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Abstract
PURPOSE OF REVIEW Genetic mutations in animals advance our understanding of disease mechanisms and treatments of neurodevelopmental disorders. Research with mutant mouse models is being extended to nonhuman primates whose brain development is closer to that of humans. This review summaries advances in mouse and nonhuman primate models. RECENT FINDINGS Mutant mouse models recapitulate key symptoms in neurodevelopmental disorders. However, successful phenotypic reversal of symptoms in mouse models has not been replicated in human studies; this failure may be because of differences in the structure and physiology of the brain between rodents and humans. Rett syndrome MECP2 models and Phelan-McDermid syndrome where reduced expression of SH3 and multiple ankyrin repeat domains 3 (SHANK3) models have been introduced in nonhuman primates and are underway in other neurodevelopmental disorders. SUMMARY Mutant mouse models in neurogenetic disorders continued to be pursued along with gene-edited and cell-based models in nonhuman primates. Established ethical guidelines are being followed and infrastructure being established to facilitate dissemination of primate transgenic models as they become available.
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Affiliation(s)
- James C Harris
- The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
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52
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Unraveling Molecular Pathways Altered in MeCP2-Related Syndromes, in the Search for New Potential Avenues for Therapy. Biomedicines 2021; 9:biomedicines9020148. [PMID: 33546327 PMCID: PMC7913493 DOI: 10.3390/biomedicines9020148] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Revised: 01/25/2021] [Accepted: 01/30/2021] [Indexed: 12/27/2022] Open
Abstract
Methyl-CpG-binding protein 2 (MeCP2) is an X-linked epigenetic modulator whose dosage is critical for neural development and function. Loss-of-function mutations in MECP2 cause Rett Syndrome (RTT, OMIM #312750) while duplications in the Xq28 locus containing MECP2 and Interleukin-1 receptor-associated kinase 1 (IRAK1) cause MECP2 duplication syndrome (MDS, OMIM #300260). Both are rare neurodevelopmental disorders that share clinical symptoms, including intellectual disability, loss of speech, hand stereotypies, vasomotor deficits and seizures. The main objective of this exploratory study is to identify novel signaling pathways and potential quantitative biomarkers that could aid early diagnosis and/or the monitoring of disease progression in clinical trials. We analyzed by RT-PCR gene expression in whole blood and microRNA (miRNA) expression in plasma, in a cohort of 20 females with Rett syndrome, 2 males with MECP2 duplication syndrome and 28 healthy controls, and correlated RNA expression with disease and clinical parameters. We have identified a set of potential biomarker panels for RTT diagnostic and disease stratification of patients with microcephaly and vasomotor deficits. Our study sets the basis for larger studies leading to the identification of specific miRNA signatures for early RTT detection, stratification, disease progression and segregation from other neurodevelopmental disorders. Nevertheless, these data will require verification and validation in further studies with larger sample size including a whole range of ages.
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53
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Pejhan S, Rastegar M. Role of DNA Methyl-CpG-Binding Protein MeCP2 in Rett Syndrome Pathobiology and Mechanism of Disease. Biomolecules 2021; 11:75. [PMID: 33429932 PMCID: PMC7827577 DOI: 10.3390/biom11010075] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2020] [Revised: 01/01/2021] [Accepted: 01/03/2021] [Indexed: 12/16/2022] Open
Abstract
Rett Syndrome (RTT) is a severe, rare, and progressive developmental disorder with patients displaying neurological regression and autism spectrum features. The affected individuals are primarily young females, and more than 95% of patients carry de novo mutation(s) in the Methyl-CpG-Binding Protein 2 (MECP2) gene. While the majority of RTT patients have MECP2 mutations (classical RTT), a small fraction of the patients (atypical RTT) may carry genetic mutations in other genes such as the cyclin-dependent kinase-like 5 (CDKL5) and FOXG1. Due to the neurological basis of RTT symptoms, MeCP2 function was originally studied in nerve cells (neurons). However, later research highlighted its importance in other cell types of the brain including glia. In this regard, scientists benefitted from modeling the disease using many different cellular systems and transgenic mice with loss- or gain-of-function mutations. Additionally, limited research in human postmortem brain tissues provided invaluable findings in RTT pathobiology and disease mechanism. MeCP2 expression in the brain is tightly regulated, and its altered expression leads to abnormal brain function, implicating MeCP2 in some cases of autism spectrum disorders. In certain disease conditions, MeCP2 homeostasis control is impaired, the regulation of which in rodents involves a regulatory microRNA (miR132) and brain-derived neurotrophic factor (BDNF). Here, we will provide an overview of recent advances in understanding the underlying mechanism of disease in RTT and the associated genetic mutations in the MECP2 gene along with the pathobiology of the disease, the role of the two most studied protein variants (MeCP2E1 and MeCP2E2 isoforms), and the regulatory mechanisms that control MeCP2 homeostasis network in the brain, including BDNF and miR132.
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Affiliation(s)
| | - Mojgan Rastegar
- Regenerative Medicine Program, and Department of Biochemistry and Medical Genetics, Rady Faculty of Health Sciences, Max Rady College of Medicine, University of Manitoba, Winnipeg, MB R3E 0J9, Canada;
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Williams K, Jacoby P, Whitehouse A, Kim R, Epstein A, Murphy N, Reid S, Leonard H, Reddihough D, Downs J. Functioning, participation, and quality of life in children with intellectual disability: an observational study. Dev Med Child Neurol 2021; 63:89-96. [PMID: 32862445 DOI: 10.1111/dmcn.14657] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 07/22/2020] [Indexed: 12/19/2022]
Abstract
AIMS To investigate associations between functioning, community participation, and quality of life (QoL) and identify whether participation mediates the effects of functioning on QoL. METHOD The caregivers of 435 children (211 females, 224 males; mean age 12y; SD 3y 11mo; age range 5-18y) with intellectual disability and autism spectrum disorder, cerebral palsy, Down syndrome, or Rett syndrome reported on their child's functioning (dependence for managing personal needs, mobility, communication, eye contact when speaking), frequency of participation, and QoL. Linear regression and mediation analyses were used to evaluate the relationships between child functioning, participation, and QoL. RESULTS Children with greater dependency for managing personal needs and limited eye contact when speaking experienced poorer QoL. Less impaired functioning was associated with more frequent participation, which, in turn, was associated with a 3-point gain in QoL for each additional point in frequency of participation (coefficient=2.67, 95% confidence interval 1.56-3.78). The effect of impaired functioning on QoL was partially mediated by participation in children with greater dependency in managing personal needs and those with mildly impaired communication. INTERPRETATION Greater levels of impairments with poorer functioning, notably a high level of dependence, were associated with poorer QoL. Poorer QoL can be partly explained by less frequent community participation.
