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Chen CY, Tian R, Ge T, Lam M, Sanchez-Andrade G, Singh T, Urpa L, Liu JZ, Sanderson M, Rowley C, Ironfield H, Fang T, Daly M, Palotie A, Tsai EA, Huang H, Hurles ME, Gerety SS, Lencz T, Runz H. The impact of rare protein coding genetic variation on adult cognitive function. Nat Genet 2023:10.1038/s41588-023-01398-8. [PMID: 37231097 DOI: 10.1038/s41588-023-01398-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2022] [Accepted: 04/13/2023] [Indexed: 05/27/2023]
Abstract
Compelling evidence suggests that human cognitive function is strongly influenced by genetics. Here, we conduct a large-scale exome study to examine whether rare protein-coding variants impact cognitive function in the adult population (n = 485,930). We identify eight genes (ADGRB2, KDM5B, GIGYF1, ANKRD12, SLC8A1, RC3H2, CACNA1A and BCAS3) that are associated with adult cognitive function through rare coding variants with large effects. Rare genetic architecture for cognitive function partially overlaps with that of neurodevelopmental disorders. In the case of KDM5B we show how the genetic dosage of one of these genes may determine the variability of cognitive, behavioral and molecular traits in mice and humans. We further provide evidence that rare and common variants overlap in association signals and contribute additively to cognitive function. Our study introduces the relevance of rare coding variants for cognitive function and unveils high-impact monogenic contributions to how cognitive function is distributed in the normal adult population.
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Affiliation(s)
- Chia-Yen Chen
- Research and Development, Biogen Inc, Cambridge, MA, USA.
| | - Ruoyu Tian
- Research and Development, Biogen Inc, Cambridge, MA, USA
- Dewpoint Therapeutics, Boston, MA, USA
| | - Tian Ge
- Psychiatric and Neurodevelopmental Genetics Unit, Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA, USA
- Department of Psychiatry, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Max Lam
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA, USA
- Division of Psychiatry Research, The Zucker Hillside Hospital, Northwell Health, Glen Oaks, NY, USA
- Institute of Behavioral Science, Feinstein Institutes for Medical Research, Manhasset, NY, USA
| | | | - Tarjinder Singh
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA, USA
- Analytic and Translational Genetics Unit, Massachusetts General Hospital, Boston, MA, USA
| | - Lea Urpa
- Institute for Molecular Medicine Finland, HiLIFE, University of Helsinki, Helsinki, Finland
| | - Jimmy Z Liu
- Research and Development, Biogen Inc, Cambridge, MA, USA
- GlaxoSmithKline, Philadelphia, PA, USA
| | | | | | | | - Terry Fang
- Research and Development, Biogen Inc, Cambridge, MA, USA
| | - Mark Daly
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA, USA
- Analytic and Translational Genetics Unit, Massachusetts General Hospital, Boston, MA, USA
- Institute for Molecular Medicine Finland, HiLIFE, University of Helsinki, Helsinki, Finland
- Program in Medical and Population Genetics, Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Aarno Palotie
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA, USA
- Analytic and Translational Genetics Unit, Massachusetts General Hospital, Boston, MA, USA
- Institute for Molecular Medicine Finland, HiLIFE, University of Helsinki, Helsinki, Finland
- Program in Medical and Population Genetics, Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Ellen A Tsai
- Research and Development, Biogen Inc, Cambridge, MA, USA
| | - Hailiang Huang
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA, USA
- Analytic and Translational Genetics Unit, Massachusetts General Hospital, Boston, MA, USA
- Department of Medicine, Harvard Medical School, Boston, MA, USA
| | | | | | - Todd Lencz
- Division of Psychiatry Research, The Zucker Hillside Hospital, Northwell Health, Glen Oaks, NY, USA
- Institute of Behavioral Science, Feinstein Institutes for Medical Research, Manhasset, NY, USA
- Department of Psychiatry, Zucker School of Medicine at Hofstra/Northwell, Hempstead, NY, USA
- Department of Molecular Medicine, Zucker School of Medicine at Hofstra/Northwell, Hempstead, NY, USA
| | - Heiko Runz
- Research and Development, Biogen Inc, Cambridge, MA, USA.
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Indelicato E, Boesch S. CACNA1A-Related Channelopathies: Clinical Manifestations and Treatment Options. Handb Exp Pharmacol 2023; 279:227-248. [PMID: 36592223 DOI: 10.1007/164_2022_625] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
In the last decade, variants in the Ca2+ channel gene CACNA1A emerged as a frequent aetiology of rare neurological phenotypes sharing a common denominator of variable paroxysmal manifestations and chronic cerebellar dysfunction. The spectrum of paroxysmal manifestations encompasses migraine with hemiplegic aura, episodic ataxia, epilepsy and paroxysmal non-epileptic movement disorders. Additional chronic neurological symptoms range from severe developmental phenotypes in early-onset cases to neurobehavioural disorders and chronic cerebellar ataxia in older children and adults.In the present review we systematically approach the clinical manifestations of CACNA1A variants, delineate genotype-phenotype correlations and elaborate on the emerging concept of an age-dependent phenotypic spectrum in CACNA1A disease. We furthermore reflect on different therapy options available for paroxysmal symptoms in CACNA1A and address open issues to prioritize in the future clinical research.
