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Rinaldi D, Tangari MM, Ledda C, Dematteis F, Rizzone MG, Lopiano L, Artusi CA. CACNA1A variant associated with generalized dystonia. Neurol Sci 2024:10.1007/s10072-024-07592-8. [PMID: 38743163 DOI: 10.1007/s10072-024-07592-8] [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: 01/16/2024] [Accepted: 05/07/2024] [Indexed: 05/16/2024]
Abstract
INTRODUCTION CACNA1A gene variants are correlated with different disorders, including episodic ataxia type 2, spinocerebellar ataxia type 6, and familial hemiplegic migraine type 1. Despite dystonia not being a typical manifestation of CACNA1A variants, there are reports indicating a link between this gene mutation and dystonic features. METHODS We report the case of a patient with a novel missense variant of the CACNA1A gene presenting headache, head and arm tremor, dystonia, episodic painful focal dystonic attacks, and unexplained falls. RESULTS A 57-year-old woman presented with a history of neck dystonia, head and arm tremor, and headaches since age 15. In 2017, she progressively developed dystonic tremor of the head and arms with an unremarkable brain MRI. In 2018 she experienced worsening of tremor and developed painful dystonic attacks, resistant to treatments including clonazepam, trihexyphenidyl, baclofen, and levodopa/benserazide. Botulinum toxin injections for neck dystonia provided limited benefit. The next-generation sequencing exam revealed a CACNA1A gene missense variant (NM_023035.2:c.1630C > T; p.Arg544Trp). In 2021 we observed a worsening of dystonia, accompanied by weight loss, mood changes, and unexplained falls. Deep brain stimulation was considered but ruled out due to cortical atrophy and mild cognitive deficits revealed by the neuropsychological examination. DISCUSSION Only a few studies reported dystonia as part of the clinical features in carriers of CACNA1A mutations. This case points out the relevance of a need to expand the literature on voltage-dependent P/Q-type Ca2 + channels' role in dystonia's pathogenesis and stresses the complex phenotype-genotype presentation of CACNA1A mutation.
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Affiliation(s)
- Domiziana Rinaldi
- Department of Neuroscience, Mental Health, and Sense Organs (NESMOS), Sapienza University of Rome, Via Di Grottarossa, 1035-00189, Rome, Italy
| | - Marta Maria Tangari
- Department of Neuroscience "Rita Levi Montalcini", University of Torino, Turin, Italy
- Neurology 2 Unit, A.O.U. Città Della Salute E Della Scienza Di Torino, Corso Bramante 88, 10126, Turin, Italy
| | - Claudia Ledda
- Department of Neuroscience "Rita Levi Montalcini", University of Torino, Turin, Italy
- Neurology 2 Unit, A.O.U. Città Della Salute E Della Scienza Di Torino, Corso Bramante 88, 10126, Turin, Italy
| | - Francesca Dematteis
- Department of Neurology, Ospedale Di Rivoli, ASL TO 3, Via Rivalta 29, 10098, Rivoli, Turin, Italy
| | - Mario Giorgio Rizzone
- Department of Neuroscience "Rita Levi Montalcini", University of Torino, Turin, Italy
- Neurology 2 Unit, A.O.U. Città Della Salute E Della Scienza Di Torino, Corso Bramante 88, 10126, Turin, Italy
| | - Leonardo Lopiano
- Department of Neuroscience "Rita Levi Montalcini", University of Torino, Turin, Italy
- Neurology 2 Unit, A.O.U. Città Della Salute E Della Scienza Di Torino, Corso Bramante 88, 10126, Turin, Italy
| | - Carlo Alberto Artusi
- Department of Neuroscience "Rita Levi Montalcini", University of Torino, Turin, Italy.
- Neurology 2 Unit, A.O.U. Città Della Salute E Della Scienza Di Torino, Corso Bramante 88, 10126, Turin, Italy.
