNA expression or function. An integrated approach to identify tRNA species and contextually characterize tRNA function will be imperative to drive future tool development and novel therapeutic design for tRNA-associated disorders.
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Affiliation(s)
- Ashleigh E Schaffer
- Department of Genetics and Genome Sciences and Center for RNA Science and Therapeutics, Case Western Reserve University, Cleveland, Ohio 44106, USA;
| | - Otis Pinkard
- Department of Genetics and Genome Sciences and Center for RNA Science and Therapeutics, Case Western Reserve University, Cleveland, Ohio 44106, USA;
| | - Jeffery M Coller
- Department of Genetics and Genome Sciences and Center for RNA Science and Therapeutics, Case Western Reserve University, Cleveland, Ohio 44106, USA;
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29
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González-Serrano LE, Chihade JW, Sissler M. When a common biological role does not imply common disease outcomes: Disparate pathology linked to human mitochondrial aminoacyl-tRNA synthetases. J Biol Chem 2019; 294:5309-5320. [PMID: 30647134 PMCID: PMC6462531 DOI: 10.1074/jbc.rev118.002953] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Mitochondrial aminoacyl-tRNA synthetases (mt-aaRSs) are essential components of the mitochondrial translation machinery. The correlation of mitochondrial disorders with mutations in these enzymes has raised the interest of the scientific community over the past several years. Most surprising has been the wide-ranging presentation of clinical manifestations in patients with mt-aaRS mutations, despite the enzymes' common biochemical role. Even among cases where a common physiological system is affected, phenotypes, severity, and age of onset varies depending on which mt-aaRS is mutated. Here, we review work done thus far and propose a categorization of diseases based on tissue specificity that highlights emerging patterns. We further discuss multiple in vitro and in cellulo efforts to characterize the behavior of WT and mutant mt-aaRSs that have shaped hypotheses about the molecular causes of these pathologies. Much remains to do in order to complete our understanding of these proteins. We expect that futher work is likely to result in the discovery of new roles for the mt-aaRSs in addition to their fundamental function in mitochondrial translation, informing the development of treatment strategies and diagnoses.
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Affiliation(s)
- Ligia Elena González-Serrano
- From the Université de Strasbourg, CNRS, Architecture et Réactivité de l'ARN, UPR9002, F-67000 Strasbourg, France and
| | - Joseph W Chihade
- the Department of Chemistry, Carleton College, Northfield, Minnesota 55057
| | - Marie Sissler
- From the Université de Strasbourg, CNRS, Architecture et Réactivité de l'ARN, UPR9002, F-67000 Strasbourg, France and
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30
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Accogli A, Russell L, Sébire G, Rivière JB, St-Onge J, Addour-Boudrahem N, Laporte AD, Rouleau GA, Saint-Martin C, Srour M. Pathogenic variants in AIMP1 cause pontocerebellar hypoplasia. Neurogenetics 2019; 20:103-108. [PMID: 30924036 DOI: 10.1007/s10048-019-00572-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2018] [Accepted: 03/06/2019] [Indexed: 10/27/2022]
Abstract
Aminoacyl-tRNA synthetase-interacting multifunctional protein 1 (AIMP1) is a non-catalytic component of the multi-tRNA synthetase complex which catalyzes the ligation of amino acids to the correct tRNAs. Pathogenic variants in several aminoacyl-tRNA synthetases genes have been linked to various neurological disorders, including leukodystrophies and pontocerebellar hypoplasias (PCH). To date, loss-of-function variants in AIMP1 have been associated with hypomyelinating leukodystrophy-3 (MIM 260600). Here, we report a novel frameshift AIMP1 homozygous variant (c.160delA,p.Lys54Asnfs) in a child with pontocerebellar hypoplasia and simplified gyral pattern, a phenotype not been previously described with AIMP1 variants, thus expanding the phenotypic spectrum. AIMP1 should be included in diagnostic PCH gene panels.
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Affiliation(s)
- Andrea Accogli
- Departments of Pediatrics, Neurology & Neurosurgery, MUHC-Research Institute, McGill University, 1001 Blvd Décarie, Montreal, H4A 3J1, Canada.,IRCCS Istituto Giannina Gaslini, 16147, Genoa, Italy.,DINOGMI-Università degli Studi di Genova, 16126, Genoa, Italy
| | - Laura Russell
- Division of Medical Genetics, Department of Medicine, McGill University, Montreal, Canada
| | - Guillaume Sébire
- Departments of Pediatrics, Neurology & Neurosurgery, MUHC-Research Institute, McGill University, 1001 Blvd Décarie, Montreal, H4A 3J1, Canada
| | | | - Judith St-Onge
- McGill University Health Center (MUHC) Research Institute, Montreal, Canada
| | | | | | - Guy A Rouleau
- Montreal Neurological Institute, McGill University, Montreal, Canada
| | - Christine Saint-Martin
- Department of Radiology, Montreal Children's Hospital, McGill University Health Center, Montreal, Canada
| | - Myriam Srour
- Departments of Pediatrics, Neurology & Neurosurgery, MUHC-Research Institute, McGill University, 1001 Blvd Décarie, Montreal, H4A 3J1, Canada. .,McGill University Health Center (MUHC) Research Institute, Montreal, Canada.
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31
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Maffezzini C, Laine I, Dallabona C, Clemente P, Calvo-Garrido J, Wibom R, Naess K, Barbaro M, Falk A, Donnini C, Freyer C, Wredenberg A, Wedell A. Mutations in the mitochondrial tryptophanyl-tRNA synthetase cause growth retardation and progressive leukoencephalopathy. Mol Genet Genomic Med 2019; 7:e654. [PMID: 30920170 PMCID: PMC6565557 DOI: 10.1002/mgg3.654] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2018] [Revised: 01/23/2019] [Accepted: 03/04/2019] [Indexed: 01/02/2023] Open
Abstract
Background Mutations in mitochondrial aminoacyl tRNA synthetases form a subgroup of mitochondrial disorders often only perturbing brain function by affecting mitochondrial translation. Here we report two siblings with mitochondrial disease, due to compound heterozygous mutations in the mitochondrial tryptophanyl‐tRNA synthetase (WARS2) gene, presenting with severe neurological symptoms but normal mitochondrial function in skeletal muscle biopsies and cultured skin fibroblasts. Methods Whole exome sequencing on genomic DNA samples from both subjects and their parents identified two compound heterozygous variants c.833T>G (p.Val278Gly) and c.938A>T (p.Lys313Met) in the WARS2 gene as potential disease‐causing variants. We generated patient‐derived neuroepithelial stem cells and modeled the disease in yeast and Drosophila melanogaster to confirm pathogenicity. Results Biochemical analysis of patient‐derived neuroepithelial stem cells revealed a mild combined complex I and IV defect, while modeling the disease in yeast demonstrated that the reported aminoacylation defect severely affects respiration and viability. Furthermore, silencing of wild type WARS2 in Drosophila melanogaster showed that a partial defect in aminoacylation is enough to cause lethality. Conclusions Our results establish the identified WARS2 variants as disease‐causing and highlight the benefit of including human neuronal models, when investigating mutations specifically affecting the nervous system.
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Affiliation(s)
- Camilla Maffezzini
- Max Planck Institute Biology of Ageing - Karolinska Institutet Laboratory, Stockholm, Sweden.,Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
| | - Isabelle Laine
- Max Planck Institute Biology of Ageing - Karolinska Institutet Laboratory, Stockholm, Sweden.,Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
| | - Cristina Dallabona
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parma, Italy
| | - Paula Clemente
- Max Planck Institute Biology of Ageing - Karolinska Institutet Laboratory, Stockholm, Sweden.,Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
| | - Javier Calvo-Garrido
- Max Planck Institute Biology of Ageing - Karolinska Institutet Laboratory, Stockholm, Sweden.,Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden
| | - Rolf Wibom
- Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden.,Centre for Inherited Metabolic Diseases, Karolinska University Hospital, Stockholm, Sweden
| | - Karin Naess
- Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden.,Centre for Inherited Metabolic Diseases, Karolinska University Hospital, Stockholm, Sweden
| | - Michela Barbaro
- Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden.,Centre for Inherited Metabolic Diseases, Karolinska University Hospital, Stockholm, Sweden
| | - Anna Falk
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Claudia Donnini
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parma, Italy
| | - Christoph Freyer
- Max Planck Institute Biology of Ageing - Karolinska Institutet Laboratory, Stockholm, Sweden.,Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden.,Centre for Inherited Metabolic Diseases, Karolinska University Hospital, Stockholm, Sweden
| | - Anna Wredenberg
- Max Planck Institute Biology of Ageing - Karolinska Institutet Laboratory, Stockholm, Sweden.,Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden.,Centre for Inherited Metabolic Diseases, Karolinska University Hospital, Stockholm, Sweden
| | - Anna Wedell
- Max Planck Institute Biology of Ageing - Karolinska Institutet Laboratory, Stockholm, Sweden.,Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden.,Centre for Inherited Metabolic Diseases, Karolinska University Hospital, Stockholm, Sweden
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32
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Friedman J, Smith DE, Issa MY, Stanley V, Wang R, Mendes MI, Wright MS, Wigby K, Hildreth A, Crawford JR, Koehler AE, Chowdhury S, Nahas S, Zhai L, Xu Z, Lo WS, James KN, Musaev D, Accogli A, Guerrero K, Tran LT, Omar TEI, Ben-Omran T, Dimmock D, Kingsmore SF, Salomons GS, Zaki MS, Bernard G, Gleeson JG. Biallelic mutations in valyl-tRNA synthetase gene VARS are associated with a progressive neurodevelopmental epileptic encephalopathy. Nat Commun 2019; 10:707. [PMID: 30755602 PMCID: PMC6372641 DOI: 10.1038/s41467-018-07067-3] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2018] [Accepted: 10/03/2018] [Indexed: 12/27/2022] Open
Abstract
Aminoacyl-tRNA synthetases (ARSs) function to transfer amino acids to cognate tRNA molecules, which are required for protein translation. To date, biallelic mutations in 31 ARS genes are known to cause recessive, early-onset severe multi-organ diseases. VARS encodes the only known valine cytoplasmic-localized aminoacyl-tRNA synthetase. Here, we report seven patients from five unrelated families with five different biallelic missense variants in VARS. Subjects present with a range of global developmental delay, epileptic encephalopathy and primary or progressive microcephaly. Longitudinal assessment demonstrates progressive cortical atrophy and white matter volume loss. Variants map to the VARS tRNA binding domain and adjacent to the anticodon domain, and disrupt highly conserved residues. Patient primary cells show intact VARS protein but reduced enzymatic activity, suggesting partial loss of function. The implication of VARS in pediatric neurodegeneration broadens the spectrum of human diseases due to mutations in tRNA synthetase genes.
