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Srivastava S, Cole JJ, Cohen JS, Chopra M, Smith HS, Deardorff MA, Pedapati E, Corner B, Anixt JS, Jeste S, Sahin M, Gurnett CA, Campbell CA. Survey of the Landscape of Society Practice Guidelines for Genetic Testing of Neurodevelopmental Disorders. Ann Neurol 2024. [PMID: 39319594 DOI: 10.1002/ana.27045] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2024] [Revised: 07/09/2024] [Accepted: 07/15/2024] [Indexed: 09/26/2024]
Abstract
Genetic testing of patients with neurodevelopmental disabilities (NDDs) is critical for diagnosis, medical management, and access to precision therapies. Because genetic testing approaches evolve rapidly, professional society practice guidelines serve an essential role in guiding clinical care; however, several challenges exist regarding the creation and equitable implementation of these guidelines. In this scoping review, we assessed the current state of United States professional societies' guidelines pertaining to genetic testing for unexplained global developmental delay, intellectual disability, autism spectrum disorder, and cerebral palsy. We describe several identified shortcomings and argue the need for a unified, frequently updated, and easily-accessible cross-specialty society guideline. ANN NEUROL 2024.
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Affiliation(s)
- Siddharth Srivastava
- Department of Neurology, Rosamund Stone Zander Translational Neuroscience Center, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Jordan J Cole
- Department of Pediatrics, University of Colorado, Children's Hospital Colorado, Aurora, CO, USA
| | - Julie S Cohen
- Department of Neurology and Developmental Medicine, Kennedy Krieger Institute, Baltimore, MD, USA
- Department of Neurology, Johns Hopkins School of Medicine, Baltimore, MD, USA
| | - Maya Chopra
- Department of Neurology, Rosamund Stone Zander Translational Neuroscience Center, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Hadley Stevens Smith
- Department of Population Medicine, Harvard Medical School and Harvard Pilgrim Health Care Institute, Boston, MA, USA
| | - Matthew A Deardorff
- Departments of Pathology and Pediatrics, Keck School of Medicine of USC, Children's Hospital Los Angeles, Los Angeles, CA, USA
| | - Ernest Pedapati
- Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital, Cincinnati, OH, USA
| | - Brian Corner
- Department of Pediatrics and Genetics, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Julia S Anixt
- Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital, Cincinnati, OH, USA
| | - Shafali Jeste
- Department of Neurology, Keck School of Medicine of USC, Children's Hospital Los Angeles, Los Angeles, CA, USA
| | - Mustafa Sahin
- Department of Neurology, Rosamund Stone Zander Translational Neuroscience Center, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Christina A Gurnett
- Department of Neurology, Washington University School of Medicine in St. Louis, St. Louis, MO, USA
| | - Colleen A Campbell
- Department of Internal Medicine, University of Iowa, Carver College of Medicine, Iowa City, IA, USA
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2
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Mesci P, LaRock CN, Jeziorski JJ, Nakashima H, Chermont N, Ferrasa A, Herai RH, Ozaki T, Saleh A, Snethlage CE, Sanchez S, Goldberg G, Trujillo CA, Nakashima K, Nizet V, Muotri AR. Human microglial cells as a therapeutic target in a neurodevelopmental disease model. Stem Cell Reports 2024; 19:1074-1091. [PMID: 39059378 PMCID: PMC11368698 DOI: 10.1016/j.stemcr.2024.06.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2023] [Revised: 06/27/2024] [Accepted: 06/28/2024] [Indexed: 07/28/2024] Open
Abstract
Although microglia are macrophages of the central nervous system, their involvement is not limited to immune functions. The roles of microglia during development in humans remain poorly understood due to limited access to fetal tissue. To understand how microglia can impact human neurodevelopment, the methyl-CpG binding protein 2 (MECP2) gene was knocked out in human microglia-like cells (MGLs). Disruption of the MECP2 in MGLs led to transcriptional and functional perturbations, including impaired phagocytosis. The co-culture of healthy MGLs with MECP2-knockout (KO) neurons rescued synaptogenesis defects, suggesting a microglial role in synapse formation. A targeted drug screening identified ADH-503, a CD11b agonist, restored phagocytosis and synapse formation in spheroid-MGL co-cultures, significantly improved disease progression, and increased survival in MeCP2-null mice. These results unveil a MECP2-specific regulation of human microglial phagocytosis and identify a novel therapeutic treatment for MECP2-related conditions.
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Affiliation(s)
- Pinar Mesci
- University of California, San Diego, School of Medicine, Department of Pediatrics/Rady Children's Hospital San Diego, Department of Cellular & Molecular Medicine, La Jolla, CA 92037, USA.
| | - Christopher N LaRock
- Department of Pediatrics, University of California San Diego School of Medicine and Skaggs School of Pharmacy and Pharmaceutical Sciences, La Jolla, CA 92037, USA; Department of Microbiology and Immunology, Department of Medicine, Division of Infectious Diseases, Emory School of Medicine, Atlanta, GA 30322, USA
| | - Jacob J Jeziorski
- University of California, San Diego, School of Medicine, Department of Pediatrics/Rady Children's Hospital San Diego, Department of Cellular & Molecular Medicine, La Jolla, CA 92037, USA
| | - Hideyuki Nakashima
- Department of Stem Cell Biology and Medicine, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Natalia Chermont
- University of California, San Diego, School of Medicine, Department of Pediatrics/Rady Children's Hospital San Diego, Department of Cellular & Molecular Medicine, La Jolla, CA 92037, USA
| | - Adriano Ferrasa
- Experimental Multiuser Laboratory (LEM), Graduate Program in Health Sciences (PPGCS), School of Medicine, Pontifícia Universidade Católica do Paraná (PUCPR), Curitiba, Paraná 80215-901, Brazil; Department of Informatics (DEINFO), Universidade Estadual de Ponta Grossa (UEPG), Ponta Grossa, Paraná 84030-900, Brazil
| | - Roberto H Herai
- Experimental Multiuser Laboratory (LEM), Graduate Program in Health Sciences (PPGCS), School of Medicine, Pontifícia Universidade Católica do Paraná (PUCPR), Curitiba, Paraná 80215-901, Brazil; Research Department, Lico Kaesemodel Institute (ILK), Curitiba, Paraná, Brazil
| | - Tomoka Ozaki
- University of California, San Diego, School of Medicine, Department of Pediatrics/Rady Children's Hospital San Diego, Department of Cellular & Molecular Medicine, La Jolla, CA 92037, USA
| | - Aurian Saleh
- University of California, San Diego, School of Medicine, Department of Pediatrics/Rady Children's Hospital San Diego, Department of Cellular & Molecular Medicine, La Jolla, CA 92037, USA
| | - Cedric E Snethlage
- University of California, San Diego, School of Medicine, Department of Pediatrics/Rady Children's Hospital San Diego, Department of Cellular & Molecular Medicine, La Jolla, CA 92037, USA
| | - Sandra Sanchez
- University of California, San Diego, School of Medicine, Department of Pediatrics/Rady Children's Hospital San Diego, Department of Cellular & Molecular Medicine, La Jolla, CA 92037, USA
| | - Gabriela Goldberg
- University of California, San Diego, School of Medicine, Department of Pediatrics/Rady Children's Hospital San Diego, Department of Cellular & Molecular Medicine, La Jolla, CA 92037, USA
| | - Cleber A Trujillo
- University of California, San Diego, School of Medicine, Department of Pediatrics/Rady Children's Hospital San Diego, Department of Cellular & Molecular Medicine, La Jolla, CA 92037, USA
| | - Kinichi Nakashima
- Department of Stem Cell Biology and Medicine, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Victor Nizet
- Department of Pediatrics, University of California San Diego School of Medicine and Skaggs School of Pharmacy and Pharmaceutical Sciences, La Jolla, CA 92037, USA
| | - Alysson R Muotri
- University of California, San Diego, School of Medicine, Department of Pediatrics/Rady Children's Hospital San Diego, Department of Cellular & Molecular Medicine, La Jolla, CA 92037, USA; University of California, San Diego, Kavli Institute for Brain and Mind, Center for Academic Research and Training in Anthropogeny (CARTA), La Jolla, CA 92093, USA.
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3
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Singh J, Wilkins G, Goodman-Vincent E, Chishti S, Bonilla Guerrero R, Fiori F, Ameenpur S, McFadden L, Zahavi Z, Santosh P. Using Precision Medicine to Disentangle Genotype-Phenotype Relationships in Twins with Rett Syndrome: A Case Report. Curr Issues Mol Biol 2024; 46:8424-8440. [PMID: 39194714 DOI: 10.3390/cimb46080497] [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: 06/26/2024] [Revised: 07/20/2024] [Accepted: 07/26/2024] [Indexed: 08/29/2024] Open
Abstract
Rett syndrome (RTT) is a paediatric neurodevelopmental disorder spanning four developmental stages. This multi-system disorder offers a unique window to explore genotype-phenotype relationships in a disease model. However, genetic prognosticators of RTT have limited clinical value due to the disorder's heterogeneity on multiple levels. This case report used a precision medicine approach to better understand the clinical phenotype of RTT twins with an identical pathogenic MECP2 mutation and discordant neurodevelopmental profiles. Targeted genotyping, objective physiological monitoring of heart rate variability (HRV) parameters, and clinical severity were assessed in a RTT twin pair (5 years 7 months old) with an identical pathogenic MECP2 mutation. Longitudinal assessment of autonomic HRV parameters was conducted using the Empatica E4 wristband device, and clinical severity was assessed using the RTT-anchored Clinical Global Impression Scale (RTT-CGI) and the Multi-System Profile of Symptoms Scale (MPSS). Genotype data revealed impaired BDNF function for twin A when compared to twin B. Twin A also had poorer autonomic health than twin B, as indicated by lower autonomic metrics (autonomic inflexibility). Hospitalisation, RTT-CGI-S, and MPSS subscale scores were used as measures of clinical severity, and these were worse in twin A. Treatment using buspirone shifted twin A from an inflexible to a flexible autonomic profile. This was mirrored in the MPSS scores, which showed a reduction in autonomic and cardiac symptoms following buspirone treatment. Our findings showed that a combination of a co-occurring rs6265 BDNF polymorphism, and worse autonomic and clinical profiles led to a poorer prognosis for twin A compared to twin B. Buspirone was able to shift a rigid autonomic profile to a more flexible one for twin A and thereby prevent cardiac and autonomic symptoms from worsening. The clinical profile for twin A represents a departure from the disorder trajectory typically observed in RTT and underscores the importance of wider genotype profiling and longitudinal objective physiological monitoring alongside measures of clinical symptoms and severity when assessing genotype-phenotype relationships in RTT patients with identical pathogenic mutations. A precision medicine approach that assesses genetic and physiological risk factors can be extended to other neurodevelopmental disorders to monitor risk when genotype-phenotype relationships are not so obvious.