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Lazar SM, Abid F. Pearls & Oy-sters: CACNA1A-Related Paroxysmal Tonic Upgaze With Ataxia Responsive to Acetazolamide. Neurology 2024; 102:e207992. [PMID: 38175838 PMCID: PMC10834120 DOI: 10.1212/wnl.0000000000207992] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2023] [Accepted: 09/20/2023] [Indexed: 01/06/2024] Open
Abstract
A 9-month-old male infant was evaluated for sudden onset of paroxysmal episodes of forced, conjugate upward eye deviation. Extensive in-hospital evaluation including electrophysiology and neuroimaging studies were reassuring against seizures or a structural abnormality. Given the clinical presentation of sudden onset intermittent upward eye deviations, downbeating saccades, associated ataxia, and typical development, a clinical diagnosis of paroxysmal tonic upgaze (PTU) with ataxia was made. Targeted genetic testing of CACNA1A was performed, which revealed a variant of undetermined significance, which was later classified as a de novo pathogenic variant after protein modeling and parental testing performed. Off-label use of oral acetazolamide was prescribed, which led to dose-responsive decrease in the frequency and intensity of eye movement episodes. After 6 months of episode freedom at 2 years of age, acetazolamide was discontinued without return of episodes. Neurodevelopmental assessments revealed continued typical development. This case is presented to describe the diagnostic formulation, etiologic evaluation, and symptomatic treatment of CACNA1A-related PTU with ataxia.
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Affiliation(s)
- Steven M Lazar
- From the Section of Pediatric Neurology and Developmental Neuroscience (S.M.L., F.A.), Baylor College of Medicine, Houston, TX; and Meyer Center for Developmental Pediatrics & Autism (S.M.L.), Texas Children's Hospital, Houston
| | - Farida Abid
- From the Section of Pediatric Neurology and Developmental Neuroscience (S.M.L., F.A.), Baylor College of Medicine, Houston, TX; and Meyer Center for Developmental Pediatrics & Autism (S.M.L.), Texas Children's Hospital, Houston
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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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Lauerer RJ, Lerche H. Voltage-gated calcium channels in genetic epilepsies. J Neurochem 2023. [PMID: 37822150 DOI: 10.1111/jnc.15983] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2023] [Revised: 09/17/2023] [Accepted: 09/25/2023] [Indexed: 10/13/2023]
Abstract
Voltage-gated calcium channels (VGCC) are abundant in the central nervous system and serve a broad spectrum of functions, either directly in cellular excitability or indirectly to regulate Ca2+ homeostasis. Ca2+ ions act as one of the main connections in excitation-transcription coupling, muscle contraction and excitation-exocytosis coupling, including synaptic transmission. In recent years, many genes encoding VGCCs main α or additional auxiliary subunits have been associated with epilepsy. This review sums up the current state of knowledge on disease mechanisms and provides guidance on disease-specific therapies where applicable.