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Affiliation(s)
- Katrina Williams
- Paediatric Education and Research, Monash University, Melbourne, Victoria, Australia.,Developmental Paediatrics, Monash Children's Hospital, Clayton, Victoria, Australia.,Developmental Disability and Rehabilitation Research, Murdoch Children's Research Institute, Melbourne, Victoria, Australia.,Department of Paediatrics, University of Melbourne, Melbourne, Victoria, Australia
| | - Peter Jacoby
- Telethon Kids Institute, The University of Western Australia, Perth, Western Australia, Australia
| | - Andrew Whitehouse
- Telethon Kids Institute, The University of Western Australia, Perth, Western Australia, Australia
| | - Rachel Kim
- Department of Sociology, Princeton University, Princeton, NJ, USA
| | - Amy Epstein
- Telethon Kids Institute, The University of Western Australia, Perth, Western Australia, Australia
| | - Nada Murphy
- Telethon Kids Institute, The University of Western Australia, Perth, Western Australia, Australia
| | - Sue Reid
- Developmental Disability and Rehabilitation Research, Murdoch Children's Research Institute, Melbourne, Victoria, Australia.,Department of Paediatrics, University of Melbourne, Melbourne, Victoria, Australia
| | - Helen Leonard
- Telethon Kids Institute, The University of Western Australia, Perth, Western Australia, Australia
| | - Dinah Reddihough
- Developmental Disability and Rehabilitation Research, Murdoch Children's Research Institute, Melbourne, Victoria, Australia.,Department of Paediatrics, University of Melbourne, Melbourne, Victoria, Australia.,Royal Children's Hospital, Parkville, Victoria, Australia
| | - Jenny Downs
- Telethon Kids Institute, The University of Western Australia, Perth, Western Australia, Australia.,School of Physiotherapy and Exercise Science, Curtin University, Perth, Western Australia, Australia
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55
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Downs J, Lotan M, Elefant C, Leonard H, Wong K, Buckley N, Stahlhut M. Implementing telehealth support to increase physical activity in girls and women with Rett syndrome -ActivRett: protocol for a waitlist randomised controlled trial. BMJ Open 2020; 10:e042446. [PMID: 33376177 PMCID: PMC7778785 DOI: 10.1136/bmjopen-2020-042446] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
INTRODUCTION Individuals with Rett syndrome (RTT) experience impaired gross motor skills, limiting their capacity to engage in physical activities and participation in activities. There is limited evidence of the effectiveness of supported physical activity interventions. This study aims to evaluate the effects of a telehealth-delivered physical activity programme on physical activity, sedentary behaviour and quality of life in RTT. METHODS AND ANALYSIS This is a multicentre study, conducted in Australia, Denmark and Israel. It is a randomised waitlist-controlled trial comparing an intervention to support physical activity with usual care. Participants are children and adults with RTT, recruited from the Australian Rett Syndrome Database, the Danish Center for Rett Syndrome and the Rett Syndrome Association of Israel. The intervention duration is 12 weeks, including fortnightly telephone contact to plan, monitor and develop individual activity programmes. Outcomes are measured at baseline, at 13 weeks and then at 25 weeks. The primary outcomes are sedentary behaviour assessed with an activPAL accelerometer and the number of daily steps measured with a StepWatch Activity Monitor. Secondary outcomes include sleep, behaviour and quality of life. Caregiver experiences will be assessed immediately after the intervention using a satisfaction questionnaire. Group differences for each outcome will be evaluated with analysis of covariance, adjusting for baseline values on an intention-to-treat basis. ETHICS AND DISSEMINATION Ethics approval has been obtained in Western Australia from the Child and Adolescent Health Services (RGS3371), in Denmark from the Capital Region Ethics Committee (H-19040514) and in Israel from the Ariel University Institutional Review Board (AU-HEA-ML-20190331). Manuscripts on the development of the intervention from pilot work and the results of the intervention will be submitted to peer-reviewed journals. Results will be presented at conferences and consumer forums. We will develop an online resource documenting the physical activity programme and available supporting evidence. TRIAL REGISTRATION NUMBER NCT04167059; Pre-results.
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Affiliation(s)
- Jenny Downs
- Telethon Kids Institute, The University of Western Australia, Nedlands, Western Australia, Australia
- School of Physiotherapy and Exercise Science, Curtin University, Perth, Western Australia, Australia
| | - Meir Lotan
- Department of Physiotherapy, Ariel University, Ariel, Israel
| | - Cochavit Elefant
- School of Creative Arts Therapies, University of Haifa, Haifa, Israel
| | - Helen Leonard
- Telethon Kids Institute, The University of Western Australia, Nedlands, Western Australia, Australia
| | - Kingsley Wong
- Telethon Kids Institute, The University of Western Australia, Nedlands, Western Australia, Australia
| | - Nicholas Buckley
- Telethon Kids Institute, The University of Western Australia, Nedlands, Western Australia, Australia
- School of Physiotherapy and Exercise Science, Curtin University, Perth, Western Australia, Australia
| | - Michelle Stahlhut
- Department of Paediatrics and Adolescent Medicine, Center for Rett Syndrome, Copenhagen, Denmark
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56
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Romano A, Caprì T, Semino M, Bizzego I, Di Rosa G, Fabio RA. Gross Motor, Physical Activity and Musculoskeletal Disorder Evaluation Tools for Rett Syndrome: A Systematic Review. Dev Neurorehabil 2020; 23:485-501. [PMID: 31668104 DOI: 10.1080/17518423.2019.1680761] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
In recent years, much attention has been paid to motor impairment of persons with Rett Syndrome (RTT), with increasing literature aimed to describe gross motor functioning and musculoskeletal disorders of the RTT population. The aim of this systematic review is to describe clinical evaluation tools used in the last decade to assess motor functioning and musculoskeletal abnormalities of patients with RTT. Thirty-four studies were reviewed and 20 tools were presented. Results showed that only two tools were used to measure functional change after rehabilitative or therapeutic interventions. This review underlies the lack of adequate evaluation tools to assess musculoskeletal abnormalities and deformities in RTT population. The absence of these assessments could be due to a statistical difficulty as it is challenging to build an evaluation tool that can score the entities of the abnormalities related to the amount of disability they cause.