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Affiliation(s)
- Jennifer Friedman
- Department of Neurosciences, University of California San Diego, La Jolla, CA, 92093, USA
- Division of Child Neurology, Rady Children's Hospital, San Diego, CA, 92123, USA
- Department of Pediatrics, University of California San Diego, La Jolla, CA, 92093, USA
- Rady Children's Institute for Genomic Medicine, Rady Children's Hospital, San Diego, CA, 92123, USA
| | - Desiree E Smith
- Department of Clinical Chemistry, Metabolic Unit, Amsterdam UMC (University Medical Centers), Vrije Universiteit Amsterdam, 1081 HV, Amsterdam, The Netherlands
- Gastroenterology & Metabolism Amsterdam Neuroscience, 1081 HV, Amsterdam, The Netherlands
| | - Mahmoud Y Issa
- Department of Clinical Genetics, National Research Centre, Cairo, 12311, Egypt
| | - Valentina Stanley
- Department of Neurosciences, University of California San Diego, La Jolla, CA, 92093, USA
- Department of Neurosciences, Howard Hughes Medical Institute, University of California, San Diego, La Jolla, CA, 92093, USA
| | - Rengang Wang
- Department of Neurosciences, University of California San Diego, La Jolla, CA, 92093, USA
- Department of Neurosciences, Howard Hughes Medical Institute, University of California, San Diego, La Jolla, CA, 92093, USA
| | - Marisa I Mendes
- Department of Clinical Chemistry, Metabolic Unit, Amsterdam UMC (University Medical Centers), Vrije Universiteit Amsterdam, 1081 HV, Amsterdam, The Netherlands
- Gastroenterology & Metabolism Amsterdam Neuroscience, 1081 HV, Amsterdam, The Netherlands
| | - Meredith S Wright
- Rady Children's Institute for Genomic Medicine, Rady Children's Hospital, San Diego, CA, 92123, USA
| | - Kristen Wigby
- Department of Pediatrics, University of California San Diego, La Jolla, CA, 92093, USA
- Rady Children's Institute for Genomic Medicine, Rady Children's Hospital, San Diego, CA, 92123, USA
| | - Amber Hildreth
- Department of Pediatrics, University of California San Diego, La Jolla, CA, 92093, USA
- Rady Children's Institute for Genomic Medicine, Rady Children's Hospital, San Diego, CA, 92123, USA
| | - John R Crawford
- Department of Neurosciences, University of California San Diego, La Jolla, CA, 92093, USA
- Division of Child Neurology, Rady Children's Hospital, San Diego, CA, 92123, USA
- Department of Pediatrics, University of California San Diego, La Jolla, CA, 92093, USA
| | - Alanna E Koehler
- Department of Neurosciences, Howard Hughes Medical Institute, University of California, San Diego, La Jolla, CA, 92093, USA
| | - Shimul Chowdhury
- Rady Children's Institute for Genomic Medicine, Rady Children's Hospital, San Diego, CA, 92123, USA
| | - Shareef Nahas
- Rady Children's Institute for Genomic Medicine, Rady Children's Hospital, San Diego, CA, 92123, USA
| | - Liting Zhai
- IAS HKUST-Scripps R&D Laboratory, Institute for Advanced Study, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China
| | - Zhiwen Xu
- IAS HKUST-Scripps R&D Laboratory, Institute for Advanced Study, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China
- Pangu Biopharma, Edinburgh Tower, The Landmark, 15 Queen's Road Central, Hong Kong, China
| | - Wing-Sze Lo
- IAS HKUST-Scripps R&D Laboratory, Institute for Advanced Study, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China
- Pangu Biopharma, Edinburgh Tower, The Landmark, 15 Queen's Road Central, Hong Kong, China
| | - Kiely N James
- Department of Neurosciences, University of California San Diego, La Jolla, CA, 92093, USA
- Department of Neurosciences, Howard Hughes Medical Institute, University of California, San Diego, La Jolla, CA, 92093, USA
| | - Damir Musaev
- Department of Neurosciences, University of California San Diego, La Jolla, CA, 92093, USA
- Department of Neurosciences, Howard Hughes Medical Institute, University of California, San Diego, La Jolla, CA, 92093, USA
| | - Andrea Accogli
- Departments of Neurology and Neurosurgery, Pediatrics and Human Genetics, McGill University, Montreal, H3A 0G4, Canada
- IRCCS Istituto Giannina Gaslini, Genova, 16147, Italy
| | - Kether Guerrero
- Departments of Neurology and Neurosurgery, Pediatrics and Human Genetics, McGill University, Montreal, H3A 0G4, Canada
- Division of Medical Genetics, Montreal Children's Hospital, McGill University Health Center, Montreal, H4A 3J1, Canada
- Child Health and Human Development Program, Research Institute of the McGill University Health Center, Montreal, H4A 3J1, Canada
| | - Luan T Tran
- Departments of Neurology and Neurosurgery, Pediatrics and Human Genetics, McGill University, Montreal, H3A 0G4, Canada
- Division of Medical Genetics, Montreal Children's Hospital, McGill University Health Center, Montreal, H4A 3J1, Canada
- Child Health and Human Development Program, Research Institute of the McGill University Health Center, Montreal, H4A 3J1, Canada
| | - Tarek E I Omar
- Department of Pediatrics, Alexandria University, Alexandria, 21526, Egypt
| | - Tawfeg Ben-Omran
- Clinical and Metabolic Genetics, Department of Pediatrics, Hamad Medical Corporation, 3050, Doha, Qatar
| | - David Dimmock
- Rady Children's Institute for Genomic Medicine, Rady Children's Hospital, San Diego, CA, 92123, USA
| | - Stephen F Kingsmore
- Rady Children's Institute for Genomic Medicine, Rady Children's Hospital, San Diego, CA, 92123, USA
| | - Gajja S Salomons
- Department of Clinical Chemistry, Metabolic Unit, Amsterdam UMC (University Medical Centers), Vrije Universiteit Amsterdam, 1081 HV, Amsterdam, The Netherlands
- Gastroenterology & Metabolism Amsterdam Neuroscience, 1081 HV, Amsterdam, The Netherlands
| | - Maha S Zaki
- Department of Clinical Genetics, National Research Centre, Cairo, 12311, Egypt
| | - Geneviève Bernard
- Departments of Neurology and Neurosurgery, Pediatrics and Human Genetics, McGill University, Montreal, H3A 0G4, Canada
- Division of Medical Genetics, Montreal Children's Hospital, McGill University Health Center, Montreal, H4A 3J1, Canada
- Child Health and Human Development Program, Research Institute of the McGill University Health Center, Montreal, H4A 3J1, Canada
| | - Joseph G Gleeson
- Department of Neurosciences, University of California San Diego, La Jolla, CA, 92093, USA.
- Division of Child Neurology, Rady Children's Hospital, San Diego, CA, 92123, USA.
- Department of Pediatrics, University of California San Diego, La Jolla, CA, 92093, USA.
- Rady Children's Institute for Genomic Medicine, Rady Children's Hospital, San Diego, CA, 92123, USA.
- Department of Neurosciences, Howard Hughes Medical Institute, University of California, San Diego, La Jolla, CA, 92093, USA.
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Accogli A, Guerrero K, D'Agostino MD, Tran L, Cieuta-Walti C, Thiffault I, Chénier S, Schwartzentruber J, Majewski J, Bernard G. Biallelic Loss-of-Function Variants in AIMP1 Cause a Rare Neurodegenerative Disease. J Child Neurol 2019; 34:74-80. [PMID: 30486714 DOI: 10.1177/0883073818811223] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
AIMP1/p43, is a noncatalytic component of the mammalian multi-tRNA synthetase complex that catalyzes the ligation of amino acids to their cognate tRNAs. AIMP1 is largely expressed in the central nervous system, where it is part of the regulatory machine of the neurofilament assembly, playing a crucial role in neuronal development and function. To date, nonsense mutations in AIMP1 have been associated with a primary neurodegenerative disorder consisting of cerebral atrophy, hypomyelination, microcephaly and epilepsy, whereas missense mutations have recently been linked to intellectual disability without neurodegeneration. Here, we report the first French-Canadian patient with a novel frameshift AIMP1 homozygous mutation (c.191_192delAA, p.Gln64Argfs*25), resulting in a severe neurodegenerative phenotype. We review and discuss the phenotypic spectrum associated with AIMP1 pathogenic variants.