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Affiliation(s)
- Robert J Lauerer
- Department of Neurology and Epileptology, Hertie Institute for Clinical Brain Research, University and University Hospital Tuebingen, Tuebingen, Germany
| | - Holger Lerche
- Department of Neurology and Epileptology, Hertie Institute for Clinical Brain Research, University and University Hospital Tuebingen, Tuebingen, Germany
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Massuyama BK, Tonholo Silva TY, Gambirasio BG, Pedroso JL, Barsottini OGP. Paroxysmal Tonic Upward Gaze: A Clinical Clue for CACNA1A-Related Disorders. Mov Disord Clin Pract 2023; 10:1225-1227. [PMID: 37635773 PMCID: PMC10450236 DOI: 10.1002/mdc3.13809] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2022] [Revised: 05/19/2023] [Accepted: 05/24/2023] [Indexed: 08/29/2023] Open
Affiliation(s)
| | | | | | - José Luiz Pedroso
- Ataxia Unit, Department of NeurologyFederal University of Sao PauloSao PauloBrazil
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Kessi M, Chen B, Pang N, Yang L, Peng J, He F, Yin F. The genotype-phenotype correlations of the CACNA1A-related neurodevelopmental disorders: a small case series and literature reviews. Front Mol Neurosci 2023; 16:1222321. [PMID: 37555011 PMCID: PMC10406136 DOI: 10.3389/fnmol.2023.1222321] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2023] [Accepted: 07/10/2023] [Indexed: 08/10/2023] Open
Abstract
BACKGROUND Genotype-phenotype correlations of the CACNA1A-related neurodevelopmental disorders such as global developmental delay (GDD)/intellectual disability (ID), epileptic encephalopathy (EE), and autism spectrum disorder (ASD) are unknown. We aimed to summarize genotype-phenotype correlations and potential treatment for CACNA1A-related neurodevelopmental disorders. METHODS Six children diagnosed with CACNA1A-related neurodevelopmental disorders at Xiangya Hospital, Central South University from April 2018 to July 2021 were enrolled. The PubMed database was systematically searched for all reported patients with CACNA1A-related neurodevelopmental disorders until February 2023. Thereafter, we divided patients into several groups for comparison. RESULTS Six patients were recruited from our hospital. Three cases presented with epilepsy, five with GDD/ID, five with ataxia, and two with ASD. The variants included p.G701R, p.R279C, p.D1644N, p.Y62C, p.L1422Sfs*8, and p. R1664Q [two gain-of-function (GOF) and four loss-of-function (LOF) variants]. About 187 individuals with GDD/ID harboring 123 variants were found (case series plus data from literature). Of those 123 variants, p.A713T and p.R1664* were recurrent, 37 were LOF, and 7 were GOF. GOF variants were linked with severe-profound GDD/ID while LOF variants were associated with mild-moderate GDD/ID (p = 0.001). The p.A713T variant correlated with severe-profound GDD/ID (p = 0.003). A total of 130 epileptic patients harboring 83 variants were identified. The epileptic manifestations included status epilepticus (n = 64), provoked seizures (n = 49), focal seizures (n = 37), EE (n = 29), absence seizures (n = 26), and myoclonic seizures (n = 10). About 49 (42.20%) patients had controlled seizures while 67 (57.80%) individuals remained with refractory seizures. Status epilepticus correlated with variants located on S4, S5, and S6 (p = 0.000). Among the 83 epilepsy-related variants, 23 were recurrent, 32 were LOF, and 11 were GOF. Status epilepticus was linked with GOF variants (p = 0.000). LOF variants were associated with absence seizures (p = 0.000). Six patients died at an early age (3 months to ≤5 years). We found 18 children with ASD. Thirteen variants including recurrent ones were identified in those 18 cases. GOF changes were more linked to ASD. CONCLUSION The p.A713T variant is linked with severe-profound GDD/ID. More than half of CACNA1A-related epilepsy is refractory. The most common epileptic manifestation is status epilepticus, which correlates with variants located on S4, S5, and S6.
