1
|
Andjelkovic M, Klaassen K, Skakic A, Marjanovic I, Kravljanac R, Djordjevic M, Vucetic Tadic B, Kecman B, Pavlovic S, Stojiljkovic M. Characterization of 13 Novel Genetic Variants in Genes Associated with Epilepsy: Implications for Targeted Therapeutic Strategies. Mol Diagn Ther 2024; 28:645-663. [PMID: 39003674 PMCID: PMC11349789 DOI: 10.1007/s40291-024-00720-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/26/2024] [Indexed: 07/15/2024]
Abstract
BACKGROUND Childhood epilepsies are caused by heterogeneous underlying disorders where approximately 40% of the origins of epilepsy can be attributed to genetic factors. The application of next-generation sequencing (NGS) has revolutionized molecular diagnostics and has enabled the identification of disease-causing genes and variants in childhood epilepsies. The objective of this study was to use NGS to identify variants in patients with childhood epilepsy, to expand the variant spectrum and discover potential therapeutic targets. METHODS In our study, 55 children with epilepsy of unknown etiology were analyzed by combining clinical-exome and whole-exome sequencing. Novel variants were characterized using various in silico algorithms for pathogenicity and structure prediction. RESULTS The molecular genetic cause of epilepsy was identified in 28 patients and the overall diagnostic success rate was 50.9%. We identified variants in 22 different genes associated with epilepsy that correlate well with the described phenotype. SCN1A gene variants were found in five unrelated patients, while ALDH7A1 and KCNQ2 gene variants were found twice. In the other 19 genes, variants were found only in a single patient. This includes genes such as ASH1L, CSNK2B, RHOBTB2, and SLC13A5, which have only recently been associated with epilepsy. Almost half of diagnosed patients (46.4%) carried novel variants. Interestingly, we identified variants in ALDH7A1, KCNQ2, PNPO, SCN1A, and SCN2A resulting in gene-directed therapy decisions for 11 children from our study, including four children who all carried novel SCN1A genetic variants. CONCLUSIONS Described novel variants will contribute to a better understanding of the European genetic landscape, while insights into the genotype-phenotype correlation will contribute to a better understanding of childhood epilepsies worldwide. Given the expansion of molecular-based approaches, each newly identified genetic variant could become a potential therapeutic target.
Collapse
Affiliation(s)
- Marina Andjelkovic
- Institute of Molecular Genetics and Genetic Engineering, University of Belgrade, Vojvode Stepe 444a, 11042, Belgrade, Serbia
| | - Kristel Klaassen
- Institute of Molecular Genetics and Genetic Engineering, University of Belgrade, Vojvode Stepe 444a, 11042, Belgrade, Serbia
| | - Anita Skakic
- Institute of Molecular Genetics and Genetic Engineering, University of Belgrade, Vojvode Stepe 444a, 11042, Belgrade, Serbia
| | - Irena Marjanovic
- Institute of Molecular Genetics and Genetic Engineering, University of Belgrade, Vojvode Stepe 444a, 11042, Belgrade, Serbia
| | - Ruzica Kravljanac
- Institute for Mother and Child Healthcare of Serbia, "Dr Vukan Cupic", Belgrade, Serbia
- Faculty of Medicine, University of Belgrade, Belgrade, Serbia
| | - Maja Djordjevic
- Institute for Mother and Child Healthcare of Serbia, "Dr Vukan Cupic", Belgrade, Serbia
- Faculty of Medicine, University of Belgrade, Belgrade, Serbia
| | - Biljana Vucetic Tadic
- Institute for Mother and Child Healthcare of Serbia, "Dr Vukan Cupic", Belgrade, Serbia
- Faculty of Medicine, University of Belgrade, Belgrade, Serbia
| | - Bozica Kecman
- Institute for Mother and Child Healthcare of Serbia, "Dr Vukan Cupic", Belgrade, Serbia
| | - Sonja Pavlovic
- Institute of Molecular Genetics and Genetic Engineering, University of Belgrade, Vojvode Stepe 444a, 11042, Belgrade, Serbia
| | - Maja Stojiljkovic
- Institute of Molecular Genetics and Genetic Engineering, University of Belgrade, Vojvode Stepe 444a, 11042, Belgrade, Serbia.
| |
Collapse
|
2
|
Couto B, Galosi S, Steel D, Kurian MA, Friedman J, Gorodetsky C, Lang AE. Severe Acute Motor Exacerbations (SAME) across Metabolic, Developmental and Genetic Disorders. Mov Disord 2024. [PMID: 39119747 DOI: 10.1002/mds.29905] [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: 10/02/2023] [Revised: 06/08/2024] [Accepted: 06/13/2024] [Indexed: 08/10/2024] Open
Abstract
Acute presentation of severe motor disorders is a diagnostic and management challenge. We define severe acute motor exacerbations (SAME) as acute/subacute motor symptoms that persist for hours-to-days with a severity that compromise vital signs (temperature, breath, and heart rate) and bulbar function (swallowing/dysphagia). Phenomenology includes dystonia, choreoathetosis, combined movement disorders, weakness, and hemiplegic attacks. SAME can develop in diverse diseases and can be preceded by triggers or catabolic states. Recent descriptions of SAME in complex neurodevelopmental and epileptic encephalopathies have broadened appreciation of this presentation beyond inborn errors of metabolism. A high degree of clinical suspicion is required to identify appropriately targeted investigations and management. We conducted a comprehensive literature analysis of etiologies. Reported triggers are described and classified as per pathophysiological mechanism. A video of six cases displaying multiple SAME with diverse outcomes is provided. We identified 50 different conditions that manifest SAME, some associated with developmental regression. Etiologies include disorders of metabolism: energy substrate, amino acids, complex molecules, vitamins/cofactors, minerals, and neurotransmitters/synaptic vesicle cycling. Non-metabolic neurodegenerative and genetic disorders that present with movement disorders and epilepsy can additionally manifest SAME. A limited number of triggers are grouped here, together with an approach to investigations and general management strategies. Several neurogenetic and neurometabolic disorders manifest SAME. Identifying triggers can help in certain cases narrow the differential diagnosis and guide the expeditious application of targeted therapies to minimize adverse developmental and neurological consequences. This process may inform pathogenesis and eventually improve our understanding of the mechanisms that lead to the development of SAME. © 2024 International Parkinson and Movement Disorder Society.