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Affiliation(s)
- Elisabetta Indelicato
- Center for Rare Movement Disorders Innsbruck, Department of Neurology, Medical University of Innsbruck, Innsbruck, Austria.
| | - Sylvia Boesch
- Center for Rare Movement Disorders Innsbruck, Department of Neurology, Medical University of Innsbruck, Innsbruck, Austria
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Batum M, Kısabay Ak A, Çetin G, Çelebi HBG, Çam S, Mavioğlu H. Coincidental occurance of episodic ataxia and multiple sclerosis: a case report and review of the literature. Int J Neurosci 2022; 132:656-661. [DOI: 10.1080/00207454.2020.1835896] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Affiliation(s)
- Melike Batum
- Neurology Department, Celal Bayar Unıversity, Manisa, Turkey
| | | | - Güldeniz Çetin
- Neurology Department, Celal Bayar Unıversity, Manisa, Turkey
| | | | - Sırrı Çam
- Genetics Department, Celal Bayar Unıversity, Manisa, Turkey
| | - Hatice Mavioğlu
- Neurology Department, Celal Bayar Unıversity, Manisa, Turkey
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4
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Indelicato E, Boesch S. From Genotype to Phenotype: Expanding the Clinical Spectrum of CACNA1A Variants in the Era of Next Generation Sequencing. Front Neurol 2021; 12:639994. [PMID: 33737904 PMCID: PMC7960780 DOI: 10.3389/fneur.2021.639994] [Citation(s) in RCA: 39] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Accepted: 02/08/2021] [Indexed: 12/15/2022] Open
Abstract
Ion channel dysfunction is a key pathological substrate of episodic neurological disorders. A classical gene associated to paroxysmal movement disorders is CACNA1A, which codes for the pore-forming subunit of the neuronal calcium channel P/Q. Non-polyglutamine CACNA1A variants underlie familial hemiplegic ataxia type 1 (FHM1) and episodic ataxia type 2 (EA2). Classical paroxysmal manifestations of FHM1 are migraine attacks preceded by motor aura consisting of hemiparesis, aphasia, and disturbances of consciousness until coma. Patients with EA2 suffer of recurrent episodes of vertigo, unbalance, diplopia, and vomiting. Beyond these typical presentations, several reports highlighted manifold clinical features associated with P/Q channelopathies, from chronic progressive cerebellar ataxia to epilepsy and psychiatric disturbances. These manifestations may often outlast the burden of classical episodic symptoms leading to pitfalls in the diagnostic work-up. Lately, the spreading of next generation sequencing techniques linked de novo CACNA1A variants to an even broader phenotypic spectrum including early developmental delay, autism spectrum disorders, epileptic encephalopathy, and early onset paroxysmal dystonia. The age-dependency represents a striking new aspect of these phenotypes und highlights a pivotal role for P/Q channels in the development of the central nervous system in a defined time window. While several reviews addressed the clinical presentation and treatment of FHM1 and EA2, an overview of the newly described age-dependent manifestations is lacking. In this Mini-Review we present a clinical update, delineate genotype-phenotype correlations as well as summarize evidence on the pathophysiological mechanisms underlying the expanded phenotype associated with CACNA1A variants.
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Affiliation(s)
| | - Sylvia Boesch
- Center for Rare Movement Disorders Innsbruck, Department of Neurology, Medical University of Innsbruck, Innsbruck, Austria
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Jaudon F, Baldassari S, Musante I, Thalhammer A, Zara F, Cingolani LA. Targeting Alternative Splicing as a Potential Therapy for Episodic Ataxia Type 2. Biomedicines 2020; 8:E332. [PMID: 32899500 PMCID: PMC7555146 DOI: 10.3390/biomedicines8090332] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2020] [Revised: 09/01/2020] [Accepted: 09/04/2020] [Indexed: 12/26/2022] Open
Abstract
Episodic ataxia type 2 (EA2) is an autosomal dominant neurological disorder characterized by paroxysmal attacks of ataxia, vertigo, and nausea that usually last hours to days. It is caused by loss-of-function mutations in CACNA1A, the gene encoding the pore-forming α1 subunit of P/Q-type voltage-gated Ca2+ channels. Although pharmacological treatments, such as acetazolamide and 4-aminopyridine, exist for EA2, they do not reduce or control the symptoms in all patients. CACNA1A is heavily spliced and some of the identified EA2 mutations are predicted to disrupt selective isoforms of this gene. Modulating splicing of CACNA1A may therefore represent a promising new strategy to develop improved EA2 therapies. Because RNA splicing is dysregulated in many other genetic diseases, several tools, such as antisense oligonucleotides, trans-splicing, and CRISPR-based strategies, have been developed for medical purposes. Here, we review splicing-based strategies used for genetic disorders, including those for Duchenne muscular dystrophy, spinal muscular dystrophy, and frontotemporal dementia with Parkinsonism linked to chromosome 17, and discuss their potential applicability to EA2.
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Affiliation(s)
- Fanny Jaudon
- Department of Life Sciences, University of Trieste, 34127 Trieste, Italy;
| | - Simona Baldassari
- Unit of Medical Genetics, IRCCS Istituto Giannina Gaslini, 16147 Genoa, Italy; (S.B.); (I.M.); (F.Z.)
| | - Ilaria Musante
- Unit of Medical Genetics, IRCCS Istituto Giannina Gaslini, 16147 Genoa, Italy; (S.B.); (I.M.); (F.Z.)
- Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health (DINOGMI), University of Genoa, 16126 Genoa, Italy
| | - Agnes Thalhammer
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia (IIT), 16132 Genoa, Italy;
- IRCCS Ospedale Policlinico San Martino, 16132 Genoa, Italy
| | - Federico Zara
- Unit of Medical Genetics, IRCCS Istituto Giannina Gaslini, 16147 Genoa, Italy; (S.B.); (I.M.); (F.Z.)
- Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health (DINOGMI), University of Genoa, 16126 Genoa, Italy
| | - Lorenzo A. Cingolani
- Department of Life Sciences, University of Trieste, 34127 Trieste, Italy;
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia (IIT), 16132 Genoa, Italy;
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De Gusmao CM, Silveira-Moriyama L. Paroxysmal movement disorders - practical update on diagnosis and management. Expert Rev Neurother 2019; 19:807-822. [PMID: 31353980 DOI: 10.1080/14737175.2019.1648211] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Introduction: Paroxysmal dyskinesias and episodic ataxias are often caused by mutations in genes related to cell membrane and synaptic function. Despite the exponential increase in publications of genetically confirmed cases, management remains largely clinical based on non-systematic evidence. Areas covered: The authors provide a historical and clinical review of the main types of paroxysmal dyskinesias and episodic ataxias, with recommendations for diagnosis and management of patients suffering from these conditions. Expert opinion: After secondary paroxysmal dyskinesias, the most common paroxysmal movement disorders are likely to be PRRT2-associated paroxysmal kinesigenic dyskinesias, which respond well to small doses of carbamazepine, and episodic ataxia type 2, which often responds to acetazolamide. Familial paroxysmal non-kinesigenic dyskinesias are largely caused by mutations in PNKD and have poor response to therapy but improve with age. Exercise-induced dyskinesias are genetically heterogeneous, caused by disorders of glucose transport, mitochondrial function, dopaminergic pathways or neurodegenerative conditions amongst others. GNAO1 and ADCY5 mutations can also cause paroxysmal movement disorders, often in the context of ongoing motor symptoms. Although a therapeutic trial is justified for classic cases and in limited resource settings, genetic testing may help direct initial or rescue therapy. Deep brain stimulation may be an option for severe cases.