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Affiliation(s)
- Miriam Kessi
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China
- Hunan Intellectual and Developmental Disabilities Research Center, Pediatrics, Changsha, China
- Clinical Research Center for Children’s Neurodevelopmental Disabilities of Hunan Province, Xiangya Hospital, Central South University, Changsha, China
| | - Baiyu Chen
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China
- Hunan Intellectual and Developmental Disabilities Research Center, Pediatrics, Changsha, China
- Clinical Research Center for Children’s Neurodevelopmental Disabilities of Hunan Province, Xiangya Hospital, Central South University, Changsha, China
| | - Nan Pang
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China
- Hunan Intellectual and Developmental Disabilities Research Center, Pediatrics, Changsha, China
- Clinical Research Center for Children’s Neurodevelopmental Disabilities of Hunan Province, Xiangya Hospital, Central South University, Changsha, China
| | - Lifen Yang
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China
- Hunan Intellectual and Developmental Disabilities Research Center, Pediatrics, Changsha, China
- Clinical Research Center for Children’s Neurodevelopmental Disabilities of Hunan Province, Xiangya Hospital, Central South University, Changsha, China
| | - Jing Peng
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China
- Hunan Intellectual and Developmental Disabilities Research Center, Pediatrics, Changsha, China
- Clinical Research Center for Children’s Neurodevelopmental Disabilities of Hunan Province, Xiangya Hospital, Central South University, Changsha, China
| | - Fang He
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China
- Hunan Intellectual and Developmental Disabilities Research Center, Pediatrics, Changsha, China
- Clinical Research Center for Children’s Neurodevelopmental Disabilities of Hunan Province, Xiangya Hospital, Central South University, Changsha, China
| | - Fei Yin
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China
- Hunan Intellectual and Developmental Disabilities Research Center, Pediatrics, Changsha, China
- Clinical Research Center for Children’s Neurodevelopmental Disabilities of Hunan Province, Xiangya Hospital, Central South University, Changsha, China
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Hassan A. Episodic Ataxias: Primary and Secondary Etiologies, Treatment, and Classification Approaches. Tremor Other Hyperkinet Mov (N Y) 2023; 13:9. [PMID: 37008993 PMCID: PMC10064912 DOI: 10.5334/tohm.747] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2022] [Accepted: 03/03/2023] [Indexed: 03/30/2023] Open
Abstract
Background Episodic ataxia (EA), characterized by recurrent attacks of cerebellar dysfunction, is the manifestation of a group of rare autosomal dominant inherited disorders. EA1 and EA2 are most frequently encountered, caused by mutations in KCNA1 and CACNA1A. EA3-8 are reported in rare families. Advances in genetic testing have broadened the KCNA1 and CACNA1A phenotypes, and detected EA as an unusual presentation of several other genetic disorders. Additionally, there are various secondary causes of EA and mimicking disorders. Together, these can pose diagnostic challenges for neurologists. Methods A systematic literature review was performed in October 2022 for 'episodic ataxia' and 'paroxysmal ataxia', restricted to publications in the last 10 years to focus on recent clinical advances. Clinical, genetic, and treatment characteristics were summarized. Results EA1 and EA2 phenotypes have further broadened. In particular, EA2 may be accompanied by other paroxysmal disorders of childhood with chronic neuropsychiatric features. New treatments for EA2 include dalfampridine and fampridine, in addition to 4-aminopyridine and acetazolamide. There are recent proposals for EA9-10. EA may also be caused by gene mutations associated with chronic ataxias (SCA-14, SCA-27, SCA-42, AOA2, CAPOS), epilepsy syndromes (KCNA2, SCN2A, PRRT2), GLUT-1, mitochondrial disorders (PDHA1, PDHX, ACO2), metabolic disorders (Maple syrup urine disease, Hartnup disease, type I citrullinemia, thiamine and biotin metabolism defects), and others. Secondary causes of EA are more commonly encountered than primary EA (vascular, inflammatory, toxic-metabolic). EA can be misdiagnosed as migraine, peripheral vestibular disorders, anxiety, and functional symptoms. Primary and secondary EA are frequently treatable which should prompt a search for the cause. Discussion EA may be overlooked or misdiagnosed for a variety of reasons, including phenotype-genotype variability and clinical overlap between primary and secondary causes. EA is highly treatable, so it is important to consider in the differential diagnosis of paroxysmal disorders. Classical EA1 and EA2 phenotypes prompt single gene test and treatment pathways. For atypical phenotypes, next generation genetic testing can aid diagnosis and guide treatment. Updated classification systems for EA are discussed which may assist diagnosis and management.
