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Moura J, Oliveira J, Santos M, Costa S, Silva L, Lemos C, Barros J, Sequeiros J, Damásio J. Spinocerebellar Ataxias: Phenotypic Spectrum of PolyQ versus Non-Repeat Expansion Forms. CEREBELLUM (LONDON, ENGLAND) 2024:10.1007/s12311-024-01723-9. [PMID: 39048885 DOI: 10.1007/s12311-024-01723-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 07/17/2024] [Indexed: 07/27/2024]
Abstract
Spinocerebellar ataxias (SCA) are most frequently due to (CAG)n (coding for polyglutamine, polyQ) expansions and, less so, to expansion of other oligonucleotide repeats (non-polyQ) or other type of variants (non-repeat expansion SCA). In this study we compared polyQ and non-repeat expansion SCA, in a cohort of patients with hereditary ataxia followed at a tertiary hospital. From a prospective study, 88 patients (51 families) with SCA were selected, 74 (40 families) of whom genetically diagnosed. Thirty-eight patients (51.4%, 19 families) were confirmed as having a polyQ (no other repeat-expansions were identified) and 36 (48.6%, 21 families) a non-repeat expansion SCA. Median age-at-onset was 39.5 [30.0-45.5] for polyQ and 7.0 years [1.00-21.50] for non-repeat expansion SCA. PolyQ SCA were associated with cerebellar onset, and non-repeat expansion forms with non-cerebellar onset. Time to diagnosis was longer for non-repeat expansion SCA. The most common polyQ SCA were Machado-Joseph disease (MJD/SCA3) (73.7%) and SCA2 (15.8%); whereas in non-repeat expansion SCA ATX-CACNA1A (14.3%), ATP1A3-related ataxia, ATX-ITPR1, ATX/HSP-KCNA2, and ATX-PRKCG (9.5% each) predominated. Disease duration (up to inclusion) was significantly higher in non-repeat expansion SCA, but the difference in SARA score was not statistically significant. Cerebellar peduncles and pons atrophy were more common in polyQ ataxias, as was axonal neuropathy. SCA had a wide range of genetic etiology, age-at-onset and presentation. Proportion of polyQ and non-repeat expansion SCA was similar; the latter had a higher genetic heterogeneity. While polyQ ataxias were typically linked to cerebellar onset in adulthood, non-repeat expansion forms associated with early onset and non-cerebellar presentations.
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Affiliation(s)
- João Moura
- Neurology Department, Centro Hospitalar Universitário de Santo António, ULS de Santo António, Porto, Portugal
| | - Jorge Oliveira
- Centro de Genética Preditiva e Preventiva (CGPP), IBMC - Institute for Molecular and Cell Biology, Universidade do Porto, Porto, Portugal
- IBMC - Institute for Molecular and Cell Biology, i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal
| | - Mariana Santos
- IBMC - Institute for Molecular and Cell Biology, i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal
| | - Sara Costa
- Neurology Department, Centro Hospitalar Universitário de Santo António, ULS de Santo António, Porto, Portugal
| | - Lénia Silva
- Neurology Department, Centro Hospitalar Universitário de Santo António, ULS de Santo António, Porto, Portugal
| | - Carolina Lemos
- IBMC - Institute for Molecular and Cell Biology, i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal
- ICBAS School of Medicine and Biomedical Sciences, Universidade do Porto, Porto, Portugal
| | - José Barros
- Neurology Department, Centro Hospitalar Universitário de Santo António, ULS de Santo António, Porto, Portugal
- ICBAS School of Medicine and Biomedical Sciences, Universidade do Porto, Porto, Portugal
| | - Jorge Sequeiros
- Centro de Genética Preditiva e Preventiva (CGPP), IBMC - Institute for Molecular and Cell Biology, Universidade do Porto, Porto, Portugal
- IBMC - Institute for Molecular and Cell Biology, i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal
- ICBAS School of Medicine and Biomedical Sciences, Universidade do Porto, Porto, Portugal
| | - Joana Damásio
- Neurology Department, Centro Hospitalar Universitário de Santo António, ULS de Santo António, Porto, Portugal.
- Centro de Genética Preditiva e Preventiva (CGPP), IBMC - Institute for Molecular and Cell Biology, Universidade do Porto, Porto, Portugal.
- IBMC - Institute for Molecular and Cell Biology, i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal.
- ICBAS School of Medicine and Biomedical Sciences, Universidade do Porto, Porto, Portugal.
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Sekerková G, Kilic S, Cheng YH, Fredrick N, Osmani A, Kim H, Opal P, Martina M. Phenotypical, genotypical and pathological characterization of the moonwalker mouse, a model of ataxia. Neurobiol Dis 2024; 195:106492. [PMID: 38575093 PMCID: PMC11089908 DOI: 10.1016/j.nbd.2024.106492] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2023] [Revised: 03/13/2024] [Accepted: 04/01/2024] [Indexed: 04/06/2024] Open
Abstract
We performed a comprehensive study of the morphological, functional, and genetic features of moonwalker (MWK) mice, a mouse model of spinocerebellar ataxia caused by a gain of function of the TRPC3 channel. These mice show numerous behavioral symptoms including tremor, altered gait, circling behavior, impaired motor coordination, impaired motor learning and decreased limb strength. Cerebellar pathology is characterized by early and almost complete loss of unipolar brush cells as well as slowly progressive, moderate loss of Purkinje cell (PCs). Structural damage also includes loss of synaptic contacts from parallel fibers, swollen ER structures, and degenerating axons. Interestingly, no obvious correlation was observed between PC loss and severity of the symptoms, as the phenotype stabilizes around 2 months of age, while the cerebellar pathology is progressive. This is probably due to the fact that PC function is severely impaired much earlier than the appearance of PC loss. Indeed, PC firing is already impaired in 3 weeks old mice. An interesting feature of the MWK pathology that still remains to be explained consists in a strong lobule selectivity of the PC loss, which is puzzling considering that TRPC is expressed in every PC. Intriguingly, genetic analysis of MWK cerebella shows, among other alterations, changes in the expression of both apoptosis inducing and resistance factors possibly suggesting that damaged PCs initiate specific cellular pathways that protect them from overt cell loss.