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Affiliation(s)
- Alberto Romano
- Movement Analysis and Robotics Laboratory (MARLab) , Rome, Italy
| | - Tindara Caprì
- Department of Clinical and Experimental Medicine, University of Messina , Via Bivona, Messina, Italy
| | - Martina Semino
- Centro AIRETT Ricerca e Innovazione (CARI), Research and Innovation Airett Center , Verona, Italy
| | - Ilaria Bizzego
- Centro AIRETT Ricerca e Innovazione (CARI), Research and Innovation Airett Center , Verona, Italy
| | - Gabriella Di Rosa
- Division of Child Neurology and Psychiatry, G. Martino Hospital, University of Messina , Messina, Italy
| | - Rosa Angela Fabio
- Department of Clinical and Experimental Medicine, University of Messina , Via Bivona, Messina, Italy
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Saikusa T, Kawaguchi M, Tanioka Tetsu T T, Nabatame Shin N S, Takahashi S, Yuge K, Nagamitsu SI, Takahashi T, Yamashita Y, Kobayashi Y, Hirayama C, Kakuma T, Matsuishi T, Itoh M. Meaningful word acquisition is associated with walking ability over 10 years in Rett syndrome. Brain Dev 2020; 42:705-712. [PMID: 32684376 DOI: 10.1016/j.braindev.2020.06.012] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/13/2020] [Revised: 05/29/2020] [Accepted: 06/22/2020] [Indexed: 10/23/2022]
Abstract
PURPOSE To investigate walking ability in Japanese patients with Rett syndrome (RTT). METHODS Walking ability was assessed in 100 female Japanese patients with RTT using univariate and multivariate analysis in all age groups, and in patients over 10 years of age. We analyzed walking ability and confounding factors including prenatal-perinatal histories, developmental milestones, somatic and head growth, anthropometric data, body mass index, age of loss of purposeful hand use, age at onset of stereotypic hand movement, history of autistic behavior, age at regression, presence or absence of seizures, and the results of MECP2 genetic examination from the Japanese Rett syndrome database. RESULTS Univariate analysis revealed that acquisition of walking in all age groups was significantly correlated with the acquisition of meaningful words, microcephaly, and crawling (P < 0.0001, P = 0.005, P < 0.0001, respectively). Univariate analysis revealed that walking ability over 10 years of age was significantly correlated with acquisition of meaningful words, microcephaly, and body mass index (P < 0,0001, P = 0.005, P = 0.0018, respectively). MECP2 mutations R306C, R133C, and R294X were significantly associated with different acquisition of crawling (P = 0.004) and walking (P = 0.01). Multivariate analysis revealed that only acquisition of meaningful words was significantly correlated with walking ability over 10 years of age. This trend excluded the genetic effects of R306C, R133C, and R294X. CONCLUSIONS Meaningful word acquisition was robustly associated with walking ability over 10 years. Prognosis of walking ability may be predicted by the acquisition of meaningful words. This information is potentially useful for early intervention and the planning of comprehensive treatment for young children with RTT.
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Affiliation(s)
- Tomoko Saikusa
- Department of Pediatrics and Child Health, Kurume University School of Medicine, 67 Asahi-machi, Kurume, Fukuoka 830-0011, Japan
| | - Machiko Kawaguchi
- Biostatistics Center, Kurume University, 67 Asahi-machi, Kurume, Fukuoka 830-0011, Japan
| | | | - Shin Nabatame Shin N
- Department of Pediatrics, Osaka University Graduate School of Medicine, Osaka 565-0871, Japan
| | - Satoru Takahashi
- Department of Pediatrics, Asahikawa University, Asahikawa 078-8510, Japan
| | - Kotaro Yuge
- Department of Pediatrics and Child Health, Kurume University School of Medicine, 67 Asahi-machi, Kurume, Fukuoka 830-0011, Japan
| | - Shin-Ichiro Nagamitsu
- Department of Pediatrics and Child Health, Kurume University School of Medicine, 67 Asahi-machi, Kurume, Fukuoka 830-0011, Japan
| | - Tomoyuki Takahashi
- Department of Pediatrics and Child Health, Kurume University School of Medicine, 67 Asahi-machi, Kurume, Fukuoka 830-0011, Japan
| | - Yushiro Yamashita
- Department of Pediatrics and Child Health, Kurume University School of Medicine, 67 Asahi-machi, Kurume, Fukuoka 830-0011, Japan
| | - Yasuyuki Kobayashi
- Japan Rett Syndrome Association, 2-29-20-101 Kamiigusa, Suginami, Tokyo 167-002, Japan
| | - Chisato Hirayama
- Sakuranbokai-Rett Syndrome, 63-2-101 Kawatsu, Iizuka, Fukuoka, Japan
| | - Tatsuyuki Kakuma
- Biostatistics Center, Kurume University, 67 Asahi-machi, Kurume, Fukuoka 830-0011, Japan
| | - Toyojiro Matsuishi
- Research Center for Children, Research Center for Rett Syndrome, St. Mary's Hospital, Kurume, Fukuoka 830-8543, Japan.