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Affiliation(s)
- Claudio M De Gusmao
- Department of Neurology, Harvard Medical School, Boston Children's Hospital , Boston , MA , USA.,Department of Neurology, Universidade Estadual de Campinas (UNICAMP) , São Paulo , Brazil
| | - Laura Silveira-Moriyama
- Department of Neurology, Universidade Estadual de Campinas (UNICAMP) , São Paulo , Brazil.,Education Unit, UCL Institute of Neurology, University College London , London , UK.,Department of Neurology, Hospital Bairral, Fundação Espírita Américo Bairral , Itapira , Brazil
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7
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Tarnutzer AA, Straumann D, Salman MS. Neuro-ophthalmologic assessment and investigations in children and adults with cerebellar diseases. THE CEREBELLUM: FROM EMBRYOLOGY TO DIAGNOSTIC INVESTIGATIONS 2018; 154:305-327. [DOI: 10.1016/b978-0-444-63956-1.00019-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
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8
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Heimer G, Sadaka Y, Israelian L, Feiglin A, Ruggieri A, Marshall CR, Scherer SW, Ganelin-Cohen E, Marek-Yagel D, Tzadok M, Nissenkorn A, Anikster Y, Minassian BA, Zeev BB. CAOS-Episodic Cerebellar Ataxia, Areflexia, Optic Atrophy, and Sensorineural Hearing Loss: A Third Allelic Disorder of the ATP1A3 Gene. J Child Neurol 2015; 30:1749-56. [PMID: 25895915 DOI: 10.1177/0883073815579708] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/18/2014] [Accepted: 03/04/2015] [Indexed: 11/17/2022]
Abstract
We describe the molecular basis of a distinctive syndrome characterized by infantile stress-induced episodic weakness, ataxia, and sensorineural hearing loss, with permanent areflexia and optic nerve pallor. Whole exome sequencing identified a deleterious heterozygous c.2452 G>A, p.(E818K) variant in the ATP1A3 gene and structural analysis predicted its protein-destabilizing effect. This variant has not been reported in context with rapid-onset dystonia parkinsonism and alternating hemiplegia of childhood, the 2 main diseases associated with ATP1A3. The clinical presentation in the family described here differs categorically from these diseases in age of onset, clinical course, cerebellar over extrapyramidal movement disorder predominance, and peripheral nervous system involvement. While this paper was in review, a highly resembling phenotype was reported in additional patients carrying the same c.2452 G>A variant. Our findings substantiate this variant as the cause of a unique inherited autosomal dominant neurologic syndrome that constitutes a third allelic disease of the ATP1A3 gene.
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Affiliation(s)
- Gali Heimer
- Pediatric Neurology Unit, Edmond and Lily Children's Hospital, The Chaim Sheba Medical Center, Ramat Gan, Israel The Pinchas Borenstein Talpiot Medical Leadership Program, The Chaim Sheba Medical Center, Ramat Gan, Israel
| | - Yair Sadaka
- Program in Genetics and Genome Biology, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Lori Israelian
- Division of Neurology, Department of Pediatrics, The Hospital for Sick Children, and University of Toronto, Toronto, Ontario, Canada
| | - Ariel Feiglin
- Center for Biomedical Informatics, Harvard Medical School, Boston, MA, USA
| | - Alessandra Ruggieri
- Program in Genetics and Genome Biology, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Christian R Marshall
- Program in Genetics and Genome Biology, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Stephen W Scherer
- Program in Genetics and Genome Biology, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Esther Ganelin-Cohen
- Pediatric Neurology Unit, Edmond and Lily Children's Hospital, The Chaim Sheba Medical Center, Ramat Gan, Israel
| | - Dina Marek-Yagel
- Metabolic Disease Unit, Edmond and Lily Children's Hospital, the Chaim Sheba Medical Center, Ramat Gan, Israel
| | - Michal Tzadok
- Pediatric Neurology Unit, Edmond and Lily Children's Hospital, The Chaim Sheba Medical Center, Ramat Gan, Israel
| | - Andreea Nissenkorn
- Pediatric Neurology Unit, Edmond and Lily Children's Hospital, The Chaim Sheba Medical Center, Ramat Gan, Israel
| | - Yair Anikster
- Metabolic Disease Unit, Edmond and Lily Children's Hospital, the Chaim Sheba Medical Center, Ramat Gan, Israel The Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Berge A Minassian
- Program in Genetics and Genome Biology, The Hospital for Sick Children, Toronto, Ontario, Canada Division of Neurology, Department of Pediatrics, The Hospital for Sick Children, and University of Toronto, Toronto, Ontario, Canada
| | - Bruria Ben Zeev
- Pediatric Neurology Unit, Edmond and Lily Children's Hospital, The Chaim Sheba Medical Center, Ramat Gan, Israel The Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
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9
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10
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Can the adverse effects of antiepileptic drugs be detected in saccadic eye movements? Seizure 2014; 25:33-6. [PMID: 25645633 DOI: 10.1016/j.seizure.2014.12.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2014] [Revised: 12/02/2014] [Accepted: 12/03/2014] [Indexed: 11/23/2022] Open
Abstract
PURPOSE The objective of this study was to determine whether the adverse effects of antiepileptic-drugs could be assessed by the eye movements of epilepsy patients. METHODS This study was performed prospectively in a single tertiary hospital. The inclusion criteria for this study were as follows: (1) consecutive patients with epilepsy taking antiepileptic-drugs regularly for at least 1 year, (2) the absence of structural lesions on MRI, (3) an age ≥16 years old, (4) not using medications that could influence eye movement, and (5) a normal neurological examination. The latency, peak velocity and accuracy of the saccades and the gain of the pursuits were recorded by video-based electro-oculography. We analyzed the differences in the parameters of the eye movements for 75 patients with epilepsy and 20 normal controls matched for age and sex. RESULTS The total latency (1017.7 ± 148.9 ms vs. 1150.7 ± 106.6 ms, p=0.0003) and accuracy [370.7% (95% CI 364.1-376.4%, range 306-408.2%), 92.7% as total accuracy normalized value vs. 383.6% (95% CI 378.8-398%, range 322.9-417.4%), 95.9% as total accuracy normalized value, p=0.0005] were significantly different between the patients with epilepsy and normal controls. For the detection of nystagmus with video-based electro-oculography, the clear cutoff values of total accuracy (≤388.7%, 97.2% as total accuracy normalized value) revealed 93.4% sensitivity and 28.6% specificity, and the clear cutoff values of total latency (≤1005.5 ms) showed 49.2% sensitivity and 78.6% specificity. CONCLUSIONS The total latency and accuracy of video-based electro-oculography may be screened to identify patients with a high risk of adverse effects with antiepileptic-drugs.