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Affiliation(s)
- Gabriella Sekerková
- Department of Neuroscience, Northwestern University, Feinberg School of Medicine, 300 E. Superior, Chicago, IL 60611, USA.
| | - Sumeyra Kilic
- Department of Neuroscience, Northwestern University, Feinberg School of Medicine, 300 E. Superior, Chicago, IL 60611, USA
| | - Yen-Hsin Cheng
- Department of Neuroscience, Northwestern University, Feinberg School of Medicine, 300 E. Superior, Chicago, IL 60611, USA
| | - Natalie Fredrick
- Department of Neurology, Northwestern University, Feinberg School of Medicine, 300 E. Superior, Chicago, IL 60611, USA
| | - Anne Osmani
- Department of Neuroscience, Northwestern University, Feinberg School of Medicine, 300 E. Superior, Chicago, IL 60611, USA
| | - Haram Kim
- Department of Neuroscience, Northwestern University, Feinberg School of Medicine, 300 E. Superior, Chicago, IL 60611, USA
| | - Puneet Opal
- Department of Neurology, Northwestern University, Feinberg School of Medicine, 300 E. Superior, Chicago, IL 60611, USA
| | - Marco Martina
- Department of Neuroscience, Northwestern University, Feinberg School of Medicine, 300 E. Superior, Chicago, IL 60611, USA.
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3
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Rudaks LI, Yeow D, Ng K, Deveson IW, Kennerson ML, Kumar KR. An Update on the Adult-Onset Hereditary Cerebellar Ataxias: Novel Genetic Causes and New Diagnostic Approaches. CEREBELLUM (LONDON, ENGLAND) 2024:10.1007/s12311-024-01703-z. [PMID: 38760634 DOI: 10.1007/s12311-024-01703-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 05/07/2024] [Indexed: 05/19/2024]
Abstract
The hereditary cerebellar ataxias (HCAs) are rare, progressive neurologic disorders caused by variants in many different genes. Inheritance may follow autosomal dominant, autosomal recessive, X-linked or mitochondrial patterns. The list of genes associated with adult-onset cerebellar ataxia is continuously growing, with several new genes discovered in the last few years. This includes short-tandem repeat (STR) expansions in RFC1, causing cerebellar ataxia, neuropathy, vestibular areflexia syndrome (CANVAS), FGF14-GAA causing spinocerebellar ataxia type 27B (SCA27B), and THAP11. In addition, the genetic basis for SCA4, has recently been identified as a STR expansion in ZFHX3. Given the large and growing number of genes, and different gene variant types, the approach to diagnostic testing for adult-onset HCA can be complex. Testing methods include targeted evaluation of STR expansions (e.g. SCAs, Friedreich ataxia, fragile X-associated tremor/ataxia syndrome, dentatorubral-pallidoluysian atrophy), next generation sequencing for conventional variants, which may include targeted gene panels, whole exome, or whole genome sequencing, followed by various potential additional tests. This review proposes a diagnostic approach for clinical testing, highlights the challenges with current testing technologies, and discusses future advances which may overcome these limitations. Implementing long-read sequencing has the potential to transform the diagnostic approach in HCA, with the overall aim to improve the diagnostic yield.
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Affiliation(s)
- Laura Ivete Rudaks
- Molecular Medicine Laboratory and Neurology Department, Concord Repatriation General Hospital, Sydney, Australia.
- Faculty of Medicine and Health, The University of Sydney, Sydney, Australia.
- Genomics and Inherited Disease Program, The Garvan Institute of Medical Research, Sydney, Australia.
- Clinical Genetics Unit, Royal North Shore Hospital, Sydney, Australia.
| | - Dennis Yeow
- Molecular Medicine Laboratory and Neurology Department, Concord Repatriation General Hospital, Sydney, Australia
- Faculty of Medicine and Health, The University of Sydney, Sydney, Australia
- Genomics and Inherited Disease Program, The Garvan Institute of Medical Research, Sydney, Australia
- Neurodegenerative Service, Prince of Wales Hospital, Sydney, Australia
- Neuroscience Research Australia, Sydney, Australia
| | - Karl Ng
- Faculty of Medicine and Health, The University of Sydney, Sydney, Australia
- Neurology Department, Royal North Shore Hospital, Sydney, Australia
| | - Ira W Deveson
- Genomics and Inherited Disease Program, The Garvan Institute of Medical Research, Sydney, Australia
- Faculty of Medicine, University of New South Wales, Sydney, Australia
| | - Marina L Kennerson
- Molecular Medicine Laboratory and Neurology Department, Concord Repatriation General Hospital, Sydney, Australia
- Faculty of Medicine and Health, The University of Sydney, Sydney, Australia
- The Northcott Neuroscience Laboratory, ANZAC Research Institute, Sydney Local Health District, Sydney, Australia
| | - Kishore Raj Kumar
- Molecular Medicine Laboratory and Neurology Department, Concord Repatriation General Hospital, Sydney, Australia
- Faculty of Medicine and Health, The University of Sydney, Sydney, Australia
- Genomics and Inherited Disease Program, The Garvan Institute of Medical Research, Sydney, Australia
- Faculty of Medicine, University of New South Wales, Sydney, Australia
- Faculty of Medicine, St Vincent's Healthcare Campus, UNSW Sydney, Sydney, Australia
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Perlman SL. CRPD frontiers in movement disorders Therapeutics: From evidence to treatment and applications: Addressing Patients' Needs in the Management of the Ataxias. Clin Park Relat Disord 2024; 10:100255. [PMID: 38798918 PMCID: PMC11126860 DOI: 10.1016/j.prdoa.2024.100255] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2023] [Revised: 04/02/2024] [Accepted: 05/05/2024] [Indexed: 05/29/2024] Open
Abstract
The genetic ataxias have no cures and no proven ways to delay progression (no disease-modifying therapies). The acquired ataxias may have treatments that address the underlying cause and may slow or stop progression, but will not reverse damage already sustained. The idiopathic ataxias (of unknown genetic or acquired cause) also have no proven disease-modifying therapies. However, for all patients with ataxia of any cause, there is always something that can be done to improve quality of life-treat associated symptoms, provide information and resources, counsel patient and family, help with insurance and disability concerns, be available to listen and answer the many questions they will have.