| | - Masayuki Itoh
- Department of Mental Retardation and Birth Defect Research, National Center of Neurology and Psychiatry, 4-1-1 Ogawahigashi-machi, Kodaira, Tokyo 187-8502, Japan
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58
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Raspa M, Bann CM, Gwaltney A, Benke TA, Fu C, Glaze DG, Haas R, Heydemann P, Jones M, Kaufmann WE, Lieberman D, Marsh E, Peters S, Ryther R, Standridge S, Skinner SA, Percy AK, Neul JL. A Psychometric Evaluation of the Motor-Behavioral Assessment Scale for Use as an Outcome Measure in Rett Syndrome Clinical Trials. AMERICAN JOURNAL ON INTELLECTUAL AND DEVELOPMENTAL DISABILITIES 2020; 125:493-509. [PMID: 33211820 PMCID: PMC7778880 DOI: 10.1352/1944-7558-125.6.493] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Accepted: 07/23/2020] [Indexed: 05/13/2023]
Abstract
Rett syndrome (RTT) is a neurodevelopmental disorder that primarily affects females. Recent work indicates the potential for disease modifying therapies. However, there remains a need to develop outcome measures for use in clinical trials. Using data from a natural history study (n = 1,075), we examined the factor structure, internal consistency, and validity of the clinician-reported Motor Behavior Assessment scale (MBA). The analysis resulted in a five-factor model: (1) motor dysfunction, (2) functional skills, (3) social skills, (4) aberrant behavior, and (5) respiratory behaviors. Item Response Theory (IRT) analyses demonstrated that all items had acceptable discrimination. The revised MBA subscales showed a positive relationship with parent reported items, age, and a commonly used measure of clinical severity in RTT, and mutation type. Further work is needed to evaluate this measure longitudinally and to add items related to the RTT phenotype.
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Affiliation(s)
- Melissa Raspa
- Melissa Raspa, Carla M. Bann, and Angela Gwaltney, RTI International
| | - Carla M Bann
- Melissa Raspa, Carla M. Bann, and Angela Gwaltney, RTI International
| | - Angela Gwaltney
- Melissa Raspa, Carla M. Bann, and Angela Gwaltney, RTI International
| | | | - Cary Fu
- Cary Fu, Vanderbilt Kennedy Center
| | | | - Richard Haas
- Richard Haas, University of California San Diego
| | | | | | | | | | - Eric Marsh
- David Lieberman and Eric Marsh, Children's Hospital Boston
| | | | - Robin Ryther
- Robin Ryther, Washington University School of Medicine
| | | | | | - Alan K Percy
- Alan K. Percy, University of Alabama at Birmingham
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59
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Affiliation(s)
- Wei Hou
- Stony Brook University Medical Center, Stony Brook, New York
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60
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Flores Gutiérrez J, De Felice C, Natali G, Leoncini S, Signorini C, Hayek J, Tongiorgi E. Protective role of mirtazapine in adult female Mecp2 +/- mice and patients with Rett syndrome. J Neurodev Disord 2020; 12:26. [PMID: 32988385 PMCID: PMC7523042 DOI: 10.1186/s11689-020-09328-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Accepted: 08/27/2020] [Indexed: 12/23/2022] Open
Abstract
BACKGROUND Rett syndrome (RTT), an X-linked neurodevelopmental rare disease mainly caused by MECP2-gene mutations, is a prototypic intellectual disability disorder. Reversibility of RTT-like phenotypes in an adult mouse model lacking the Mecp2-gene has given hope of treating the disease at any age. However, adult RTT patients still urge for new treatments. Given the relationship between RTT and monoamine deficiency, we investigated mirtazapine (MTZ), a noradrenergic and specific-serotonergic antidepressant, as a potential treatment. METHODS Adult heterozygous-Mecp2 (HET) female mice (6-months old) were treated for 30 days with 10 mg/kg MTZ and assessed for general health, motor skills, motor learning, and anxiety. Motor cortex, somatosensory cortex, and amygdala were analyzed for parvalbumin expression. Eighty RTT adult female patients harboring a pathogenic MECP2 mutation were randomly assigned to treatment to MTZ for insomnia and mood disorders (mean age = 23.1 ± 7.5 years, range = 16-47 years; mean MTZ-treatment duration = 1.64 ± 1.0 years, range = 0.08-5.0 years). Rett clinical severity scale (RCSS) and motor behavior assessment scale (MBAS) were retrospectively analyzed. RESULTS In HET mice, MTZ preserved motor learning from deterioration and normalized parvalbumin levels in the primary motor cortex. Moreover, MTZ rescued the aberrant open-arm preference behavior observed in HET mice in the elevated plus-maze (EPM) and normalized parvalbumin expression in the barrel cortex. Since whisker clipping also abolished the EPM-related phenotype, we propose it is due to sensory hypersensitivity. In patients, MTZ slowed disease progression or induced significant improvements for 10/16 MBAS-items of the M1 social behavior area: 4/7 items of the M2 oro-facial/respiratory area and 8/14 items of the M3 motor/physical signs area. CONCLUSIONS This study provides the first evidence that long-term treatment of adult female heterozygous Mecp2tm1.1Bird mice and adult Rett patients with the antidepressant mirtazapine is well tolerated and that it protects from disease progression and improves motor, sensory, and behavioral symptoms.
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Affiliation(s)
- Javier Flores Gutiérrez
- Department of Life Sciences, University of Trieste, Via Licio Giorgieri, 5 - 34127, Trieste, Italy
| | - Claudio De Felice
- Neonatal Intensive Care Unit, Azienda Ospedaliera Universitaria Senese, 53100, Siena, Italy
| | - Giulia Natali
- Department of Life Sciences, University of Trieste, Via Licio Giorgieri, 5 - 34127, Trieste, Italy
| | - Silvia Leoncini
- Neonatal Intensive Care Unit, Azienda Ospedaliera Universitaria Senese, 53100, Siena, Italy.,Child Neuropsychiatry Unit, Azienda Ospedaliera Universitaria Senese, 53100, Siena, Italy
| | - Cinzia Signorini
- Department of Molecular and Developmental Medicine, University of Siena, 53100, Siena, Italy
| | - Joussef Hayek
- Child Neuropsychiatry Unit, Azienda Ospedaliera Universitaria Senese, 53100, Siena, Italy.,Pediatric Speciality Center "L'Isola di Bau", 50052 Certaldo, Florence, Italy
| | - Enrico Tongiorgi
- Department of Life Sciences, University of Trieste, Via Licio Giorgieri, 5 - 34127, Trieste, Italy.