Collapse
Affiliation(s)
- Blas Couto
- Edmond J. Safra Program in Parkinson's Disease, Rossy PSP Centre and the Morton and Gloria Shulman Movement Disorders Clinic, Toronto Western Hospital, Toronto, Ontario, Canada
- Instituto de Neurociencia Cognitiva y Traslacional, INECO-Favaloro-CONICET, Buenos Aires, Argentina
| | - Serena Galosi
- Department of Human Neuroscience, Sapienza University, Rome, Italy
| | - Dora Steel
- Molecular Neurosciences, Developmental Neurosciences, Zayed Centre for Research into Rare Disease in Children, UCL Great Ormond Street Institute of Child Health, London, United Kingdom
- Department of Neurology, Great Ormond Street Hospital, London, United Kingdom
| | - Manju A Kurian
- Molecular Neurosciences, Developmental Neurosciences, Zayed Centre for Research into Rare Disease in Children, UCL Great Ormond Street Institute of Child Health, London, United Kingdom
- Department of Neurology, Great Ormond Street Hospital, London, United Kingdom
| | - Jennifer Friedman
- Departments of Neurosciences and Pediatrics, University of California San Diego, San Diego, California, USA
- Division of Neurology, Rady Children's Hospital; Rady Children's Institute for Genomic Medicine, San Diego, California, USA
| | - Carolina Gorodetsky
- Division of Neurology, Pediatric Deep Brain Stimulation Program, Movement Disorder and Neuromodulation Program at the Hospital for Sick Children, Toronto, Ontario, Canada
- Department of Pediatrics, University of Toronto, Toronto, Ontario, Canada
| | - Anthony E Lang
- Edmond J. Safra Program in Parkinson's Disease, Rossy PSP Centre and the Morton and Gloria Shulman Movement Disorders Clinic, Toronto Western Hospital, Toronto, Ontario, Canada
- Tanz Centre for Research in Neurodegenerative Disease, University of Toronto, Toronto, Ontario, Canada
- Department of Medicine, Division of Neurology, University Health Network and the University of Toronto, Toronto, Ontario, Canada
| |
Collapse
|
3
|
Panagiotakaki E, Tiziano FD, Mikati MA, Vijfhuizen LS, Nicole S, Lesca G, Abiusi E, Novelli A, Di Pietro L, Harder AVE, Walley NM, De Grandis E, Poulat AL, Portes VD, Lépine A, Nassogne MC, Arzimanoglou A, Vavassori R, Koenderink J, Thompson CH, George AL, Gurrieri F, van den Maagdenberg AMJM, Heinzen EL. Exome sequencing of ATP1A3-negative cases of alternating hemiplegia of childhood reveals SCN2A as a novel causative gene. Eur J Hum Genet 2024; 32:224-231. [PMID: 38097767 PMCID: PMC10853263 DOI: 10.1038/s41431-023-01489-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Revised: 09/25/2023] [Accepted: 10/18/2023] [Indexed: 02/10/2024] Open
Abstract
Alternating hemiplegia of childhood (AHC) is a rare neurodevelopment disorder that is typically characterized by debilitating episodic attacks of hemiplegia, seizures, and intellectual disability. Over 85% of individuals with AHC have a de novo missense variant in ATP1A3 encoding the catalytic α3 subunit of neuronal Na+/K+ ATPases. The remainder of the patients are genetically unexplained. Here, we used next-generation sequencing to search for the genetic cause of 26 ATP1A3-negative index patients with a clinical presentation of AHC or an AHC-like phenotype. Three patients had affected siblings. Using targeted sequencing of exonic, intronic, and flanking regions of ATP1A3 in 22 of the 26 index patients, we found no ultra-rare variants. Using exome sequencing, we identified the likely genetic diagnosis in 9 probands (35%) in five genes, including RHOBTB2 (n = 3), ATP1A2 (n = 3), ANK3 (n = 1), SCN2A (n = 1), and CHD2 (n = 1). In follow-up investigations, two additional ATP1A3-negative individuals were found to have rare missense SCN2A variants, including one de novo likely pathogenic variant and one likely pathogenic variant for which inheritance could not be determined. Functional evaluation of the variants identified in SCN2A and ATP1A2 supports the pathogenicity of the identified variants. Our data show that genetic variants in various neurodevelopmental genes, including SCN2A, lead to AHC or AHC-like presentation. Still, the majority of ATP1A3-negative AHC or AHC-like patients remain unexplained, suggesting that other mutational mechanisms may account for the phenotype or that cases may be explained by oligo- or polygenic risk factors.
Collapse
Affiliation(s)
- Eleni Panagiotakaki
- Department of Paediatric Clinical Epileptology, Sleep Disorders and Functional Neurology, Member of the ERN EpiCare, University Hospitals of Lyon (HCL), Lyon, France
| | - Francesco D Tiziano
- Institute of Genomic Medicine, Catholic University and Policlinico Gemelli, Fondazione Policlinico Universitario Agostino Gemelli IRCSS, Rome, Italy
| | - Mohamad A Mikati
- Division of Pediatric Neurology and Developmental Medicine, Duke University, Durham, NC, USA
| | - Lisanne S Vijfhuizen
- Department of Human Genetics, Leiden University Medical Center, Leiden, The Netherlands
| | - Sophie Nicole
- Institute of Functional Genomics, University of Montpellier, CNRS, INSERM, Montpellier, France
| | - Gaetan Lesca
- Department of Medical Genetics, University Hospital of Lyon and Claude Bernard Lyon I University, Lyon France - Pathophysiology and Genetics of Neuron and Muscle (PNMG), UCBL, CNRS UMR5261 - INSERM U1315, Lyon, France
| | - Emanuela Abiusi
- Department of Life Sciences and Public Health, Section of Genomic Medicine, Università Cattolica del Sacro Cuore, Roma, Italy
| | - Agnese Novelli
- Department of Life Sciences and Public Health, Section of Genomic Medicine, Università Cattolica del Sacro Cuore, Roma, Italy
| | - Lorena Di Pietro