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Affiliation(s)
- Susan L. Perlman
- Department of Neurology David Geffen School of Medicine at UCLA Health Sciences 300 UCLA Medical Plaza, Suite B200 Los Angeles, CA 90095, United States
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5
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Indelicato E, Reetz K, Maier S, Nachbauer W, Amprosi M, Giunti P, Mariotti C, Durr A, de Rivera Garrido FJR, Klopstock T, Schöls L, Klockgether T, Bürk K, Pandolfo M, Didszun C, Grobe-Einsler M, Nanetti L, Nenning L, Kiechl S, Dichtl W, Ulmer H, Schulz JB, Boesch S. Predictors of Survival in Friedreich's Ataxia: A Prospective Cohort Study. Mov Disord 2024; 39:510-518. [PMID: 38140802 DOI: 10.1002/mds.29687] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2023] [Revised: 10/24/2023] [Accepted: 11/27/2023] [Indexed: 12/24/2023] Open
Abstract
BACKGROUND Friedreich's ataxia (FA) is a rare multisystemic disorder which can cause premature death. OBJECTIVES To investigate predictors of survival in FA. METHODS Within a prospective registry established by the European Friedreich's Ataxia Consortium for Translational Studies (EFACTS; ClinicalTrials.gov identifier NCT02069509) we enrolled genetically confirmed FA patients at 11 tertiary centers and followed them in yearly intervals. We investigated overall survival applying the Kaplan-Meier method, life tables, and log-rank test. We explored prognostic factors applying Cox proportional hazards regression and subsequently built a risk score which was assessed for discrimination and calibration performance. RESULTS Between September 2010 and March 2017, we enrolled 631 FA patients. Median age at inclusion was 31 (range, 6-76) years. Until December 2022, 44 patients died and 119 terminated the study for other reasons. The 10-year cumulative survival rate was 87%. In a multivariable analysis, the disability stage (hazard ratio [HR] 1.51, 95% CI 1.08-2.12, P = 0.02), history of arrhythmic disorder (HR 2.93, 95% CI 1.34-6.39, P = 0.007), and diabetes mellitus (HR 2.31, 95% CI 1.05-5.10, P = 0.04) were independent predictors of survival. GAA repeat lengths did not improve the survival model. A risk score built on the previously described factors plus the presence of left ventricular systolic dysfunction at echocardiography enabled identification of four trajectories to prognosticate up to 10-year survival (log-rank test P < 0.001). CONCLUSIONS Arrhythmias, progressive neurological disability, and diabetes mellitus influence the overall survival in FA. We built a survival prognostic score which identifies patients meriting closer surveillance and who may benefit from early invasive cardiac monitoring and therapy. © 2023 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.
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Affiliation(s)
- Elisabetta Indelicato
- Center for Rare Movement Disorders Innsbruck, Department of Neurology, Medical University Innsbruck, Innsbruck, Austria
| | - Kathrin Reetz
- Department of Neurology, RWTH Aachen University, Aachen, Germany
- JARA-BRAIN Institute of Molecular Neuroscience and Neuroimaging, Forschungszentrum Jülich GmbH and RWTH Aachen University, Aachen, Germany
| | - Sarah Maier
- Institute of Medical Statistics and Informatics, Medical University Innsbruck, Innsbruck, Austria
| | - Wolfgang Nachbauer
- Center for Rare Movement Disorders Innsbruck, Department of Neurology, Medical University Innsbruck, Innsbruck, Austria
| | - Matthias Amprosi
- Center for Rare Movement Disorders Innsbruck, Department of Neurology, Medical University Innsbruck, Innsbruck, Austria
| | - Paola Giunti
- Department of Molecular Neuroscience, UCL Institute of Neurology, London, UK
| | - Caterina Mariotti
- Unit of Genetics of Neurodegenerative and Metabolic Diseases, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Alexandra Durr
- Institut du Cerveau et de la Moelle Epinière, INSERM U1127, CNRS UMR 7225, Sorbonne Universités, UPMC Université Paris VI UMR S1127, Paris, France
- APHP, Genetics Department, Pitié-Salpêtrière University Hospital, Paris, France
| | - Francisco J R de Rivera Garrido
- Reference Unit of Hereditary Ataxias and Paraplegias, Department of Neurology, IdiPAZ, Hospital Universitario La Paz, Madrid, Spain
| | - Thomas Klopstock
- Department of Neurology with Friedrich-Baur-Institute, University of Munich, Munich, Germany
- German Center for Neurodegenerative Diseases (DZNE), Munich, Germany
| | - Ludger Schöls
- Department of Neurodegenerative Diseases, Hertie-Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany
- German Center for Neurodegenerative Diseases (DZNE), Tübingen, Germany
| | - Thomas Klockgether
- Department of Neurology, University Hospital of Bonn, Bonn, Germany
- German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany
| | - Katrin Bürk
- Department of Neurology, Philipps University of Marburg, Marburg, Germany
| | - Massimo Pandolfo
- Laboratory of Experimental Neurology, Université Libre de Bruxelles, Brussels, Belgium
- Department of Neurology and Neurosurgery, McGill University, Montreal, Canada
| | - Claire Didszun
- Department of Neurology, RWTH Aachen University, Aachen, Germany
- JARA-BRAIN Institute of Molecular Neuroscience and Neuroimaging, Forschungszentrum Jülich GmbH and RWTH Aachen University, Aachen, Germany
| | - Marcus Grobe-Einsler
- Department of Neurology, University Hospital of Bonn, Bonn, Germany
- German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany
| | - Lorenzo Nanetti
- Unit of Genetics of Neurodegenerative and Metabolic Diseases, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Lukas Nenning
- Center for Rare Movement Disorders Innsbruck, Department of Neurology, Medical University Innsbruck, Innsbruck, Austria
| | - Stefan Kiechl
- Center for Rare Movement Disorders Innsbruck, Department of Neurology, Medical University Innsbruck, Innsbruck, Austria
- VASCage, Centre on Clinical Stroke Research, Innsbruck, Austria
| | - Wolfgang Dichtl
- Department of Internal Medicine III (Cardiology and Angiology), Medical University Innsbruck, Innsbruck, Austria
| | - Hanno Ulmer
- Institute of Medical Statistics and Informatics, Medical University Innsbruck, Innsbruck, Austria
| | - Jörg B Schulz
- Department of Neurology, RWTH Aachen University, Aachen, Germany
- JARA-BRAIN Institute of Molecular Neuroscience and Neuroimaging, Forschungszentrum Jülich GmbH and RWTH Aachen University, Aachen, Germany