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61
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Sandweiss AJ, Brandt VL, Zoghbi HY. Advances in understanding of Rett syndrome and MECP2 duplication syndrome: prospects for future therapies. Lancet Neurol 2020; 19:689-698. [PMID: 32702338 DOI: 10.1016/s1474-4422(20)30217-9] [Citation(s) in RCA: 97] [Impact Index Per Article: 24.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2019] [Revised: 05/07/2020] [Accepted: 05/12/2020] [Indexed: 01/07/2023]
Abstract
The X-linked gene encoding MECP2 is involved in two severe and complex neurodevelopmental disorders. Loss of function of the MeCP2 protein underlies Rett syndrome, whereas duplications of the MECP2 locus cause MECP2 duplication syndrome. Research on the mechanisms by which MeCP2 exerts effects on gene expression in neurons, studies of animal models bearing different disease-causing mutations, and more in-depth observations of clinical presentations have clarified some issues even as they have raised further questions. Yet there is enough evidence so far to suggest possible approaches to therapy for these two diseases that could go beyond attempting to address specific signs and symptoms (of which there are many) and instead target the pathophysiology underlying MECP2 disorders. Further work could bring antisense oligonucleotides, deep brain stimulation, and gene therapy into the clinic within the next decade or so.
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Affiliation(s)
- Alexander J Sandweiss
- Department of Pediatrics, Section of Neurology and Developmental Neurosciences, Baylor College of Medicine, Houston, TX, USA; Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, TX, USA
| | - Vicky L Brandt
- Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, TX, USA
| | - Huda Y Zoghbi
- Department of Pediatrics, Section of Neurology and Developmental Neurosciences, Baylor College of Medicine, Houston, TX, USA; Howard Hughes Medical Institute, and Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA; Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, TX, USA.
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62
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Iakovidou N, Lanzarini E, Singh J, Fiori F, Santosh P. Differentiating Females with Rett Syndrome and Those with Multi-Comorbid Autism Spectrum Disorder Using Physiological Biomarkers: A Novel Approach. J Clin Med 2020; 9:jcm9092842. [PMID: 32887357 PMCID: PMC7563706 DOI: 10.3390/jcm9092842] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Revised: 08/28/2020] [Accepted: 08/30/2020] [Indexed: 12/12/2022] Open
Abstract
This study explored the use of wearable sensor technology to investigate autonomic function in children with autism spectrum disorder (ASD) and Rett syndrome (RTT). We aimed to identify autonomic biomarkers that can correctly differentiate females with ASD and Rett Syndrome using an innovative methodology that applies machine learning approaches. Our findings suggest that we can predict (95%) the status of ASD/Rett. We conclude that physiological biomarkers may be able to assist in the differentiation between patients with RTT and ASD and could allow the development of timely therapeutic strategies.
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Affiliation(s)
- Nantia Iakovidou
- Department of Child and Adolescent Psychiatry, Institute of Psychiatry, Psychology and Neuroscience, King’s College London, London SE5 8AF, UK; (N.I.); (J.S.); (F.F.)
| | - Evamaria Lanzarini
- Child and Adolescent Neuropsychiatry Unit, Infermi Hospital, 47923 Rimini, Italy;
| | - Jatinder Singh
- Department of Child and Adolescent Psychiatry, Institute of Psychiatry, Psychology and Neuroscience, King’s College London, London SE5 8AF, UK; (N.I.); (J.S.); (F.F.)
- Centre for Personalised Medicine in Rett Syndrome (CPMRS) & Centre for Interventional Paediatric Psychopharmacology and Rare Diseases (CIPPRD), South London and Maudsley NHS Foundation Trust, London SE5 8AZ, UK
| | - Federico Fiori
- Department of Child and Adolescent Psychiatry, Institute of Psychiatry, Psychology and Neuroscience, King’s College London, London SE5 8AF, UK; (N.I.); (J.S.); (F.F.)
- Centre for Personalised Medicine in Rett Syndrome (CPMRS) & Centre for Interventional Paediatric Psychopharmacology and Rare Diseases (CIPPRD), South London and Maudsley NHS Foundation Trust, London SE5 8AZ, UK
- HealthTracker Limited, 76–78 High Street Medical Dental, High Street, Gillingham, Kent ME7 1AY, UK
| | - Paramala Santosh
- Department of Child and Adolescent Psychiatry, Institute of Psychiatry, Psychology and Neuroscience, King’s College London, London SE5 8AF, UK; (N.I.); (J.S.); (F.F.)