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11
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Kipfer S, Strupp M. The Clinical Spectrum of Autosomal-Dominant Episodic Ataxias. Mov Disord Clin Pract 2014; 1:285-290. [PMID: 30713867 DOI: 10.1002/mdc3.12075] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2014] [Revised: 06/16/2014] [Accepted: 06/20/2014] [Indexed: 11/06/2022] Open
Abstract
Autosomal-dominant episodic ataxias (EAs) represent a clinically and genetically heterogeneous group of disorders characterized by recurrent episodes of cerebellar ataxia (CA). Ataxia episodes are usually of short duration and often triggered by specific stimuli. There are currently seven classified subtypes of EA. EA types 1 and 2 have the highest prevalence and are therefore the clinically most relevant. Between attacks, EA 1 is associated with myokymia. In EA 2, often an interictal downbeat nystagmus with other cerebellar ocular dysfunctions is present; patients with EA 2 may display slowly progessive ataxia and vermian atrophy. EA 1 and 2 are both channelopathies, affecting the potassium channel gene, KCNA1, in EA 1 and the PQ calcium channel-encoding gene, CACNA1A, in EA 2. The types EA 3 to 7 are very rare and have to be further elucidated. Here, we review the historical, clinical, and genetic aspects of autosomal-dominant EAs and their current treatment, focusing on EA 1 and 2.
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Affiliation(s)
- Stefan Kipfer
- Department of Neurology Kantonsspital Olten Switzerland
| | - Michael Strupp
- Department of Neurology and German Center for Vertigo and Balance Disorders University Hospital Munich Munich Germany
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12
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Coebergh JA, Fransen van de Putte DE, Snoeck IN, Ruivenkamp C, van Haeringen A, Smit LM. A new variable phenotype in spinocerebellar ataxia 27 (SCA 27) caused by a deletion in the FGF14 gene. Eur J Paediatr Neurol 2014; 18:413-5. [PMID: 24252256 DOI: 10.1016/j.ejpn.2013.10.006] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/19/2013] [Revised: 10/06/2013] [Accepted: 10/20/2013] [Indexed: 10/26/2022]
Abstract
We present a young boy whose mild ataxia and abnormal eye movements repeatedly deteriorated with fever, making him unable to sit or walk during fever episodes. SNP-array analysis identified a 202 kb deletion in chromosome 13q33.1 containing the fibroblast growth factor (FGF)14 gene, which is associated with spinocerebellar ataxia (SCA) 27. This 13q deletion was also present in the proband's mother and grandmother. The mother was unable to perform tandem gait walking and had abnormal eye movements but had never sought medical attention. The grandmother predominantly had a postural tremor. FGF14 regulates brain sodium channels, especially in the cerebellum. Sodium channels can be fever sensitive. This family demonstrates phenotypic variability of FGF14 deletions (SCA 27), fever sensitivity of ataxia and the added value of SNP-array analysis in making a diagnosis.
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Affiliation(s)
- J A Coebergh
- Department of Paediatric Neurology, Haga Teaching Hospital, The Hague, The Netherlands; Department of Neurology, Ashford and St Peter's Hospitals, United Kingdom; Department of Neurology, St George's Hospitals, United Kingdom.
| | | | - I N Snoeck
- Department of Paediatric Neurology, Haga Teaching Hospital, The Hague, The Netherlands
| | - C Ruivenkamp
- Department of Clinical Genetics, Leiden University Medical Center, Leiden, The Netherlands
| | - A van Haeringen
- Department of Clinical Genetics, Leiden University Medical Center, Leiden, The Netherlands
| | - L M Smit
- Department of Paediatric Neurology, Haga Teaching Hospital, The Hague, The Netherlands
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13
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Kipfer S, Jung S, Lemke JR, Kipfer-Kauer A, Howell JP, Kaelin-Lang A, Nyffeler T, Gutbrod K, Abicht A, Müri RM. Novel CACNA1A mutation(s) associated with slow saccade velocities. J Neurol 2013; 260:3010-4. [DOI: 10.1007/s00415-013-7099-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2013] [Revised: 08/23/2013] [Accepted: 09/06/2013] [Indexed: 01/11/2023]
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14
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Fujioka S, Rayaprolu S, Sundal C, Broderick DF, Langley WA, Shoffner J, Hyams LC, Rademakers R, Graff-Radford NR, Tatum W, Ross OA, Wszolek ZK. A novel de novo pathogenic mutation in the CACNA1A gene. Mov Disord 2012; 27:1578-9. [PMID: 23038654 DOI: 10.1002/mds.25198] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
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15
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Parker JL, Santiago M. Oculomotor aspects of the hereditary cerebellar ataxias. HANDBOOK OF CLINICAL NEUROLOGY 2012; 103:63-83. [PMID: 21827881 DOI: 10.1016/b978-0-444-51892-7.00003-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Affiliation(s)
- J Larry Parker
- Department of Neurology, University of Mississippi Medical Center, Jackson, MS 39216-4505, USA.