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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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Wong‐Spracklen VMY, Kolesnik A, Eck J, Sabanathan S, Spasic‐Boskovic O, Maw A, Baker K. Biallelic CACNA1A variants: Review of literature and report of a child with drug-resistant epilepsy and developmental delay. Am J Med Genet A 2022; 188:3306-3311. [PMID: 36063114 PMCID: PMC9826308 DOI: 10.1002/ajmg.a.62960] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Revised: 07/19/2022] [Accepted: 07/24/2022] [Indexed: 01/31/2023]
Abstract
Biallelic variants in CACNA1A have previously been reported in nine individuals (four families) presenting with epilepsy and cognitive impairments of variable severity and age-of-onset. Here, we describe a child who presented at 6 months of age with drug-resistant epilepsy and developmental delay. At 10 years of age, she has profound impairments in motor function and communication. MRI was initially unremarkable, but progressed to severe cerebellar atrophy by age 3 years. Next Generation Sequencing and panel analysis identified a maternally inherited truncating variant c.2042_2043delAG, p.(Gln681ArgfsTer100) and paternally inherited missense variant c.1693G>A, p.(Glu565Lys). In contrast to previously reported biallelic cases, parents carrying these monoallelic variants did not display clear signs of a CACNA1A-associated syndrome. In conclusion, we provide further evidence that biallelic CACNA1A variants can cause a severe epileptic and developmental encephalopathy with progressive cerebellar atrophy, and highlight complexities of genetic counseling in such situations.
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Affiliation(s)
| | - Anna Kolesnik
- MRC Cognition and Brain Sciences UnitUniversity of CambridgeCambridgeUK
| | - Josefine Eck
- MRC Cognition and Brain Sciences UnitUniversity of CambridgeCambridgeUK
| | - Saras Sabanathan
- Department of Paediatric NeurosciencesEvelina Childrens HospitalLondonUK
| | | | - Anna Maw
- Department of Paediatric NeurologyCambridge University Hospitals NHS Foundation TrustCambridgeUK
| | - Kate Baker
- MRC Cognition and Brain Sciences UnitUniversity of CambridgeCambridgeUK
- Department of Medical GeneticsUniversity of CambridgeCambridgeUK
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Filippopulos FM, Schnabel L, Dunker K, Strobl R, Huppert D. Episodic ataxias in children and adolescents: Clinical findings and suggested diagnostic criteria. Front Neurol 2022; 13:1016856. [PMID: 36353133 PMCID: PMC9638128 DOI: 10.3389/fneur.2022.1016856] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2022] [Accepted: 10/06/2022] [Indexed: 11/15/2022] Open
Abstract
Background The main clinical presentation of episodic ataxias (EAs) consists of vertigo and dizziness attacks lasting for minutes to hours with widely varying accompanying symptoms. The differentiation of EA and episodic vertigo/dizziness syndromes in childhood and adolescence such as vestibular migraine (VM) and recurrent vertigo of childhood (RVC) can be challenging. Furthermore, only few prospective studies of children/adolescents with EA are available. Objective This study aims to characterize clinical and instrument-based findings in EA patients under 18 years of age, to delineate the clinical and therapeutic course in EA, and to present potentially new genetic mutations. Furthermore, the study aims to differentiate distinct characteristics between EA, VM, and RVC patients. Methods We prospectively collected clinical and instrument-based data of patients younger than 18 years, who presented at the German Center for Vertigo and Balance Disorders (DSGZ) at the LMU University Hospital in Munich with EA, VM, or RVC between January 2016 and December 2021. All patients underwent a comprehensive evaluation of neurological, ocular-motor, vestibular and cochlear function, including video-oculography with caloric testing, video head impulse test, vestibular evoked myogenic potentials, posturography, and gait analysis. Results Ten patients with EA, 15 with VM, and 15 with RVC were included. In EA the main symptoms were vertigo/dizziness attacks lasting between 5 min and 12 h. Common accompanying symptoms included walking difficulties, paleness, and speech difficulties. Six EA patients had a previously unknown gene mutation. In the interictal interval all EA patients showed distinct ocular-motor deficits. Significant differences between EA, VM, and RVC were found for accompanying symptoms such as speech disturbances and paleness, and for the trigger factor “physical activity”. Furthermore, in the interictal interval significant group differences were observed for different pathological nystagmus types, a saccadic smooth pursuit, and disturbed fixation suppression. Conclusion By combining clinical and ocular-motor characteristics we propose diagnostic criteria that can help to diagnose EA among children/adolescents and identify patients with EA even without distinct genetic findings. Nevertheless, broad genetic testing (e.g., next generation sequencing) in patients fulfilling the diagnostic criteria should be conducted to identify even rare or unknown genetic mutations for EA.