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Affiliation(s)
- Andrea Accogli
- 1 Departments of Neurology and Neurosurgery, Pediatrics and Human Genetics, McGill University, Montreal, Canada.,2 UOC Neurochirurgia, Istituto Giannina Gaslini, Genova, Italy.,3 Università degli Studi di Genova, Genoa, Italy
| | - Kether Guerrero
- 1 Departments of Neurology and Neurosurgery, Pediatrics and Human Genetics, McGill University, Montreal, Canada.,4 Department of Internal Medicine, Division of Medical Genetics, McGill University Health Center, Montreal, Canada.,5 Child Health and Human Development Program, Research Institute of the McGill University Health Center, Montreal, Canada
| | - Maria Daniela D'Agostino
- 4 Department of Internal Medicine, Division of Medical Genetics, McGill University Health Center, Montreal, Canada.,6 Department of Human Genetics, McGill University, Montreal, Canada
| | - Luan Tran
- 1 Departments of Neurology and Neurosurgery, Pediatrics and Human Genetics, McGill University, Montreal, Canada.,4 Department of Internal Medicine, Division of Medical Genetics, McGill University Health Center, Montreal, Canada.,5 Child Health and Human Development Program, Research Institute of the McGill University Health Center, Montreal, Canada
| | - Cécile Cieuta-Walti
- 7 Service de Neuropédiatre, Université de Sherbrooke, Quebec, Canada.,8 Institut Lejeune, Paris, France
| | - Isabelle Thiffault
- 9 Center for Pediatric Genomic Medicine, Children's Mercy Hospital, Kansas City, MO, USA.,10 University of Missouri-Kansas City School of Medicine, Kansas City, MO, USA
| | - Sébastien Chénier
- 11 Department of Pediatrics, Division of Medical Genetics, Centre Hospitalier Universitaire de Sherbrooke, Université de Sherbrooke, Sherbrooke, Canada
| | | | - Jacek Majewski
- 6 Department of Human Genetics, McGill University, Montreal, Canada
| | | | - Geneviève Bernard
- 1 Departments of Neurology and Neurosurgery, Pediatrics and Human Genetics, McGill University, Montreal, Canada.,4 Department of Internal Medicine, Division of Medical Genetics, McGill University Health Center, Montreal, Canada.,5 Child Health and Human Development Program, Research Institute of the McGill University Health Center, Montreal, Canada
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34
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Liguori M, Nuzziello N, Simone M, Amoroso N, Viterbo RG, Tangaro S, Consiglio A, Giordano P, Bellotti R, Trojano M. Association between miRNAs expression and cognitive performances of Pediatric Multiple Sclerosis patients: A pilot study. Brain Behav 2019; 9:e01199. [PMID: 30656857 PMCID: PMC6379516 DOI: 10.1002/brb3.1199] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/12/2018] [Accepted: 11/28/2018] [Indexed: 12/11/2022] Open
Abstract
INTRODUCTION The Pediatric onset of Multiple Sclerosis (PedMS) occurs in up to 10% of all cases. Cognitive impairment is one of the frequent symptoms, exerting severe impact in patients' quality of life and school performances. The underlying pathogenic mechanisms are not fully understood, and molecular markers predictive of cognitive dysfunctions need to be identified. On these grounds, we searched for molecular signature/s (i.e., miRNAs and target genes) associated with cognitive impairment in a selected population of PedMS patients. Additionally, changes of their regional brain volumes associated with the miRNAs of interest were investigated. METHODS Nineteen PedMS subjects received a full cognitive evaluation; total RNA from peripheral blood samples was processed by next-generation sequencing followed by a bioinformatics/biostatistics analysis. RESULTS The expression of 11 miRNAs significantly correlated with the scores obtained at different cognitive tests; among the others, eight miRNAs correlated with the Trail Making Tests. The computational target prediction identified 337 genes targeted by the miRNAs of interest; a tangled network of molecular connections was hypothesized, where genes like BST1, NTNG2, SPTB, and STAB1, already associated with cognitive dysfunctions, were nodes of the net. Furthermore, the expression of some miRNAs significantly correlated with cerebral volumes, for example, four miRNAs with the cerebellum cortex. CONCLUSIONS As far as we know, this is the first evaluation exploring miRNAs in the cognitive performances of PedMS. Although none of these results survived the multiple tests' corrections, we believe that they may represent a step forward the identification of biomarkers useful for monitoring and targeting the onset/progression of cognitive impairments in MS.
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Affiliation(s)
- Maria Liguori
- National Research CouncilBari UnitInstitute of Biomedical TechnologiesBariItaly
| | - Nicoletta Nuzziello
- National Research CouncilBari UnitInstitute of Biomedical TechnologiesBariItaly
| | - Marta Simone
- Unit for Severe Disabilities in Developmental Age and Young Adults, Developmental Neurology and NeurorehabilitationScientific Institute IRCCS E. MedeaBrindisiItaly
- Department of Basic Sciences, Neurosciences and Sense OrgansUniversity of BariBariItaly
| | - Nicola Amoroso
- Dipartimento Interateneo di Fisica “M. Merlin”Università degli studi di Bari “A. Moro”BariItaly
- Istituto Nazionale di Fisica Nucleare, Sezione di BariBariItaly
| | - Rosa Gemma Viterbo
- Department of Basic Sciences, Neurosciences and Sense OrgansUniversity of BariBariItaly
| | - Sabina Tangaro
- Istituto Nazionale di Fisica Nucleare, Sezione di BariBariItaly
| | - Arianna Consiglio
- National Research CouncilBari UnitInstitute of Biomedical TechnologiesBariItaly
| | - Paola Giordano
- General Paediatric Unit “B. Trambusti”, Azienda Policlinico‐Giovanni XXIIIUniversity of BariBariItaly
| | - Roberto Bellotti
- Dipartimento Interateneo di Fisica “M. Merlin”Università degli studi di Bari “A. Moro”BariItaly
- Istituto Nazionale di Fisica Nucleare, Sezione di BariBariItaly
| | - Maria Trojano
- Department of Basic Sciences, Neurosciences and Sense OrgansUniversity of BariBariItaly
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35
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Sommerville EW, Zhou XL, Oláhová M, Jenkins J, Euro L, Konovalova S, Hilander T, Pyle A, He L, Habeebu S, Saunders C, Kelsey A, Morris AAM, McFarland R, Suomalainen A, Gorman GS, Wang ED, Thiffault I, Tyynismaa H, Taylor RW. Instability of the mitochondrial alanyl-tRNA synthetase underlies fatal infantile-onset cardiomyopathy. Hum Mol Genet 2019; 28:258-268. [PMID: 30285085 PMCID: PMC6321959 DOI: 10.1093/hmg/ddy294] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2018] [Revised: 08/02/2018] [Accepted: 08/07/2018] [Indexed: 11/14/2022] Open
Abstract
Recessively inherited variants in AARS2 (NM_020745.2) encoding mitochondrial alanyl-tRNA synthetase (mt-AlaRS) were first described in patients presenting with fatal infantile cardiomyopathy and multiple oxidative phosphorylation defects. To date, all described patients with AARS2-related fatal infantile cardiomyopathy are united by either a homozygous or compound heterozygous c.1774C>T (p.Arg592Trp) missense founder mutation that is absent in patients with other AARS2-related phenotypes. We describe the clinical, biochemical and molecular investigations of two unrelated boys presenting with fatal infantile cardiomyopathy, lactic acidosis and respiratory failure. Oxidative histochemistry showed cytochrome c oxidase-deficient fibres in skeletal and cardiac muscle. Biochemical studies showed markedly decreased activities of mitochondrial respiratory chain complexes I and IV with a mild decrease of complex III activity in skeletal and cardiac muscle. Using next-generation sequencing, we identified a c.1738C>T (p.Arg580Trp) AARS2 variant shared by both patients that was in trans with a loss-of-function heterozygous AARS2 variant; a c.1008dupT (p.Asp337*) nonsense variant or an intragenic deletion encompassing AARS2 exons 5-7. Interestingly, our patients did not harbour the p.Arg592Trp AARS2 founder mutation. In silico modelling of the p.Arg580Trp substitution suggested a deleterious impact on protein stability and folding. We confirmed markedly decreased mt-AlaRS protein levels in patient fibroblasts, skeletal and cardiac muscle, although mitochondrial protein synthesis defects were confined to skeletal and cardiac muscle. In vitro data showed that the p.Arg580Trp variant had a minimal effect on activation, aminoacylation or misaminoacylation activities relative to wild-type mt-AlaRS, demonstrating that instability of mt-AlaRS is the biological mechanism underlying the fatal cardiomyopathy phenotype in our patients.