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16
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Blumkin L, Michelson M, Leshinsky-Silver E, Kivity S, Lev D, Lerman-Sagie T. Congenital ataxia, mental retardation, and dyskinesia associated with a novel CACNA1A mutation. J Child Neurol 2010; 25:892-7. [PMID: 20097664 DOI: 10.1177/0883073809351316] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The CACNA1A gene encodes the pore forming alpha-1A subunit of neuronal voltage-dependent P/Q-type Ca( 2+) channels. Mutations in this gene result in clinical heterogeneity, and present with either chronic progressive symptoms, paroxysmal events, or both, with clinical overlap among the different phenotypes. The authors describe a seven year-old boy with mental retardation and congenital cerebellar ataxia that developed dyskinesia at the age of a few months, and recurrent episodes of coma following mild head trauma associated with motor and autonomic signs, from the second year of life. An extensive metabolic evaluation, interictal electroencephalography (EEG), and muscle biopsy were normal. Brain magnetic resonance imaging (MRI) during one of these episodes revealed edema of the right hemisphere and cerebellar atrophy. Genetic testing revealed a R1350Q mutation in the CACNA1A gene. This is a novel de novo mutation.Congenital cerebellar ataxia can be a result of CACNA1A mutations, especially when associated with recurrent unexplained coma.
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Affiliation(s)
- Lubov Blumkin
- Pediatric Neurology Unit, Wolfson Medical Center, Sackler School of Medicine, Tel- Aviv University, Holon, Israel
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Abstract
Dysfunction of the Brain Calcium Channel Cav2.1 in Absence Epilepsy and Episodic Ataxia Imbrici P, Jaffe SL, Eunson LH, Davies NP, Herd C, Robertson R, Kullmann DM, Hanna MG Brain 2004;127(Pt 12):2682–2692 The molecular basis of idiopathic generalized epilepsy remains poorly understood. Absence epilepsy with 3-Hz spike–wave EEG is one of the most common human epilepsies and is associated with significant morbidity. Several spontaneously occurring genetic mouse models of absence epilepsy are caused by dysfunction of the P/Q-type voltage-gated calcium channel CaV2.1. Such mice exhibit a primary generalized spike–wave EEG, with frequencies in the range of 5 to 7 Hz, often associated with ataxia, evidence of cerebellar degeneration and abnormal posturing. Previously, we identified a single case of severe primary generalized epilepsy with ataxia associated with CaV2.1 dysfunction, suggesting a possible link between this channel and human absence epilepsy. We now report a family in which absence epilepsy segregates in an autosomal dominant fashion through three generations. Five members exhibit a combination of absence epilepsy (with 3-Hz spike–wave) and cerebellar ataxia. In patients with the absence epilepsy/ataxia phenotype, genetic marker analysis was consistent with linkage to the CACNA1A gene on chromosome 19, which encodes the main pore-forming α1A subunit of CaV2.1 channels (CaV2.1 α1). DNA sequence analysis identified a novel point mutation resulting in a radical amino acid substitution (E147K) in CaV2.1 α1, which segregated with the epilepsy/ataxia phenotype. Functional expression studies using human CACNA1A cDNA demonstrated that the E147K mutation results in impairment of calcium channel function. Impaired function of the brain calcium channel CaV2.1 may have a central role in the pathogenesis of certain cases of primary generalized epilepsy, particularly when associated with ataxia, which may be wrongly ascribed to anticonvulsant medication.
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Montagna P. The primary headaches: genetics, epigenetics and a behavioural genetic model. J Headache Pain 2008; 9:57-69. [PMID: 18345478 PMCID: PMC2276243 DOI: 10.1007/s10194-008-0026-x] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2008] [Accepted: 02/04/2008] [Indexed: 12/14/2022] Open
Abstract
The primary headaches, migraine with (MA) and without aura (MO) and cluster headache, all carry a substantial genetic liability. Familial hemiplegic migraine (FHM), an autosomal dominant mendelian disorder classified as a subtype of MA, is due to mutations in genes encoding neural channel subunits. MA/MO are considered multifactorial genetic disorders, and FHM has been proposed as a model for migraine aetiology. However, a review of the genetic studies suggests that the FHM genes are not involved in the typical migraines and that FHM should be considered as a syndromic migraine rather than a subtype of MA. Adopting the concept of syndromic migraine could be useful in understanding migraine pathogenesis. We hypothesise that epigenetic mechanisms play an important role in headache pathogenesis. A behavioural model is proposed, whereby the primary headaches are construed as behaviours, not symptoms, evolutionarily conserved for their adaptive value and engendered out of a genetic repertoire by a network of pattern generators present in the brain and signalling homeostatic imbalance. This behavioural model could be incorporated into migraine genetic research.
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Affiliation(s)
- Pasquale Montagna
- Department of Neurological Sciences, University of Bologna Medical School, Via Ugo Foscolo, 7, 40123 Bologna, Italy.
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Lo C, Shorvon SD, Luxon LM, Bamiou DDE. Saccadic eye movements and anti-epileptic drugs. Epilepsy Res 2008; 78:93-101. [DOI: 10.1016/j.eplepsyres.2007.11.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2007] [Revised: 11/06/2007] [Accepted: 11/18/2007] [Indexed: 10/22/2022]
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Haan J, Kors EE, Vanmolkot KRJ, van den Maagdenberg AMJM, Frants RR, Ferrari MD. Migraine genetics: an update. Curr Pain Headache Rep 2006; 9:213-20. [PMID: 15907261 DOI: 10.1007/s11916-005-0065-9] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
A growing interest in genetic research in migraine has resulted in the identification of several chromosomal regions that are involved in migraine. However, the identification of mutations in the genes for familial hemiplegic migraine (FHM) forms the only true molecular genetic knowledge of migraine thus far. The increased number of mutations in the FHM1 (CACNA1A) and the FHM2 (ATP1A2) genes allow studying the relationship between genetic findings in both genes and the clinical features in patients. A wide spectrum of symptoms is seen in patients. Additional cerebellar ataxia and (childhood) epilepsy can occur in FHM1 and FHM2. Functional studies show a dysfunction in ion transport as the key factor in the pathophysiology of (familial hemiplegic) migraine that predict an increased susceptibility to cortical spreading depression--the underlying mechanism of migraine aura.
