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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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Kalotay E, Klugmann M, Housley GD, Fröhlich D. Recessive aminoacyl-tRNA synthetase disorders: lessons learned from in vivo disease models. Front Neurosci 2023; 17:1182874. [PMID: 37274208 PMCID: PMC10234152 DOI: 10.3389/fnins.2023.1182874] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2023] [Accepted: 04/17/2023] [Indexed: 06/06/2023] Open
Abstract
Protein synthesis is a fundamental process that underpins almost every aspect of cellular functioning. Intriguingly, despite their common function, recessive mutations in aminoacyl-tRNA synthetases (ARSs), the family of enzymes that pair tRNA molecules with amino acids prior to translation on the ribosome, cause a diverse range of multi-system disorders that affect specific groups of tissues. Neurological development is impaired in most ARS-associated disorders. In addition to central nervous system defects, diseases caused by recessive mutations in cytosolic ARSs commonly affect the liver and lungs. Patients with biallelic mutations in mitochondrial ARSs often present with encephalopathies, with variable involvement of peripheral systems. Many of these disorders cause severe disability, and as understanding of their pathogenesis is currently limited, there are no effective treatments available. To address this, accurate in vivo models for most of the recessive ARS diseases are urgently needed. Here, we discuss approaches that have been taken to model recessive ARS diseases in vivo, highlighting some of the challenges that have arisen in this process, as well as key results obtained from these models. Further development and refinement of animal models is essential to facilitate a better understanding of the pathophysiology underlying recessive ARS diseases, and ultimately to enable development and testing of effective therapies.
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Affiliation(s)
- Elizabeth Kalotay
- Translational Neuroscience Facility and Department of Physiology, School of Biomedical Sciences, University of New South Wales, Sydney, NSW, Australia
| | - Matthias Klugmann
- Translational Neuroscience Facility and Department of Physiology, School of Biomedical Sciences, University of New South Wales, Sydney, NSW, Australia
- Research Beyond Borders, Boehringer Ingelheim Pharma GmbH & Co. KG, Biberach an der Riss, Germany
| | - Gary D. Housley
- Translational Neuroscience Facility and Department of Physiology, School of Biomedical Sciences, University of New South Wales, Sydney, NSW, Australia
| | - Dominik Fröhlich
- Translational Neuroscience Facility and Department of Physiology, School of Biomedical Sciences, University of New South Wales, Sydney, NSW, Australia
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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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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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Roux CJ, Barcia G, Schiff M, Sissler M, Levy R, Dangouloff-Ros V, Desguerre I, Edvardson S, Elpeleg O, Rötig A, Munnich A, Boddaert N. Phenotypic diversity of brain MRI patterns in mitochondrial aminoacyl-tRNA synthetase mutations. Mol Genet Metab 2021; 133:222-229. [PMID: 33972171 DOI: 10.1016/j.ymgme.2021.04.004] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Revised: 02/15/2021] [Accepted: 04/16/2021] [Indexed: 12/16/2022]
Abstract
BACKGROUND AND PURPOSE Mitochondrial aminoacyl-tRNA synthetases-encoded by ARS2 genes-are evolutionarily conserved enzymes that catalyse the attachment of amino acids to their cognate tRNAs, ensuring the accuracy of the mitochondrial translation process. ARS2 gene mutations are associated with a wide range of clinical presentations affecting the CNS. METHODS Two senior neuroradiologists analysed brain MRI of 25 patients (age range: 3 d-25 yrs.; 11 males; 14 females) with biallelic pathogenic variants of 11 ARS2 genes in a retrospective study conducted between 2002 and 2019. RESULTS Though several combinations of brain MRI anomalies were highly suggestive of specific aetiologies (DARS2, EARS2, AARS2 and RARS2 mutations), our study detected no MRI pattern common to all patients. Stroke-like lesions were associated with pathogenic SARS2 and FARS2 variants. We also report early onset cerebellar atrophy and calcifications in AARS2 mutations, early white matter involvement in RARS2 mutations, and absent involvement of thalami in EARS2 mutations. Finally, our findings show that normal brain MRI results do not exclude the presence of ARS2 mutations: 5 patients with normal MRI images were carriers of pathogenic IARS2, YARS2, and FARS2 variants. CONCLUSION Our study extends the spectrum of brain MRI anomalies associated with pathogenic ARS2 variants and suggests ARS2 mutations are largely underdiagnosed.