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Affiliation(s)
- Jatinder Singh
- Department of Child and Adolescent Psychiatry, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London SE5 8AF, UK
- Centre for Interventional Paediatric Psychopharmacology and Rare Diseases (CIPPRD), South London and Maudsley NHS Foundation Trust, London SE5 8AZ, UK
- Centre for Interventional Paediatric Psychopharmacology (CIPP) Rett Centre, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London SE5 8AF, UK
| | - Georgina Wilkins
- Department of Child and Adolescent Psychiatry, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London SE5 8AF, UK
- Centre for Interventional Paediatric Psychopharmacology and Rare Diseases (CIPPRD), South London and Maudsley NHS Foundation Trust, London SE5 8AZ, UK
- Centre for Interventional Paediatric Psychopharmacology (CIPP) Rett Centre, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London SE5 8AF, UK
| | - Ella Goodman-Vincent
- Department of Child and Adolescent Psychiatry, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London SE5 8AF, UK
- Centre for Interventional Paediatric Psychopharmacology and Rare Diseases (CIPPRD), South London and Maudsley NHS Foundation Trust, London SE5 8AZ, UK
- Centre for Interventional Paediatric Psychopharmacology (CIPP) Rett Centre, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London SE5 8AF, UK
| | - Samiya Chishti
- Department of Child and Adolescent Psychiatry, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London SE5 8AF, UK
- Centre for Interventional Paediatric Psychopharmacology and Rare Diseases (CIPPRD), South London and Maudsley NHS Foundation Trust, London SE5 8AZ, UK
- Centre for Interventional Paediatric Psychopharmacology (CIPP) Rett Centre, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London SE5 8AF, UK
| | | | - Federico Fiori
- Department of Child and Adolescent Psychiatry, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London SE5 8AF, UK
- Centre for Interventional Paediatric Psychopharmacology and Rare Diseases (CIPPRD), South London and Maudsley NHS Foundation Trust, London SE5 8AZ, UK
- Centre for Interventional Paediatric Psychopharmacology (CIPP) Rett Centre, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London SE5 8AF, UK
| | - Shashidhar Ameenpur
- Department of Child and Adolescent Psychiatry, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London SE5 8AF, UK
- Centre for Interventional Paediatric Psychopharmacology and Rare Diseases (CIPPRD), South London and Maudsley NHS Foundation Trust, London SE5 8AZ, UK
- Centre for Interventional Paediatric Psychopharmacology (CIPP) Rett Centre, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London SE5 8AF, UK
| | - Leighton McFadden
- Department of Child and Adolescent Psychiatry, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London SE5 8AF, UK
- Centre for Interventional Paediatric Psychopharmacology and Rare Diseases (CIPPRD), South London and Maudsley NHS Foundation Trust, London SE5 8AZ, UK
- Centre for Interventional Paediatric Psychopharmacology (CIPP) Rett Centre, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London SE5 8AF, UK
| | - Zvi Zahavi
- Myogenes Limited, Borehamwood WD6 4PJ, UK
| | - Paramala Santosh
- Department of Child and Adolescent Psychiatry, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London SE5 8AF, UK
- Centre for Interventional Paediatric Psychopharmacology and Rare Diseases (CIPPRD), South London and Maudsley NHS Foundation Trust, London SE5 8AZ, UK
- Centre for Interventional Paediatric Psychopharmacology (CIPP) Rett Centre, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London SE5 8AF, UK
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Spencer PS, Valdes Angues R, Palmer VS. Nodding syndrome: A role for environmental biotoxins that dysregulate MECP2 expression? J Neurol Sci 2024; 462:123077. [PMID: 38850769 DOI: 10.1016/j.jns.2024.123077] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2023] [Revised: 05/15/2024] [Accepted: 05/30/2024] [Indexed: 06/10/2024]
Abstract
Nodding syndrome is an epileptic encephalopathy associated with neuroinflammation and tauopathy. This initially pediatric brain disease, which has some clinical overlap with Methyl-CpG-binding protein 2 (MECP2) Duplication Syndrome, has impacted certain impoverished East African communities coincident with local civil conflict and internal displacement, conditions that forced dependence on contaminated food and water. A potential role in Nodding syndrome for certain biotoxins (freshwater cyanotoxins plus/minus mycotoxins) with neuroinflammatory, excitotoxic, tauopathic, and MECP2-dysregulating properties, is considered here for the first time.
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Affiliation(s)
- Peter S Spencer
- Department of Neurology, School of Medicine and Oregon Institute of Occupational Health Sciences, Oregon Health & Science University, Portland, OR, USA; Oregon Institute of Occupational Health Sciences, Oregon Health & Science University, Portland, OR, USA; Gulu University School of Medicine, Gulu, Uganda.
| | - Raquel Valdes Angues
- Department of Neurology, School of Medicine and Oregon Institute of Occupational Health Sciences, Oregon Health & Science University, Portland, OR, USA
| | - Valerie S Palmer
- Department of Neurology, School of Medicine and Oregon Institute of Occupational Health Sciences, Oregon Health & Science University, Portland, OR, USA; Gulu University School of Medicine, Gulu, Uganda
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Fang X, Baggett LM, Caylor RC, Percy AK, Neul JL, Lane JB, Glaze DG, Benke TA, Marsh ED, Motil KJ, Barrish JO, Annese FE, Skinner SA. Parental age effects and Rett syndrome. Am J Med Genet A 2024; 194:160-173. [PMID: 37768187 DOI: 10.1002/ajmg.a.63396] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2022] [Accepted: 08/18/2023] [Indexed: 09/29/2023]
Abstract
Rett syndrome (RTT) is a progressive neurodevelopmental disorder, and pathogenic Methyl-CpG-binding Protein 2 (MECP2) variants are identified in >95% of individuals with typical RTT. Most of RTT-causing variants in MECP2 are de novo and usually on the paternally inherited X chromosome. While paternal age has been reported to be associated with increased risk of genetic disorders, it is unknown whether parental age contributes to the risk of the development of RTT. Clinical data including parental age, RTT diagnostic status, and clinical severity are collected from 1226 participants with RTT and confirmed MECP2 variants. Statistical analyses are performed using Student t-test, single factor analysis of variance (ANOVA), and multi-factor regression. No significant difference is observed in parental ages of RTT probands compared to that of the general population. A small increase in parental ages is observed in participants with missense variants compared to those with nonsense variants. When we evaluate the association between clinical severity and parental ages by multiple regression analysis, there is no clear association between clinical severity and parental ages. Advanced parental ages do not appear to be a risk factor for RTT, and do not contribute to the clinical severity in individuals with RTT.
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Affiliation(s)
- Xiaolan Fang
- Greenwood Genetic Center, Greenwood, South Carolina, USA
| | | | | | - Alan K Percy
- The University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Jeffrey L Neul
- Vanderbilt Kennedy Center, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Jane B Lane
- The University of Alabama at Birmingham, Birmingham, Alabama, USA
| | | | - Tim A Benke
- University of Colorado School of Medicine, Children's Hospital Colorado-Aurora, Denver, Colorado, USA
| | - Eric D Marsh
- Children's Hospital of Philadelphia and University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Kathleen J Motil
- Vanderbilt Kennedy Center, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | | | - Fran E Annese
- Greenwood Genetic Center, Greenwood, South Carolina, USA
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Zade K, Campbell C, Bach S, Fernandes H, Tropea D. Rett syndrome in Ireland: a demographic study. Orphanet J Rare Dis 2024; 19:34. [PMID: 38291497 PMCID: PMC10829226 DOI: 10.1186/s13023-024-03046-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2023] [Accepted: 01/19/2024] [Indexed: 02/01/2024] Open
Abstract
BACKGROUND Rett syndrome (RTT) is a rare neurodevelopmental condition associated with mutations in the gene coding for the methyl-CpG-binding protein 2 (MECP2). It is primarily observed in girls and affects individuals globally. The understanding of the neurobiology of RTT and patient management has been improved by studies that describe the demographic and clinical presentation of individuals with RTT. However, in Ireland, there is a scarcity of data regarding individuals with RTT, which impedes the ability to fully characterize the Irish RTT population. Together with the Rett Syndrome Association of Ireland (RSAI), we prepared a questionnaire to determine the characteristics of RTT individuals in Ireland. Twenty-five families have participated in the study to date, providing information about demographics, genetics, familial history, clinical features, and regression. RESULTS The results show that Irish individuals with RTT have comparable presentation with respect to individuals in other countries; however, they had a better response to anti-epileptic drugs, and fewer skeletal deformities were reported. Nonetheless, seizures, involuntary movements and regression were more frequently observed in Irish individuals. One of the main findings of this study is the limited genetic information available to individuals to support the clinical diagnosis of RTT. CONCLUSIONS Despite the limited sample size, this study is the first to characterize the RTT population in Ireland and highlights the importance of having a swift access to genetic testing to sharpen the characterization of the phenotype and increase the visibility of Irish individuals in the international RTT community.