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Affiliation(s)
- J Haan
- Department of Neurology, Leiden University Medical Centre, P.O. Box 9600, 2300 RC Leiden, The Netherlands. E-mail:
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Raike RS, Kordasiewicz HB, Thompson RM, Gomez CM. Dominant-negative suppression of Cav2.1 currents by alpha(1)2.1 truncations requires the conserved interaction domain for beta subunits. Mol Cell Neurosci 2006; 34:168-77. [PMID: 17161621 PMCID: PMC3236250 DOI: 10.1016/j.mcn.2006.10.011] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2006] [Revised: 10/11/2006] [Accepted: 10/19/2006] [Indexed: 11/20/2022] Open
Abstract
Episodic ataxia type 2 (EA2) is an autosomal dominant disorder arising from CACNA1A mutations, which commonly predict heterozygous expression of Ca(v)2.1 calcium channels with truncated alpha(1)2.1 pore subunits. We hypothesized that alpha(1)2.1 truncations in EA2 exert dominant-negative effects on the function of wild-type subunits. Wild-type and truncated alpha(1)2.1 subunits with fluorescent protein tags were transiently co-expressed in cells stably expressing Ca(v) auxiliary beta subunits, which facilitate alpha1 subunit functional expression through high-affinity interactions with the alpha interaction domain (AID). Co-expression of wild-type subunits with truncations often resulted in severely reduced whole-cell currents compared to expression of wild-type subunits alone. Cellular image analyses revealed that current suppression was not due to reduced wild-type expression levels. Instead, the current suppression depended on truncations terminating distal to the AID. Moreover, only AID-bearing alpha(1)2.1 proteins co-immunoprecipitated with Ca(v) beta subunits. These results indicate that Ca(v) beta subunits may play a prominent role in EA2 disease pathogenesis.
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Affiliation(s)
- Robert S. Raike
- Departments of Neurology and Neuroscience, University of Minnesota, Minneapolis, MN 55455
| | - Holly B. Kordasiewicz
- Departments of Neurology and Neuroscience, University of Minnesota, Minneapolis, MN 55455
| | - Randall M. Thompson
- Departments of Neurology and Neuroscience, University of Minnesota, Minneapolis, MN 55455
| | - Christopher M. Gomez
- Departments of Neurology and Neuroscience, University of Minnesota, Minneapolis, MN 55455
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de Theije-Kors E, Haan J. Hemiplegic and Basilar-type Migraine: Epidemiology, Genetics, and Mechanisms. ACTA ACUST UNITED AC 2006. [DOI: 10.1111/j.1743-5013.2006.00036.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Kang JQ, Shen W, Macdonald RL. Why does fever trigger febrile seizures? GABAA receptor gamma2 subunit mutations associated with idiopathic generalized epilepsies have temperature-dependent trafficking deficiencies. J Neurosci 2006; 26:2590-7. [PMID: 16510738 PMCID: PMC6793669 DOI: 10.1523/jneurosci.4243-05.2006] [Citation(s) in RCA: 97] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
With a worldwide incidence as high as 6.7% of children, febrile seizures are one of the most common reasons for seeking pediatric care, but the mechanisms underlying generation of febrile seizures are poorly understood. Febrile seizures have been suspected to have a genetic basis, and recently, mutations in GABAA receptor and sodium channel genes have been identified that are associated with febrile seizures and generalized seizures with febrile seizures plus pedigrees. Pentameric GABAA receptors mediate the majority of fast synaptic inhibition in the brain and are composed of combinations of alpha(1-6), beta(1-3), and gamma(1-3) subunits. In alphabetagamma2 GABAA receptors, the gamma2 subunit is critical for receptor trafficking, clustering, and synaptic maintenance, and mutations in the gamma2 subunit have been monogenically associated with autosomal dominant transmission of febrile seizures. Here, we report that whereas trafficking of wild-type alpha1beta2gamma2 receptors was slightly temperature dependent, trafficking of mutant alpha1beta2gamma2 receptors containing gamma2 subunit mutations [gamma2(R43Q), gamma2(K289M), and gamma2(Q351X)] associated with febrile seizures was highly temperature dependent. In contrast, trafficking of mutant alpha1beta2gamma2 receptors containing an alpha1 subunit mutation [alpha1(A322D)] not associated with febrile seizures was not highly temperature dependent. Brief increases in temperature from 37 to 40 degrees C rapidly (<10 min) impaired trafficking and/or accelerated endocytosis of heterozygous mutant alpha1beta2gamma2 receptors containing gamma2 subunit mutations associated with febrile seizures but not of wild-type alpha1beta2gamma2 receptors or heterozygous mutant alpha1(A322D)beta2gamma2 receptors, suggesting that febrile seizures may be produced by a temperature-induced dynamic reduction of susceptible mutant surface GABAA receptors in response to fever.