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Affiliation(s)
- Ewen W Sommerville
- Wellcome Centre for Mitochondrial Research, Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, UK
| | - Xiao-Long Zhou
- State Key Laboratory of Molecular Biology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai, China
| | - Monika Oláhová
- Wellcome Centre for Mitochondrial Research, Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, UK
| | - Janda Jenkins
- Center for Pediatric Genomic Medicine, Children's Mercy Hospital, Kansas City, MO, USA
| | - Liliya Euro
- Research Programs Unit, Molecular Neurology, University of Helsinki, Helsinki, Finland
| | - Svetlana Konovalova
- Research Programs Unit, Molecular Neurology, University of Helsinki, Helsinki, Finland
| | - Taru Hilander
- Research Programs Unit, Molecular Neurology, University of Helsinki, Helsinki, Finland
| | - Angela Pyle
- Wellcome Centre for Mitochondrial Research, Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, UK
| | - Langping He
- Wellcome Centre for Mitochondrial Research, Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, UK
| | - Sultan Habeebu
- Center for Pediatric Genomic Medicine, Children's Mercy Hospital, Kansas City, MO, USA
| | - Carol Saunders
- Center for Pediatric Genomic Medicine, Children's Mercy Hospital, Kansas City, MO, USA
- Department of Pathology and Laboratory Medicine, Children's Mercy Hospital, Kansas City, MO, USA
- School of Medicine, University of Missouri Kansas City, Kansas City, MO , USA
| | - Anna Kelsey
- Institute of Human Development, University of Manchester, Manchester M13 9PL, UK; Willink Metabolic Unit, Genomic Medicine, Saint Mary’s Hospital, Manchester University Hospitals NHS Foundation Trust, Manchester M13 9WL, UK
| | - Andrew A M Morris
- Institute of Human Development, University of Manchester, Manchester M13 9PL, UK; Willink Metabolic Unit, Genomic Medicine, Saint Mary’s Hospital, Manchester University Hospitals NHS Foundation Trust, Manchester M13 9WL, UK
| | - Robert McFarland
- Wellcome Centre for Mitochondrial Research, Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, UK
| | - Anu Suomalainen
- Research Programs Unit, Molecular Neurology, University of Helsinki, Helsinki, Finland
- Neuroscience Center, Helsinki Institute of Life Sciences, University of Helsinki, Helsinki Finland
- Department of Neurosciences, Helsinki University Hospital, Helsinki, Finland
| | - Gráinne S Gorman
- Wellcome Centre for Mitochondrial Research, Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, UK
| | - En-Duo Wang
- State Key Laboratory of Molecular Biology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai, China
| | - Isabelle Thiffault
- Center for Pediatric Genomic Medicine, Children's Mercy Hospital, Kansas City, MO, USA
- Department of Pathology and Laboratory Medicine, Children's Mercy Hospital, Kansas City, MO, USA
- School of Medicine, University of Missouri Kansas City, Kansas City, MO , USA
| | - Henna Tyynismaa
- Research Programs Unit, Molecular Neurology, University of Helsinki, Helsinki, Finland
| | - Robert W Taylor
- Wellcome Centre for Mitochondrial Research, Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, UK
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36
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McLachlan F, Sires AM, Abbott CM. The role of translation elongation factor eEF1 subunits in neurodevelopmental disorders. Hum Mutat 2018; 40:131-141. [PMID: 30370994 DOI: 10.1002/humu.23677] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2018] [Revised: 10/16/2018] [Accepted: 10/23/2018] [Indexed: 11/06/2022]
Abstract
The multi-subunit eEF1 complex plays a crucial role in de novo protein synthesis. The central functional component of the complex is eEF1A, which occurs as two independently encoded variants with reciprocal expression patterns: whilst eEF1A1 is widely expressed, eEF1A2 is found only in neurons and muscle. Heterozygous mutations in the gene encoding eEF1A2, EEF1A2, have recently been shown to cause epilepsy, autism, and intellectual disability. The remaining subunits of the eEF1 complex, eEF1Bα, eEF1Bδ, eEF1Bγ, and valyl-tRNA synthetase (VARS), together form the GTP exchange factor for eEF1A and are ubiquitously expressed, in keeping with their housekeeping role. However, mutations in the genes encoding these subunits EEF1B2 (eEF1Bα), EEF1D (eEF1Bδ), and VARS (valyl-tRNA synthetase) have also now been identified as causes of neurodevelopmental disorders. In this review, we describe the mutations identified so far in comparison with the degree of normal variation in each gene, and the predicted consequences of the mutations on the functions of the proteins and their isoforms. We discuss the likely effects of the mutations in the context of the role of protein synthesis in neuronal development.
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Affiliation(s)
- Fiona McLachlan
- Centre for Genomic and Experimental Medicine, Institute of Genetics and Molecular Medicine, The University of Edinburgh, Western General Hospital, Crewe Road, Edinburgh, UK
| | - Anna Martinez Sires
- Centre for Genomic and Experimental Medicine, Institute of Genetics and Molecular Medicine, The University of Edinburgh, Western General Hospital, Crewe Road, Edinburgh, UK
| | - Catherine M Abbott
- Centre for Genomic and Experimental Medicine, Institute of Genetics and Molecular Medicine, The University of Edinburgh, Western General Hospital, Crewe Road, Edinburgh, UK
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37
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Shurtleff H, Barry D, Chanprasert S, Firman T, Warner M, Saneto RP. Cognitive characteristics of mitochondrial diseases in children. Epilepsy Behav 2018; 88:235-243. [PMID: 30316150 DOI: 10.1016/j.yebeh.2018.09.013] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/13/2018] [Revised: 09/12/2018] [Accepted: 09/12/2018] [Indexed: 01/28/2023]
Abstract
INTRODUCTION This retrospective descriptive study was undertaken to further define the intelligence profiles of children with mitochondrial disorders, in the context of seizures and age of symptom onset. METHODS We retrospectively identified forty-nine pediatric patients with definitive mitochondrial disease diagnoses and complete intelligence or adaptive functioning testing data. Patients were 0-216 months at onset of symptoms and 61-250 months of age at testing. Twenty-four of 49 patients had seizures. Twenty-one of the 24 patients with seizures had medically intractable seizures. All patients had Wechsler Intellectual Quotient (IQ) testing, except nine patients with seizures who were unable to engage in IQ testing and were assessed with a structured parent interview measure, the Vineland Adaptive Behavior Scales. We used descriptive and exploratory data analysis methods to characterize test results. RESULTS Distribution of ages for patients with the Vineland assessment was younger than those given the Wechsler. The median overall score (combining Wechsler and Vineland summary scores) for all patients was 85 (interquartile range [IQR]: 50, 102), with the group without seizures obtaining a higher median Full Scale IQ (FSIQ) of 100 (IQR: 86, 109), compared to the group with seizures with a median FSIQ of 67 (IQR: 49.5, 89), a difference that is both statistically and clinically different (Δ = 33; 95% CI: 9, 52). The adaptive function measure was composed of patients only with intractable epilepsy and yielded the lowest overall median summary score of 43 (IQR: 37, 50). This general trend in differences between the FSIQ scores of the groups with and without seizures was also seen across all subscale measures analyzed-IQ index scores and two subtest scores, Digit Span and Coding-though differences were not always statistically different. Vargha-Delaney's A effect sizes ranged between 0.68 and 0.90, trends that mirrored those of distributional and median differences. Groups without versus with seizures differed most distinctly in Performance IQ (PIQ), with the group without seizures' median PIQ being 100 (IQR 94, 112) versus the group with seizures' median PIQ being 63 (IQR 54, 84), a difference of 37 points (95% CI). DISCUSSION Results suggest that patients with mitochondrial diseases with seizures and early onset disease represent a worse cognitive phenotype, as compared with those with no seizures, who can have average intelligence. Results are discussed in the context of current literature.
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Affiliation(s)
- Hillary Shurtleff
- Department of Neurology, University of Washington, Seattle, WA, USA; Seattle Children's Hospital, Seattle, WA, USA
| | - Dwight Barry
- Seattle Children's Hospital, Seattle, WA, USA; Enterprise Analytics, Seattle Children's Hospital, Seattle, WA, USA
| | - Sirisak Chanprasert
- Division of Medical Genetics, Department of Medicine, University of Washington, Seattle, WA, USA
| | - Tim Firman
- Seattle Children's Hospital, Seattle, WA, USA
| | - Molly Warner
- Department of Neurology, University of Washington, Seattle, WA, USA; Seattle Children's Hospital, Seattle, WA, USA
| | - Russell P Saneto
- Department of Neurology, University of Washington, Seattle, WA, USA; Seattle Children's Hospital, Seattle, WA, USA; Division of Pediatric Neurology, Seattle Children's Hospital, Seattle, WA, USA; Center for Integrative Brain Research, Neuroscience Institute, Seattle Children's Hospital, Seattle, WA, USA.
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38
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Sahai SK, Steiner RE, Au MG, Graham JM, Salamon N, Ibba M, Pierson TM. FARS2 mutations presenting with pure spastic paraplegia and lesions of the dentate nuclei. Ann Clin Transl Neurol 2018; 5:1128-1133. [PMID: 30250868 PMCID: PMC6144452 DOI: 10.1002/acn3.598] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2018] [Revised: 05/26/2018] [Accepted: 05/29/2018] [Indexed: 01/14/2023] Open
Abstract
Mutations in FARS2, the gene encoding the mitochondrial phenylalanine‐tRNA synthetase (mtPheRS), have been linked to a range of phenotypes including epileptic encephalopathy, developmental delay, and motor dysfunction. We report a 9‐year‐old boy with novel compound heterozygous variants of FARS2, presenting with a pure spastic paraplegia syndrome associated with bilateral signal abnormalities in the dentate nuclei. Exome sequencing identified a paternal nonsense variant (Q216X) lacking the catalytic core and anticodon‐binding regions, and a maternal missense variant (P136H) possessing partial enzymatic activity. This case confirms and expands the phenotype related to FARS2 mutations with regards to clinical presentation and neuroimaging findings.
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Affiliation(s)
- Supreet K Sahai
- Department of Neurology Cedars-Sinai Medical Center Los Angeles California
| | - Rebecca E Steiner
- Department of Microbiology Ohio State University Columbus Ohio 43210.,Center for RNA Biology Ohio State University Columbus Ohio 43210.,Ohio State Biochemistry Program Ohio State University Columbus Ohio 43210
| | - Margaret G Au
- Department of Pediatrics Cedars-Sinai Medical Center Los Angeles California
| | - John M Graham
- Department of Pediatrics Cedars-Sinai Medical Center Los Angeles California
| | - Noriko Salamon
- Department of Radiological Sciences David Geffen School of Medicine University of California Los Angeles Los Angeles California
| | - Michael Ibba
- Department of Microbiology Ohio State University Columbus Ohio 43210.,Center for RNA Biology Ohio State University Columbus Ohio 43210.,Ohio State Biochemistry Program Ohio State University Columbus Ohio 43210
| | - Tyler M Pierson
- Department of Neurology Cedars-Sinai Medical Center Los Angeles California.,Department of Pediatrics Cedars-Sinai Medical Center Los Angeles California.,Board of Governors Regenerative Medicine Institute Cedars-Sinai Medical Center Los Angeles California
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39
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Mitochondrial DNA transcription and translation: clinical syndromes. Essays Biochem 2018; 62:321-340. [PMID: 29980628 PMCID: PMC6056718 DOI: 10.1042/ebc20170103] [Citation(s) in RCA: 61] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2018] [Revised: 05/17/2018] [Accepted: 05/21/2018] [Indexed: 01/15/2023]
Abstract
Diagnosing primary mitochondrial diseases is challenging in clinical practice. Although, defective oxidative phosphorylation (OXPHOS) is the common final pathway, it is unknown why different mtDNA or nuclear mutations result in largely heterogeneous and often tissue -specific clinical presentations. Mitochondrial tRNA (mt-tRNA) mutations are frequent causes of mitochondrial diseases both in children and adults. However numerous nuclear mutations involved in mitochondrial protein synthesis affecting ubiquitously expressed genes have been reported in association with very tissue specific clinical manifestations suggesting that there are so far unknown factors determining the tissue specificity in mitochondrial translation. Most of these gene defects result in histological abnormalities and multiple respiratory chain defects in the affected organs. The clinical phenotypes are usually early-onset, severe, and often fatal, implying the importance of mitochondrial translation from birth. However, some rare, reversible infantile mitochondrial diseases are caused by very specific defects of mitochondrial translation. An unbiased genetic approach (whole exome sequencing, RNA sequencing) combined with proteomics and functional studies revealed novel factors involved in mitochondrial translation which contribute to the clinical manifestation and recovery in these rare reversible mitochondrial conditions.