- Centre for Personalised Medicine in Rett Syndrome (CPMRS) & Centre for Interventional Paediatric Psychopharmacology and Rare Diseases (CIPPRD), South London and Maudsley NHS Foundation Trust, London SE5 8AZ, UK
- HealthTracker Limited, 76–78 High Street Medical Dental, High Street, Gillingham, Kent ME7 1AY, UK
- Correspondence:
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Mendoza J, Downs J, Wong K, Leonard H. Determinants of quality of life in Rett syndrome: new findings on associations with genotype. J Med Genet 2020; 58:637-644. [PMID: 32843489 DOI: 10.1136/jmedgenet-2020-107120] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Revised: 06/26/2020] [Accepted: 07/05/2020] [Indexed: 11/04/2022]
Abstract
BACKGROUND Rett syndrome is a genetically caused neurodevelopmental disorder associated with functional deficits and comorbidities. This study investigated relationships between genotype, functional abilities and comorbidities and quality of life in Rett syndrome. METHODS The International Rett Syndrome Database, InterRett, was used as a sampling frame for this observational study. Information was collected to describe functional abilities (walking and feeding), health (Sleep Disorder Scale for Children, the Rett Syndrome Behavioural Questionnaire), parental health (12-item Short Form Health Survey) sociodemographic factors (parental employment and education) and quality of life (Quality of Life Inventory-Disability) for 210 individuals with Rett syndrome. Univariate and multivariate regressions were used to analyse the relationships between the independent variables and quality of life. RESULTS Compared with individuals with the p.Arg270* mutation, those with the p.Arg294* mutation type had the poorest quality of life (coeff -12.81, 95% CI -23.49 to 2.12), despite this being recognised as a clinically milder genotype. Overall better walking and feeding skills and seizure parameters were more associated with better quality of life and poor sleep and behavioural difficulties with poorer quality of life. CONCLUSIONS These findings suggest that genotype, functioning and health each have implications for quality of life and should be considered when counselling families and planning clinical and support management strategies.
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Affiliation(s)
- Jonathan Mendoza
- Telethon Kids Institute, The University of Western Australia, Nedlands, Western Australia, Australia
| | - Jenny Downs
- Telethon Kids Institute, The University of Western Australia, Nedlands, Western Australia, Australia .,School of Physiotherapy and Exercise Science, Curtin University, Perth, Western Australia, Australia
| | - Kingsley Wong
- Telethon Kids Institute, The University of Western Australia, Nedlands, Western Australia, Australia
| | - Helen Leonard
- Telethon Kids Institute, The University of Western Australia, Nedlands, Western Australia, Australia
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Silvennoinen K, Balestrini S, Rothwell JC, Sisodiya SM. Transcranial magnetic stimulation as a tool to understand genetic conditions associated with epilepsy. Epilepsia 2020; 61:1818-1839. [PMID: 32783192 PMCID: PMC8432162 DOI: 10.1111/epi.16634] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Revised: 07/09/2020] [Accepted: 07/09/2020] [Indexed: 12/30/2022]
Abstract
Advances in genetics may enable a deeper understanding of disease mechanisms and promote a shift to more personalised medicine in the epilepsies. At present, understanding of consequences of genetic variants mainly relies on preclinical functional work; tools for acquiring similar data from the living human brain are needed. Transcranial magnetic stimulation (TMS), in particular paired-pulse TMS protocols which depend on the function of cortical GABAergic interneuron networks, has the potential to become such a tool. For this report, we identified and reviewed 23 publications on TMS studies of cortical excitability and inhibition in 15 different genes or conditions relevant to epilepsy. Reduced short-interval intracortical inhibition (SICI) and reduced cortical silent period (CSP) duration were the most commonly reported findings, suggesting abnormal GABAA - (SICI) or GABAB ergic (CSP) signalling. For several conditions, these findings are plausible based on established evidence of involvement of the GABAergic system; for some others, they may inform future research around such mechanisms. Challenges of TMS include lack of complete understanding of the neural underpinnings of the measures used: hypotheses and analyses should be based on existing clinical and preclinical data. Further pitfalls include gathering sufficient numbers of participants, and the effect of confounding factors, especially medications. TMS-EEG is a unique perturbational technique to study the intrinsic properties of the cortex with excellent temporal resolution; while it has the potential to provide further information of use in interpreting effects of genetic variants, currently the links between measures and neurophysiology are less established. Despite these challenges, TMS is a tool with potential for elucidating the system-level in vivo functional consequences of genetic variants in people carrying genetic changes of interest, providing unique insights.
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Affiliation(s)
- Katri Silvennoinen
- Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, London, UK.,Chalfont Centre for Epilepsy, Chalfont St. Peter, UK
| | - Simona Balestrini
- Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, London, UK.,Chalfont Centre for Epilepsy, Chalfont St. Peter, UK
| | - John C Rothwell
- Sobell Department of Motor Neuroscience and Movement Disorders, Department of UCL Queen Square, Institute of Neurology, London, UK
| | - Sanjay M Sisodiya
- Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, London, UK.,Chalfont Centre for Epilepsy, Chalfont St. Peter, UK
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Cell-Type-Specific Gene Inactivation and In Situ Restoration via Recombinase-Based Flipping of Targeted Genomic Region. J Neurosci 2020; 40:7169-7186. [PMID: 32801153 DOI: 10.1523/jneurosci.1044-20.2020] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Revised: 06/22/2020] [Accepted: 07/30/2020] [Indexed: 11/21/2022] Open
Abstract
Conditional gene inactivation and restoration are powerful tools for studying gene functions in the nervous system and for modeling neuropsychiatric diseases. The combination of the two is necessary to interrogate specific cell types within defined developmental stages. However, very few methods and animal models have been developed for such purpose. Here we present a versatile method for conditional gene inactivation and in situ restoration through reversibly inverting a critical part of its endogenous genomic sequence by Cre- and Flp-mediated recombinations. Using this method, we generated a mouse model to manipulate Mecp2, an X-linked dosage-sensitive gene whose mutations cause Rett syndrome. Combined with multiple Cre- and Flp-expressing drivers and viral tools, we achieved efficient and reliable Mecp2 inactivation and restoration in the germline and several neuronal cell types, and demonstrated phenotypic reversal and prevention on cellular and behavioral levels in male mice. This study not only provides valuable tools and critical insights for Mecp2 and Rett syndrome, but also offers a generally applicable strategy to decipher other neurologic disorders.SIGNIFICANCE STATEMENT Studying neurodevelopment and modeling neurologic disorders rely on genetic tools, such as conditional gene regulation. We developed a new method to combine conditional gene inactivation and restoration on a single allele without disturbing endogenous expression pattern or dosage. We applied it to manipulate Mecp2, a gene residing on X chromosome whose malfunction leads to neurologic disease, including Rett syndrome. Our results demonstrated the efficiency, specificity, and versatility of this new method, provided valuable tools and critical insights for Mecp2 function and Rett syndrome research, and offered a generally applicable strategy to investigate other genes and genetic disorders.