| | - Sylvia Boesch
- Center for Rare Movement Disorders Innsbruck, Department of Neurology, Medical University Innsbruck, Innsbruck, Austria
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Gullulu O, Ozcelik E, Tuzlakoglu Ozturk M, Karagoz MS, Tazebay UH. A multi-faceted approach to unravel coding and non-coding gene fusions and target chimeric proteins in ataxia. J Biomol Struct Dyn 2024:1-21. [PMID: 38411012 DOI: 10.1080/07391102.2024.2321510] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2023] [Accepted: 02/15/2024] [Indexed: 02/28/2024]
Abstract
Ataxia represents a heterogeneous group of neurodegenerative disorders characterized by a loss of balance and coordination, often resulting from mutations in genes vital for cerebellar function and maintenance. Recent advances in genomics have identified gene fusion events as critical contributors to various cancers and neurodegenerative diseases. However, their role in ataxia pathogenesis remains largely unexplored. Our study Hdelved into this possibility by analyzing RNA sequencing data from 1443 diverse samples, including cell and mouse models, patient samples, and healthy controls. We identified 7067 novel gene fusions, potentially pivotal in disease onset. These fusions, notably in-frame, could produce chimeric proteins, disrupt gene regulation, or introduce new functions. We observed conservation of specific amino acids at fusion breakpoints and identified potential aggregate formations in fusion proteins, known to contribute to ataxia. Through AI-based protein structure prediction, we identified topological changes in three high-confidence fusion proteins-TEN1-ACOX1, PEX14-NMNAT1, and ITPR1-GRID2-which could potentially alter their functions. Subsequent virtual drug screening identified several molecules and peptides with high-affinity binding to fusion sites. Molecular dynamics simulations confirmed the stability of these protein-ligand complexes at fusion breakpoints. Additionally, we explored the role of non-coding RNA fusions as miRNA sponges. One such fusion, RP11-547P4-FLJ33910, showed strong interaction with hsa-miR-504-5p, potentially acting as its sponge. This interaction correlated with the upregulation of hsa-miR-504-5p target genes, some previously linked to ataxia. In conclusion, our study unveils new aspects of gene fusions in ataxia, suggesting their significant role in pathogenesis and opening avenues for targeted therapeutic interventions.Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
- Omer Gullulu
- Department of Structural Biology, St Jude Children's Research Hospital, Memphis, TN, USA
| | - Emrah Ozcelik
- Department of Molecular Biology and Genetics, Gebze Technical University, Gebze, Kocaeli, Turkey
- Central Research Laboratory (GTU-MAR), Gebze Technical University, Gebze, Kocaeli, Turkey
| | - Merve Tuzlakoglu Ozturk
- Department of Molecular Biology and Genetics, Gebze Technical University, Gebze, Kocaeli, Turkey
- Central Research Laboratory (GTU-MAR), Gebze Technical University, Gebze, Kocaeli, Turkey
| | - Mustafa Safa Karagoz
- Institut für Mikrobiologie, Technische Universität Braunschweig, Braunschweig, Germany
- Biochemistry and Biophysics Center, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, MD, USA
| | - Uygar Halis Tazebay
- Department of Molecular Biology and Genetics, Gebze Technical University, Gebze, Kocaeli, Turkey
- Central Research Laboratory (GTU-MAR), Gebze Technical University, Gebze, Kocaeli, Turkey
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7
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Tolonen JP, Parolin Schnekenberg R, McGowan S, Sims D, McEntagart M, Elmslie F, Shears D, Stewart H, Tofaris GK, Dabir T, Morrison PJ, Johnson D, Hadjivassiliou M, Ellard S, Shaw‐Smith C, Znaczko A, Dixit A, Suri M, Sarkar A, Harrison RE, Jones G, Houlden H, Ceravolo G, Jarvis J, Williams J, Shanks ME, Clouston P, Rankin J, Blumkin L, Lerman‐Sagie T, Ponger P, Raskin S, Granath K, Uusimaa J, Conti H, McCann E, Joss S, Blakes AJ, Metcalfe K, Kingston H, Bertoli M, Kneen R, Lynch SA, Martínez Albaladejo I, Moore AP, Jones WD, Becker EB, Németh AH. Detailed Analysis of ITPR1 Missense Variants Guides Diagnostics and Therapeutic Design. Mov Disord 2024; 39:141-151. [PMID: 37964426 PMCID: PMC10952845 DOI: 10.1002/mds.29651] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2023] [Revised: 09/16/2023] [Accepted: 10/16/2023] [Indexed: 11/16/2023] Open
Abstract
BACKGROUND The ITPR1 gene encodes the inositol 1,4,5-trisphosphate (IP3 ) receptor type 1 (IP3 R1), a critical player in cerebellar intracellular calcium signaling. Pathogenic missense variants in ITPR1 cause congenital spinocerebellar ataxia type 29 (SCA29), Gillespie syndrome (GLSP), and severe pontine/cerebellar hypoplasia. The pathophysiological basis of the different phenotypes is poorly understood. OBJECTIVES We aimed to identify novel SCA29 and GLSP cases to define core phenotypes, describe the spectrum of missense variation across ITPR1, standardize the ITPR1 variant nomenclature, and investigate disease progression in relation to cerebellar atrophy. METHODS Cases were identified using next-generation sequencing through the Deciphering Developmental Disorders study, the 100,000 Genomes project, and clinical collaborations. ITPR1 alternative splicing in the human cerebellum was investigated by quantitative polymerase chain reaction. RESULTS We report the largest, multinational case series of 46 patients with 28 unique ITPR1 missense variants. Variants clustered in functional domains of the protein, especially in the N-terminal IP3 -binding domain, the carbonic anhydrase 8 (CA8)-binding region, and the C-terminal transmembrane channel domain. Variants outside these domains were of questionable clinical significance. Standardized transcript annotation, based on our ITPR1 transcript expression data, greatly facilitated analysis. Genotype-phenotype associations were highly variable. Importantly, while cerebellar atrophy was common, cerebellar volume loss did not correlate with symptom progression. CONCLUSIONS This dataset represents the largest cohort of patients with ITPR1 missense variants, expanding the clinical spectrum of SCA29 and GLSP. Standardized transcript annotation is essential for future reporting. Our findings will aid in diagnostic interpretation in the clinic and guide selection of variants for preclinical studies. © 2023 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.