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Affiliation(s)
- Komal Zade
- Department of Psychiatry, School of Medicine, Trinity Centre for Health Sciences, Trinity College Dublin, St James Hospital, Dublin, D08 W9RT, Ireland
| | - Ciara Campbell
- Department of Psychiatry, School of Medicine, Trinity Centre for Health Sciences, Trinity College Dublin, St James Hospital, Dublin, D08 W9RT, Ireland
| | - Snow Bach
- Department of Psychiatry, School of Medicine, Trinity Centre for Health Sciences, Trinity College Dublin, St James Hospital, Dublin, D08 W9RT, Ireland
| | - Hazel Fernandes
- Consultant Child and Adolescent Psychiatrist, Barnet, Enfield and Haringey Mental Health NHS Trust, London, UK
| | - Daniela Tropea
- Department of Psychiatry, School of Medicine, Trinity Centre for Health Sciences, Trinity College Dublin, St James Hospital, Dublin, D08 W9RT, Ireland.
- Neuropsychiatric Genetics, Department of Psychiatry, School of Medicine, Trinity College Dublin, Trinity Translational Medicine Institute, St James's Hospital, Dublin, Ireland.
- Trinity College Institute of Neuroscience, Trinity College Dublin, Dublin, Ireland.
- FutureNeuro, The SFI Research Centre for Chronic and Rare Neurological Diseases, Dublin, Ireland.
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Mehmood A, Shah S, Guo RY, Haider A, Shi M, Ali H, Ali I, Ullah R, Li B. Methyl-CpG-Binding Protein 2 Emerges as a Central Player in Multiple Sclerosis and Neuromyelitis Optica Spectrum Disorders. Cell Mol Neurobiol 2023; 43:4071-4101. [PMID: 37955798 DOI: 10.1007/s10571-023-01432-7] [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: 08/27/2023] [Accepted: 10/27/2023] [Indexed: 11/14/2023]
Abstract
MECP2 and its product methyl-CpG binding protein 2 (MeCP2) are associated with multiple sclerosis (MS) and neuromyelitis optica spectrum disorders (NMOSD), which are inflammatory, autoimmune, and demyelinating disorders of the central nervous system (CNS). However, the mechanisms and pathways regulated by MeCP2 in immune activation in favor of MS and NMOSD are not fully understood. We summarize findings that use the binding properties of MeCP2 to identify its targets, particularly the genes recognized by MeCP2 and associated with several neurological disorders. MeCP2 regulates gene expression in neurons, immune cells and during development by modulating various mechanisms and pathways. Dysregulation of the MeCP2 signaling pathway has been associated with several disorders, including neurological and autoimmune diseases. A thorough understanding of the molecular mechanisms underlying MeCP2 function can provide new therapeutic strategies for these conditions. The nervous system is the primary system affected in MeCP2-associated disorders, and other systems may also contribute to MeCP2 action through its target genes. MeCP2 signaling pathways provide promise as potential therapeutic targets in progressive MS and NMOSD. MeCP2 not only increases susceptibility and induces anti-inflammatory responses in immune sites but also leads to a chronic increase in pro-inflammatory cytokines gene expression (IFN-γ, TNF-α, and IL-1β) and downregulates the genes involved in immune regulation (IL-10, FoxP3, and CX3CR1). MeCP2 may modulate similar mechanisms in different pathologies and suggest that treatments for MS and NMOSD disorders may be effective in treating related disorders. MeCP2 regulates gene expression in MS and NMOSD. However, dysregulation of the MeCP2 signaling pathway is implicated in these disorders. MeCP2 plays a role as a therapeutic target for MS and NMOSD and provides pathways and mechanisms that are modulated by MeCP2 in the regulation of gene expression.
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Affiliation(s)
- Arshad Mehmood
- Department of Neurology, The Second Hospital of Hebei Medical University, Shijiazhuang, 050000, Hebei, People's Republic of China
- Key Laboratory of Neurology of Hebei Province, Shijiazhuang, 050000, Hebei, People's Republic of China
| | - Suleman Shah
- Department of Cell Biology and Genetics, School of Basic Medical Sciences, Health Science Center, Shenzhen University, Shenzhen, China
| | - Ruo-Yi Guo
- Department of Neurology, The Second Hospital of Hebei Medical University, Shijiazhuang, 050000, Hebei, People's Republic of China
- Key Laboratory of Neurology of Hebei Province, Shijiazhuang, 050000, Hebei, People's Republic of China
| | - Arsalan Haider
- Key Lab of Health Psychology, Institute of Psychology, University of Chinese Academy of Sciences, Beijing, China
| | - Mengya Shi
- Department of Neurology, The Second Hospital of Hebei Medical University, Shijiazhuang, 050000, Hebei, People's Republic of China
- Key Laboratory of Neurology of Hebei Province, Shijiazhuang, 050000, Hebei, People's Republic of China
| | - Hamid Ali
- Department of Biosciences, COMSATS University Islamabad, Park Road Tarlai Kalan, Islamabad, 44000, Pakistan
| | - Ijaz Ali
- Centre for Applied Mathematics and Bioinformatics, Gulf University for Science and Technology, Hawally, 32093, Kuwait
| | - Riaz Ullah
- Medicinal Aromatic and Poisonous Plants Research Center, College of Pharmacy, King Saud University, Riyadh, Saudi Arabia
| | - Bin Li
- Department of Neurology, The Second Hospital of Hebei Medical University, Shijiazhuang, 050000, Hebei, People's Republic of China.
- Key Laboratory of Neurology of Hebei Province, Shijiazhuang, 050000, Hebei, People's Republic of China.
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8
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Singh J, Goodman-Vincent E, Santosh P. Evidence Synthesis of Gene Therapy and Gene Editing from Different Disorders-Implications for Individuals with Rett Syndrome: A Systematic Review. Int J Mol Sci 2023; 24:ijms24109023. [PMID: 37240368 DOI: 10.3390/ijms24109023] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2023] [Revised: 05/06/2023] [Accepted: 05/12/2023] [Indexed: 05/28/2023] Open
Abstract
This systematic review and thematic analysis critically evaluated gene therapy trials in amyotrophic lateral sclerosis, haemoglobinopathies, immunodeficiencies, leukodystrophies, lysosomal storage disorders and retinal dystrophies and extrapolated the key clinical findings to individuals with Rett syndrome (RTT). The PRISMA guidelines were used to search six databases during the last decade, followed by a thematic analysis to identify the emerging themes. Thematic analysis across the different disorders revealed four themes: (I) Therapeutic time window of gene therapy; (II) Administration and dosing strategies for gene therapy; (III) Methods of gene therapeutics and (IV) Future areas of clinical interest. Our synthesis of information has further enriched the current clinical evidence base and can assist in optimising gene therapy and gene editing studies in individuals with RTT, but it would also benefit when applied to other disorders. The findings suggest that gene therapies have better outcomes when the brain is not the primary target. Across different disorders, early intervention appears to be more critical, and targeting the pre-symptomatic stage might prevent symptom pathology. Intervention at later stages of disease progression may benefit by helping to clinically stabilise patients and preventing disease-related symptoms from worsening. If gene therapy or editing has the desired outcome, older patients would need concerted rehabilitation efforts to reverse their impairments. The timing of intervention and the administration route would be critical parameters for successful outcomes of gene therapy/editing trials in individuals with RTT. Current approaches also need to overcome the challenges of MeCP2 dosing, genotoxicity, transduction efficiencies and biodistribution.
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Affiliation(s)
- Jatinder Singh
- Department of Child and Adolescent Psychiatry, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London SE5 8AF, UK
- Centre for Interventional Paediatric Psychopharmacology and Rare Diseases (CIPPRD), South London and Maudsley NHS Foundation Trust, London SE5 8AZ, UK
- Centre for Interventional Paediatric Psychopharmacology (CIPP) Rett Centre, Institute of Psychiatry, Psychology and Neuroscience, King's College London and South London and Maudsley NHS Foundation Trust, London SE5 8AZ, UK
| | - Ella Goodman-Vincent
- Department of Child and Adolescent Psychiatry, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London SE5 8AF, UK
- Centre for Interventional Paediatric Psychopharmacology and Rare Diseases (CIPPRD), South London and Maudsley NHS Foundation Trust, London SE5 8AZ, UK
- Centre for Interventional Paediatric Psychopharmacology (CIPP) Rett Centre, Institute of Psychiatry, Psychology and Neuroscience, King's College London and South London and Maudsley NHS Foundation Trust, London SE5 8AZ, UK
| | - Paramala Santosh
- Department of Child and Adolescent Psychiatry, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London SE5 8AF, UK
- Centre for Interventional Paediatric Psychopharmacology and Rare Diseases (CIPPRD), South London and Maudsley NHS Foundation Trust, London SE5 8AZ, UK
- Centre for Interventional Paediatric Psychopharmacology (CIPP) Rett Centre, Institute of Psychiatry, Psychology and Neuroscience, King's College London and South London and Maudsley NHS Foundation Trust, London SE5 8AZ, UK
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9
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Wen Y, Wang J, Zhang Q, Yang X, Wei L, Bao X. MECP2 germline mosaicism plays an important part in the inheritance of Rett syndrome: a study of MECP2 germline mosaicism in males. BMC Med 2023; 21:155. [PMID: 37081442 PMCID: PMC10120091 DOI: 10.1186/s12916-023-02846-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/09/2022] [Accepted: 03/23/2023] [Indexed: 04/22/2023] Open
Abstract
BACKGROUND Germline mosaicisms could be inherited to offspring, which considered as "de novo" in most cases. Paternal germline MECP2 mosaicism has been reported in fathers of girls with Rett syndrome (RTT) previously. For further study, we focused on MECP2 germline mosaicism in males, not only RTT fathers. METHODS Thirty-two fathers of RTT girls with MECP2 pathogenic mutations and twenty-five healthy adult males without history and family history of RTT or other genetic disorders were recruited. Sperm samples were collected and ten MECP2 hotspot mutations were detected by micro-droplet digital PCR (mDDPCR). And routine semen test was performed at the same time if the sample was sufficient. Additionally, blood samples were also detected for those with sperm MECP2 mosaicisms. RESULTS Nine fathers with RTT daughters (28.1%, 9/32) were found to have MECP2 mosaicism in their sperm samples, with the mutant allele fractions (MAFs) ranging from 0.05% to 7.55%. Only one father with MECP2 c.806delG germline mosaicism (MAF 7.55%) was found to have mosaicism in the blood sample, with the MAF was 0.28%. In the group of healthy adult males, MECP2 mosaicism was found in 7 sperm samples (28.0%, 7/25), with the MAFs ranging from 0.05% to 0.18%. None of the healthy adult males with MECP2 germline mosaicisms were found with MECP2 mosaicism in blood samples. There were no statistical differences in age, or the incidence of asthenospermia between fathers with RTT daughters and healthy adult males with MECP2 germline mosaicisms. Additionally, there was no linear correlation between MAFs of MECP2 mosaicisms and the age of males with germline MECP2 mosaicisms. CONCLUSIONS Germline MECP2 mosaicism could be found not only in fathers with RTT daughters but also in healthy adult males without family history of RTT. As germline mosaic mutations may be passed on to offspring which commonly known as "de novo", more attention should be paid to germline mosaicism, especially in families with a proband diagnosed with genetic disorders.