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40
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Fuchs SA, Schene IF, Kok G, Jansen JM, Nikkels PGJ, van Gassen KLI, Terheggen-Lagro SWJ, van der Crabben SN, Hoeks SE, Niers LEM, Wolf NI, de Vries MC, Koolen DA, Houwen RHJ, Mulder MF, van Hasselt PM. Aminoacyl-tRNA synthetase deficiencies in search of common themes. Genet Med 2018; 21:319-330. [PMID: 29875423 PMCID: PMC7091658 DOI: 10.1038/s41436-018-0048-y] [Citation(s) in RCA: 67] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2017] [Accepted: 04/10/2018] [Indexed: 12/22/2022] Open
Abstract
Purpose Pathogenic variations in genes encoding aminoacyl-tRNA synthetases (ARSs) are increasingly associated with human disease. Clinical features of autosomal recessive ARS deficiencies appear very diverse and without apparent logic. We searched for common clinical patterns to improve disease recognition, insight into pathophysiology, and clinical care. Methods Symptoms were analyzed in all patients with recessive ARS deficiencies reported in literature, supplemented with unreported patients evaluated in our hospital. Results In literature, we identified 107 patients with AARS, DARS, GARS, HARS, IARS, KARS, LARS, MARS, RARS, SARS, VARS, YARS, and QARS deficiencies. Common symptoms (defined as present in ≥4/13 ARS deficiencies) included abnormalities of the central nervous system and/or senses (13/13), failure to thrive, gastrointestinal symptoms, dysmaturity, liver disease, and facial dysmorphisms. Deep phenotyping of 5 additional patients with unreported compound heterozygous pathogenic variations in IARS, LARS, KARS, and QARS extended the common phenotype with lung disease, hypoalbuminemia, anemia, and renal tubulopathy. Conclusion We propose a common clinical phenotype for recessive ARS deficiencies, resulting from insufficient aminoacylation activity to meet translational demand in specific organs or periods of life. Assuming residual ARS activity, adequate protein/amino acid supply seems essential instead of the traditional replacement of protein by glucose in patients with metabolic diseases.
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Affiliation(s)
- Sabine A Fuchs
- Department of Metabolic Diseases, Wilhelmina Children's Hospital, University Medical Center Utrecht, Lundlaan 6, Utrecht, 3584 EA, The Netherlands.
| | - Imre F Schene
- Department of Metabolic Diseases, Wilhelmina Children's Hospital, University Medical Center Utrecht, Lundlaan 6, Utrecht, 3584 EA, The Netherlands
| | - Gautam Kok
- Department of Metabolic Diseases, Wilhelmina Children's Hospital, University Medical Center Utrecht, Lundlaan 6, Utrecht, 3584 EA, The Netherlands
| | - Jurriaan M Jansen
- Department of Metabolic Diseases, Wilhelmina Children's Hospital, University Medical Center Utrecht, Lundlaan 6, Utrecht, 3584 EA, The Netherlands
| | - Peter G J Nikkels
- Department of Pathology, University Medical Center Utrecht, Lundlaan 6, Utrecht, 3584 EA, The Netherlands
| | - Koen L I van Gassen
- Department of Genetics, University Medical Centre Utrecht, Lundlaan 6, Utrecht, 3584 EA, The Netherlands
| | - Suzanne W J Terheggen-Lagro
- Department of Pediatric Pulmonology, Academic Medical Center Amsterdam, Meibergdreef 9, Amsterdam, 1105 AZ, The Netherlands
| | - Saskia N van der Crabben
- Department of Clinical Genetics, VU University Medical Center, De Boelelaan 1117, Amsterdam, 1081HV, The Netherlands
| | - Sanne E Hoeks
- Department of Neonatology, University Medical Center Utrecht, Lundlaan 6, Utrecht, 3584 EA, The Netherlands
| | - Laetitia E M Niers
- Department of Pediatrics, Maxima Medical Centre Veldhoven, De Run 4600, Veldhoven, 5504 DB, The Netherlands
| | - Nicole I Wolf
- Department of Child Neurology, VU University Medical Center, De Boelelaan 1117, Amsterdam, 1081HV, The Netherlands
| | - Maaike C de Vries
- Nijmegen Centre for Mitochondrial Disorders at Department of Pediatrics, Radboud University Nijmegen Centre, Nijmegen, The Netherlands
| | - David A Koolen
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, 6500 HB, The Netherlands
| | - Roderick H J Houwen
- Division of Pediatric Gastroenterology, Wilhelmina Children's Hospital, University Medical Center Utrecht, Lundlaan 6, Utrecht, 3584 EA, The Netherlands
| | - Margot F Mulder
- Department of Pediatrics, VU University Medical Center, De Boelelaan 1117, Amsterdam, 1081HV, The Netherlands
| | - Peter M van Hasselt
- Department of Metabolic Diseases, Wilhelmina Children's Hospital, University Medical Center Utrecht, Lundlaan 6, Utrecht, 3584 EA, The Netherlands
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41
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Vantroys E, Smet J, Vanlander AV, Vergult S, De Bruyne R, Roels F, Stepman H, Roeyers H, Menten B, Van Coster R. Severe hepatopathy and neurological deterioration after start of valproate treatment in a 6-year-old child with mitochondrial tryptophanyl-tRNA synthetase deficiency. Orphanet J Rare Dis 2018; 13:80. [PMID: 29783990 PMCID: PMC5963168 DOI: 10.1186/s13023-018-0822-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2018] [Accepted: 05/08/2018] [Indexed: 01/08/2023] Open
Abstract
Background The first subjects with deficiency of mitochondrial tryptophanyl-tRNA synthetase (WARS2) were reported in 2017. Their clinical characteristics can be subdivided into three phenotypes (neonatal phenotype, severe infantile onset phenotype, Parkinson-like phenotype). Results Here, we report on a subject who presented with early developmental delay, motor weakness and intellectual disability and who was considered during several years as having a non-progressive encephalopathy. At the age of six years, she had an epileptic seizure which was treated with sodium valproate. In the months after treatment was started, she developed acute liver failure and severe progressive encephalopathy. Although valproate was discontinued, she died six months later. Spectrophotometric analysis of the oxidative phosphorylation complexes in liver revealed a deficient activity of complex III and low normal activities of the complexes I and IV. Activity staining in the BN-PAGE gel confirmed the low activities of complex I, III and IV and, in addition, showed the presence of a subcomplex of complex V. Histochemically, a mosaic pattern was seen in hepatocytes after cytochrome c oxidase staining. Using Whole Exome Sequencing two known pathogenic variants were detected in WARS2 (c.797delC, p.Pro266ArgfsTer10/ c.938 A > T, p.Lys313Met). Conclusion This is the first report of severe hepatopathy in a subject with WARS2 deficiency. The hepatopathy occurred soon after start of sodium valproate treatment. In the literature, valproate-induced hepatotoxicity was reported in the subjects with pathogenic mutations in POLG and TWNK. This case report illustrates that the course of the disease in the subjects with a mitochondrial defect can be non-progressive during several years. The subject reported here was first diagnosed as having cerebral palsy. Only after a mitochondriotoxic medication was started, the disease became progressive, and the diagnosis of a mitochondrial defect was made.
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Affiliation(s)
- Elise Vantroys
- Department of Pediatric Neurology and Metabolism, Ghent University Hospital, Ghent, Belgium
| | - Joél Smet
- Department of Pediatric Neurology and Metabolism, Ghent University Hospital, Ghent, Belgium
| | - Arnaud V Vanlander
- Department of Pediatric Neurology and Metabolism, Ghent University Hospital, Ghent, Belgium
| | - Sarah Vergult
- Center for Medical Genetics Ghent, Ghent University, Ghent, Belgium
| | - Ruth De Bruyne
- Department of Pediatric Gastroenterology, Hepatology and Nutrition, Ghent University Hospital, Ghent, Belgium
| | - Frank Roels
- Department of Pathology, Ghent University Hospital, Ghent, Belgium
| | - Hedwig Stepman
- Department of Laboratory Medicine, Ghent University Hospital, Ghent, Belgium
| | - Herbert Roeyers
- Department of Experimental Clinical and Health Psychology, Ghent University, Ghent, Belgium
| | - Björn Menten
- Center for Medical Genetics Ghent, Ghent University, Ghent, Belgium
| | - Rudy Van Coster
- Department of Pediatric Neurology and Metabolism, Ghent University Hospital, Ghent, Belgium.