- Institute of Genomic Medicine, Catholic University and Policlinico Gemelli, Fondazione Policlinico Universitario Agostino Gemelli IRCSS, Rome, Italy
- Department of Life Sciences and Public Health, Section of Genomic Medicine, Università Cattolica del Sacro Cuore, Roma, Italy
| | - Aster V E Harder
- Department of Human Genetics, Leiden University Medical Center, Leiden, The Netherlands
- Department of Neurology, Leiden University Medical Center, Leiden, The Netherlands
| | - Nicole M Walley
- Department of Pediatrics, Division of Medical Genetics, Duke Health, Durham, NC, USA
| | - Elisa De Grandis
- Department of Neuroscience, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health, University of Genoa, Genoa, Italy
- Child Neuropsychiatry Unit, IRCCS Istituto Giannina Gaslini, Genova, Italy
| | - Anne-Lise Poulat
- Pediatric Neurology Department, Member of the ERN EpiCARE, University Hospitals of Lyon (HCL), Lyon, France
| | - Vincent Des Portes
- Pediatric Neurology Department, Member of the ERN EpiCARE, University Hospitals of Lyon (HCL), Lyon, France
| | - Anne Lépine
- Service de neuropédiatrie, Centre hospitalo universitaire de la Timone, Marseille, France
| | - Marie-Cecile Nassogne
- Institut des Maladies Rares, Cliniques Universitaires Saint-Luc, UCLouvain, Brussels, Belgium
- Service de Neurologie Pédiatrique, Member of the ERN MetabERN, Cliniques Universitaires Saint-Luc, UCLouvain, Brussels, Belgium
| | - Alexis Arzimanoglou
- Department of Paediatric Clinical Epileptology, Sleep Disorders and Functional Neurology, Member of the ERN EpiCare, University Hospitals of Lyon (HCL), Lyon, France
- Department of Child Neurology and Epilepsy Research Unit, Member of the ERN EpiCARE, Hospital San Juan de Dios, Barcelona, Spain
| | - Rosaria Vavassori
- Euro-Mediterranean Institute for Science and Technology I.E.ME.S.T., Palermo, Italy
| | - Jan Koenderink
- Department of Pharmacology and Toxicology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Christopher H Thompson
- Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - Alfred L George
- Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - Fiorella Gurrieri
- Department of Medicine, Research Unit of Medical Genetics, Università Campus Bio-Medico di Roma, Roma, Italy
- Operative Research Unit of Medical Genetics Fondazione Policlinico Universitario Campus Bio-Medico, Roma, Italy
| | - Arn M J M van den Maagdenberg
- Department of Human Genetics, Leiden University Medical Center, Leiden, The Netherlands.
- Department of Neurology, Leiden University Medical Center, Leiden, The Netherlands.
| | - Erin L Heinzen
- Division of Pharmacology and Experimental Therapeutics, Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.
- Department of Genetics, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.
| |
Collapse
|
4
|
de Pedro Baena S, Sariego Jamardo A, Castro P, López González FJ, Sánchez Carpintero R, Cerisola A, Troncoso M, Witting S, Barrios A, Fons C, López Pisón J, Ortigoza‐Escobar JD. Exploring the Spectrum of RHOBTB2 Variants Associated with Developmental Encephalopathy 64: A Case Series and Literature Review. Mov Disord Clin Pract 2023; 10:1671-1679. [PMID: 37982109 PMCID: PMC10654829 DOI: 10.1002/mdc3.13880] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2022] [Revised: 08/20/2023] [Accepted: 08/24/2023] [Indexed: 11/21/2023] Open
Abstract
Background Rho-related BTB domain-containing protein 2 (RHOBTB2) is a protein that interacts with cullin-3, a crucial E3 ubiquitin ligase for mitotic cell division. RHOBTB2 has been linked to early infantile epileptic encephalopathy, autosomal dominant type 64 (OMIM618004), in 34 reported patients. Methods We present a case series of seven patients with RHOBTB2-related disorders (RHOBTB2-RD), including a description of a novel heterozygous variant. We also reviewed previously published cases of RHOBTB2-RD. Results The seven patients had ages ranging from 2 years and 8 months to 26 years, and all had experienced seizures before the age of one (onset, 4-12 months, median, 4 months), including various types of seizures. All patients in this cohort also had a movement disorder (onset, 0.3-14 years, median, 1.5 years). Six of seven had a baseline movement disorder, and one of seven only had paroxysmal dystonia. Stereotypies were noted in four of six, choreodystonia in three of six, and ataxia in one case with multiple movement phenotypes at baseline. Paroxysmal movement disorders were observed in six of seven patients for whom carbamazepine or oxcarbazepine treatment was effective in controlling acute or paroxysmal movement disorders. Four patients had acute encephalopathic episodes at ages 4 (one patient) and 6 (three patients), which improved following treatment with methylprednisolone. Magnetic resonance imaging scans revealed transient fluid-attenuated inversion recovery abnormalities during these episodes, as well as myelination delay, thin corpus callosum, and brain atrophy. One patient had a novel RHOBTB2 variant (c.359G>A/p.Gly120Glu). Conclusion RHOBTB2-RD is characterized by developmental delay or intellectual disability, early-onset seizures, baseline movement disorders, acute or paroxysmal motor phenomena, acquired microcephaly, and episodes of acute encephalopathy. Early onsets of focal dystonia, acute encephalopathic episodes, episodes of tongue protrusion, or peripheral vasomotor disturbances are important diagnostic clues. Treatment with carbamazepine or oxcarbazepine was found to be effective in controlling acute or paroxysmal movement disorders. Our study highlights the clinical features and treatment response of RHOBTB2-RD.