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Weisz CJC, Raike RS, Soria-Jasso LE, Hess EJ. Potassium channel blockers inhibit the triggers of attacks in the calcium channel mouse mutant tottering. J Neurosci 2006; 25:4141-5. [PMID: 15843617 PMCID: PMC6724952 DOI: 10.1523/jneurosci.0098-05.2005] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Humans with the disorder episodic ataxia type 2 (EA2) and the tottering mouse mutant exhibit episodic attacks induced by emotional and chemical stress. Both the human and mouse disorders result from mutations in CACNA1A, the gene encoding the alpha(1)2.1 subunit of Ca(v)2.1 voltage-gated calcium channels. These mutations predict reduced calcium currents, particularly in cerebellar Purkinje cells, where these channels are most abundant. 4-Aminopyridine (4-AP), a nonselective blocker of K(v) voltage-gated potassium channels, alleviates attacks of ataxia in EA2 patients. To test the specificity of the effect for K(v) channels, aminopyridine analogs were assessed for their ability to ameliorate attacks of dyskinesia in tottering mice. 4-AP and 3,4-diaminopyridine (3,4-DiAP), which have relatively high affinities for K(v) channels, reduced the frequency of restraint- and caffeine-induced attacks. Furthermore, microinjection of 3,4-DiAP into the cerebellum completely blocked attacks in tottering mice. Other aminopyridine analogs reduced attack frequency but, consistent with their lower affinities for K(v) channels, required comparatively higher doses. These results suggest that aminopyridines block tottering mouse attacks via cerebellar K(v) channels. That both stress- and caffeine-induced attacks were blocked by aminopyridines suggests that these triggers act via similar mechanisms. Although 4-AP and 3,4-DiAP were effective in preventing attacks in tottering mice, these compounds did not affect the severity of "breakthrough" attacks that occurred in the presence of a drug. These results suggest that the aminopyridines increase the threshold for attack initiation without mitigating the character of the attack, indicating that attack initiation is mediated by mechanisms that are independent of the neurological phenotype.
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Affiliation(s)
- Catherine J C Weisz
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, Maryland 21287, USA
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26
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Nahm SS, Jung KY, Enger MK, Griffith WH, Abbott LC. Differential expression of T-type calcium channels in P/Q-type calcium channel mutant mice with ataxia and absence epilepsy. ACTA ACUST UNITED AC 2005; 62:352-60. [PMID: 15514988 DOI: 10.1002/neu.20107] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Mutations in P/Q-type calcium channels generate common phenotypes in mice and humans, which are characterized by ataxia, paroxysmal dyskinesia, and absence seizures. Subsequent functional changes of T-type calcium channels in thalamus are observed in P/Q-type calcium channel mutant mice and these changes play important roles in generation of absence seizures. However, the changes in T-type calcium channel function and/or expression in the cerebellum, which may be related to movement disorders, are still unknown. The leaner mouse exhibits severe ataxia, paroxysmal dyskinesia, and absence epilepsy due to a P/Q-type calcium channel mutation. We investigated changes in T-type calcium channel expression in the leaner mouse thalamus and cerebellum using quantitative real-time polymerase chain reaction (qRT-PCR) and quantitative in situ hybridization histochemistry (ISHH). qRT-PCR analysis showed no change in T-type calcium channel alpha 1G subunit (Cav3.1) expression in the leaner thalamus, but a significant decrease in alpha 1G expression in the whole leaner mouse cerebellum. Interestingly, quantitative ISHH revealed differential changes in alpha 1G expression in the leaner cerebellum, where the granule cell layer showed decreased alpha 1G expression while Purkinje cells showed increased alpha 1G expression. To confirm these observations, the granule cell layer and the Purkinje cell layer were laser capture microdissected separately, then analyzed with qRT-PCR. Similar to the observation obtained by ISHH, the leaner granule cell layer showed decreased alpha 1G expression and the leaner Purkinje cell layer showed increased alpha 1G expression. These results suggest that differential expression of T-type calcium channels in the leaner cerebellum may be involved in the observed movement disorders.
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MESH Headings
- Analysis of Variance
- Animals
- Animals, Newborn
- Ataxia/complications
- Ataxia/genetics
- Ataxia/metabolism
- Autoradiography/methods
- Calcium Channels, P-Type/genetics
- Calcium Channels, Q-Type/genetics
- Calcium Channels, T-Type/genetics
- Calcium Channels, T-Type/metabolism
- Cerebellum/cytology
- Cerebellum/metabolism
- Disease Models, Animal
- Epilepsy, Absence/complications
- Epilepsy, Absence/metabolism
- Female
- Gene Expression Regulation, Developmental/genetics
- In Situ Hybridization/methods
- Lasers
- Male
- Mice
- Mice, Inbred C57BL
- Mice, Neurologic Mutants
- Microdissection/methods
- Mutation
- Neurons/metabolism
- Protein Subunits/genetics
- Protein Subunits/metabolism
- RNA, Messenger/biosynthesis
- Reverse Transcriptase Polymerase Chain Reaction/methods
- Thalamus/cytology
- Thalamus/metabolism
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Affiliation(s)
- Sang-Soep Nahm
- Department of Human Anatomy & Medical Neurobiology, College of Medicine, Texas A&M University System Health Science Center, College Station, Texas 77843-1114, USA
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Yu GY, Howell MJ, Roller MJ, Xie TD, Gomez CM. Spinocerebellar ataxia type 26 maps to chromosome 19p13.3 adjacent to SCA6. Ann Neurol 2005; 57:349-54. [PMID: 15732118 DOI: 10.1002/ana.20371] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
The dominantly inherited spinocerebellar ataxias (SCA) are a clinically and genetically heterogeneous group of neurodegenerative disorders characterized by progressive gait ataxia, upper limb incoordination, and dysarthria. We studied a six-generation kindred of Norwegian ancestry with pure cerebellar ataxia inherited in an autosomal dominant pattern. All affected family members had a slowly progressive cerebellar ataxia, with an age of onset range from 26 to 60 years. Brain magnetic resonance imaging study of 11 affected patients showed that atrophy was confined to the cerebellum. After excluding all the known SCAs using linkage analysis or direct mutation screen, we conducted a genomewide genetic linkage scan. With the aid of a novel linkage analysis strategy, we found linkage between the disease locus and marker D19S591 and D19S1034. Subsequent genetic and clinical analysis identified a critical region of 15.55cM interval on chromosome 19p13.3, flanked by markers D19S886 and D19S894, and have established a new genetic locus designated SCA26. The SCA26 locus is adjacent to the genes for Cayman ataxia and SCA6. The region consists of 3.3 million base pairs (Mb) of DNA sequences with approximately 100 known and predicted genes. Identification of the responsible gene for SCA26 ataxia will provide further insight into mechanisms of neurodegeneration.
