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Raslan IR, Silva TYT, Kok F, Rodrigues MM, Aragão MM, Pinho RS, França MC, Barsottini OG, Pedroso JL. Clinical and Genetic Characterization of a Cohort of Brazilian Patients With Congenital Ataxia. Neurol Genet 2024; 10:e200153. [PMID: 38681507 PMCID: PMC11052569 DOI: 10.1212/nxg.0000000000200153] [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: 08/28/2023] [Accepted: 02/29/2024] [Indexed: 05/01/2024]
Abstract
Background and Objectives Congenital ataxias are rare hereditary disorders characterized by hypotonia and developmental motor delay in the first few months of life, followed by cerebellar ataxia in early childhood. The course of the disease is predominantly nonprogressive, and many patients are incorrectly diagnosed with cerebral palsy. Despite significant advancements in next-generation sequencing in the past few decades, a specific genetic diagnosis is seldom obtained in cases of congenital ataxia. The aim of the study was to analyze the clinical, radiologic, and genetic features of a cohort of Brazilian patients with congenital ataxia. Methods Thirty patients with a clinical diagnosis of congenital ataxia were enrolled in this study. Clinical and demographic features and neuroimaging studies were analyzed. Genetic testing (whole-exome sequencing) was also performed. Results A heterogeneous pattern of genetic variants was detected. Eighteen genes were involved: ALDH5A1, BRF1, CACNA1A CACNA1G, CC2D2A, CWF19L1, EXOSC3, ITPR1, KIF1A, MME, PEX10, SCN2A, SNX14, SPTBN2, STXBP1, TMEM240, THG1L, and TUBB4A. Pathogenic/likely pathogenic variants involving 11 genes (ALDH5A1, CACNA1A, EXOSC3, MME, ITPR1, KIF1A, STXBP1, SNX14, SPTBN2, TMEM240, and TUBB4A) were identified in 46.7% of patients. Variants of uncertain significance involving 8 genes were detected in 33.3% of patients. Congenital ataxias were characterized by a broad phenotype. A genetic diagnosis was more often obtained in patients with cerebellar-plus syndrome than in patients with a pure cerebellar syndrome. Discussion This study re-emphasizes the genetic heterogeneity of congenital ataxias and the absence of a clear phenotype-genotype relationship. A specific genetic diagnosis was established in 46.7% of patients. Autosomal dominant, associated with sporadic cases, was recognized as an important genetic inheritance. The results of this analysis highlight the value of whole-exome sequencing as an efficient screening tool in patients with congenital ataxia.
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Affiliation(s)
- Ivana R Raslan
- From the Department of Ataxia Unit of the Federal University of São Paulo (UNIFESP) (I.R.R., T.Y.T.S., O.G.B., J.L.P.); Neurology Department (F.K.), Hospital das Clínicas da Universidade de São Paulo and Mendelics; Department of Neurology and Neurosurgery (M.M.R., M.M.A., R.S.P.), Universidade Federal de São Paulo (UNIFESP); and Department of Neurology (M.C.F.), Universidade de Campinas (UNICAMP), Brazil
| | - Thiago Yoshinaga Tonholo Silva
- From the Department of Ataxia Unit of the Federal University of São Paulo (UNIFESP) (I.R.R., T.Y.T.S., O.G.B., J.L.P.); Neurology Department (F.K.), Hospital das Clínicas da Universidade de São Paulo and Mendelics; Department of Neurology and Neurosurgery (M.M.R., M.M.A., R.S.P.), Universidade Federal de São Paulo (UNIFESP); and Department of Neurology (M.C.F.), Universidade de Campinas (UNICAMP), Brazil
| | - Fernando Kok
- From the Department of Ataxia Unit of the Federal University of São Paulo (UNIFESP) (I.R.R., T.Y.T.S., O.G.B., J.L.P.); Neurology Department (F.K.), Hospital das Clínicas da Universidade de São Paulo and Mendelics; Department of Neurology and Neurosurgery (M.M.R., M.M.A., R.S.P.), Universidade Federal de São Paulo (UNIFESP); and Department of Neurology (M.C.F.), Universidade de Campinas (UNICAMP), Brazil
| | - Marcelo M Rodrigues
- From the Department of Ataxia Unit of the Federal University of São Paulo (UNIFESP) (I.R.R., T.Y.T.S., O.G.B., J.L.P.); Neurology Department (F.K.), Hospital das Clínicas da Universidade de São Paulo and Mendelics; Department of Neurology and Neurosurgery (M.M.R., M.M.A., R.S.P.), Universidade Federal de São Paulo (UNIFESP); and Department of Neurology (M.C.F.), Universidade de Campinas (UNICAMP), Brazil