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Affiliation(s)
- Jussi Pekka Tolonen
- Nuffield Department of Clinical NeurosciencesUniversity of OxfordOxfordUK
- Kavli Institute of Nanoscience DiscoveryUniversity of OxfordOxfordUK
| | - Ricardo Parolin Schnekenberg
- Nuffield Department of Clinical NeurosciencesUniversity of OxfordOxfordUK
- Oxford Center for Genomic MedicineOxford University Hospitals National Health Service Foundation Trust, University of OxfordOxfordUK
| | - Simon McGowan
- Centre for Computational Biology, MRC Weatherall Institute of Molecular MedicineUniversity of OxfordOxfordUK
| | - David Sims
- Centre for Computational Biology, MRC Weatherall Institute of Molecular MedicineUniversity of OxfordOxfordUK
| | - Meriel McEntagart
- South West Regional Genetics ServiceSt. George's University HospitalsLondonUK
| | - Frances Elmslie
- South West Regional Genetics ServiceSt. George's University HospitalsLondonUK
| | - Debbie Shears
- Oxford Center for Genomic MedicineOxford University Hospitals National Health Service Foundation Trust, University of OxfordOxfordUK
| | - Helen Stewart
- Oxford Center for Genomic MedicineOxford University Hospitals National Health Service Foundation Trust, University of OxfordOxfordUK
| | - George K. Tofaris
- Nuffield Department of Clinical NeurosciencesUniversity of OxfordOxfordUK
- Kavli Institute of Nanoscience DiscoveryUniversity of OxfordOxfordUK
| | - Tabib Dabir
- Northern Ireland Regional Genetics ServiceBelfast City HospitalBelfastUK
| | - Patrick J. Morrison
- Patrick G. Johnston Centre for Cancer Research and Cell BiologyQueen's University BelfastBelfastUK
| | - Diana Johnson
- Sheffield Clinical Genetics ServiceSheffield Children's NHS Foundation TrustSheffieldUK
| | - Marios Hadjivassiliou
- Department of NeurologyRoyal Hallamshire Hospital, Sheffield Teaching Hospital NHS Foundation TrustSheffieldUK
| | - Sian Ellard
- Exeter Genomics LaboratoryRoyal Devon University Healthcare NHS Foundation TrustUK
| | - Charles Shaw‐Smith
- Peninsula Clinical Genetics Service, Royal Devon University HospitalRoyal Devon University Healthcare NHS Foundation TrustExeterUK
| | - Anna Znaczko
- Peninsula Clinical Genetics Service, Royal Devon University HospitalRoyal Devon University Healthcare NHS Foundation TrustExeterUK
| | - Abhijit Dixit
- Department of Clinical GeneticsNottingham University Hospitals NHS TrustNottinghamUK
| | - Mohnish Suri
- Department of Clinical GeneticsNottingham University Hospitals NHS TrustNottinghamUK
| | - Ajoy Sarkar
- Department of Clinical GeneticsNottingham University Hospitals NHS TrustNottinghamUK
| | - Rachel E. Harrison
- Department of Clinical GeneticsNottingham University Hospitals NHS TrustNottinghamUK
| | - Gabriela Jones
- Department of Clinical GeneticsNottingham University Hospitals NHS TrustNottinghamUK
| | - Henry Houlden
- Department of Neuromuscular DisordersUCL Queen Square Institute of Neurology, University College LondonLondonUK
| | - Giorgia Ceravolo
- Department of Neuromuscular DisordersUCL Queen Square Institute of Neurology, University College LondonLondonUK
- Unit of Pediatric Emergency, Department of Adult and Childhood Human PathologyUniversity Hospital of MessinaMessinaItaly
| | - Joanna Jarvis
- Birmingham Women's and Children's NHS Foundation TrustBirminghamUK
| | - Jonathan Williams
- Oxford Regional Genetics Laboratory, Churchill HospitalOxford University Hospitals NHS Foundation TrustOxfordUK
| | - Morag E. Shanks
- Oxford Regional Genetics Laboratory, Churchill HospitalOxford University Hospitals NHS Foundation TrustOxfordUK
| | - Penny Clouston
- Oxford Regional Genetics Laboratory, Churchill HospitalOxford University Hospitals NHS Foundation TrustOxfordUK
| | - Julia Rankin
- Department of Clinical GeneticsRoyal Devon and Exeter NHS Foundation TrustExeterUK
| | - Lubov Blumkin
- Sackler School of MedicineTel Aviv UniversityTel AvivIsrael
- Pediatric Movement Disorders Service, Pediatric Neurology UnitEdith Wolfson Medical CenterHolonIsrael
| | - Tally Lerman‐Sagie
- Sackler School of MedicineTel Aviv UniversityTel AvivIsrael
- Magen Center for Rare Diseases‐Metabolic, NeurogeneticWolfson Medical CenterHolonIsrael
| | - Penina Ponger
- Sackler School of MedicineTel Aviv UniversityTel AvivIsrael
- Movement Disorders Unit, Department of NeurologyTel Aviv Sourasky Medical CenterTel AvivIsrael
| | - Salmo Raskin
- Genetika Centro de Aconselhamento e LaboratórioCuritibaBrazil
| | - Katariina Granath
- Research Unit of Clinical MedicineMedical Research Center, Oulu University Hospital and University of OuluOuluFinland
| | - Johanna Uusimaa
- Research Unit of Clinical MedicineMedical Research Center, Oulu University Hospital and University of OuluOuluFinland
| | - Hector Conti
- All Wales Medical Genomics ServiceWrexham Maelor HospitalWrexhamUK
| | - Emma McCann
- Liverpool Women's Hospital Foundation TrustLiverpoolUK
| | - Shelagh Joss
- West of Scotland Centre for Genomic MedicineQueen Elizabeth University HospitalGlasgowUK
| | - Alexander J.M. Blakes
- Division of Evolution, Infection and Genomics, School of Biological Sciences, Faculty of BiologyMedicine and Health, University of ManchesterManchesterUK