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Affiliation(s)
- Guo-Yun Yu
- Department of Neurology, University of Minnesota, MMC 295, 420 Delaware Street SE, Minneapolis, MN 55455, USA
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28
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Subramony SH. GENETICS OF INHERITED ATAXIAS. Continuum (Minneap Minn) 2005. [DOI: 10.1212/01.con.0000293702.31088.0d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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29
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Abstract
We discovered intronic mutations in two episodic ataxia type 2 (EA2) families: a four-nucleotide GAGT deletion at IVS41+(3-6) and a single nucleotide insertion (insT) at IVS24+3. We expressed minigenes harboring the mutations in cell lines to demonstrate exon skipping from the deletion mutation and the activation of a cryptic splice donor site from the insertion mutation. The identification of these disease-causing mutations expands the spectrum of EA2 mutations and emphasizes the importance of intronic sequences in regulating gene expression.
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Affiliation(s)
- Jijun Wan
- Department of Neurology, University of California at Los Angeles, 710 Westwood Plaza, Los Angeles, CA 90095-1769, USA
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30
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Engel KC, Anderson JH, Gomez CM, Soechting JF. Deficits in ocular and manual tracking due to episodic ataxia type 2. Mov Disord 2004; 19:778-787. [PMID: 15254935 DOI: 10.1002/mds.20121] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Four patients with a novel mutation leading to episodic ataxia type 2 were studied in a task that required them to track target motion either with the eyes or with the index finger of the right hand. The target initially moved in a straight line and then changed direction at an unpredictable time by an unpredictable amount. On the day of testing, 3 of the patients were evaluated as normal on a neurological exam, whereas the fourth was severely ataxic. Nevertheless, all 4 showed deficits in tracking behavior with common features. Ocular tracking tended to result in hypermetric saccades at longer than normal latencies. Smooth pursuit tracking was absent in 1 patient and had lower than normal gain in the others. Deficits in manual tracking showed similarities to the deficits in ocular tracking, with hypermetric compensations for changes in target direction. The similarities in the deficits in manual and ocular tracking suggest that they are subject to similar control by the cerebellar structures.
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Affiliation(s)
- Kevin C Engel
- Department of Neuroscience, University of Minnesota, Minneapolis, Minnesota, USA
| | - John H Anderson
- Department of Otolaryngology, University of Minnesota, Minneapolis, Minnesota, USA
| | - Christopher M Gomez
- Department of Neuroscience, University of Minnesota, Minneapolis, Minnesota, USA
- Department of Neurology, University of Minnesota, Minneapolis, Minnesota, USA
| | - John F Soechting
- Department of Neuroscience, University of Minnesota, Minneapolis, Minnesota, USA
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Page KM, Heblich F, Davies A, Butcher AJ, Leroy J, Bertaso F, Pratt WS, Dolphin AC. Dominant-negative calcium channel suppression by truncated constructs involves a kinase implicated in the unfolded protein response. J Neurosci 2004; 24:5400-9. [PMID: 15190113 PMCID: PMC6729303 DOI: 10.1523/jneurosci.0553-04.2004] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Expression of the calcium channel Ca(V)2.2 is markedly suppressed by coexpression with truncated constructs of Ca(V)2.2. Furthermore, a two-domain construct of Ca(V)2.1 mimicking an episodic ataxia-2 mutation strongly inhibited Ca(V)2.1 currents. We have now determined the specificity of this effect, identified a potential mechanism, and have shown that such constructs also inhibit endogenous calcium currents when transfected into neuronal cell lines. Suppression of calcium channel expression requires interaction between truncated and full-length channels, because there is inter-subfamily specificity. Although there is marked cross-suppression within the Ca(V)2 calcium channel family, there is no cross-suppression between Ca(V)2 and Ca(V)3 channels. The mechanism involves activation of a component of the unfolded protein response, the endoplasmic reticulum resident RNA-dependent kinase (PERK), because it is inhibited by expression of dominant-negative constructs of this kinase. Activation of PERK has been shown previously to cause translational arrest, which has the potential to result in a generalized effect on protein synthesis. In agreement with this, coexpression of the truncated domain I of Ca(V)2.2, together with full-length Ca(V)2.2, reduced the level not only of Ca(V)2.2 protein but also the coexpressed alpha2delta-2. Thapsigargin, which globally activates the unfolded protein response, very markedly suppressed Ca(V)2.2 currents and also reduced the expression level of both Ca(V)2.2 and alpha2delta-2 protein. We propose that voltage-gated calcium channels represent a class of difficult-to-fold transmembrane proteins, in this case misfolding is induced by interaction with a truncated cognate Ca(V) channel. This may represent a mechanism of pathology in episodic ataxia-2.
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Affiliation(s)
- Karen M Page
- Department of Pharmacology, University College London, London WC1E 6BT, United Kingdom
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Kors EE, Vanmolkot KRJ, Haan J, Frants RR, van den Maagdenberg AMJM, Ferrari MD. Recent findings in headache genetics. Curr Opin Neurol 2004; 17:283-8. [PMID: 15167062 DOI: 10.1097/00019052-200406000-00008] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE OF REVIEW The progress in headache genetics, especially migraine genetics, recently jumped ahead with some major discoveries. RECENT FINDINGS Family and epidemiological studies further strengthen the genetic contribution to migraine and two recent observations gave new molecular insights in the disease. Studies on the genetics of familial hemiplegic migraine revealed, in addition to the previously identified familial hemiplegic migraine type 1 gene CACNA1A on chromosome 19, the familial hemiplegic migraine type 2 gene ATP1A2, encoding the alpha2-subunit of sodium/potassium pumps. Recent genome screens in families with migraine identified susceptibility loci on chromosomes 4, 6, 11 and 14. SUMMARY The findings in familial hemiplegic migraine confirm that dysfunction in ion transport is a key factor in migraine pathophysiology and might help us in the elucidation of migraine molecular pathways. The identification of several migraine susceptibility loci underline its genetically complex nature.
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Affiliation(s)
- Esther E Kors
- Department of Neurology and Human Genetics, Leiden University Medical Center, Leiden, The Netherlands
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33
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Millichap JG. Febrile Episodic Ataxia with Novel Mutation. Pediatr Neurol Briefs 2004. [DOI: 10.15844/pedneurbriefs-18-1-10] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
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