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66
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Nam KH, Yi SA, Jang HJ, Han JW, Lee J. In vitro modeling for inherited neurological diseases using induced pluripotent stem cells: from 2D to organoid. Arch Pharm Res 2020; 43:877-889. [PMID: 32761309 DOI: 10.1007/s12272-020-01260-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2020] [Accepted: 07/29/2020] [Indexed: 12/20/2022]
Abstract
Stem cells are characterized by self-renewal and by their ability to differentiate into cells of various organs. With massive progress in 2D and 3D cell culture techniques, in vitro generation of various types of such organoids from patient-derived stem cells is now possible. As in vitro differentiation protocols are usually made to resemble human developmental processes, organogenesis of patient-derived stem cells can provide key information regarding a range of developmental diseases. Human stem cell-based in vitro modeling as opposed to using animal models can particularly benefit the evaluation of neurological diseases because of significant differences in structure and developmental processes between the human and the animal brain. This review focuses on stem cell-based in vitro modeling of neurodevelopmental disorders, more specifically, the fundamentals and technical advancements in monolayer neuron and brain organoid cultures. Furthermore, we discuss the drawbacks of the conventional culture method and explore the advanced, cutting edge 3D organoid models for several neurodevelopmental diseases, including genetic diseases such as Down syndrome, Rett syndrome, and Miller-Dieker syndrome, as well as brain malformations like macrocephaly and microcephaly. Finally, we discuss the limitations of the current organoid techniques and some potential solutions that pave the way for accurate modeling of neurological disorders in a dish.
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Affiliation(s)
- Ki Hong Nam
- School of Pharmacy, Sungkyunkwan University, Suwon, 16419, Republic of Korea
| | - Sang Ah Yi
- School of Pharmacy, Sungkyunkwan University, Suwon, 16419, Republic of Korea
| | - Hyun Ji Jang
- School of Pharmacy, Sungkyunkwan University, Suwon, 16419, Republic of Korea
| | - Jeung-Whan Han
- School of Pharmacy, Sungkyunkwan University, Suwon, 16419, Republic of Korea
| | - Jaecheol Lee
- School of Pharmacy, Sungkyunkwan University, Suwon, 16419, Republic of Korea. .,Biomedical Institute for Convergence at SKKU (BICS), Sungkyunkwan University, Suwon, 16419, Republic of Korea. .,Imnewrun Biosciences Inc., Suwon, 16419, Republic of Korea.
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Functional Network Mapping Reveals State-Dependent Response to IGF1 Treatment in Rett Syndrome. Brain Sci 2020; 10:brainsci10080515. [PMID: 32756423 PMCID: PMC7465931 DOI: 10.3390/brainsci10080515] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2020] [Revised: 07/22/2020] [Accepted: 07/24/2020] [Indexed: 01/20/2023] Open
Abstract
Rett Syndrome (RTT) is a neurodevelopmental disorder associated with mutations in the gene MeCP2, which is involved in the development and function of cortical networks. The clinical presentation of RTT is generally severe and includes developmental regression and marked neurologic impairment. Insulin-Like growth factor 1 (IGF1) ameliorates RTT-relevant phenotypes in animal models and improves some clinical manifestations in early human trials. However, it remains unclear whether IGF1 treatment has an impact on cortical electrophysiology in line with MeCP2’s role in network formation, and whether these electrophysiological changes are related to clinical response. We performed clinical assessments and resting-state electroencephalogram (EEG) recordings in eighteen patients with classic RTT, nine of whom were treated with IGF1. Among the treated patients, we distinguished those who showed improvements after treatment (responders) from those who did not show any changes (nonresponders). Clinical assessments were carried out for all individuals with RTT at baseline and 12 months after treatment. Network measures were derived using statistical modelling techniques based on interelectrode coherence measures. We found significant interaction between treatment groups and timepoints, indicating an effect of IGF1 on network measures. We also found a significant effect of responder status and timepoint, indicating that these changes in network measures are associated with clinical response to treatment. Further, we found baseline variability in network characteristics, and a machine learning model using these measures applied to pretreatment data predicted treatment response with 100% accuracy (100% sensitivity and 100% specificity) in this small patient group. These results highlight the importance of network pathology in RTT, as well as providing preliminary evidence for the potential of network measures as tools for the characterisation of disease subtypes and as biomarkers for clinical trials.
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68
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Wong K, Glasson EJ, Jacoby P, Srasuebkul P, Forbes D, Ravikumara M, Wilson A, Bourke J, Trollor J, Leonard H, Nagarajan L, Downs J. Survival of children and adolescents with intellectual disability following gastrostomy insertion. JOURNAL OF INTELLECTUAL DISABILITY RESEARCH : JIDR 2020; 64:497-511. [PMID: 32319159 DOI: 10.1111/jir.12729] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2020] [Revised: 04/01/2020] [Accepted: 04/02/2020] [Indexed: 06/11/2023]
Abstract
BACKGROUND Positive health outcomes have been observed following gastrostomy insertion in children with intellectual disability, which is being increasingly used at younger ages to improve nutritional intake. This study investigated the effect of gastrostomy insertion on survival of children with severe intellectual disability. METHODS We used linked disability and health data of children and adolescents who were born in Western Australia between 1983 and 2009 to compare survival of individuals with severe intellectual disability by exposure to gastrostomy status. For those born in 2000-2009, we employed propensity score matching to adjust for confounding by indication. Effect of gastrostomy insertion on survival was compared by pertinent health and sociodemographic risk factors. RESULTS Compared with children born in the 1980s-1990s, probability of survival following first gastrostomy insertion for those born in 2000-2009 was higher (2 years: 94% vs. 83%). Mortality risk was higher in cases than that in their matched controls (hazard ratio 2.9, 95% confidence interval 1.1, 7.3). The relative risk of mortality (gastrostomy vs. non-gastrostomy) may have differed by sex, birthweight and time at first gastrostomy insertion. Respiratory conditions were a common immediate or underlying cause of death among all children, particularly among those undergoing gastrostomy insertion. CONCLUSIONS Whilst gastrostomy insertion was associated with lower survival rates than children without gastrostomy, survival improved with time, and gastrostomy afforded some protection for the more vulnerable groups, and earlier use appears beneficial to survival. Specific clinical data that may be used to prioritise the need for gastrostomy insertion may be responsible for the survival differences observed.