Collapse
Affiliation(s)
| | - Andrea Sariego Jamardo
- Pediatric Neurology DepartmentHospital Universitario Marqués de ValdecillaSantanderSpain
| | - Pedro Castro
- Department of Pediatric NeurologyHospital Gregorio MarañónMadridSpain
| | | | | | - Alfredo Cerisola
- Pediatric Neurology DepartmentInstitut de Recerca, Hospital Sant Joan de Déu BarcelonaBarcelonaSpain
| | - Mónica Troncoso
- Centro de Referencia Nacional en Defectos Congénitos y Enfermedades Raras (CRENADECER) del Banco de Previsión Social (BPS), Uruguay; Cátedra de Neuropediatría, Facultad de MedicinaUniversidad de la RepúblicaMontevideoUruguay
| | - Scarlet Witting
- Centro de Referencia Nacional en Defectos Congénitos y Enfermedades Raras (CRENADECER) del Banco de Previsión Social (BPS), Uruguay; Cátedra de Neuropediatría, Facultad de MedicinaUniversidad de la RepúblicaMontevideoUruguay
| | - Andrés Barrios
- Centro de Referencia Nacional en Defectos Congénitos y Enfermedades Raras (CRENADECER) del Banco de Previsión Social (BPS), Uruguay; Cátedra de Neuropediatría, Facultad de MedicinaUniversidad de la RepúblicaMontevideoUruguay
| | - Carmen Fons
- Pediatric Neurology DepartmentInstitut de Recerca, Hospital Sant Joan de Déu BarcelonaBarcelonaSpain
| | - Javier López Pisón
- Child Neurology ServiceHospital San Borja Arriarán, Universidad de ChileSantiagoChile
| | - Juan Darío Ortigoza‐Escobar
- Pediatric Neurology DepartmentHospital Infantil Universitario Miguel ServetZaragozaSpain
- Movement Disorders Unit, Pediatric Neurology DepartmentInstitut de Recerca, Hospital Sant Joan de Déu BarcelonaBarcelonaSpain
- U‐703 Centre for Biomedical Research on Rare Diseases (CIBER‐ER)Instituto de Salud Carlos IIIBarcelonaSpain
- European Reference Network for Rare Neurological Diseases (ERN‐RND)BarcelonaSpain
| |
Collapse
|
5
|
Kern HM, Waugh JL. Expanding Knowledge of the Causes of Childhood Chorea. Semin Pediatr Neurol 2023; 47:101088. [PMID: 37919039 DOI: 10.1016/j.spen.2023.101088] [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: 09/18/2023] [Accepted: 09/21/2023] [Indexed: 11/04/2023]
Abstract
INHERITED AND ACQUIRED CHOREAS Paolo Claudio M. de Gusmao, Jeff L. Waugh Seminars in Pediatric Neurology Volume 25, April 2018, Pages 42-53 Chorea is a symptom of a broad array of genetic, structural, and metabolic disorders. While chorea can result from systemic illness and damage to diverse brain structures, injury to the basal ganglia, especially the putamen or globus pallidus, appears to be a uniting features of these diverse neuropathologies. The timing of onset, rate of progression, and the associated neurological or systemic symptoms can often narrow the differential diagnosis to a few disorders. Recognizing the correct etiology for childhood chorea is critical, as numerous disorders in this category are potentially curable, or are remediable, with early treatment.
Collapse
Affiliation(s)
- H M Kern
- Division of Pediatric Neurology, Department of Pediatrics, University of Texas Southwestern, Dallas, TX
| | - J L Waugh
- Division of Pediatric Neurology, Department of Pediatrics, University of Texas Southwestern, Dallas, TX.
| |
Collapse
|
6
|
Langhammer F, Maroofian R, Badar R, Gregor A, Rochman M, Ratliff JB, Koopmans M, Herget T, Hempel M, Kortüm F, Heron D, Mignot C, Keren B, Brooks S, Botti C, Ben-Zeev B, Argilli E, Sherr EH, Gowda VK, Srinivasan VM, Bakhtiari S, Kruer MC, Salih MA, Kuechler A, Muller EA, Blocker K, Kuismin O, Park KL, Kochhar A, Brown K, Ramanathan S, Clark RD, Elgizouli M, Melikishvili G, Tabatadze N, Stark Z, Mirzaa GM, Ong J, Grasshoff U, Bevot A, von Wintzingerode L, Jamra RA, Hennig Y, Goldenberg P, Al Alam C, Charif M, Boulouiz R, Bellaoui M, Amrani R, Al Mutairi F, Tamim AM, Abdulwahab F, Alkuraya FS, Khouj EM, Alvi JR, Sultan T, Hashemi N, Karimiani EG, Ashrafzadeh F, Imannezhad S, Efthymiou S, Houlden H, Sticht H, Zweier C. Genotype-phenotype correlations in RHOBTB2-associated neurodevelopmental disorders. Genet Med 2023; 25:100885. [PMID: 37165955 DOI: 10.1016/j.gim.2023.100885] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2023] [Revised: 05/03/2023] [Accepted: 05/03/2023] [Indexed: 05/12/2023] Open
Abstract
PURPOSE Missense variants clustering in the BTB domain region of RHOBTB2 cause a developmental and epileptic encephalopathy with early-onset seizures and severe intellectual disability. METHODS By international collaboration, we assembled individuals with pathogenic RHOBTB2 variants and a variable spectrum of neurodevelopmental disorders. By western blotting, we investigated the consequences of missense variants in vitro. RESULTS In accordance with previous observations, de novo heterozygous missense variants in the BTB domain region led to a severe developmental and epileptic encephalopathy in 16 individuals. Now, we also identified de novo missense variants in the GTPase domain in 6 individuals with apparently more variable neurodevelopmental phenotypes with or without epilepsy. In contrast to variants in the BTB domain region, variants in the GTPase domain do not impair proteasomal degradation of RHOBTB2 in vitro, indicating different functional consequences. Furthermore, we observed biallelic splice-site and truncating variants in 9 families with variable neurodevelopmental phenotypes, indicating that complete loss of RHOBTB2 is pathogenic as well. CONCLUSION By identifying genotype-phenotype correlations regarding location and consequences of de novo missense variants in RHOBTB2 and by identifying biallelic truncating variants, we further delineate and expand the molecular and clinical spectrum of RHOBTB2-related phenotypes, including both autosomal dominant and recessive neurodevelopmental disorders.