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Stephen J, Nampoothiri S, Banerjee A, Tolman NJ, Penninger JM, Elling U, Agu CA, Burke JD, Devadathan K, Kannan R, Huang Y, Steinbach PJ, Martinis SA, Gahl WA, Malicdan MCV. Loss of function mutations in VARS encoding cytoplasmic valyl-tRNA synthetase cause microcephaly, seizures, and progressive cerebral atrophy. Hum Genet 2018; 137:293-303. [PMID: 29691655 DOI: 10.1007/s00439-018-1882-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2018] [Accepted: 04/12/2018] [Indexed: 12/23/2022]
Abstract
Progressive microcephaly and neurodegeneration are genetically heterogenous conditions, largely associated with genes that are essential for the survival of neurons. In this study, we interrogate the genetic etiology of two siblings from a non-consanguineous family with severe early onset of neurological manifestations. Whole exome sequencing identified novel compound heterozygous mutations in VARS that segregated with the proband: a missense (c.3192G>A; p.Met1064Ile) and a splice site mutation (c.1577-2A>G). The VARS gene encodes cytoplasmic valyl-tRNA synthetase (ValRS), an enzyme that is essential during eukaryotic translation. cDNA analysis on patient derived fibroblasts revealed that the splice site acceptor variant allele led to nonsense mediated decay, thus resulting in a null allele. Three-dimensional modeling of ValRS predicts that the missense mutation lies in a highly conserved region and could alter side chain packing, thus affecting tRNA binding or destabilizing the interface between the catalytic and tRNA binding domains. Further quantitation of the expression of VARS showed remarkably reduced levels of mRNA and protein in skin derived fibroblasts. Aminoacylation experiments on patient derived cells showed markedly reduced enzyme activity of ValRS suggesting the mutations to be loss of function. Bi-allelic mutations in cytoplasmic amino acyl tRNA synthetases are well-known for their role in neurodegenerative disorders, yet human disorders associated with VARS mutations have not yet been clinically well characterized. Our study describes the phenotype associated with recessive VARS mutations and further functional delineation of the pathogenicity of novel variants identified, which widens the clinical and genetic spectrum of patients with progressive microcephaly.
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Affiliation(s)
- Joshi Stephen
- Section of Human Biochemical Genetics, Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA
| | - Sheela Nampoothiri
- Department of Pediatric Genetics, Amrita Institute of Medical Sciences and Research Center, Cochin, Kerala, India
| | - Aditi Banerjee
- Department of Biochemistry, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Nathanial J Tolman
- Office of the Clinical Director, National Human Genome Research Institute (NHGRI), National Institutes of Health, Bethesda, MD, USA
| | - Josef Martin Penninger
- Institute of Molecular Biotechnology of the Austrian Academy of Science (IMBA), Vienna Biocenter (VBC), Dr. Bohr Gasse 3, Vienna, Austria
| | - Ullrich Elling
- Institute of Molecular Biotechnology of the Austrian Academy of Science (IMBA), Vienna Biocenter (VBC), Dr. Bohr Gasse 3, Vienna, Austria
| | - Chukwuma A Agu
- Institute of Molecular Biotechnology of the Austrian Academy of Science (IMBA), Vienna Biocenter (VBC), Dr. Bohr Gasse 3, Vienna, Austria
| | - John D Burke
- Section of Human Biochemical Genetics, Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA
| | - Kalpana Devadathan
- Department of Pediatric Neurology, KIMS Hospital, Thiruvananthapuram, Kerala, India
| | - Rajesh Kannan
- Department of Radiology, Amrita Institute of Medical Sciences and Research Center, Cochin, Kerala, India
| | - Yan Huang
- NIH Undiagnosed Diseases Program, National Human Genome Research Institute (NHGRI) and the Common Fund, National Institutes of Health, Bethesda, MD, USA
| | - Peter J Steinbach
- Center for Molecular Modeling, Center for Information Technology, National Institutes of Health, Bethesda, MD, USA
| | - Susan A Martinis
- Department of Biochemistry, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - William A Gahl
- Section of Human Biochemical Genetics, Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA.,Office of the Clinical Director, National Human Genome Research Institute (NHGRI), National Institutes of Health, Bethesda, MD, USA.,NIH Undiagnosed Diseases Program, National Human Genome Research Institute (NHGRI) and the Common Fund, National Institutes of Health, Bethesda, MD, USA
| | - May Christine V Malicdan
- Section of Human Biochemical Genetics, Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA. .,Office of the Clinical Director, National Human Genome Research Institute (NHGRI), National Institutes of Health, Bethesda, MD, USA. .,NIH Undiagnosed Diseases Program, National Human Genome Research Institute (NHGRI) and the Common Fund, National Institutes of Health, Bethesda, MD, USA.
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43
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Paley EL, Perry G. Towards an Integrative Understanding of tRNA Aminoacylation-Diet-Host-Gut Microbiome Interactions in Neurodegeneration. Nutrients 2018; 10:nu10040410. [PMID: 29587458 PMCID: PMC5946195 DOI: 10.3390/nu10040410] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2018] [Revised: 03/19/2018] [Accepted: 03/22/2018] [Indexed: 02/07/2023] Open
Abstract
Transgenic mice used for Alzheimer’s disease (AD) preclinical experiments do not recapitulate the human disease. In our models, the dietary tryptophan metabolite tryptamine produced by human gut microbiome induces tryptophanyl-tRNA synthetase (TrpRS) deficiency with consequent neurodegeneration in cells and mice. Dietary supplements, antibiotics and certain drugs increase tryptamine content in vivo. TrpRS catalyzes tryptophan attachment to tRNAtrp at initial step of protein biosynthesis. Tryptamine that easily crosses the blood–brain barrier induces vasculopathies, neurodegeneration and cell death via TrpRS competitive inhibition. TrpRS inhibitor tryptophanol produced by gut microbiome also induces neurodegeneration. TrpRS inhibition by tryptamine and its metabolites preventing tryptophan incorporation into proteins lead to protein biosynthesis impairment. Tryptophan, a least amino acid in food and proteins that cannot be synthesized by humans competes with frequent amino acids for the transport from blood to brain. Tryptophan is a vulnerable amino acid, which can be easily lost to protein biosynthesis. Some proteins marking neurodegenerative pathology, such as tau lack tryptophan. TrpRS exists in cytoplasmic (WARS) and mitochondrial (WARS2) forms. Pathogenic gene variants of both forms cause TrpRS deficiency with consequent intellectual and motor disabilities in humans. The diminished tryptophan-dependent protein biosynthesis in AD patients is a proof of our model-based disease concept.
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Affiliation(s)
- Elena L Paley
- Expert Biomed, Inc., 11933 SW 271st TER Homestead, Miami Dade, FL 33032-3305, USA.
- Stop Alzheimers Corp., Miami Dade, FL 33032, USA.
- Nova Southeastern University, 3301 College Ave, Fort Lauderdale, FL 33314, USA.
| | - George Perry
- Stop Alzheimers Corp., Miami Dade, FL 33032, USA.
- University of Texas at San Antonio, 1 UTSA Circle, San Antonio, TX 78249, USA.
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44
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Burke EA, Frucht SJ, Thompson K, Wolfe LA, Yokoyama T, Bertoni M, Huang Y, Sincan M, Adams DR, Taylor RW, Gahl WA, Toro C, Malicdan MCV. Biallelic mutations in mitochondrial tryptophanyl-tRNA synthetase cause Levodopa-responsive infantile-onset Parkinsonism. Clin Genet 2018; 93:712-718. [PMID: 29120065 PMCID: PMC5828974 DOI: 10.1111/cge.13172] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2017] [Revised: 10/30/2017] [Accepted: 11/05/2017] [Indexed: 12/30/2022]
Abstract
Mitochondrial aminoacyl‐tRNA synthetases (mtARSs) are essential, ubiquitously expressed enzymes that covalently attach amino acids to their corresponding tRNA molecules during translation of mitochondrial genes. Deleterious variants in the mtARS genes cause a diverse array of phenotypes, many of which involve the nervous system. Moreover, distinct mutations in mtARSs often cause different clinical manifestations. Recently, the gene encoding mitochondrial tryptophanyl tRNA synthetase (WARS2) was reported to cause 2 different neurological phenotypes, a form of autosomal recessive intellectual disability and a syndrome of severe infantile‐onset leukoencephalopathy. Here, we report the case of a 17‐year‐old boy with compound heterozygous mutations in WARS2 (p.Trp13Gly, p.Ser228Trp) who presented with infantile‐onset, Levodopa‐responsive Parkinsonism at the age of 2 years. Analysis of patient‐derived dermal fibroblasts revealed decreased steady‐state WARS2 protein and normal OXPHOS content. Muscle mitochondrial studies suggested mitochondrial proliferation without obvious respiratory chain deficiencies at the age of 9 years. This case expands the phenotypic spectrum of WARS2 deficiency and emphasizes the importance of mitochondrial protein synthesis in the pathogenesis of Parkinsonism.