- Manchester Centre for Genomic MedicineUniversity of Manchester, St. Mary's Hospital, Manchester Academic Health Science CentreManchesterUK
| | - Kay Metcalfe
- Division of Evolution, Infection and Genomics, School of Biological Sciences, Faculty of BiologyMedicine and Health, University of ManchesterManchesterUK
- Manchester Centre for Genomic MedicineUniversity of Manchester, St. Mary's Hospital, Manchester Academic Health Science CentreManchesterUK
| | - Helen Kingston
- Manchester Centre for Genomic MedicineUniversity of Manchester, St. Mary's Hospital, Manchester Academic Health Science CentreManchesterUK
| | - Marta Bertoli
- Northern Genetics ServiceInternational Centre for LifeNewcastle upon TyneUK
| | - Rachel Kneen
- Department of NeurologyAlder Hey Children's NHS Foundation TrustLiverpoolUK
| | - Sally Ann Lynch
- Department of Clinical GeneticsChildren's Health Ireland (CHI) at CrumlinDublinIreland
| | | | | | - Wendy D. Jones
- North East Thames Regional Genetics ServiceGreat Ormond Street Hospital for Children, Great Ormond Street NHS Foundation TrustLondonUK
| | | | - Esther B.E. Becker
- Nuffield Department of Clinical NeurosciencesUniversity of OxfordOxfordUK
- Kavli Institute of Nanoscience DiscoveryUniversity of OxfordOxfordUK
| | - Andrea H. Németh
- Nuffield Department of Clinical NeurosciencesUniversity of OxfordOxfordUK
- Oxford Center for Genomic MedicineOxford University Hospitals National Health Service Foundation Trust, University of OxfordOxfordUK
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8
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Méreaux JL, Davoine CS, Pellerin D, Coarelli G, Coutelier M, Ewenczyk C, Monin ML, Anheim M, Le Ber I, Thobois S, Gobert F, Guillot-Noël L, Forlani S, Jornea L, Heinzmann A, Sangare A, Gaymard B, Guyant-Maréchal L, Charles P, Marelli C, Honnorat J, Degos B, Tison F, Sangla S, Simonetta-Moreau M, Salachas F, Tchikviladzé M, Castelnovo G, Mochel F, Klebe S, Castrioto A, Fenu S, Méneret A, Bourdain F, Wandzel M, Roth V, Bonnet C, Riant F, Stevanin G, Noël S, Fauret-Amsellem AL, Bahlo M, Lockhart PJ, Brais B, Renaud M, Brice A, Durr A. Clinical and genetic keys to cerebellar ataxia due to FGF14 GAA expansions. EBioMedicine 2024; 99:104931. [PMID: 38150853 PMCID: PMC10784672 DOI: 10.1016/j.ebiom.2023.104931] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2023] [Revised: 11/26/2023] [Accepted: 12/06/2023] [Indexed: 12/29/2023] Open
Abstract
BACKGROUND SCA27B caused by FGF14 intronic heterozygous GAA expansions with at least 250 repeats accounts for 10-60% of cases with unresolved cerebellar ataxia. We aimed to assess the size and frequency of FGF14 expanded alleles in individuals with cerebellar ataxia as compared with controls and to characterize genetic and clinical variability. METHODS We sized this repeat in 1876 individuals from France sampled for research purposes in this cross-sectional study: 845 index cases with cerebellar ataxia and 324 affected relatives, 475 controls, as well as 119 cases with spastic paraplegia, and 113 with familial essential tremor. FINDINGS A higher frequency of expanded allele carriers in index cases with ataxia was significant only above 300 GAA repeats (10.1%, n = 85) compared with controls (1.1%, n = 5) (p < 0.0001) whereas GAA250-299 alleles were detected in 1.7% of both groups. Eight of 14 index cases with GAA250-299 repeats had other causal pathogenic variants (4/14) and/or discordance of co-segregation (5/14), arguing against GAA causality. We compared the clinical signs in 127 GAA≥300 carriers to cases with non-expanded GAA ataxia resulting in defining a key phenotype triad: onset after 45 years, downbeat nystagmus, episodic ataxic features including diplopia; and a frequent absence of dysarthria. All maternally transmitted alleles above 100 GAA were unstable with a median expansion of +18 repeats per generation (r2 = 0.44; p < 0.0001). In comparison, paternally transmitted alleles above 100 GAA mostly decreased in size (-15 GAA (r2 = 0.63; p < 0.0001)), resulting in the transmission bias observed in SCA27B pedigrees. INTERPRETATION SCA27B diagnosis must consider both the phenotype and GAA expansion size. In carriers of GAA250-299 repeats, the absence of documented familial transmission and a presentation deviating from the key SCA27B phenotype, should prompt the search for an alternative cause. Affected fathers have a reduced risk of having affected children, which has potential implications for genetic counseling. FUNDING This work was supported by the Fondation pour la Recherche Médicale, grant number 13338 to JLM, the Association Connaître les Syndrome Cérébelleux - France (to GS) and by the European Union's Horizon 2020 research and innovation program under grant agreement No 779257 ("SOLVE-RD" to GS). DP holds a Fellowship award from the Canadian Institutes of Health Research (CIHR). SK received a grant (01GM1905C) from the Federal Ministry of Education and Research, Germany, through the TreatHSP network. This work was supported by the Australian Government National Health and Medical Research Council grants (GNT2001513 and MRFF2007677) to MB and PJL.