Collapse
Affiliation(s)
- Franziska Langhammer
- Department of Human Genetics, Inselspital Bern, University of Bern, Bern, Switzerland; Department for Biomedical Research (DBMR), University of Bern, Bern, Switzerland
| | - Reza Maroofian
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology, London, United Kingdom
| | - Rueda Badar
- Department of Human Genetics, Inselspital Bern, University of Bern, Bern, Switzerland; Department for Biomedical Research (DBMR), University of Bern, Bern, Switzerland
| | - Anne Gregor
- Department of Human Genetics, Inselspital Bern, University of Bern, Bern, Switzerland; Department for Biomedical Research (DBMR), University of Bern, Bern, Switzerland
| | - Michelle Rochman
- Department of Neurology, Thomas Jefferson University, Philadelphia, PA
| | - Jeffrey B Ratliff
- Department of Neurology, Thomas Jefferson University, Philadelphia, PA
| | - Marije Koopmans
- Department of Genetics, Center for Molecular Medicine, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
| | - Theresia Herget
- Institute of Human Genetics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Maja Hempel
- Institute of Human Genetics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Fanny Kortüm
- Institute of Human Genetics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Delphine Heron
- Department of Genetics, La Pitié-Salpêtrière Hospital, APHP, Sorbonne University, Paris, France
| | - Cyril Mignot
- Department of Genetics, La Pitié-Salpêtrière Hospital, APHP, Sorbonne University, Paris, France
| | - Boris Keren
- Department of Genetics, La Pitié-Salpêtrière Hospital, APHP, Sorbonne University, Paris, France
| | - Susan Brooks
- Division of Medical Genetics, Department of Pediatrics, Rutgers Robert Wood Johnson Medical School, New Brunswick, NJ
| | - Christina Botti
- Division of Medical Genetics, Department of Pediatrics, Rutgers Robert Wood Johnson Medical School, New Brunswick, NJ
| | - Bruria Ben-Zeev
- The Neurology Department at Sheba Medical Center, Ramat Gan, Israel
| | - Emanuela Argilli
- Brain Development Research Program, Department of Neurology, University of California San Francisco, San Francisco, CA
| | - Elliot H Sherr
- Brain Development Research Program, Department of Neurology, University of California San Francisco, San Francisco, CA
| | - Vykuntaraju K Gowda
- Department of Pediatric Neurology, Indira Gandhi Institute of Child Health, Bangalore, Karnataka, India
| | - Varunvenkat M Srinivasan
- Department of Pediatric Neurology, Indira Gandhi Institute of Child Health, Bangalore, Karnataka, India
| | - Somayeh Bakhtiari
- Pediatric Movement Disorders Program, Division of Pediatric Neurology, Barrow Neurological Institute, Phoenix Children's Hospital, Phoenix, AZ; Departments of Child Health, Neurology, and Cellular & Molecular Medicine, and Program in Genetics, University of Arizona College of Medicine-Phoenix, Phoenix, AZ
| | - Michael C Kruer
- Pediatric Movement Disorders Program, Division of Pediatric Neurology, Barrow Neurological Institute, Phoenix Children's Hospital, Phoenix, AZ; Departments of Child Health, Neurology, and Cellular & Molecular Medicine, and Program in Genetics, University of Arizona College of Medicine-Phoenix, Phoenix, AZ
| | - Mustafa A Salih
- Division of Pediatric Neurology, College of Medicine, King Saud University, Riyadh, Saudi Arabia; Department of Pediatrics, College of Medicine, Almughtaribeen University, Khartoum, Sudan
| | - Alma Kuechler
- Institute of Human Genetics, University Hospital Essen, University of Duisburg-Essen, Essen, Germany
| | - Eric A Muller
- Clinical Genetics, Stanford Children's Health, San Francisco, CA
| | - Karli Blocker
- Clinical Genetics, Stanford Children's Health, San Francisco, CA
| | - Outi Kuismin
- Department of Clinical Genetics, PEDEGO Research Unit and Medical Research Center Oulu, Oulu University Hospital and University of Oulu, Oulu, Finland
| | - Kristen L Park
- Anschutz Medical Campus Department of Pediatrics and Neurology, University of Colorado School of Medicine, Aurora, CO
| | - Aaina Kochhar
- Section of Genetics, Department of Pediatrics, University of Colorado School of Medicine, Aurora, CO
| | - Kathleen Brown
- Section of Genetics, Department of Pediatrics, University of Colorado School of Medicine, Aurora, CO
| | | | - Robin D Clark
- Division of Genetics, Loma Linda University Health, San Bernardino, CA
| | - Magdeldin Elgizouli
- Institute of Human Genetics, University Hospital Essen, University of Duisburg-Essen, Essen, Germany
| | - Gia Melikishvili
- Department of pediatrics, MediClubGeorgia Medical Center, Tbilisi, Georgia
| | - Nazhi Tabatadze
- Department of pediatrics, MediClubGeorgia Medical Center, Tbilisi, Georgia
| | - Zornitza Stark
- Victorian Clinical Genetics Services, Murdoch Children's Research Institute, Melbourne, VIC, Australia; Department of Paediatrics, University of Melbourne, Melbourne, VIC, Australia
| | - Ghayda M Mirzaa
- Center for Integrative Brain Research, Seattle Children's Research Institute, Seattle, WA; Department of Pediatrics, University of Washington, Seattle, WA; Brotman Baty Institute for Precision Medicine, Seattle, WA
| | - Jinfon Ong
- Child Neurology Consultants of Austin, Austin, TX
| | - Ute Grasshoff
- Institute of Medical Genetics and Applied Genomics, University of Tuebingen, Tuebingen, Germany
| | - Andrea Bevot
- Department of Pediatric Neurology and Developmental Medicine, Children's Hospital, University Hospital of Tuebingen, Tuebingen, Germany
| | | | - Rami A Jamra
- Institute of Human Genetics, University of Leipzig Medical Center, Leipzig, Germany
| | - Yvonne Hennig
- Department of Pediatrics, University of Leipzig Medical Center, Leipzig, Germany
| | - Paula Goldenberg
- Division of Medical Genetics, Massachusetts General Hospital, Boston, MA
| | - Chadi Al Alam
- Pediatric Neurology Department, American Center for Psychiatry and Neurology, Abu Dhabi, United Arab Emirates; Pediatric Neurology department, Haykel Hospital, El Koura, Lebanon
| | - Majida Charif
- Genetics Unit, Medical Sciences Research Laboratory, Faculty of Medicine and Pharmacy, University Mohammed Premier, Oujda, Morocco; BRO Biobank, Faculty of Medicine and Pharmacy, University Mohammed Premier, Oujda, Morocco; Genetics and Immuno-Cell Therapy Team, Mohammed First University, Oujda, Morocco
| | - Redouane Boulouiz
- Genetics Unit, Medical Sciences Research Laboratory, Faculty of Medicine and Pharmacy, University Mohammed Premier, Oujda, Morocco; BRO Biobank, Faculty of Medicine and Pharmacy, University Mohammed Premier, Oujda, Morocco
| | - Mohammed Bellaoui
- Genetics Unit, Medical Sciences Research Laboratory, Faculty of Medicine and Pharmacy, University Mohammed Premier, Oujda, Morocco; BRO Biobank, Faculty of Medicine and Pharmacy, University Mohammed Premier, Oujda, Morocco
| | - Rim Amrani
- Department of Neonatology, Mohammed VI University Hospital, Faculty of Medicine and Pharmacy, University Mohammed Premier, Oujda, Morocco
| | - Fuad Al Mutairi
- Genetic and Precision Medicine Department, King Abdullah Specialized Children Hospital, King Abdulaziz Medical City, King Abdullah International Medical Research Center, King Saud bin Abdulaziz University for Health Sciences, Riyadh, Saudi Arabia
| | - Abdullah M Tamim
- Pediatric Neurology Section-Pediatric Department, King Faisal Specialist Hospital & Research Center (Gen. Org) - Jeddah Branch, Riyadh, Saudi Arabia
| | - Firdous Abdulwahab
- Department of Translational Genomics, Center for Genomic Medicine, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Fowzan S Alkuraya
- Department of Translational Genomics, Center for Genomic Medicine, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Ebtissal M Khouj
- Department of Translational Genomics, Center for Genomic Medicine, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Javeria R Alvi
- Department of Pediatric Neurology, Children's Hospital and Institute of Child Health, Lahore, Pakistan
| | - Tipu Sultan
- Department of Pediatric Neurology, Children's Hospital and Institute of Child Health, Lahore, Pakistan
| | - Narges Hashemi
- Department of Pediatrics, School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Ehsan G Karimiani
- Molecular and Clinical Sciences Institute, St. George's, University of London, Cranmer Terrace, London, United Kingdom
| | - Farah Ashrafzadeh
- Department of Pediatrics, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Shima Imannezhad
- Department of Pediatric Neurology, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Stephanie Efthymiou
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology, London, United Kingdom
| | - Henry Houlden
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology, London, United Kingdom
| | - Heinrich Sticht
- Institute of Biochemistry, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Christiane Zweier
- Department of Human Genetics, Inselspital Bern, University of Bern, Bern, Switzerland; Department for Biomedical Research (DBMR), University of Bern, Bern, Switzerland.