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Affiliation(s)
- Yongxin Wen
- Department of Pediatrics, Peking University First Hospital, Beijing, China
- Department of Pediatric Neurology, Guangdong Women and Children Hospital, Guangzhou, Guangdong Province, China
| | - Jiaping Wang
- Department of Pediatrics, Peking University First Hospital, Beijing, China
| | - Qingping Zhang
- Department of Pediatrics, Peking University First Hospital, Beijing, China
| | - Xiaoxu Yang
- Center for Bioinformatics, State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing, China
| | - Liping Wei
- Center for Bioinformatics, State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing, China
| | - Xinhua Bao
- Department of Pediatrics, Peking University First Hospital, Beijing, China.
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10
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Collins BE, Neul JL. Rett Syndrome and MECP2 Duplication Syndrome: Disorders of MeCP2 Dosage. Neuropsychiatr Dis Treat 2022; 18:2813-2835. [PMID: 36471747 PMCID: PMC9719276 DOI: 10.2147/ndt.s371483] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/08/2022] [Accepted: 11/14/2022] [Indexed: 11/30/2022] Open
Abstract
Rett syndrome (RTT) is a neurodevelopmental disorder caused predominantly by loss-of-function mutations in the gene Methyl-CpG-binding protein 2 (MECP2), which encodes the MeCP2 protein. RTT is a MECP2-related disorder, along with MECP2 duplication syndrome (MDS), caused by gain-of-function duplications of MECP2. Nearly two decades of research have advanced our knowledge of MeCP2 function in health and disease. The following review will discuss MeCP2 protein function and its dysregulation in the MECP2-related disorders RTT and MDS. This will include a discussion of the genetic underpinnings of these disorders, specifically how sporadic X-chromosome mutations arise and manifest in specific populations. We will then review current diagnostic guidelines and clinical manifestations of RTT and MDS. Next, we will delve into MeCP2 biology, describing the dual landscapes of methylated DNA and its reader MeCP2 across the neuronal genome as well as the function of MeCP2 as a transcriptional modulator. Following this, we will outline common MECP2 mutations and genotype-phenotype correlations in both diseases, with particular focus on mutations associated with relatively mild disease in RTT. We will also summarize decades of disease modeling and resulting molecular, synaptic, and behavioral phenotypes associated with RTT and MDS. Finally, we list several therapeutics in the development pipeline for RTT and MDS and available evidence of their safety and efficacy.
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Affiliation(s)
- Bridget E Collins
- Medical Scientist Training Program, Vanderbilt University, Nashville, TN, USA
| | - Jeffrey L Neul
- Vanderbilt Kennedy Center, Departments of Pediatrics, Pharmacology, and Special Education, Vanderbilt University Medical Center and Vanderbilt University, Nashville, TN, USA
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11
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Methyl-CpG-binding protein 2 mediates overlapping mechanisms across brain disorders. Sci Rep 2020; 10:22255. [PMID: 33335218 PMCID: PMC7746753 DOI: 10.1038/s41598-020-79268-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Accepted: 12/01/2020] [Indexed: 12/16/2022] Open
Abstract
MECP2 and its product, Methyl-CpG binding protein 2 (MeCP2), are mostly known for their association to Rett Syndrome (RTT), a rare neurodevelopmental disorder. Additional evidence suggests that MECP2 may underlie other neuropsychiatric and neurological conditions, and perhaps modulate common presentations and pathophysiology across disorders. To clarify the mechanisms of these interactions, we develop a method that uses the binding properties of MeCP2 to identify its targets, and in particular, the genes recognized by MeCP2 and associated to several neurological and neuropsychiatric disorders. Analysing mechanisms and pathways modulated by these genes, we find that they are involved in three main processes: neuronal transmission, immuno-reactivity, and development. Also, while the nervous system is the most relevant in the pathophysiology of the disorders, additional systems may contribute to MeCP2 action through its target genes. We tested our results with transcriptome analysis on Mecp2-null models and cells derived from a patient with RTT, confirming that the genes identified by our procedure are directly modulated by MeCP2. Thus, MeCP2 may modulate similar mechanisms in different pathologies, suggesting that treatments for one condition may be effective for related disorders.
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12
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Scrutinizing the molecular, biochemical, and cytogenetic attributes in subjects with Rett syndrome (RTT) and their mothers. Epilepsy Behav 2020; 111:107277. [PMID: 32653844 DOI: 10.1016/j.yebeh.2020.107277] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/17/2020] [Revised: 06/18/2020] [Accepted: 06/19/2020] [Indexed: 11/21/2022]
Abstract
Rett syndrome (RTT) is a stern dominant progressive neurological development disorder linked with X chromosome ranking second for mental slowdown, exclusively in females after few months of birth with normal development and growth period. Genetically any defects in universally expressed methyl-CpG binding protein 2 (MeCP2) transcription regulator gene are considered as radix for RTT in almost all the previous studies. Our study mainly focuses in unraveling the genetic alterations like identifying MeCP2 gene polymorphisms, chromosomal abnormalities, or X-chromosome inactivation (XCI) as underlying cause of RTT in prototypes sorted through Diagnostic and Statistical Manual of Mental Disorders-Text Revised (DSM IV). In addition, we have examined the probable surrogates of brain function disabilities like serotonin, homocysteine (Hcy), calcium, potassium, and lead from blood in both RTT porotypes and their mothers. In our investigation, we have observed varied amino acid substitution of MeCP2 and varied frequency of skewed XCI in RTT prototype. Our study validates that the demonstration of chromosomal analysis, biochemical analysis, and genomic observations helps in concluding RTT condition and can be helpful in providing appropriate treatment and counseling as well as improve the currently available protocol of diagnosis.
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13
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Wen Y, Wang J, Zhang Q, Chen Y, Wu X, Bao X. MECP2 mutation spectrum and its clinical characteristics in a Chinese cohort. Clin Genet 2020; 98:240-250. [PMID: 32472557 DOI: 10.1111/cge.13790] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2019] [Revised: 05/24/2020] [Accepted: 05/25/2020] [Indexed: 01/08/2023]
Abstract
The dysfunction of methyl-CpG-binding protein 2 (MeCP2) is associated with several neurological disorders, of which Rett syndrome (RTT) is the most prominent. This study focused on a Chinese patient cohort with MECP2 mutations, and analyzed the characteristics of these mutations and their clinical manifestations. In total, 666 patients were identified with 126 different MECP2 mutations, including 22 novel mutations. Over 80% of patients carried an MECP2 mutation on exon 4. Nonsense and missense mutations were the most commonly reported types. Missense mutations were mainly located on methyl-CpG-binding domain (MBD), and nonsense mutations predominantly occurred on transcription repression domain (TRD) and inter domain. The predilection site of large deletion was exon 3 and/or exon 4. Patients with p.R133C, p.R294*, p.R306C, and C-terminal domain (CTD) deletions were less severely affected. Significant differences were found in ambulation ability, hand function, and language among different mutation groups. Three female patients with MECP2 mutations (1 with p.R306P and 2 with p.R309W) only presented with intellectual disability/developmental delay (ID/DD), and no obvious RTT symptoms were reported. Eight male individuals with MECP2 mutations were also identified in this study, including 2 diagnosed with typical RTT, 3 with atypical RTT and 3 with ID/DD.