| | - Marcelo M Aragão
- From the Department of Ataxia Unit of the Federal University of São Paulo (UNIFESP) (I.R.R., T.Y.T.S., O.G.B., J.L.P.); Neurology Department (F.K.), Hospital das Clínicas da Universidade de São Paulo and Mendelics; Department of Neurology and Neurosurgery (M.M.R., M.M.A., R.S.P.), Universidade Federal de São Paulo (UNIFESP); and Department of Neurology (M.C.F.), Universidade de Campinas (UNICAMP), Brazil
| | - Ricardo S Pinho
- From the Department of Ataxia Unit of the Federal University of São Paulo (UNIFESP) (I.R.R., T.Y.T.S., O.G.B., J.L.P.); Neurology Department (F.K.), Hospital das Clínicas da Universidade de São Paulo and Mendelics; Department of Neurology and Neurosurgery (M.M.R., M.M.A., R.S.P.), Universidade Federal de São Paulo (UNIFESP); and Department of Neurology (M.C.F.), Universidade de Campinas (UNICAMP), Brazil
| | - Marcondes C França
- From the Department of Ataxia Unit of the Federal University of São Paulo (UNIFESP) (I.R.R., T.Y.T.S., O.G.B., J.L.P.); Neurology Department (F.K.), Hospital das Clínicas da Universidade de São Paulo and Mendelics; Department of Neurology and Neurosurgery (M.M.R., M.M.A., R.S.P.), Universidade Federal de São Paulo (UNIFESP); and Department of Neurology (M.C.F.), Universidade de Campinas (UNICAMP), Brazil
| | - Orlando G Barsottini
- From the Department of Ataxia Unit of the Federal University of São Paulo (UNIFESP) (I.R.R., T.Y.T.S., O.G.B., J.L.P.); Neurology Department (F.K.), Hospital das Clínicas da Universidade de São Paulo and Mendelics; Department of Neurology and Neurosurgery (M.M.R., M.M.A., R.S.P.), Universidade Federal de São Paulo (UNIFESP); and Department of Neurology (M.C.F.), Universidade de Campinas (UNICAMP), Brazil
| | - José Luiz Pedroso
- From the Department of Ataxia Unit of the Federal University of São Paulo (UNIFESP) (I.R.R., T.Y.T.S., O.G.B., J.L.P.); Neurology Department (F.K.), Hospital das Clínicas da Universidade de São Paulo and Mendelics; Department of Neurology and Neurosurgery (M.M.R., M.M.A., R.S.P.), Universidade Federal de São Paulo (UNIFESP); and Department of Neurology (M.C.F.), Universidade de Campinas (UNICAMP), Brazil
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Janzing AM, Eklund E, De Koning TJ, Eggink H. Clinical Characteristics Suggestive of a Genetic Cause in Cerebral Palsy: A Systematic Review. Pediatr Neurol 2024; 153:144-151. [PMID: 38382247 DOI: 10.1016/j.pediatrneurol.2024.01.025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Revised: 01/11/2024] [Accepted: 01/27/2024] [Indexed: 02/23/2024]
Abstract
BACKGROUND Cerebral palsy (CP) is a clinical diagnosis and was long categorized as an acquired disorder, but more and more genetic etiologies are being identified. This review aims to identify the clinical characteristics that are associated with genetic CP to aid clinicians in selecting candidates for genetic testing. METHODS The PubMed database was systematically searched to identify genes associated with CP. The clinical characteristics accompanying these genetic forms of CP were compared with published data of large CP populations resulting in the identification of potential indicators of genetic CP. RESULLTS Of 1930 articles retrieved, 134 were included. In these, 55 CP genes (described in two or more cases, n = 272) and 79 candidate genes (described in only one case) were reported. The most frequently CP-associated genes were PLP1 (21 cases), ARG1 (17 cases), and CTNNB1 (13 cases). Dyskinesia and the absence of spasticity were identified as strong potential indicators of genetic CP. Presence of intellectual disability, no preterm birth, and no unilateral distribution of symptoms were classified as moderate genetic indicators. CONCLUSIONS Genetic causes of CP are increasingly identified. The clinical characteristics associated with genetic CP can aid clinicians regarding to which individual with CP to offer genetic testing. The identified potential genetic indicators need to be validated in large CP cohorts but can provide the first step toward a diagnostic algorithm for genetic CP.