| |
Collapse
|
7
|
Nott E, Behl KE, Brambilla I, Green TE, Lucente M, Vavassori R, Watson A, Dalla Bernardina B, Hildebrand MS. Rare. The importance of research, analysis, reporting and education in 'solving' the genetic epilepsies: A perspective from the European patient advocacy group for EpiCARE. Eur J Med Genet 2023; 66:104680. [PMID: 36623768 DOI: 10.1016/j.ejmg.2022.104680] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Revised: 11/14/2022] [Accepted: 12/11/2022] [Indexed: 01/09/2023]
Affiliation(s)
- E Nott
- European Patient Advocacy Group (ePAG) EpiCARE, France; Hope for Hypothalamic Hamartomas and Hope for Hypothalamic Hamartomas-UK, UK.
| | - K E Behl
- Alternating Hemiplegia of Childhood UK (AHCUK) and Alternating Hemiplegia of Childhood Federation of Europe (AHCFE), UK
| | - I Brambilla
- European Patient Advocacy Group (ePAG) EpiCARE, France; Dravet Italia Onlus; Epilepsy Research Centre, Department of Medicine, The University of Melbourne, Austin Health, Heidelberg, Victoria, 3084, Australia
| | - T E Green
- Epilepsy Research Centre, Department of Medicine, The University of Melbourne, Austin Health, Heidelberg, Victoria, 3084, Australia; Murdoch Children's Research Institute, The Royal Children's Hospital, Parkville, Victoria, 3052, Australia
| | - M Lucente
- European Patient Advocacy Group (ePAG) EpiCARE, France; Associazione Italiana GLUT1 Onlus, Italy
| | - R Vavassori
- European Patient Advocacy Group (ePAG) EpiCARE, France; International Alternating Hemiplegia of Childhood Research Consortium (IAHCRC), USA; Alternating Hemiplegia of Childhood 18+ (AHC18+ e.V.) Association, Germany
| | - A Watson
- European Patient Advocacy Group (ePAG) EpiCARE, France; Ring20 Research and Support UK, UK
| | - B Dalla Bernardina
- Dravet Italia Onlus; Research Center for Pediatric Epilepsies Verona, Department of Surgical Sciences, Dentistry, Gynecology and Pediatrics, University of Verona, Italy
| | - M S Hildebrand
- Hope for Hypothalamic Hamartomas and Hope for Hypothalamic Hamartomas-UK, UK; Epilepsy Research Centre, Department of Medicine, The University of Melbourne, Austin Health, Heidelberg, Victoria, 3084, Australia; Murdoch Children's Research Institute, The Royal Children's Hospital, Parkville, Victoria, 3052, Australia
| |
Collapse
|
8
|
Zhang X, Qiu S, Yang L, Li Y, Xu L, Xu N, Mi C, Li M. A novel heterozygous ATP1A2 pathogenic variant in a Chinese child with MELAS-like alternating hemiplegia. Mol Genet Genomic Med 2023; 11:e2146. [PMID: 36749827 PMCID: PMC10178798 DOI: 10.1002/mgg3.2146] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2022] [Revised: 12/22/2022] [Accepted: 01/25/2023] [Indexed: 02/09/2023] Open
Abstract
BACKGROUND Pathogenic variants of ATP1A2 (OMIM ID: 182340) are usually associated with familial hemiplegic migraine type 2 (FHM-2), alternating hemiplegia of childhood (AHC), early infantile epileptic encephalopathy (EIEE), transient cytotoxic edema, and so on. Here, we present a novel heterozygous ATP1A2 variant in a girl with alternating hemiplegia, febrile seizures, developmental delay (which subsequently subsided), and MELAS-like syndrome (as indicated by brain MRI). The patient did not experience migraine with aura. METHODS The patient was an 8-year-old girl with normal growth and development. Beginning from the age of 3 years and 8 months, the patient experienced several episodes of alternating limb paralysis. The episodes were accompanied by the appearance of MELAS-like findings on brain MRI, which corresponded to the hemiplegia. There were abnormal linear signals in the cerebral cortex on the opposite side of the hemiplegic limb. Each time the patient recovered from hemiplegia, and each time MRI showed no lesions remained after recovery. No obvious abnormality was found in other examinations. Finally, the patient underwent whole-exome sequencing (WES). RESULTS WES revealed a novel and de novo heterozygous variant in the ATP1A2 (NM_000702.3) c.335C>A:p.Ala112Asp (not previously reported). We examined the variant position in the 3D protein structure and found that a missense mutation at this site is a nonconservative substitution. The variation is nonpolymorphic. It occurs at a very low frequency in the population, and its ACMG classification is likely pathogenic. CONCLUSION At present, there are limited reports of mutations in the ATP1A2 gene causing AHC. This is the first case of brain MRI showing MELAS-like imaging in an AHC patient, and more cases are needed for verification. Early genetic testing and family screening can aid in the diagnosis and treatment of genetic diseases. The relationship between ATP1A2 gene mutation genotype and clinical phenotype needs to be further studied.