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Affiliation(s)
- E A Burke
- NIH Undiagnosed Diseases Program, Common Fund, Office of the Director, NHGRI, NIH, Bethesda, Maryland
| | - S J Frucht
- Movement Disorders Division, School of Medicine, New York University Langone, New York, New York
| | - K Thompson
- Wellcome Centre for Mitochondrial Research, Institute of Neuroscience, The Medical School, Newcastle University, Newcastle upon Tyne, UK
| | - L A Wolfe
- NIH Undiagnosed Diseases Program, Common Fund, Office of the Director, NHGRI, NIH, Bethesda, Maryland.,Office of the Clinical Director, NHGRI, NIH, Bethesda, Maryland
| | - T Yokoyama
- Section of Human Biochemical Genetics, Medical Genetics Branch, NHGRI, NIH, Bethesda, Maryland
| | - M Bertoni
- NIH Undiagnosed Diseases Program, Common Fund, Office of the Director, NHGRI, NIH, Bethesda, Maryland
| | - Y Huang
- Office of the Clinical Director, NHGRI, NIH, Bethesda, Maryland
| | - M Sincan
- NIH Undiagnosed Diseases Program, Common Fund, Office of the Director, NHGRI, NIH, Bethesda, Maryland
| | - D R Adams
- NIH Undiagnosed Diseases Program, Common Fund, Office of the Director, NHGRI, NIH, Bethesda, Maryland.,Office of the Clinical Director, NHGRI, NIH, Bethesda, Maryland
| | - R W Taylor
- Wellcome Centre for Mitochondrial Research, Institute of Neuroscience, The Medical School, Newcastle University, Newcastle upon Tyne, UK
| | - W A Gahl
- NIH Undiagnosed Diseases Program, Common Fund, Office of the Director, NHGRI, NIH, Bethesda, Maryland.,Office of the Clinical Director, NHGRI, NIH, Bethesda, Maryland.,Section of Human Biochemical Genetics, Medical Genetics Branch, NHGRI, NIH, Bethesda, Maryland
| | - C Toro
- NIH Undiagnosed Diseases Program, Common Fund, Office of the Director, NHGRI, NIH, Bethesda, Maryland.,Office of the Clinical Director, NHGRI, NIH, Bethesda, Maryland
| | - M C V Malicdan
- NIH Undiagnosed Diseases Program, Common Fund, Office of the Director, NHGRI, NIH, Bethesda, Maryland.,Office of the Clinical Director, NHGRI, NIH, Bethesda, Maryland
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45
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Boczonadi V, Jennings MJ, Horvath R. The role of tRNA synthetases in neurological and neuromuscular disorders. FEBS Lett 2018; 592:703-717. [PMID: 29288497 PMCID: PMC5873386 DOI: 10.1002/1873-3468.12962] [Citation(s) in RCA: 61] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2017] [Revised: 12/06/2017] [Accepted: 12/21/2017] [Indexed: 12/11/2022]
Abstract
Aminoacyl‐tRNA synthetases (ARSs) are ubiquitously expressed enzymes responsible for charging tRNAs with their cognate amino acids, therefore essential for the first step in protein synthesis. Although the majority of protein synthesis happens in the cytosol, an additional translation apparatus is required to translate the 13 mitochondrial DNA‐encoded proteins important for oxidative phosphorylation. Most ARS genes in these cellular compartments are distinct, but two genes are common, encoding aminoacyl‐tRNA synthetases of glycine (GARS) and lysine (KARS) in both mitochondria and the cytosol. Mutations in the majority of the 37 nuclear‐encoded human ARS genes have been linked to a variety of recessive and dominant tissue‐specific disorders. Current data indicate that impaired enzyme function could explain the pathogenicity, however not all pathogenic ARSs mutations result in deficient catalytic function; thus, the consequences of mutations may arise from other molecular mechanisms. The peripheral nerves are frequently affected, as illustrated by the high number of mutations in cytosolic and bifunctional tRNA synthetases causing Charcot–Marie–Tooth disease (CMT). Here we provide insights on the pathomechanisms of CMT‐causing tRNA synthetases with specific focus on the two bifunctional tRNA synthetases (GARS, KARS).
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Affiliation(s)
- Veronika Boczonadi
- Wellcome Centre for Mitochondrial Research, Institute of Genetic Medicine, Newcastle University, Newcastle upon Tyne, UK
| | - Matthew J Jennings
- Wellcome Centre for Mitochondrial Research, Institute of Genetic Medicine, Newcastle University, Newcastle upon Tyne, UK
| | - Rita Horvath
- Wellcome Centre for Mitochondrial Research, Institute of Genetic Medicine, Newcastle University, Newcastle upon Tyne, UK
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46
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Frazier AE, Thorburn DR, Compton AG. Mitochondrial energy generation disorders: genes, mechanisms, and clues to pathology. J Biol Chem 2017; 294:5386-5395. [PMID: 29233888 DOI: 10.1074/jbc.r117.809194] [Citation(s) in RCA: 150] [Impact Index Per Article: 21.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Inherited disorders of oxidative phosphorylation cause the clinically and genetically heterogeneous diseases known as mitochondrial energy generation disorders, or mitochondrial diseases. Over the last three decades, mutations causing these disorders have been identified in almost 290 genes, but many patients still remain without a molecular diagnosis. Moreover, while our knowledge of the genetic causes is continually expanding, our understanding into how these defects lead to cellular dysfunction and organ pathology is still incomplete. Here, we review recent developments in disease gene discovery, functional characterization, and shared pathogenic parameters influencing disease pathology that offer promising avenues toward the development of effective therapies.
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Affiliation(s)
- Ann E Frazier
- From the Murdoch Children's Research Institute, Royal Children's Hospital and Department of Paediatrics, University of Melbourne, and
| | - David R Thorburn
- From the Murdoch Children's Research Institute, Royal Children's Hospital and Department of Paediatrics, University of Melbourne, and.,Victorian Clinical Genetic Services, Royal Children's Hospital, Melbourne, Victoria 3052, Australia
| | - Alison G Compton
- From the Murdoch Children's Research Institute, Royal Children's Hospital and Department of Paediatrics, University of Melbourne, and
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47
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Glasgow RIC, Thompson K, Barbosa IA, He L, Alston CL, Deshpande C, Simpson MA, Morris AAM, Neu A, Löbel U, Hall J, Prokisch H, Haack TB, Hempel M, McFarland R, Taylor RW. Novel GFM2 variants associated with early-onset neurological presentations of mitochondrial disease and impaired expression of OXPHOS subunits. Neurogenetics 2017; 18:227-235. [PMID: 29075935 PMCID: PMC5705740 DOI: 10.1007/s10048-017-0526-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2017] [Accepted: 10/03/2017] [Indexed: 11/29/2022]
Abstract
Mitochondrial diseases are characterised by clinical, molecular and functional heterogeneity, reflecting their bi-genomic control. The nuclear gene GFM2 encodes mtEFG2, a protein with an essential role during the termination stage of mitochondrial translation. We present here two unrelated patients harbouring different and previously unreported compound heterozygous (c.569G>A, p.(Arg190Gln); c.636delA, p.(Glu213Argfs*3)) and homozygous (c.275A>C, p.(Tyr92Ser)) recessive variants in GFM2 identified by whole exome sequencing (WES) together with histochemical and biochemical findings to support the diagnoses of pathological GFM2 variants in each case. Both patients presented similarly in early childhood with global developmental delay, raised CSF lactate and abnormalities on cranial MRI. Sanger sequencing of familial samples confirmed the segregation of bi-allelic GFM2 variants with disease, while investigations into steady-state mitochondrial protein levels revealed respiratory chain subunit defects and loss of mtEFG2 protein in muscle. These data demonstrate the effects of defective mtEFG2 function, caused by previously unreported variants, confirming pathogenicity and expanding the clinical phenotypes associated with GFM2 variants.
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Affiliation(s)
- Ruth I C Glasgow
- Wellcome Centre for Mitochondrial Research, Institute of Neuroscience, The Medical School, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK
| | - Kyle Thompson
- Wellcome Centre for Mitochondrial Research, Institute of Neuroscience, The Medical School, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK
| | - Inês A Barbosa
- Department of Medical and Molecular Genetics, King's College London School of Medicine, London, UK
| | - Langping He
- Wellcome Centre for Mitochondrial Research, Institute of Neuroscience, The Medical School, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK
| | - Charlotte L Alston
- Wellcome Centre for Mitochondrial Research, Institute of Neuroscience, The Medical School, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK
| | - Charu Deshpande
- Department of Medical and Molecular Genetics, King's College London School of Medicine, London, UK
| | - Michael A Simpson
- Department of Medical and Molecular Genetics, King's College London School of Medicine, London, UK
| | - Andrew A M Morris
- Division of Evolution and Genomic Sciences, School of Biological Sciences, University of Manchester, Manchester, UK
- Alder Hey Children's Hospital NHS Foundation Trust, Liverpool, UK
| | - Axel Neu
- University Children's Hospital, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Ulrike Löbel
- Department of Diagnostic and Interventional Neuroradiology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Julie Hall
- Department of Neuroradiology, Royal Victoria Infirmary, Newcastle upon Tyne, UK
| | - Holger Prokisch
- Institute of Human Genetics, Helmholtz Zentrum München, Oberschleißheim, Germany
- Institute of Human Genetics, Technische Universität München, Munich, Germany
| | - Tobias B Haack
- Institute of Human Genetics, Technische Universität München, Munich, Germany
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Tübingen, Germany
| | - Maja Hempel
- Institute of Human Genetics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Robert McFarland
- Wellcome Centre for Mitochondrial Research, Institute of Neuroscience, The Medical School, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK
| | - Robert W Taylor
- Wellcome Centre for Mitochondrial Research, Institute of Neuroscience, The Medical School, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK.
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48
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Vantroys E, Larson A, Friederich M, Knight K, Swanson MA, Powell CA, Smet J, Vergult S, De Paepe B, Seneca S, Roeyers H, Menten B, Minczuk M, Vanlander A, Van Hove J, Van Coster R. New insights into the phenotype of FARS2 deficiency. Mol Genet Metab 2017; 122:172-181. [PMID: 29126765 PMCID: PMC5734183 DOI: 10.1016/j.ymgme.2017.10.004] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/18/2017] [Revised: 10/09/2017] [Accepted: 10/10/2017] [Indexed: 12/12/2022]
Abstract
Mutations in FARS2 are known to cause dysfunction of mitochondrial translation due to deficient aminoacylation of the mitochondrial phenylalanine tRNA. Here, we report three novel mutations in FARS2 found in two patients in a compound heterozygous state. The missense mutation c.1082C>T (p.Pro361Leu) was detected in both patients. The mutations c.461C>T (p.Ala154Val) and c.521_523delTGG (p.Val174del) were each detected in one patient. We report abnormal in vitro aminoacylation assays as a functional validation of the molecular genetic findings. Based on the phenotypic data of previously reported subjects and the two subjects reported here, we conclude that FARS2 deficiency can be associated with two phenotypes: (i) an epileptic phenotype, and (ii) a spastic paraplegia phenotype.