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Affiliation(s)
- Yongxin Wen
- Department of Pediatrics, Peking University First Hospital, Beijing, China
| | - Jiaping Wang
- Department of Pediatrics, Peking University First Hospital, Beijing, China
| | - Qingping Zhang
- Department of Pediatrics, Peking University First Hospital, Beijing, China
| | - Yan Chen
- Department of Pediatrics, Peking University First Hospital, Beijing, China
| | - Xiru Wu
- Department of Pediatrics, Peking University First Hospital, Beijing, China
| | - Xinhua Bao
- Department of Pediatrics, Peking University First Hospital, Beijing, China
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14
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Jdila MB, Triki CC, Ghorbel R, Bouchalla W, Ncir SB, Kamoun F, Fakhfakh F. Unusual double mutation in MECP2 and CDKL5 genes in Rett-like syndrome: Correlation with phenotype and genes expression. Clin Chim Acta 2020; 508:287-294. [PMID: 32445745 DOI: 10.1016/j.cca.2020.05.037] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2020] [Revised: 05/12/2020] [Accepted: 05/19/2020] [Indexed: 12/16/2022]
Abstract
INTRODUCTION Rett syndrome (RTT) is a neuro-developmental disorder affecting almost exclusively females and it divided into classical and atypical forms of the disease. RTT-like syndrome was also described and presents an overlapping phenotype of RTT. RTT-like syndrome has been associated with several genes including MECP2 and CDKL5 having common biological pathways and regulatory interactions especially during neural maturation and synaptogenesis. METHODS We report patient with Rett-like syndrome for whom clinical features and their progression guided toward the screening of two candidate genes MECP2 and CDKL5 by sequencing. Severity score was evaluated by "Rett Assessment Rating Scale" (R.A.R.S.). Predictions of pahogenicity and functional effects used several bioinformatic tools and qRT-PCR was conducted to evaluate gene expression. RESULTS Mutational screening revealed two mutations c.1065 C > A (p.S355R) in MECP2 gene and c.616 G > A (p.D206N) mutation in CDKL5 gene in the patient with a high R.A.R.S. Bioinformatic investigations predicted a moderate effect of p.S355R in MECP2 gene but a more pathogenic one of p.D206N mutation in CDKL5. Effect of c.616 G > A mutation on structure and stability of CDKL5 mRNA was confirmed by qRT-PCR. Additionally, analysis of gene expression revealed a drastic effect of CDKL5 mutant on its MeCP2 and Dnmt1 substrates and also on its MYCN regulator. CONCLUSIONS The co-existence of the two mutations in CDKL5 and MECP2 genes could explain the severe phenotype in our patient with RTT-Like and is consistent with the data related to the interactions of CDKL5 with MeCP2 and Dnmt1 proteins.
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Affiliation(s)
- Marwa Ben Jdila
- Research Laboratory 'NeuroPédiatrie' (LR19ES15), Sfax Medical School, Sfax University, Tunisia; Laboratory of Molecular and Functional Genetics, Faculty of Science of Sfax, Sfax University, Tunisia.
| | - Chahnez Charfi Triki
- Research Laboratory 'NeuroPédiatrie' (LR19ES15), Sfax Medical School, Sfax University, Tunisia; Child Neurology Department, Hedi Chaker Universitary Hospital of Sfax, Tunisia
| | - Rania Ghorbel
- Laboratory of Molecular and Functional Genetics, Faculty of Science of Sfax, Sfax University, Tunisia
| | - Wafa Bouchalla
- Research Laboratory 'NeuroPédiatrie' (LR19ES15), Sfax Medical School, Sfax University, Tunisia; Child Neurology Department, Hedi Chaker Universitary Hospital of Sfax, Tunisia
| | - Sihem Ben Ncir
- Research Laboratory 'NeuroPédiatrie' (LR19ES15), Sfax Medical School, Sfax University, Tunisia; Child Neurology Department, Hedi Chaker Universitary Hospital of Sfax, Tunisia
| | - Fatma Kamoun
- Research Laboratory 'NeuroPédiatrie' (LR19ES15), Sfax Medical School, Sfax University, Tunisia; Child Neurology Department, Hedi Chaker Universitary Hospital of Sfax, Tunisia
| | - Faiza Fakhfakh
- Laboratory of Molecular and Functional Genetics, Faculty of Science of Sfax, Sfax University, Tunisia.
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15
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Abstract
Elucidating the functions of a particular gene is paramount to the understanding of how its dysfunction contributes to disease. This is especially important when the gene is implicated in multiple different disorders. One such gene is methyl-CpG-binding protein 2 (MECP2), which has been most prominently associated with the neurodevelopmental disorder Rett syndrome, as well as major neuropsychiatric disorders such as autism and schizophrenia. Being initially identified as a transcriptional regulator that modulates gene expression and subsequently also shown to be involved in other molecular events, dysfunction of the MeCP2 protein has the potential to affect many cellular processes. In this chapter, we will briefly review the functions of the MeCP2 protein and how its mutations are implicated in Rett syndrome and other neuropsychiatric disorders. We will further discuss about the mouse models that have been generated to specifically dissect the function of MeCP2 in different cell types and brain regions. It is envisioned that such thorough and targeted examination of MeCP2 functions can aid in enlightening the role that it plays in normal and dysfunctional physiological systems.
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Affiliation(s)
- Eunice W M Chin
- Neuroscience and Mental Health Faculty, Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, Singapore
| | - Eyleen L K Goh
- Neuroscience and Mental Health Faculty, Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, Singapore.
- Department of Research, National Neuroscience Institute, Singapore, Singapore.
- Neuroscience Academic Clinical Programme, Singhealth Duke-NUS Academic Medical Center, Singapore, Singapore.
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16
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Chin EWM, Goh ELK. Behavioral Characterization of MeCP2 Dysfunction-Associated Rett Syndrome and Neuropsychiatric Disorders. Methods Mol Biol 2019; 2011:593-605. [PMID: 31273723 DOI: 10.1007/978-1-4939-9554-7_34] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
The methyl-CpG-binding protein 2 (MECP2) gene has been implicated in multiple neuropsychiatric disorders such as autism and schizophrenia and, most notably, Rett syndrome (RTT). Mouse models of MeCP2 dysfunction that have been developed are thus important not only for examining the protein's contribution to RTT, but also for elucidating the etiologies of other MECP2-associated neuropsychiatric disorders. In this chapter, we present protocols for three behavioral assays for characterizing major functional domains of MeCP2 dysfunction-the open field test for measuring general locomotor activity and anxiety-like behavior, the three-chambered Crawley box test for assessing social preference and social novelty, and the rotarod assay for testing locomotor coordination. It is hoped that these information facilitate systematic characterization of mouse models that may aid in elucidating the role of MeCP2 in neurological disorders, as well as assessing the effects of putative mechanistic and therapeutic interventions.
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Affiliation(s)
- Eunice W M Chin
- Neuroscience and Mental Health Faculty, Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, Singapore
| | - Eyleen L K Goh
- Neuroscience and Mental Health Faculty, Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, Singapore.
- Department of Research, National Neuroscience Institute, Singapore, Singapore.
- Neuroscience Academic Clinical Programme, Singhealth Duke-NUS Academic Medical Center, Singapore, Singapore.
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17
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Pokorny FB, Bartl-Pokorny KD, Einspieler C, Zhang D, Vollmann R, Bölte S, Gugatschka M, Schuller BW, Marschik PB. Typical vs. atypical: Combining auditory Gestalt perception and acoustic analysis of early vocalisations in Rett syndrome. RESEARCH IN DEVELOPMENTAL DISABILITIES 2018; 82:109-119. [PMID: 29551600 PMCID: PMC6093280 DOI: 10.1016/j.ridd.2018.02.019] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2017] [Revised: 02/20/2018] [Accepted: 02/21/2018] [Indexed: 05/13/2023]
Abstract
BACKGROUND Early speech-language development of individuals with Rett syndrome (RTT) has been repeatedly characterised by a co-occurrence of apparently typical and atypical vocalisations. AIMS To describe specific features of this intermittent character of typical versus atypical early RTT-associated vocalisations by combining auditory Gestalt perception and acoustic vocalisation analysis. METHODS AND PROCEDURES We extracted N = 363 (pre-)linguistic vocalisations from home video recordings of an infant later diagnosed with RTT. In a listening experiment, all vocalisations were assessed for (a)typicality by five experts on early human development. Listeners' auditory concepts of (a)typicality were investigated in context of a comprehensive set of acoustic time-, spectral- and/or energy-related higher-order features extracted from the vocalisations. OUTCOMES AND RESULTS More than half of the vocalisations were rated as 'atypical' by at least one listener. Atypicality was mainly related to the auditory attribute 'timbre', and to prosodic, spectral, and voice quality features in the acoustic domain. CONCLUSIONS AND IMPLICATIONS Knowledge gained in our study shall contribute to the generation of an objective model of early vocalisation atypicality. Such a model might be used for increasing caregivers' and healthcare professionals' sensitivity to identify atypical vocalisation patterns, or even for a probabilistic approach to automatically detect RTT based on early vocalisations.
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Affiliation(s)
- Florian B Pokorny
- iDN - interdisciplinary Developmental Neuroscience, Department of Phoniatrics, Medical University of Graz, Graz, Austria; Machine Intelligence & Signal Processing group, MMK, Technical University of Munich, Munich, Germany; Brain, Ears & Eyes - Pattern Recognition Initiative, BioTechMed-Graz, Graz, Austria
| | - Katrin D Bartl-Pokorny
- iDN - interdisciplinary Developmental Neuroscience, Department of Phoniatrics, Medical University of Graz, Graz, Austria
| | - Christa Einspieler
- iDN - interdisciplinary Developmental Neuroscience, Department of Phoniatrics, Medical University of Graz, Graz, Austria
| | - Dajie Zhang
- iDN - interdisciplinary Developmental Neuroscience, Department of Phoniatrics, Medical University of Graz, Graz, Austria; Department of Child and Adolescent Psychiatry and Psychotherapy, iDN - interdisciplinary Developmental Neuroscience, University Medical Center Göttingen, Göttingen, Germany
| | - Ralf Vollmann
- Brain, Ears & Eyes - Pattern Recognition Initiative, BioTechMed-Graz, Graz, Austria; Department of Linguistics, University of Graz, Graz, Austria
| | - Sven Bölte
- Center of Neurodevelopmental Disorders (KIND), Department of Women's and Children's Health, Karolinska Institutet, Stockholm, Sweden; Child and Adolescent Psychiatry, Center for Psychiatry Research, Stockholm County Council, Sweden
| | - Markus Gugatschka
- iDN - interdisciplinary Developmental Neuroscience, Department of Phoniatrics, Medical University of Graz, Graz, Austria
| | - Björn W Schuller
- Chair of Embedded Intelligence for Health Care and Wellbeing, Augsburg University, Augsburg, Germany; Group on Language, Audio & Music (GLAM), Department of Computing, Imperial College London, London, UK
| | - Peter B Marschik
- iDN - interdisciplinary Developmental Neuroscience, Department of Phoniatrics, Medical University of Graz, Graz, Austria; Brain, Ears & Eyes - Pattern Recognition Initiative, BioTechMed-Graz, Graz, Austria; Department of Child and Adolescent Psychiatry and Psychotherapy, iDN - interdisciplinary Developmental Neuroscience, University Medical Center Göttingen, Göttingen, Germany; Center of Neurodevelopmental Disorders (KIND), Department of Women's and Children's Health, Karolinska Institutet, Stockholm, Sweden.