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Affiliation(s)
- Filipp Maximilian Filippopulos
- German Center for Vertigo and Balance Disorders (DSGZ), University Hospital, Ludwig-Maximilians-Universität, Munich, Germany
- Department of Neurology, University Hospital, Ludwig-Maximilians-Universität, Munich, Germany
- *Correspondence: Filipp Maximilian Filippopulos
| | - Lutz Schnabel
- German Center for Vertigo and Balance Disorders (DSGZ), University Hospital, Ludwig-Maximilians-Universität, Munich, Germany
- Department of Neurology, University Hospital, Ludwig-Maximilians-Universität, Munich, Germany
| | - Konstanze Dunker
- German Center for Vertigo and Balance Disorders (DSGZ), University Hospital, Ludwig-Maximilians-Universität, Munich, Germany
| | - Ralf Strobl
- German Center for Vertigo and Balance Disorders (DSGZ), University Hospital, Ludwig-Maximilians-Universität, Munich, Germany
| | - Doreen Huppert
- German Center for Vertigo and Balance Disorders (DSGZ), University Hospital, Ludwig-Maximilians-Universität, Munich, Germany
- Department of Neurology, University Hospital, Ludwig-Maximilians-Universität, Munich, Germany
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Lipman AR, Fan X, Shen Y, Chung WK. Clinical and genetic characterization of CACNA1A-related disease. Clin Genet 2022; 102:288-295. [PMID: 35722745 PMCID: PMC9458680 DOI: 10.1111/cge.14180] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2022] [Revised: 06/13/2022] [Accepted: 06/14/2022] [Indexed: 11/03/2022]
Abstract
Pathogenic variants in the CACNA1A gene have been associated with episodic ataxia type 2, familial hemiplegic migraine, and spinocerebellar ataxia 6. With increasing use of clinical genetic testing, associations have expanded to include developmental delay, epilepsy, paroxysmal dystonia, and neuropsychiatric disorders. We report 47 individuals with 33 unique likely pathogenic or pathogenic CACNA1A variants. A machine learning method, funNCion, was used to predict loss-of-function (LoF)/gain-of-function (GoF) impact of genetic variants, and a heuristic severity score was designed to analyze genotype/phenotype correlations. Commonly reported phenotypes include developmental delay/intellectual disability (96%), hemiplegic migraines (36%), episodic ataxia type 2 (32%), epilepsy (55%), autism spectrum disorder (23%), and paroxysmal tonic upward gaze (36%). Severity score was significantly higher for predicted GoF variants, variants in the S5/S6 helices, and the recurrent p.Val1392Met variant. Seizures/status epilepticus were correlated with GoF and were more frequent in those with the p.Val1392Met variant. Our findings demonstrate a breadth of disease severity in CACNA1A-related disease and suggest that the clinical phenotypic heterogeneity likely reflects diverse molecular phenotypes. A better understanding of the natural history of CACNA1A-related disease and genotype/phenotype correlations will help inform prognosis and prepare for future clinical trials.