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Affiliation(s)
- Charles-Joris Roux
- Department of Paediatric Radiology, Hôpital Necker-Enfants Malades, Paris, France.
| | - Giulia Barcia
- Department of Genetics, Hospital Necker-Enfants Malades, Paris, France
| | - Manuel Schiff
- Institut Imagine, INSERM UMR 1163, Paris, France; Necker Hospital, APHP, Reference Center for Inborn Error of Metabolism, Pediatrics Department, University of Paris, Paris, France
| | - Marie Sissler
- Institut Européen de Chimie et Biologie, INSERM U1212, CNRS UMR 5320, University of Bordeaux, Pessac, France
| | - Raphaël Levy
- Department of Paediatric Radiology, Hôpital Necker-Enfants Malades, Paris, France
| | | | - Isabelle Desguerre
- Department of Neurology and Metabolism, Hôpital Necker-Enfants Malades, Paris, France
| | - Shimon Edvardson
- Department of Genetics, Hadassah University Hospital, Jerusalem, Israel
| | - Orli Elpeleg
- Department of Genetics, Hadassah University Hospital, Jerusalem, Israel
| | - Agnès Rötig
- Institut Imagine, INSERM UMR 1163, Paris, France
| | - Arnold Munnich
- Department of Genetics, Hospital Necker-Enfants Malades, Paris, France; Institut Imagine, INSERM UMR 1163, Paris, France
| | - Nathalie Boddaert
- Department of Paediatric Radiology, Hôpital Necker-Enfants Malades, Paris, France; Institut Imagine, INSERM UMR 1163, Paris, France
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Leuzzi V, Nardecchia F, Pons R, Galosi S. Parkinsonism in children: Clinical classification and etiological spectrum. Parkinsonism Relat Disord 2020; 82:150-157. [PMID: 33109474 DOI: 10.1016/j.parkreldis.2020.10.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/22/2020] [Revised: 07/14/2020] [Accepted: 10/03/2020] [Indexed: 01/03/2023]
Abstract
Infantile- and childhood-onset parkinsonism is mainly due to genetic alterations and is an exceedingly rare condition, unlike Parkinson's disease (PD), which is one of the most common neurologic disorders in adulthood. The clinical characterization of parkinsonism during early stages of neuromotor development is controversial due to the lack of consensus regarding the clinical criteria of PD or parkinsonism in the immature brain. The classification here proposed is based on a review of conditions that emerge during infancy and childhood, with key symptoms evocative of adult parkinsonism. The proposed nosography is based on age at presentation, clinical features, outcome, and etiological background. It includes developmental parkinsonism, infantile degenerative parkinsonism, parkinsonism in the setting of neurodevelopmental disorders, parkinsonism in the setting of multisystem brain diseases, juvenile parkinsonism and dystonia-parkinsonism, and acquired parkinsonism. The subgroups denoting peculiar clinical presentations as a consequence of disease impact on the immature brain are developmental parkinsonism due to monoamine metabolic disorders and infantile degenerative parkinsonism caused by DAT and WASR2 defects. More tardive parkinsonisms occur in genetic conditions that cause a generalized derangement of neurodevelopmental processes, such as those due to MECP2, NR4A2, SCN1A, and RAB39B. Some conditions presenting with neurodevelopmental disorder can progress later, disclosing their neurodegenerative nature (i.e. WDR45 and KCND3). Finally, new emerging conditions with childhood-onset parkinsonism arise from the cumulative effect of multiple genetic lesions.
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Affiliation(s)
- Vincenzo Leuzzi
- Department of Human Neuroscience, Sapienza University of Rome, Italy.
| | | | - Roser Pons
- First Department of Pediatrics, National and Kapodistrian University of Athens, Medical School, Agia Sophia Children's Hospital, Athens, Greece
| | - Serena Galosi
- Department of Human Neuroscience, Sapienza University of Rome, Italy
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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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Finsterer J. NEMMLAS Due to Biallelic WARS2 Variants. J Child Neurol 2020; 35:175. [PMID: 31617452 DOI: 10.1177/0883073819880108] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Josef Finsterer
- Krankenanstalt Rudolfstiftung, Messerli Institute, Vienna, Austria
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