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Affiliation(s)
- Jean-Loup Méreaux
- Sorbonne Université, Paris Brain Institute - ICM, Inserm, CNRS, AP-HP, Paris, France
| | - Claire-Sophie Davoine
- Sorbonne Université, Paris Brain Institute - ICM, Inserm, CNRS, AP-HP, Paris, France
| | - David Pellerin
- Department of Neurology and Neurosurgery, Montreal Neurological Hospital and Institute, McGill University, Montreal, QC, Canada; Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology and the National Hospital for Neurology and Neurosurgery, University College London, London, United Kingdom
| | - Giulia Coarelli
- Sorbonne Université, Paris Brain Institute - ICM, Inserm, CNRS, AP-HP, Paris, France; Unité de Génétique Clinique, AP-HP, Hôpital Pitié-Salpêtrière, Paris, France
| | - Marie Coutelier
- Sorbonne Université, Paris Brain Institute - ICM, Inserm, CNRS, AP-HP, Paris, France
| | - Claire Ewenczyk
- Sorbonne Université, Paris Brain Institute - ICM, Inserm, CNRS, AP-HP, Paris, France; Unité de Génétique Clinique, AP-HP, Hôpital Pitié-Salpêtrière, Paris, France
| | - Marie-Lorraine Monin
- Centre de Reference Maladies Rares « Neurogénétique », Service de Génétique Médicale, Bordeaux University Hospital (CHU Bordeaux), 33000, Bordeaux, France
| | - Mathieu Anheim
- Department of Neurology, Strasbourg University Hospital, 67098, Strasbourg, France; Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), INSERM-U964, CNRS-UMR7104, University of Strasbourg, 67400, Illkirch-Graffenstaden, France
| | - Isabelle Le Ber
- Sorbonne Université, Paris Brain Institute - ICM, Inserm, CNRS, AP-HP, Paris, France
| | - Stéphane Thobois
- Department of Neurology C, Expert Parkinson Centre NS-Park/F-CRIN, Hospices Civils de Lyon, Pierre Wertheimer Neurological Hospital, 69677, Bron, France; Marc Jeannerod Cognitive Neuroscience Institute, CNRS, UMR 5229, Bron, France; Faculté de Médecine Et de Maïeutique Lyon Sud Charles Mérieux, Université Claude Bernard Lyon 1, Université de Lyon, Lyon, France
| | - Florent Gobert
- Neuro-Intensive Care Unit, Hospices Civils de Lyon, Neurological Hospital Pierre-Wertheimer, Lyon, France; University Lyon I, Villeurbanne, France
| | - Léna Guillot-Noël
- Sorbonne Université, Paris Brain Institute - ICM, Inserm, CNRS, AP-HP, Paris, France
| | - Sylvie Forlani
- Sorbonne Université, Paris Brain Institute - ICM, Inserm, CNRS, AP-HP, Paris, France
| | - Ludmila Jornea
- Sorbonne Université, Paris Brain Institute - ICM, Inserm, CNRS, AP-HP, Paris, France
| | - Anna Heinzmann
- Sorbonne Université, Paris Brain Institute - ICM, Inserm, CNRS, AP-HP, Paris, France
| | - Aude Sangare
- Sorbonne Université, Paris Brain Institute - ICM, Inserm, CNRS, AP-HP, Paris, France; Department of Neurophysiology, University Hospital Group APHP-Sorbonne University, Pitié-Salpêtrière Site, Paris, France
| | - Bertrand Gaymard
- Department of Neurophysiology, University Hospital Group APHP-Sorbonne University, Pitié-Salpêtrière Site, Paris, France
| | - Lucie Guyant-Maréchal
- Neurophysiology Department, Rouen University Hospital, Rouen, France; Medical Genetics Department, Rouen University Hospital, Rouen, France
| | - Perrine Charles
- Sorbonne Université, Paris Brain Institute - ICM, Inserm, CNRS, AP-HP, Paris, France; Unité de Génétique Clinique, AP-HP, Hôpital Pitié-Salpêtrière, Paris, France
| | - Cecilia Marelli
- MMDN, University Montpellier, EPHE, INSERM and Expert Center for Neurogenetic Diseases, CHU, 34095, Montpellier, France
| | - Jérôme Honnorat
- Reference Center for Paraneoplastic Neurological Syndromes and Autoimmune Encephalitis, Hospices Civils de Lyon, MeLiS Institute UMR CNRS 5284 - INSERM U1314, Université Claude Bernard Lyon 1, Lyon, France
| | - Bertrand Degos
- Neurology Department, Avicenne Hospital, APHP, Hôpitaux Universitaires de Paris-Seine Saint Denis (HUPSSD), Sorbonne Paris Nord, Réseau NS-PARK/FCRIN, Bobigny, France
| | - François Tison
- Institut des Maladies Neurodégénératives-Clinique (IMNc), University Hospital Bordeaux, Bordeaux, France; Institut des Maladies Neurodégénératives, CNRS, UMR 5293, Bordeaux University, Bordeaux, France
| | - Sophie Sangla
- Neurology Department, Hôpital Fondation Adolphe de Rothschild, Paris, France
| | - Marion Simonetta-Moreau
- Department of Neurology, University Hospital of Toulouse, 31300, Toulouse, France; Toulouse NeuroImaging Center (ToNIC), Inserm, UPS, Université de Toulouse, 31024, Toulouse, France; Clinical Investigation Center (CIC 1436), Toulouse University Hospital, INSERM, 31059, Toulouse, France
| | - François Salachas
- Sorbonne Université, Paris Brain Institute - ICM, Inserm, CNRS, AP-HP, Paris, France; Département de Neurologie, Assistance Publique Hôpitaux de Paris (APHP), Centre de Référence SLA Ile de France, Hôpital de la Pitié-Salpêtrière, Paris, France
| | - Maya Tchikviladzé
- Sorbonne Université, Paris Brain Institute - ICM, Inserm, CNRS, AP-HP, Paris, France
| | - Giovanni Castelnovo
- Department of Neurology, Nîmes University Hospital, Hopital Caremeau, Nîmes, France
| | - Fanny Mochel
- Sorbonne Université, Paris Brain Institute - ICM, Inserm, CNRS, AP-HP, Paris, France
| | - Stephan Klebe
- Department of Neurology, University Hospital Essen, Essen, Germany
| | - Anna Castrioto
- Univ. Grenoble Alpes, Inserm, U1216, CHU Grenoble Alpes, Grenoble Institut Neurosciences, Neurology Department, 38000, Grenoble, France
| | - Silvia Fenu
- Unit of Rare Neurological Diseases, Department of Clinical Neurosciences, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Aurélie Méneret