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Affiliation(s)
- Anna M Janzing
- Department of Neurology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands; Expertise Center Movement Disorders Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Erik Eklund
- Faculty of Medicine, Department of Clinical Sciences, Pediatrics, Lund University, Lund, Sweden
| | - Tom J De Koning
- Expertise Center Movement Disorders Groningen, University Medical Center Groningen, Groningen, The Netherlands; Faculty of Medicine, Department of Clinical Sciences, Pediatrics, Lund University, Lund, Sweden; Department of Genetics, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Hendriekje Eggink
- Department of Neurology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands; Expertise Center Movement Disorders Groningen, University Medical Center Groningen, Groningen, The Netherlands.
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Coarelli G, Coutelier M, Durr A. Autosomal dominant cerebellar ataxias: new genes and progress towards treatments. Lancet Neurol 2023; 22:735-749. [PMID: 37479376 DOI: 10.1016/s1474-4422(23)00068-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2022] [Revised: 01/07/2023] [Accepted: 02/22/2023] [Indexed: 07/23/2023]
Abstract
Dominantly inherited spinocerebellar ataxias (SCAs) are associated with phenotypes that range from pure cerebellar to multisystemic. The list of implicated genes has lengthened in the past 5 years with the inclusion of SCA37/DAB1, SCA45/FAT2, SCA46/PLD3, SCA47/PUM1, SCA48/STUB1, SCA50/NPTX1, SCA25/PNPT1, SCA49/SAM9DL, and SCA27B/FGF14. In some patients, co-occurrence of multiple potentially pathogenic variants can explain variable penetrance or more severe phenotypes. Given this extreme clinical and genetic heterogeneity, genome sequencing should become the diagnostic tool of choice but is still not available in many clinical settings. Treatments tested in phase 2 and phase 3 studies, such as riluzole and transcranial direct current stimulation of the cerebellum and spinal cord, have given conflicting results. To enable early intervention, preataxic carriers of pathogenic variants should be assessed with biomarkers, such as neurofilament light chain and brain MRI; these biomarkers could also be used as outcome measures, given that clinical outcomes are not useful in the preataxic phase. The development of bioassays measuring the concentration of the mutant protein (eg, ataxin-3) might facilitate monitoring of target engagement by gene therapies.
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Affiliation(s)
- Giulia Coarelli
- Sorbonne Université, ICM Institut du Cerveau, Pitié-Salpeêtrieère University Hospital, Paris, France; Institut National de la Santé Et de la Recherche Médicale, Paris, France; Centre National de la Recherche Scientifique, Paris, France; Assistance Publique-Hôpitaux de Paris, Paris, France
| | - Marie Coutelier
- Sorbonne Université, ICM Institut du Cerveau, Pitié-Salpeêtrieère University Hospital, Paris, France; Institut National de la Santé Et de la Recherche Médicale, Paris, France; Centre National de la Recherche Scientifique, Paris, France; Assistance Publique-Hôpitaux de Paris, Paris, France
| | - Alexandra Durr
- Sorbonne Université, ICM Institut du Cerveau, Pitié-Salpeêtrieère University Hospital, Paris, France; Institut National de la Santé Et de la Recherche Médicale, Paris, France; Centre National de la Recherche Scientifique, Paris, France; Assistance Publique-Hôpitaux de Paris, Paris, France.
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Benevides ML, França M. Expanding the Landscape of Spinocerebellar Ataxia Type 5. Neuropediatrics 2022; 53:358-360. [PMID: 35545114 DOI: 10.1055/a-1849-8128] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Spinocerebellar ataxia type 5 (SCA5) is a rare subtype of SCA that usually affects adults. It has been recently reported in children in Europe, North America, and China. This study aims to describe clinical, radiological, and genetic data of a child presenting with SCA5, caused by a heterozygous likely pathogenic missense variant in SPTBN2 (NM_006946.3: c.1052G > C, p.Arg351Pro). According to databases and a review of the literature, this is one of few cases of SCA5 from Latin America. Expanding the landscape of SCA5 is relevant to the differential diagnosis of ataxic cerebral palsy and the autosomal recessive cerebellar ataxias.
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Affiliation(s)
- Maria Luiza Benevides
- Child Neurology Service, Neurology Department, Universidade Estadual de Campinas (UNICAMP), Campinas, São Paulo, Brazil
| | - Marcondes França
- Department of Neurology, Neuromuscular Diseases, Universidade Estadual de Campinas (UNICAMP), Campinas, São Paulo, Brazil
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