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Affiliation(s)
- Amy R. Lipman
- Vagelos College of Physicians and Surgeons, New York, NY, USA
| | - Xiao Fan
- Department of Pediatrics, Columbia University, New York, NY, USA
- Department of Systems Biology, Columbia University, New York, NY, USA
| | - Yufeng Shen
- Department of Systems Biology, Columbia University, New York, NY, USA
- Department of Biomedical Informatics, Columbia University, New York, NY, USA
- JP Sulzberger Columbia Genome Center, Columbia University, New York, NY, USA
| | - Wendy K. Chung
- Department of Pediatrics, Columbia University, New York, NY, USA
- Department of Medicine, Columbia University, New York, NY, USA
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Molecular Characterization of Portuguese Patients with Hereditary Cerebellar Ataxia. Cells 2022; 11:cells11060981. [PMID: 35326432 PMCID: PMC8946949 DOI: 10.3390/cells11060981] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Revised: 03/10/2022] [Accepted: 03/11/2022] [Indexed: 01/02/2023] Open
Abstract
Hereditary cerebellar ataxia (HCA) comprises a clinical and genetic heterogeneous group of neurodegenerative disorders characterized by incoordination of movement, speech, and unsteady gait. In this study, we performed whole-exome sequencing (WES) in 19 families with HCA and presumed autosomal recessive (AR) inheritance, to identify the causal genes. A phenotypic classification was performed, considering the main clinical syndromes: spastic ataxia, ataxia and neuropathy, ataxia and oculomotor apraxia (AOA), ataxia and dystonia, and ataxia with cognitive impairment. The most frequent causal genes were associated with spastic ataxia (SACS and KIF1C) and with ataxia and neuropathy or AOA (PNKP). We also identified three families with autosomal dominant (AD) forms arising from de novo variants in KIF1A, CACNA1A, or ATP1A3, reinforcing the importance of differential diagnosis (AR vs. AD forms) in families with only one affected member. Moreover, 10 novel causal-variants were identified, and the detrimental effect of two splice-site variants confirmed through functional assays. Finally, by reviewing the molecular mechanisms, we speculated that regulation of cytoskeleton function might be impaired in spastic ataxia, whereas DNA repair is clearly associated with AOA. In conclusion, our study provided a genetic diagnosis for HCA families and proposed common molecular pathways underlying cerebellar neurodegeneration.
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de Gusmão CM, Garcia L, Mikati MA, Su S, Silveira-Moriyama L. Paroxysmal Genetic Movement Disorders and Epilepsy. Front Neurol 2021; 12:648031. [PMID: 33833732 PMCID: PMC8021799 DOI: 10.3389/fneur.2021.648031] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Accepted: 02/22/2021] [Indexed: 01/08/2023] Open
Abstract
Paroxysmal movement disorders include paroxysmal kinesigenic dyskinesia, paroxysmal non-kinesigenic dyskinesia, paroxysmal exercise-induced dyskinesia, and episodic ataxias. In recent years, there has been renewed interest and recognition of these disorders and their intersection with epilepsy, at the molecular and pathophysiological levels. In this review, we discuss how these distinct phenotypes were constructed from a historical perspective and discuss how they are currently coalescing into established genetic etiologies with extensive pleiotropy, emphasizing clinical phenotyping important for diagnosis and for interpreting results from genetic testing. We discuss insights on the pathophysiology of select disorders and describe shared mechanisms that overlap treatment principles in some of these disorders. In the near future, it is likely that a growing number of genes will be described associating movement disorders and epilepsy, in parallel with improved understanding of disease mechanisms leading to more effective treatments.
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Affiliation(s)
- Claudio M. de Gusmão
- Department of Neurology, Boston Children's Hospital and Harvard Medical School, Boston, MA, United States
- Department of Neurology, Universidade Estadual de Campinas (UNICAMP), São Paulo, Brazil
| | - Lucas Garcia
- Department of Medicine, Universidade 9 de Julho, São Paulo, Brazil
| | - Mohamad A. Mikati
- Division of Pediatric Neurology and Developmental Medicine, Duke University Medical Center, Durham, NC, United States
| | - Samantha Su
- Division of Pediatric Neurology and Developmental Medicine, Duke University Medical Center, Durham, NC, United States
| | - Laura Silveira-Moriyama
- Department of Neurology, Universidade Estadual de Campinas (UNICAMP), São Paulo, Brazil
- Department of Medicine, Universidade 9 de Julho, São Paulo, Brazil
- Education Unit, University College London Institute of Neurology, University College London, London, United Kingdom
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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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