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18
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Shovlin S, Tropea D. Transcriptome level analysis in Rett syndrome using human samples from different tissues. Orphanet J Rare Dis 2018; 13:113. [PMID: 29996871 PMCID: PMC6042368 DOI: 10.1186/s13023-018-0857-8] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2018] [Accepted: 06/27/2018] [Indexed: 01/06/2023] Open
Abstract
The mechanisms of neuro-genetic disorders have been mostly investigated in the brain, however, for some pathologies, transcriptomic analysis in multiple tissues represent an opportunity and a challenge to understand the consequences of the genetic mutation. This is the case for Rett Syndrome (RTT): a neurodevelopmental disorder predominantly affecting females that is characterised by a loss of purposeful movements and language accompanied by gait abnormalities and hand stereotypies. Although the genetic aetiology is largely associated to Methyl CpG binding protein 2 (MECP2) mutations, linking the pathophysiology of RTT and its clinical symptoms to direct molecular mechanisms has been difficult.One approach used to study the consequences of MECP2 dysfunction in patients, is to perform transcriptomic analysis in tissues derived from RTT patients or Induced Pluripotent Stem cells. The growing affordability and efficiency of this approach has led to a far greater understanding of the complexities of RTT syndrome but is also raised questions about previously held convictions such as the regulatory role of MECP2, the effects of different molecular mechanisms in different tissues and role of X Chromosome Inactivation in RTT.In this review we consider the results of a number of different transcriptomic analyses in different patients-derived preparations to unveil specific trends in differential gene expression across the studies. Although the analyses present limitations- such as the limited sample size- overlaps exist across these studies, and they report dysregulations in three main categories: dendritic connectivity and synapse maturation, mitochondrial dysfunction, and glial cell activity.These observations have a direct application to the disorder and give insights on the altered mechanisms in RTT, with implications on potential diagnostic criteria and treatments.
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Affiliation(s)
- Stephen Shovlin
- Neuropsychiatric Genetics Research Group, Trinity Translational Medicine Institute- TTMI, St James Hospital, D8, Dublin, Ireland
| | - Daniela Tropea
- Neuropsychiatric Genetics Research Group, Trinity Translational Medicine Institute- TTMI, St James Hospital, D8, Dublin, Ireland
- Trinity College Institute of Neuroscience, TCIN, Loyd Building, Dublin2, Dublin, Ireland
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19
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Ausió J. Role of MeCP2 in neurological disorders: current status and future perspectives. Epigenomics 2017; 10:5-8. [PMID: 29172690 DOI: 10.2217/epi-2017-0128] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Affiliation(s)
- Juan Ausió
- Department of Biochemistry & Microbiology, University of Victoria, Victoria, BC, V8W 3P6, Canada
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20
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Siu MT, Weksberg R. Epigenetics of Autism Spectrum Disorder. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 978:63-90. [PMID: 28523541 DOI: 10.1007/978-3-319-53889-1_4] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Autism spectrum disorder (ASD), one of the most common childhood neurodevelopmental disorders (NDDs), is diagnosed in 1 of every 68 children. ASD is incredibly heterogeneous both clinically and aetiologically. The etiopathogenesis of ASD is known to be complex, including genetic, environmental and epigenetic factors. Normal epigenetic marks modifiable by both genetics and environmental exposures can result in epigenetic alterations that disrupt the regulation of gene expression, negatively impacting biological pathways important for brain development. In this chapter we aim to summarize some of the important literature that supports a role for epigenetics in the underlying molecular mechanism of ASD. We provide evidence from work in genetics, from environmental exposures and finally from more recent studies aimed at directly determining ASD-specific epigenetic patterns, focusing mainly on DNA methylation (DNAm). Finally, we briefly discuss some of the implications of current research on potential epigenetic targets for therapeutics and novel avenues for future work.
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Affiliation(s)
- Michelle T Siu
- Program in Genetics and Genome Biology, The Hospital for Sick Children, 555 University Ave, Toronto, ON, M5G 1X8, Canada
| | - Rosanna Weksberg
- Program in Genetics and Genome Biology, The Hospital for Sick Children, 555 University Ave, Toronto, ON, M5G 1X8, Canada. .,Division of Clinical and Metabolic Genetics, The Hospital for Sick Children, 555 University Ave, Toronto, ON, M5G 1X8, Canada. .,Department of Paediatrics, University of Toronto, Toronto, ON, M5S 1A1, Canada. .,Institute of Medical Science, University of Toronto, Toronto, ON, M5S 1A8, Canada.
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21
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Zhou X, Liao Y, Xu M, Ji Z, Xu Y, Zhou L, Wei X, Hu P, Han P, Yang F, Pan S, Hu Y. A novel mutation R190H in the AT-hook 1 domain of MeCP2 identified in an atypical Rett syndrome. Oncotarget 2017; 8:82156-82164. [PMID: 29137252 PMCID: PMC5669878 DOI: 10.18632/oncotarget.18955] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2017] [Accepted: 05/10/2017] [Indexed: 01/09/2023] Open
Abstract
Background Mutations in Methyl-CpG binding protein 2 (MECP2) have been identified as the disease-causing mutations in Rett Syndrome (RTT). However, no mutation in the AT-hook 1 domain of MECP2 has been reported in RTT yet. The function of AT-hook 1 domain of MECP2 has not been described either. Methods The clinical and radiological features of a girl with progressive hyperactivity and loss of acquired linguistic and motor functions were presented. Next generation sequencing was used to screen the causative gene. Effect of the mutant protein on histone 3 methylation was assessed in vitro experiment. Results The patient was diagnosed with an atypical RTT at the age of nine. Magnetic resonance imaging revealed a loss of whole-brain volume and abnormal myelination. Genetic analysis identified a de novo novel missense mutation of MECP2 (NM_004992, c.570G->A, p.Arg190His). This mutation is located in the AT-hook 1 domain of MeCP2 protein. Overexpression of the mutant MeCP2 in cultured neuroblastoma cells SH-SY5Y revealed increased level of dimethylated histone 3 lysine 9, a transcriptional repressor marker. Conclusion A novel missense mutation in AT-hook 1 domain of MeCP2 was identified in a patient with atypical RTT. Clinical data and in vitro experiment result imply that R190H mutation in AT-hook1 may cause dysfunction of MeCP2 and be a pathogenic variant.
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Affiliation(s)
- Xiao Zhou
- Department of Neurology, Nanfang Hospital, The Southern Medical University, Guangzhou, China.,Department of Psychiatry, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Yuangao Liao
- Department of Neurology, Nanfang Hospital, The Southern Medical University, Guangzhou, China.,The First People's Hospital of Chenzhou, Chenzhou, China
| | - Miaojing Xu
- Department of Neurology, Nanfang Hospital, The Southern Medical University, Guangzhou, China
| | - Zhong Ji
- Department of Neurology, Nanfang Hospital, The Southern Medical University, Guangzhou, China
| | - Yunqi Xu
- Department of Neurology, Nanfang Hospital, The Southern Medical University, Guangzhou, China
| | - Liang Zhou
- Department of Neurology, Nanfang Hospital, The Southern Medical University, Guangzhou, China
| | | | - Peiqian Hu
- Department of Radiology, Nanfang Hospital, The Southern Medical University, Guangzhou, China
| | - Peng Han
- Beijing Genomics Institute, Shenzhen, China
| | - Fanghan Yang
- Department of Psychiatry, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Suyue Pan
- Department of Neurology, Nanfang Hospital, The Southern Medical University, Guangzhou, China
| | - Yafang Hu
- Department of Neurology, Nanfang Hospital, The Southern Medical University, Guangzhou, China
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22
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Klein M, van Donkelaar M, Verhoef E, Franke B. Imaging genetics in neurodevelopmental psychopathology. Am J Med Genet B Neuropsychiatr Genet 2017; 174:485-537. [PMID: 29984470 PMCID: PMC7170264 DOI: 10.1002/ajmg.b.32542] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/26/2016] [Revised: 02/02/2017] [Accepted: 03/10/2017] [Indexed: 01/27/2023]
Abstract
Neurodevelopmental disorders are defined by highly heritable problems during development and brain growth. Attention-deficit/hyperactivity disorder (ADHD), autism spectrum disorders (ASDs), and intellectual disability (ID) are frequent neurodevelopmental disorders, with common comorbidity among them. Imaging genetics studies on the role of disease-linked genetic variants on brain structure and function have been performed to unravel the etiology of these disorders. Here, we reviewed imaging genetics literature on these disorders attempting to understand the mechanisms of individual disorders and their clinical overlap. For ADHD and ASD, we selected replicated candidate genes implicated through common genetic variants. For ID, which is mainly caused by rare variants, we included genes for relatively frequent forms of ID occurring comorbid with ADHD or ASD. We reviewed case-control studies and studies of risk variants in healthy individuals. Imaging genetics studies for ADHD were retrieved for SLC6A3/DAT1, DRD2, DRD4, NOS1, and SLC6A4/5HTT. For ASD, studies on CNTNAP2, MET, OXTR, and SLC6A4/5HTT were found. For ID, we reviewed the genes FMR1, TSC1 and TSC2, NF1, and MECP2. Alterations in brain volume, activity, and connectivity were observed. Several findings were consistent across studies, implicating, for example, SLC6A4/5HTT in brain activation and functional connectivity related to emotion regulation. However, many studies had small sample sizes, and hypothesis-based, brain region-specific studies were common. Results from available studies confirm that imaging genetics can provide insight into the link between genes, disease-related behavior, and the brain. However, the field is still in its early stages, and conclusions about shared mechanisms cannot yet be drawn.