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Affiliation(s)
- Elise Vantroys
- Department of Pediatric Neurology and Metabolism, Ghent University Hospital, Ghent, Belgium
| | - Austin Larson
- Department of Pediatrics, Section of Clinical Genetics and Metabolism, University of Colorado School of Medicine, Aurora, CO, USA
| | - Marisa Friederich
- Department of Pediatrics, Section of Clinical Genetics and Metabolism, University of Colorado School of Medicine, Aurora, CO, USA
| | - Kaz Knight
- Department of Pediatrics, Section of Clinical Genetics and Metabolism, University of Colorado School of Medicine, Aurora, CO, USA
| | - Michael A Swanson
- Department of Pediatrics, Section of Clinical Genetics and Metabolism, University of Colorado School of Medicine, Aurora, CO, USA
| | - Christopher A Powell
- MRC Mitochondrial Biology Unit, University of Cambridge, Hills Road, Cambridge CB2 0XY, UK
| | - Joél Smet
- Department of Pediatric Neurology and Metabolism, Ghent University Hospital, Ghent, Belgium
| | - Sarah Vergult
- Center for Medical Genetics Ghent, Ghent University, Ghent, Belgium
| | - Boel De Paepe
- Department of Pediatric Neurology and Metabolism, Ghent University Hospital, Ghent, Belgium
| | - Sara Seneca
- Center for Medical Genetics, UZ Brussel and Reproduction Genetics and Regenerative Medicine, Vrije Universiteit Brussel, Brussels, Belgium
| | - Herbert Roeyers
- Department of Experimental Clinical and Health Psychology, Ghent University, Ghent, Belgium
| | - Björn Menten
- Center for Medical Genetics Ghent, Ghent University, Ghent, Belgium
| | - Michal Minczuk
- MRC Mitochondrial Biology Unit, University of Cambridge, Hills Road, Cambridge CB2 0XY, UK
| | - Arnaud Vanlander
- Department of Pediatric Neurology and Metabolism, Ghent University Hospital, Ghent, Belgium
| | - Johan Van Hove
- Department of Pediatrics, Section of Clinical Genetics and Metabolism, University of Colorado School of Medicine, Aurora, CO, USA
| | - Rudy Van Coster
- Department of Pediatric Neurology and Metabolism, Ghent University Hospital, Ghent, Belgium.
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49
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Wortmann SB, Timal S, Venselaar H, Wintjes LT, Kopajtich R, Feichtinger RG, Onnekink C, Mühlmeister M, Brandt U, Smeitink JA, Veltman JA, Sperl W, Lefeber D, Pruijn G, Stojanovic V, Freisinger P, V Spronsen F, Derks TG, Veenstra-Knol HE, Mayr JA, Rötig A, Tarnopolsky M, Prokisch H, Rodenburg RJ. Biallelic variants in WARS2 encoding mitochondrial tryptophanyl-tRNA synthase in six individuals with mitochondrial encephalopathy. Hum Mutat 2017; 38:1786-1795. [PMID: 28905505 DOI: 10.1002/humu.23340] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2017] [Revised: 09/07/2017] [Accepted: 09/10/2017] [Indexed: 12/12/2022]
Abstract
Mitochondrial protein synthesis involves an intricate interplay between mitochondrial DNA encoded RNAs and nuclear DNA encoded proteins, such as ribosomal proteins and aminoacyl-tRNA synthases. Eukaryotic cells contain 17 mitochondria-specific aminoacyl-tRNA synthases. WARS2 encodes mitochondrial tryptophanyl-tRNA synthase (mtTrpRS), a homodimeric class Ic enzyme (mitochondrial tryptophan-tRNA ligase; EC 6.1.1.2). Here, we report six individuals from five families presenting with either severe neonatal onset lactic acidosis, encephalomyopathy and early death or a later onset, more attenuated course of disease with predominating intellectual disability. Respiratory chain enzymes were usually normal in muscle and fibroblasts, while a severe combined respiratory chain deficiency was found in the liver of a severely affected individual. Exome sequencing revealed rare biallelic variants in WARS2 in all affected individuals. An increase of uncharged mitochondrial tRNATrp and a decrease of mtTrpRS protein content were found in fibroblasts of affected individuals. We hereby define the clinical, neuroradiological, and metabolic phenotype of WARS2 defects. This confidently implicates that mutations in WARS2 cause mitochondrial disease with a broad spectrum of clinical presentation.
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Affiliation(s)
- Saskia B Wortmann
- Department of Pediatrics, Salzburger Landeskliniken (SALK) and Paracelsus Medical University (PMU), Salzburg, Austria.,Institute of Human Genetics, Helmholtz Zentrum Munich, Neuherberg, Germany.,Institute of Human Genetics, Technische Universität München, Munich, Germany
| | - Sharita Timal
- Department of Pediatrics, Radboud Center for Mitochondrial Medicine, Radboud University Medical Center, Nijmegen, The Netherlands.,Department of Neurology, Donders Center for Brain, Cognition, and Behavior, Translational Metabolic Laboratory, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Hanka Venselaar
- Center for Molecular and Biomolecular Informatics, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Liesbeth T Wintjes
- Department of Pediatrics, Radboud Center for Mitochondrial Medicine, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Robert Kopajtich
- Institute of Human Genetics, Helmholtz Zentrum Munich, Neuherberg, Germany
| | - René G Feichtinger
- Department of Pediatrics, Salzburger Landeskliniken (SALK) and Paracelsus Medical University (PMU), Salzburg, Austria
| | - Carla Onnekink
- Department of Biomolecular Chemistry, Radboud Institute for Molecular Life Sciences, Nijmegen, The Netherlands.,Department of Biomolecular Chemistry, Institute for Molecules and Materials, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Mareike Mühlmeister
- Department of Pediatrics, Radboud Center for Mitochondrial Medicine, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Ulrich Brandt
- Department of Pediatrics, Radboud Center for Mitochondrial Medicine, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Jan A Smeitink
- Department of Pediatrics, Radboud Center for Mitochondrial Medicine, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Joris A Veltman
- Department of Human Genetics, Radboud Institute for Molecular Life Sciences, Nijmegen, The Netherlands.,Institute of Genetic Medicine, International Centre for Life, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Wolfgang Sperl
- Department of Pediatrics, Salzburger Landeskliniken (SALK) and Paracelsus Medical University (PMU), Salzburg, Austria
| | - Dirk Lefeber
- Department of Neurology, Donders Center for Brain, Cognition, and Behavior, Translational Metabolic Laboratory, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Ger Pruijn
- Department of Biomolecular Chemistry, Radboud Institute for Molecular Life Sciences, Nijmegen, The Netherlands.,Department of Biomolecular Chemistry, Institute for Molecules and Materials, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Vesna Stojanovic
- School of Medicine, University of Novi Sad, Novi Sad, Serbia.,Institute for Child and Youth Health Care of Vojvodina, Intensive Care Unit, Novi Sad, Serbia
| | - Peter Freisinger
- Children's Hospital, Klinikum am Steinenberg, Reutlingen, Germany
| | - Francjan V Spronsen
- Division of Metabolic Diseases, Beatrix Children's Hospital, University of Groningen, University Medical Center of Groningen, Groningen, the Netherlands
| | - Terry Gj Derks
- Division of Metabolic Diseases, Beatrix Children's Hospital, University of Groningen, University Medical Center of Groningen, Groningen, the Netherlands
| | - Hermine E Veenstra-Knol
- Department of Genetics, University of Groningen, University Medical Center of Groningen, Groningen, the Netherlands
| | - Johannes A Mayr
- Department of Pediatrics, Salzburger Landeskliniken (SALK) and Paracelsus Medical University (PMU), Salzburg, Austria
| | - Agnes Rötig
- INSERM U1163, Université Paris Descartes - Sorbonne Paris Cité, Institut Imagine, Paris, France
| | - Mark Tarnopolsky
- Department of Pediatrics, Division of Neuromuscular and Neurometabolic Diseases, McMaster University Medical Center, Hamilton, Ontario, Canada
| | - Holger Prokisch
- Institute of Human Genetics, Helmholtz Zentrum Munich, Neuherberg, Germany.,Institute of Human Genetics, Technische Universität München, Munich, Germany
| | - Richard J Rodenburg
- Department of Pediatrics, Radboud Center for Mitochondrial Medicine, Radboud University Medical Center, Nijmegen, The Netherlands
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50
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Meyer-Schuman R, Antonellis A. Emerging mechanisms of aminoacyl-tRNA synthetase mutations in recessive and dominant human disease. Hum Mol Genet 2017; 26:R114-R127. [PMID: 28633377 PMCID: PMC5886470 DOI: 10.1093/hmg/ddx231] [Citation(s) in RCA: 112] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2017] [Revised: 06/09/2017] [Accepted: 06/12/2017] [Indexed: 12/29/2022] Open
Abstract
Aminoacyl-tRNA synthetases (ARSs) are responsible for charging amino acids to cognate tRNA molecules, which is the essential first step of protein translation. Interestingly, mutations in genes encoding ARS enzymes have been implicated in a broad spectrum of human inherited diseases. Bi-allelic mutations in ARSs typically cause severe, early-onset, recessive diseases that affect a wide range of tissues. The vast majority of these mutations show loss-of-function effects and impair protein translation. However, it is not clear how a subset cause tissue-specific phenotypes. In contrast, dominant ARS-mediated diseases specifically affect the peripheral nervous system-most commonly causing axonal peripheral neuropathy-and usually manifest later in life. These neuropathies are linked to heterozygosity for missense mutations in five ARS genes, which points to a shared mechanism of disease. However, it is not clear if a loss-of-function mechanism or a toxic gain-of-function mechanism is responsible for ARS-mediated neuropathy, or if a combination of these mechanisms operate on a mutation-specific basis. Here, we review our current understanding of recessive and dominant ARS-mediated disease. We also propose future directions for defining the molecular mechanisms of ARS mutations toward designing therapies for affected patient populations.
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Affiliation(s)
- Rebecca Meyer-Schuman
- Department of Human Genetics, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | - Anthony Antonellis
- Department of Human Genetics, University of Michigan Medical School, Ann Arbor, MI 48109, USA
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