Collapse
Affiliation(s)
- Xin Zhang
- Department of Pediatrics, Linyi People's Hospital, Postgrad Training Base Jinzhou Med University, Linyi, People's Republic of China.,Department of Pediatrics, Linyi People's Hospital, Linyi, Shandong, People's Republic of China
| | - Shiyan Qiu
- Department of Pediatrics, Linyi People's Hospital, Linyi, Shandong, People's Republic of China
| | - Li Yang
- Department of Pediatrics, Linyi People's Hospital, Linyi, Shandong, People's Republic of China
| | - Yufen Li
- Department of Pediatrics, Linyi People's Hospital, Linyi, Shandong, People's Republic of China
| | - Liyun Xu
- Department of Pediatrics, Linyi People's Hospital, Linyi, Shandong, People's Republic of China
| | - Na Xu
- Department of Pediatrics, Linyi People's Hospital, Linyi, Shandong, People's Republic of China
| | - Changrui Mi
- Department of Pediatrics, Linyi People's Hospital, Linyi, Shandong, People's Republic of China
| | - Menglin Li
- Department of Pediatrics, Linyi People's Hospital, Linyi, Shandong, People's Republic of China
| |
Collapse
|
9
|
Martorell L, Macaya A, Pérez‐Dueñas B, Ortigoza‐Escobar JD. Acetazolamide Improves Episodic Ataxia in a Patient with Non-Verbal Autism and Paroxysmal Dyskinesia Due To PRRT2 Biallelic Variants. Mov Disord Clin Pract 2022; 9:979-982. [PMID: 36247910 PMCID: PMC9547142 DOI: 10.1002/mdc3.13528] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2022] [Revised: 07/05/2022] [Accepted: 07/19/2022] [Indexed: 11/10/2022] Open
Affiliation(s)
- Loreto Martorell
- Department of Genetic and Molecular Medicine‐IPERInstitut de Recerca Sant Joan de DéuBarcelonaSpain
- Centre for Biomedical Research on Rare Diseases (CIBER‐ER)Instituto de Salud Carlos IIIBarcelonaSpain
| | - Alfons Macaya
- Department of Paediatric NeurologyVall d'Hebron University HospitalBarcelonaSpain
- Universitat Autònoma de BarcelonaBarcelonaSpain
- European Reference Network for Rare Neurological Diseases (ERN‐RND)BarcelonaSpain
| | - Belén Pérez‐Dueñas
- Centre for Biomedical Research on Rare Diseases (CIBER‐ER)Instituto de Salud Carlos IIIBarcelonaSpain
- European Reference Network for Rare Neurological Diseases (ERN‐RND)BarcelonaSpain
- Paediatric Neurology Research Group, Vall d'Hebron Research Institut, Universitat Autònoma de BarcelonaBarcelonaSpain
| | - Juan Darío Ortigoza‐Escobar
- Centre for Biomedical Research on Rare Diseases (CIBER‐ER)Instituto de Salud Carlos IIIBarcelonaSpain
- European Reference Network for Rare Neurological Diseases (ERN‐RND)BarcelonaSpain
- Movement Disorders Unit, Department of Child Neurology, Institut de Recerca Sant Joan de DéuBarcelonaSpain
| |
Collapse
|
10
|
Dzinovic I, Winkelmann J, Zech M. Genetic intersection between dystonia and neurodevelopmental disorders: Insights from genomic sequencing. Parkinsonism Relat Disord 2022; 102:131-140. [DOI: 10.1016/j.parkreldis.2022.08.019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/03/2022] [Revised: 08/12/2022] [Accepted: 08/18/2022] [Indexed: 10/15/2022]
|
11
|
Spaull R, Steel D, Barwick K, Prabhakar P, Wakeling E, Kurian MA. STXBP1
stop‐loss mutation associated with complex early onset movement disorder without epilepsy. Mov Disord Clin Pract 2022; 9:837-840. [PMID: 35937496 PMCID: PMC9346254 DOI: 10.1002/mdc3.13509] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Revised: 06/01/2022] [Accepted: 06/10/2022] [Indexed: 11/07/2022] Open
Affiliation(s)
- Robert Spaull
- Molecular Neurosciences, Developmental Neurosciences, Zayed Centre for Research into Rare Disease in Children UCL Great Ormond Street Institute of Child Health, UCL London UK
- Department of Neurology Great Ormond Street Hospital London UK
| | - Dora Steel
- Molecular Neurosciences, Developmental Neurosciences, Zayed Centre for Research into Rare Disease in Children UCL Great Ormond Street Institute of Child Health, UCL London UK
- Department of Neurology Great Ormond Street Hospital London UK
| | - Katy Barwick
- Molecular Neurosciences, Developmental Neurosciences, Zayed Centre for Research into Rare Disease in Children UCL Great Ormond Street Institute of Child Health, UCL London UK
| | - Prab Prabhakar
- Department of Neurology Great Ormond Street Hospital London UK
| | - Emma Wakeling
- North East Thames Regional Genetic Service Great Ormond Street Hospital for Children NHS Foundation Trust London UK
| | - Manju A. Kurian
- Molecular Neurosciences, Developmental Neurosciences, Zayed Centre for Research into Rare Disease in Children UCL Great Ormond Street Institute of Child Health, UCL London UK
- Department of Neurology Great Ormond Street Hospital London UK
| |
Collapse
|
12
|
Defo A, Verloes A, Elenga N. Developmental and epileptic encephalopathy related to a heterozygous variant of the RHOBTB2 gene: A case report from French Guiana. Mol Genet Genomic Med 2022; 10:e1929. [PMID: 35315256 PMCID: PMC9184662 DOI: 10.1002/mgg3.1929] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Revised: 02/27/2022] [Accepted: 03/08/2022] [Indexed: 11/07/2022] Open
Affiliation(s)
- Antoine Defo
- Pediatric Medicine and Surgery, Centre Hospitalier de Cayenne, Cayenne Cedex, French Guiana
| | - Alain Verloes
- Department of Clinical Genetics, Hôpital Robert Debré, Paris, France
| | - Narcisse Elenga
- Pediatric Medicine and Surgery, Centre Hospitalier de Cayenne, Cayenne Cedex, French Guiana
| |
Collapse
|
13
|
Harvey S, King MD, Gorman KM. Paroxysmal Movement Disorders. Front Neurol 2021; 12:659064. [PMID: 34177764 PMCID: PMC8232056 DOI: 10.3389/fneur.2021.659064] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Accepted: 04/20/2021] [Indexed: 11/13/2022] Open
Abstract