- Sorbonne Université, Paris Brain Institute - ICM, Inserm, CNRS, AP-HP, Paris, France; Département de Neurologie, Hôpital de la Pitié-Salpêtrière, Assistance Publique Hôpitaux de Paris (APHP), Paris, France
| | - Frédéric Bourdain
- Service de Neurologie, Centre Hospitalier de la Côte Basque, Bayonne, France
| | - Marion Wandzel
- Laboratoire de Génétique Médicale, CHRU Nancy, Université de Lorraine, INSERM UMR_S1256, NGERE, Nancy, France
| | - Virginie Roth
- Laboratoire de Génétique Médicale, CHRU Nancy, Université de Lorraine, INSERM UMR_S1256, NGERE, Nancy, France
| | - Céline Bonnet
- Laboratoire de Génétique Médicale, CHRU Nancy, Université de Lorraine, INSERM UMR_S1256, NGERE, Nancy, France
| | - Florence Riant
- Service de Génétique Moléculaire Neurovasculaire, AP-HP, Saint Louis Hospital, Paris, France
| | - Giovanni Stevanin
- Sorbonne Université, Paris Brain Institute - ICM, Inserm, CNRS, AP-HP, Paris, France; Bordeaux University (Université de Bordeaux), Equipe « Neurogénétique Translationnelle - NRGEN », INCIA CNRS UMR5287, EPHE, 33000, Bordeaux, France
| | - Sandrine Noël
- Unité de Neurogénétique Moléculaire et Cellulaire, AP-HP, Hôpital Pitié-Salpêtrière, Paris, France
| | | | - Melanie Bahlo
- Population Health and Immunity Division, Walter and Eliza Hall Institute of Medical Research, Department of Medical Biology, University of Melbourne, Parkville, VIC, 3052, Australia
| | - Paul J Lockhart
- Bruce Lefroy Centre, Murdoch Children's Research Institute and Department of Paediatrics, University of Melbourne, Parkville, VIC, 3052, Australia
| | - Bernard Brais
- Department of Neurology and Neurosurgery, Montreal Neurological Hospital and Institute, McGill University, Montreal, QC, Canada
| | - Mathilde Renaud
- Service de Génétique Clinique et de Neurologie, Hôpital Brabois, Nancy, France; INSERM Unité 1256 N-GERE (Nutrition-Genetics and Environmental Risk Exposure), Université de Lorraine, Nancy, France
| | - Alexis Brice
- Sorbonne Université, Paris Brain Institute - ICM, Inserm, CNRS, AP-HP, Paris, France
| | - Alexandra Durr
- Sorbonne Université, Paris Brain Institute - ICM, Inserm, CNRS, AP-HP, Paris, France; Unité de Génétique Clinique, AP-HP, Hôpital Pitié-Salpêtrière, Paris, France.
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9
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Fox PM, Malepati S, Manaster L, Rossignol E, Noebels JL. Developing a pathway to clinical trials for CACNA1A-related epilepsies: A patient organization perspective. THERAPEUTIC ADVANCES IN RARE DISEASE 2024; 5:26330040241245725. [PMID: 38681799 PMCID: PMC11047245 DOI: 10.1177/26330040241245725] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/26/2023] [Accepted: 03/15/2024] [Indexed: 05/01/2024]
Abstract
CACNA1A-related disorders are rare neurodevelopmental disorders linked to variants in the CACNA1A gene. This gene encodes the α1 subunit of the P/Q-type calcium channel Cav2.1, which is globally expressed in the brain and crucial for fast synaptic neurotransmission. The broad spectrum of CACNA1A-related neurological disorders includes developmental and epileptic encephalopathies, familial hemiplegic migraine type 1, episodic ataxia type 2, spinocerebellar ataxia type 6, together with unclassified presentations with developmental delay, ataxia, intellectual disability, autism spectrum disorder, and language impairment. The severity of each disorder is also highly variable. The spectrum of CACNA1A-related seizures is broad across both loss-of-function and gain-of-function variants and includes absence seizures, focal seizures with altered consciousness, generalized tonic-clonic seizures, tonic seizures, status epilepticus, and infantile spasms. Furthermore, over half of CACNA1A-related epilepsies are refractory to current therapies. To date, almost 1700 CACNA1A variants have been reported in ClinVar, with over 400 listed as Pathogenic or Likely Pathogenic, but with limited-to-no clinical or functional data. Robust genotype-phenotype studies and impacts of variants on protein structure and function have also yet to be established. As a result, there are few definitive treatment options for CACNA1A-related epilepsies. The CACNA1A Foundation has set out to change the landscape of available and effective treatments and improve the quality of life for those living with CACNA1A-related disorders, including epilepsy. Established in March 2020, the Foundation has built a robust preclinical toolbox that includes patient-derived induced pluripotent stem cells and novel disease models, launched clinical trial readiness initiatives, and organized a global CACNA1A Research Network. This Research Network is currently composed of over 60 scientists and clinicians committed to collaborating to accelerate the path to CACNA1A-specific treatments and one day, a cure.
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Affiliation(s)
- Pangkong M. Fox
- CACNA1A Foundation, Inc., 31 Pt Road, Norwalk, CT 06854, USA
| | | | | | - Elsa Rossignol
- CACNA1A Foundation, Inc., Norwalk, CT, USA
- CHU Sainte-Justine Research Center, Departments of Neurosciences and Pediatrics, University of Montreal, Montreal, QC, Canada
| | - Jeffrey L. Noebels
- CACNA1A Foundation, Inc., Norwalk, CT, USA
- Blue Bird Circle Developmental Neurogenetics Laboratory, Department of Neurology, Baylor College of Medicine, One Baylor Plaza, Houston, TX, USA
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