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Affiliation(s)
- Marieke Klein
- Department of Human Genetics, Donders Institute for Brain, Cognition and Behaviour, Radboud university medical center, Nijmegen, The Netherlands
| | - Marjolein van Donkelaar
- Department of Human Genetics, Donders Institute for Brain, Cognition and Behaviour, Radboud university medical center, Nijmegen, The Netherlands
| | - Ellen Verhoef
- Language and Genetics Department, Max Planck Institute for Psycholinguistics, Nijmegen, The Netherlands
| | - Barbara Franke
- Department of Human Genetics, Donders Institute for Brain, Cognition and Behaviour, Radboud university medical center, Nijmegen, The Netherlands
- Department of Psychiatry, Donders Institute for Brain, Cognition and Behaviour, Radboud university medical center, Nijmegen, The Netherlands
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23
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Leonard H, Cobb S, Downs J. Clinical and biological progress over 50 years in Rett syndrome. Nat Rev Neurol 2016; 13:37-51. [PMID: 27934853 DOI: 10.1038/nrneurol.2016.186] [Citation(s) in RCA: 137] [Impact Index Per Article: 17.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
In the 50 years since Andreas Rett first described the syndrome that came to bear his name, and is now known to be caused by a mutation in the methyl-CpG-binding protein 2 (MECP2) gene, a compelling blend of astute clinical observations and clinical and laboratory research has substantially enhanced our understanding of this rare disorder. Here, we document the contributions of the early pioneers in Rett syndrome (RTT) research, and describe the evolution of knowledge in terms of diagnostic criteria, clinical variation, and the interplay with other Rett-related disorders. We provide a synthesis of what is known about the neurobiology of MeCP2, considering the lessons learned from both cell and animal models, and how they might inform future clinical trials. With a focus on the core criteria, we examine the relationships between genotype and clinical severity. We review current knowledge about the many comorbidities that occur in RTT, and how genotype may modify their presentation. We also acknowledge the important drivers that are accelerating this research programme, including the roles of research infrastructure, international collaboration and advocacy groups. Finally, we highlight the major milestones since 1966, and what they mean for the day-to-day lives of individuals with RTT and their families.
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Affiliation(s)
- Helen Leonard
- Telethon Kids Institute, 100 Roberts Road, Subiaco, Perth, Western Australia 6008, Australia
| | - Stuart Cobb
- Institute of Neuroscience and Psychology, College of Medical, Veterinary and Life Sciences, University of Glasgow, University Avenue, Glasgow G12 8QQ, UK
| | - Jenny Downs
- Telethon Kids Institute, 100 Roberts Road, Subiaco, Perth, Western Australia 6008, Australia
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24
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Veeraragavan S, Wan YW, Connolly DR, Hamilton SM, Ward CS, Soriano S, Pitcher MR, McGraw CM, Huang SG, Green JR, Yuva LA, Liang AJ, Neul JL, Yasui DH, LaSalle JM, Liu Z, Paylor R, Samaco RC. Loss of MeCP2 in the rat models regression, impaired sociability and transcriptional deficits of Rett syndrome. Hum Mol Genet 2016; 25:3284-3302. [PMID: 27365498 PMCID: PMC5179927 DOI: 10.1093/hmg/ddw178] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2016] [Revised: 05/18/2016] [Accepted: 06/08/2016] [Indexed: 01/31/2023] Open
Abstract
Mouse models of the transcriptional modulator Methyl-CpG-Binding Protein 2 (MeCP2) have advanced our understanding of Rett syndrome (RTT). RTT is a 'prototypical' neurodevelopmental disorder with many clinical features overlapping with other intellectual and developmental disabilities (IDD). Therapeutic interventions for RTT may therefore have broader applications. However, the reliance on the laboratory mouse to identify viable therapies for the human condition may present challenges in translating findings from the bench to the clinic. In addition, the need to identify outcome measures in well-chosen animal models is critical for preclinical trials. Here, we report that a novel Mecp2 rat model displays high face validity for modelling psychomotor regression of a learned skill, a deficit that has not been shown in Mecp2 mice. Juvenile play, a behavioural feature that is uniquely present in rats and not mice, is also impaired in female Mecp2 rats. Finally, we demonstrate that evaluating the molecular consequences of the loss of MeCP2 in both mouse and rat may result in higher predictive validity with respect to transcriptional changes in the human RTT brain. These data underscore the similarities and differences caused by the loss of MeCP2 among divergent rodent species which may have important implications for the treatment of individuals with disease-causing MECP2 mutations. Taken together, these findings demonstrate that the Mecp2 rat model is a complementary tool with unique features for the study of RTT and highlight the potential benefit of cross-species analyses in identifying potential disease-relevant preclinical outcome measures.
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Affiliation(s)
- Surabi Veeraragavan
- Department of Molecular and Human Genetics
- Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX, USA
| | - Ying-Wooi Wan
- Department of Molecular and Human Genetics
- Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX, USA
| | - Daniel R Connolly
- Department of Molecular and Human Genetics
- Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX, USA
| | | | - Christopher S Ward
- Department of Pediatrics, Section of Neurology
- Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX, USA
| | - Sirena Soriano
- Department of Molecular and Human Genetics
- Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX, USA
| | - Meagan R Pitcher
- Program in Translational Biology and Molecular Medicine
- Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX, USA
| | - Christopher M McGraw
- Medical Scientist Training Program, Baylor College of Medicine, Houston, TX, USA
- Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX, USA
| | - Sharon G Huang
- Department of Molecular and Human Genetics
- Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX, USA
| | | | - Lisa A Yuva
- Department of Molecular and Human Genetics
- Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX, USA
| | - Agnes J Liang
- Department of Molecular and Human Genetics
- Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX, USA
| | - Jeffrey L Neul
- Department of Pediatrics, Section of Neurology
- Program in Translational Biology and Molecular Medicine
- Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX, USA
| | - Dag H Yasui
- Rowe Program in Human Genetics, University of California Davis, Davis, CA, USA
| | - Janine M LaSalle
- Rowe Program in Human Genetics, University of California Davis, Davis, CA, USA
| | - Zhandong Liu
- Department of Pediatrics, Section of Neurology
- Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX, USA
| | | | - Rodney C Samaco
- Department of Molecular and Human Genetics
- Program in Translational Biology and Molecular Medicine
- Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX, USA
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25
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Schönewolf-Greulich B, Tejada MI, Stephens K, Hadzsiev K, Gauthier J, Brøndum-Nielsen K, Pfundt R, Ravn K, Maortua H, Gener B, Martínez-Bouzas C, Piton A, Rouleau G, Clayton-Smith J, Kleefstra T, Bisgaard AM, Tümer Z. TheMECP2variant c.925C>T (p.Arg309Trp) causes intellectual disability in both males and females without classic features of Rett syndrome. Clin Genet 2016; 89:733-8. [DOI: 10.1111/cge.12769] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2016] [Revised: 02/25/2016] [Accepted: 02/25/2016] [Indexed: 01/05/2023]
Affiliation(s)
- B. Schönewolf-Greulich
- Center for Rett Syndrome, Kennedy Center, Department of Clinical Genetics; Copenhagen University Hospital, Rigshospitalet; Glostrup Denmark
- Applied Human Molecular Genetics, Kennedy Center, Department of Clinical Genetics; Copenhagen University Hospital; Rigshospitalet Glostrup Denmark
| | - M.-I. Tejada
- Genetics Service; Cruces University Hospital, BioCruces Health Research Institute, Clinical group affiliated with the Centre for Biomedical Research on Rare Diseases (CIBERER); Barakaldo Bizkaia Spain
| | - K. Stephens
- Manchester Centre for Genomic Medicine, Manchester Academic Health Sciences Centre; Central Manchester University Hospitals; Manchester UK
| | - K. Hadzsiev
- Department of Medical Genetics; University of Pécs; Pécs Hungary
| | - J. Gauthier
- Molecular Diagnostic Laboratory and Division of Medical Genetics; CHU Sainte-Justine; Montreal Quebec Canada
| | - K. Brøndum-Nielsen
- Department of Clinical Genetics; Copenhagen University Hospital; Rigshospitalet Copenhagen Denmark
| | - R. Pfundt
- Department of Human Genetics; Radboud University Medical Center; Nijmegen the Netherlands
| | - K. Ravn
- Department of Clinical Genetics; Copenhagen University Hospital; Rigshospitalet Copenhagen Denmark
| | - H. Maortua
- Genetics Service; Cruces University Hospital, BioCruces Health Research Institute, Clinical group affiliated with the Centre for Biomedical Research on Rare Diseases (CIBERER); Barakaldo Bizkaia Spain
| | - B. Gener
- Genetics Service; Cruces University Hospital, BioCruces Health Research Institute, Clinical group affiliated with the Centre for Biomedical Research on Rare Diseases (CIBERER); Barakaldo Bizkaia Spain
| | - C. Martínez-Bouzas
- Genetics Service; Cruces University Hospital, BioCruces Health Research Institute, Clinical group affiliated with the Centre for Biomedical Research on Rare Diseases (CIBERER); Barakaldo Bizkaia Spain
| | - A. Piton
- Department of Translational Medicine and Neurogenetics; IGBMC, CNRS UMR 7104/INSERM U964/Strasbourg University; Strasbourg France
- Laboratoire de Diagnostic Génétique; Hôpitaux Universitaires de Strasbourg; Strasbourg Cedex France
| | - G. Rouleau
- Department of Human Genetics; McGill University; Montréal Quebec Canada
| | - J. Clayton-Smith
- Manchester Centre for Genomic Medicine, Manchester Academic Health Sciences Centre; Central Manchester University Hospitals; Manchester UK
| | - T. Kleefstra
- Department of Human Genetics; Radboud University Medical Center; Nijmegen the Netherlands
| | - A.-M. Bisgaard
- Center for Rett Syndrome, Kennedy Center, Department of Clinical Genetics; Copenhagen University Hospital, Rigshospitalet; Glostrup Denmark
| | - Z. Tümer
- Applied Human Molecular Genetics, Kennedy Center, Department of Clinical Genetics; Copenhagen University Hospital; Rigshospitalet Glostrup Denmark
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26
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Gold WA, Christodoulou J. The Utility of Next-Generation Sequencing in Gene Discovery for Mutation-Negative Patients with Rett Syndrome. Front Cell Neurosci 2015; 9:266. [PMID: 26236194 PMCID: PMC4500929 DOI: 10.3389/fncel.2015.00266] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2015] [Accepted: 06/29/2015] [Indexed: 01/13/2023] Open
Abstract
Rett syndrome (RTT) is a rare, severe disorder of neuronal plasticity that predominantly affects girls. Girls with RTT usually appear asymptomatic in the first 6–18 months of life, but gradually develop severe motor, cognitive, and behavioral abnormalities that persist for life. A predominance of neuronal and synaptic dysfunction, with altered excitatory–inhibitory neuronal synaptic transmission and synaptic plasticity, are overarching features of RTT in children and in mouse models. Over 90% of patients with classical RTT have mutations in the X-linked methyl-CpG-binding (MECP2) gene, while other genes, including cyclin-dependent kinase-like 5 (CDKL5), Forkhead box protein G1 (FOXG1), myocyte-specific enhancer factor 2C (MEF2C), and transcription factor 4 (TCF4), have been associated with phenotypes overlapping with RTT. However, there remain a proportion of patients who carry a clinical diagnosis of RTT, but who are mutation negative. In recent years, next-generation sequencing technologies have revolutionized approaches to genetic studies, making whole-exome and even whole-genome sequencing possible strategies for the detection of rare and de novo mutations, aiding the discovery of novel disease genes. Here, we review the recent progress that is emerging in identifying pathogenic variations, specifically from exome sequencing in RTT patients, and emphasize the need for the use of this technology to identify known and new disease genes in RTT patients.