Paroxysmal movement disorders (PxMDs) are a clinical and genetically heterogeneous group of movement disorders characterized by episodic involuntary movements (dystonia, dyskinesia, chorea and/or ataxia). Historically, PxMDs were classified clinically (triggers and characteristics of the movements) and this directed single-gene testing. With the advent of next-generation sequencing (NGS), how we classify and investigate PxMDs has been transformed. Next-generation sequencing has enabled new gene discovery (RHOBTB2, TBC1D24), expansion of phenotypes in known PxMDs genes and a better understanding of disease mechanisms. However, PxMDs exhibit phenotypic pleiotropy and genetic heterogeneity, making it challenging to predict genotype based on the clinical phenotype. For example, paroxysmal kinesigenic dyskinesia is most commonly associated with variants in PRRT2 but also variants identified in PNKD, SCN8A, and SCL2A1. There are no radiological or biochemical biomarkers to differentiate genetic causes. Even with NGS, diagnosis rates are variable, ranging from 11 to 51% depending on the cohort studied and technology employed. Thus, a large proportion of patients remain undiagnosed compared to other neurological disorders such as epilepsy, highlighting the need for further genomic research in PxMDs. Whole-genome sequencing, deep-sequencing, copy number variant analysis, detection of deep-intronic variants, mosaicism and repeat expansions, will improve diagnostic rates. Identifying the underlying genetic cause has a significant impact on patient care, modification of treatment, long-term prognostication and genetic counseling. This paper provides an update on the genetics of PxMDs, description of PxMDs classified according to causative gene rather than clinical phenotype, highlighting key clinical features and providing an algorithm for genetic testing of PxMDs.
Collapse
Affiliation(s)
- Susan Harvey
- Department of Paediatric Neurology and Clinical Neurophysiology, Children's Health Ireland at Temple Street, Dublin, Ireland
| | - Mary D King
- Department of Paediatric Neurology and Clinical Neurophysiology, Children's Health Ireland at Temple Street, Dublin, Ireland.,School of Medicine and Medical Science, University College Dublin, Dublin, Ireland
| | - Kathleen M Gorman
- Department of Paediatric Neurology and Clinical Neurophysiology, Children's Health Ireland at Temple Street, Dublin, Ireland.,School of Medicine and Medical Science, University College Dublin, Dublin, Ireland
| |
Collapse
|
14
|
Cordani R, Stagnaro M, Pisciotta L, Tiziano FD, Calevo MG, Nobili L, De Grandis E. Alternating Hemiplegia of Childhood: Genotype-Phenotype Correlations in a Cohort of 39 Italian Patients. Front Neurol 2021; 12:658451. [PMID: 33897609 PMCID: PMC8060701 DOI: 10.3389/fneur.2021.658451] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Accepted: 02/25/2021] [Indexed: 11/13/2022] Open
Abstract
Alternating hemiplegia of childhood is a rare neurological disease characterized by paroxysmal movement disorders and chronic neurological disturbances, with onset before 18 months of age. Mutations in the ATP1A3 gene have been identified in up to 80% of patients. Thirty-nine patients [20 females, 19 males, mean age 25.32 years (7.52–49.34)] have been recruited through the Italian Biobank and Clinical Registry for Alternating Hemiplegia of Childhood. Demographic data, genotype, paroxysmal movement disorders, chronic neurological features, and response to flunarizine have been analyzed. ATP1A3 gene mutations have been detected in 92.3% of patients. Patients have been divided into three groups—p.Asp801Asn mutation patients (26%), p.Glu815Lys cases (23%), and patients with other ATP1A3 mutations—and statistically compared. The Italian cohort has a higher percentage of ATP1A3 gene mutation than reported in literature (92.3%). Our data confirm a more severe phenotype in patients with p.Glu815Lys mutation, with an earlier age of onset of plegic (p = 0.02 in the correlation with other mutations) and tonic attacks. P.Glu815Lys patients most frequently present altered muscle tone, inability to walk (p = 0.01 comparing p.Glu815Lys and p.Asp801Asn mutations), epilepsy, and a more severe grade of dystonia (p < 0.05 comparing p.Glu815Lys and p.Asp801Asn mutations). They have moderate/severe intellectual disability and severe language impairment (p < 0.05). Interestingly, flunarizine seems to be more efficacious in patients with p.Glu815Lys mutation than p.Asp801Asn. In conclusion, our research suggests a genotype–phenotype correlation and provides information on this disorder's features, clinical course, and treatment.
Collapse
Affiliation(s)
- Ramona Cordani
- Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health, University of Genoa, Genoa, Italy
| | - Michela Stagnaro
- Child Neuropsychiatry Unit, Department of Clinical and Surgical Neurosciences and Rehabilitation, Istituto di Ricovero e Cura a Carattere Scientifico Giannina Gaslini, Genova, Italy
| | - Livia Pisciotta
- Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health, University of Genoa, Genoa, Italy.,Child Neuropsychiatry Unit, Azienda Socio Sanitaria Territoriale Fatebenefratelli- Sacco, Milano, Italy
| | - Francesco Danilo Tiziano
- Section of Genomic Medicine, Department of Life Science and Public Health, Catholic University of Sacred Heart, Roma, Italy
| | - Maria Grazia Calevo
- Epidemiology, Biostatistics and Committees Unit, Istituto di Ricovero e Cura a Carattere Scientifico Istituto Giannina Gaslini, Genoa, Italy
| | - Lino Nobili
- Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health, University of Genoa, Genoa, Italy.,Child Neuropsychiatry Unit, Department of Clinical and Surgical Neurosciences and Rehabilitation, Istituto di Ricovero e Cura a Carattere Scientifico Giannina Gaslini, Genova, Italy
| | | | - Elisa De Grandis
- Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health, University of Genoa, Genoa, Italy.,Child Neuropsychiatry Unit, Department of Clinical and Surgical Neurosciences and Rehabilitation, Istituto di Ricovero e Cura a Carattere Scientifico Giannina Gaslini, Genova, Italy
| |
Collapse
|