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Affiliation(s)
- Wendy Anne Gold
- Western Sydney Genetics Program, New South Wales Centre for Rett Syndrome Research, Children's Hospital at Westmead , Sydney, NSW , Australia ; Discipline of Paediatrics and Child Health, University of Sydney , Sydney, NSW , Australia
| | - John Christodoulou
- Western Sydney Genetics Program, New South Wales Centre for Rett Syndrome Research, Children's Hospital at Westmead , Sydney, NSW , Australia ; Discipline of Paediatrics and Child Health, University of Sydney , Sydney, NSW , Australia ; Discipline of Genetic Medicine, Sydney Medical School, University of Sydney , Sydney, NSW , Australia
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27
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Molecular underpinnings of prefrontal cortex development in rodents provide insights into the etiology of neurodevelopmental disorders. Mol Psychiatry 2015; 20:795-809. [PMID: 25450230 PMCID: PMC4486649 DOI: 10.1038/mp.2014.147] [Citation(s) in RCA: 108] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/20/2014] [Revised: 09/12/2014] [Accepted: 09/17/2014] [Indexed: 12/20/2022]
Abstract
The prefrontal cortex (PFC), seat of the highest-order cognitive functions, constitutes a conglomerate of highly specialized brain areas and has been implicated to have a role in the onset and installation of various neurodevelopmental disorders. The development of a properly functioning PFC is directed by transcription factors, guidance cues and other regulatory molecules and requires the intricate and temporal orchestration of a number of developmental processes. Disturbance or failure of any of these processes causing neurodevelopmental abnormalities within the PFC may contribute to several of the cognitive deficits seen in patients with neurodevelopmental disorders. In this review, we elaborate on the specific processes underlying prefrontal development, such as induction and patterning of the prefrontal area, proliferation, migration and axonal guidance of medial prefrontal progenitors, and their eventual efferent and afferent connections. We furthermore integrate for the first time the available knowledge from genome-wide studies that have revealed genes linked to neurodevelopmental disorders with experimental molecular evidence in rodents. The integrated data suggest that the pathogenic variants in the neurodevelopmental disorder-associated genes induce prefrontal cytoarchitectonical impairments. This enhances our understanding of the molecular mechanisms of prefrontal (mis)development underlying the four major neurodevelopmental disorders in humans, that is, intellectual disability, autism spectrum disorders, attention deficit hyperactivity disorder and schizophrenia, and may thus provide clues for the development of novel therapies.
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28
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Advances in Human Biology: Combining Genetics and Molecular Biophysics to Pave the Way for Personalized Diagnostics and Medicine. ACTA ACUST UNITED AC 2014. [DOI: 10.1155/2014/471836] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Advances in several biology-oriented initiatives such as genome sequencing and structural genomics, along with the progress made through traditional biological and biochemical research, have opened up a unique opportunity to better understand the molecular effects of human diseases. Human DNA can vary significantly from person to person and determines an individual’s physical characteristics and their susceptibility to diseases. Armed with an individual’s DNA sequence, researchers and physicians can check for defects known to be associated with certain diseases by utilizing various databases. However, for unclassified DNA mutations or in order to reveal molecular mechanism behind the effects, the mutations have to be mapped onto the corresponding networks and macromolecular structures and then analyzed to reveal their effect on the wild type properties of biological processes involved. Predicting the effect of DNA mutations on individual’s health is typically referred to as personalized or companion diagnostics. Furthermore, once the molecular mechanism of the mutations is revealed, the patient should be given drugs which are the most appropriate for the individual genome, referred to as pharmacogenomics. Altogether, the shift in focus in medicine towards more genomic-oriented practices is the foundation of personalized medicine. The progress made in these rapidly developing fields is outlined.
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29
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Adachi M, Monteggia LM. Decoding transcriptional repressor complexes in the adult central nervous system. Neuropharmacology 2014; 80:45-52. [PMID: 24418103 PMCID: PMC3984594 DOI: 10.1016/j.neuropharm.2013.12.024] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2013] [Revised: 12/18/2013] [Accepted: 12/30/2013] [Indexed: 12/27/2022]
Abstract
Cells maintain precise gene expression by balancing transcriptional activation and repression. While much work has focused on elucidating transcriptional activation in the central nervous system (CNS), little is known about transcriptional repression. One means to repress gene expression is to initiate binding of transcription factors to DNA, which then recruit co-repressors as well as other accessory proteins, forming a multi-protein repressor complex. These multi-protein repressor complexes include histone modifying enzymes that trigger processes such as histone acetylation, methylation, and ubiquitylation, altering chromatin structures to impact gene expression. Within these complexes transcriptional repressor proteins per se do not exhibit enzymatic reactions to remodel chromatin structure, whereas histone modifying enzymes lack intrinsic DNA binding activity but have an ability to process post-translational modifications on histones. Thus, the mutual association between transcriptional repressors and histone modifying enzymes is essential to sculpt chromatin to favor transcriptional repression and down regulate gene expression. Additionally, co-repressors are integral components in the context of gene repression as they bridge the association of transcriptional repressors and histone modifying enzymes. In this review, we will discuss the roles of some of the major components of these repressor complex in the CNS as well as their cellular functions that may underlie fundamental behavior in animals.
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Affiliation(s)
- Megumi Adachi
- Department of Neuroscience, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX 75390-9111, USA
| | - Lisa M Monteggia
- Department of Neuroscience, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX 75390-9111, USA.
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30
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Abstract
Rett syndrome (RTT) is a severe and progressive neurological disorder, which mainly affects young females. Mutations of the methyl-CpG binding protein 2 (MECP2) gene are the most prevalent cause of classical RTT cases. MECP2 mutations or altered expression are also associated with a spectrum of neurodevelopmental disorders such as autism spectrum disorders with recent links to fetal alcohol spectrum disorders. Collectively, MeCP2 relation to these neurodevelopmental disorders highlights the importance of understanding the molecular mechanisms by which MeCP2 impacts brain development, mental conditions, and compromised brain function. Since MECP2 mutations were discovered to be the primary cause of RTT, a significant progress has been made in the MeCP2 research, with respect to the expression, function and regulation of MeCP2 in the brain and its contribution in RTT pathogenesis. To date, there have been intensive efforts in designing effective therapeutic strategies for RTT benefiting from mouse models and cells collected from RTT patients. Despite significant progress in MeCP2 research over the last few decades, there is still a knowledge gap between the in vitro and in vivo research findings and translating these findings into effective therapeutic interventions in human RTT patients. In this review, we will provide a synopsis of Rett syndrome as a severe neurological disorder and will discuss the role of MeCP2 in RTT pathophysiology.
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31
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McCarroll SA, Hyman SE. Progress in the genetics of polygenic brain disorders: significant new challenges for neurobiology. Neuron 2013; 80:578-87. [PMID: 24183011 DOI: 10.1016/j.neuron.2013.10.046] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Advances in genome analysis, accompanied by the assembly of large patient cohorts, are making possible successful genetic analyses of polygenic brain disorders. If the resulting molecular clues, previously hidden in the genomes of affected individuals, are to yield useful information about pathogenesis and inform the discovery of new treatments, neurobiology will have to rise to many difficult challenges. Here we review the underlying logic of the genetic investigations, describe in more detail progress in schizophrenia and autism, and outline the challenges for neurobiology that lie ahead. We argue that technologies at the disposal of neuroscience are adequately advanced to begin to study the biology of common and devastating polygenic disorders.
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Affiliation(s)
- Steven A McCarroll
- Stanley Center for Psychiatric Research, Broad Institute of Harvard and MIT, Cambridge, MA 02141, USA; Department of Genetics, Harvard Medical School, Boston, MA 02115, USA.
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