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Affiliation(s)
- K Wong
- Telethon Kids Institute, Centre for Child Health Research, The University of Western Australia, Perth, Western Australia, Australia
| | - E J Glasson
- Telethon Kids Institute, Centre for Child Health Research, The University of Western Australia, Perth, Western Australia, Australia
| | - P Jacoby
- Telethon Kids Institute, Centre for Child Health Research, The University of Western Australia, Perth, Western Australia, Australia
| | - P Srasuebkul
- Department of Developmental Disability Neuropsychiatry, School of Psychiatry, UNSW Sydney, Sydney, New South Wales, Australia
| | - D Forbes
- Medical School, The University of Western Australia, Perth, Western Australia, Australia
| | - M Ravikumara
- Department of Gastroenterology, Perth Children's Hospital, Perth, Western Australia, Australia
| | - A Wilson
- Telethon Kids Institute, Centre for Child Health Research, The University of Western Australia, Perth, Western Australia, Australia
- Department of Respiratory Medicine, Perth Children's Hospital, Perth, Western Australia, Australia
- School of Paediatrics, The University of Western Australia, Perth, Western Australia, Australia
- School of Physiotherapy and Exercise Science, Curtin University, Perth, Western Australia, Australia
| | - J Bourke
- Telethon Kids Institute, Centre for Child Health Research, The University of Western Australia, Perth, Western Australia, Australia
| | - J Trollor
- Department of Developmental Disability Neuropsychiatry, School of Psychiatry, UNSW Sydney, Sydney, New South Wales, Australia
| | - H Leonard
- Telethon Kids Institute, Centre for Child Health Research, The University of Western Australia, Perth, Western Australia, Australia
| | - L Nagarajan
- Telethon Kids Institute, Centre for Child Health Research, The University of Western Australia, Perth, Western Australia, Australia
- Children's Neuroscience Service, Department of Neurology, Perth Children's Hospital, Perth, Western Australia, Australia
| | - J Downs
- Telethon Kids Institute, Centre for Child Health Research, The University of Western Australia, Perth, Western Australia, Australia
- School of Physiotherapy and Exercise Science, Curtin University, Perth, Western Australia, Australia
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Challenges Affecting Access to Health and Social Care Resources and Time Management among Parents of Children with Rett Syndrome: A Qualitative Case Study. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2020; 17:ijerph17124466. [PMID: 32575920 PMCID: PMC7345745 DOI: 10.3390/ijerph17124466] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Revised: 06/17/2020] [Accepted: 06/19/2020] [Indexed: 01/01/2023]
Abstract
Rare diseases face serious sustainability challenges regarding the distribution of resources geared at health and social needs. Our aim was to describe the barriers experienced by parents of children with Rett Syndrome for accessing care resources. A qualitative case study was conducted among 31 parents of children with Rett syndrome. Data were collected through in-depth interviews, focus groups, researchers’ field notes and parents’ personal documents. A thematic analysis was performed and the Standards for Reporting Qualitative Research (SRQR) guidelines were followed. Three main themes emerged from the data: (a) essential health resources; (b) bureaucracy and social care; and (c) time management constraints. Parents have difficulties accessing appropriate health services for their children. Administrative obstacles exist for accessing public health services, forcing parents to bear the financial cost of specialized care. Time is an essential factor, which conditions the organization of activities for the entire family. Qualitative research offers insight into how parents of children with Rett syndrome experience access to resources and may help improve understanding of how Rett syndrome impacts the lives of both the children and their parents.
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Saby JN, Peters SU, Roberts TPL, Nelson CA, Marsh ED. Evoked Potentials and EEG Analysis in Rett Syndrome and Related Developmental Encephalopathies: Towards a Biomarker for Translational Research. Front Integr Neurosci 2020; 14:30. [PMID: 32547374 PMCID: PMC7271894 DOI: 10.3389/fnint.2020.00030] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2019] [Accepted: 05/04/2020] [Indexed: 12/17/2022] Open
Abstract
Rett syndrome is a debilitating neurodevelopmental disorder for which no disease-modifying treatment is available. Fortunately, advances in our understanding of the genetics and pathophysiology of Rett syndrome has led to the development of promising new therapeutics for the condition. Several of these therapeutics are currently being tested in clinical trials with others likely to progress to clinical trials in the coming years. The failure of recent clinical trials for Rett syndrome and other neurodevelopmental disorders has highlighted the need for electrophysiological or other objective biological markers of treatment response to support the success of clinical trials moving forward. The purpose of this review is to describe the existing studies of electroencephalography (EEG) and evoked potentials (EPs) in Rett syndrome and discuss the open questions that must be addressed before the field can adopt these measures as surrogate endpoints in clinical trials. In addition to summarizing the human work on Rett syndrome, we also describe relevant studies with animal models and the limited research that has been carried out on Rett-related disorders, particularly methyl-CpG binding protein 2 (MECP2) duplication syndrome, CDKL5 deficiency disorder, and FOXG1 disorder.
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Affiliation(s)
- Joni N. Saby
- Lurie Family Foundations MEG Imaging Center, Department of Radiology, The Children’s Hospital of Philadelphia, Philadelphia, PA, United States
| | - Sarika U. Peters
- Department of Pediatrics, Vanderbilt University Medical Center, Nashville, TN, United States
| | - Timothy P. L. Roberts
- Lurie Family Foundations MEG Imaging Center, Department of Radiology, The Children’s Hospital of Philadelphia, Philadelphia, PA, United States,Department of Radiology, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, United States
| | - Charles A. Nelson
- Laboratories of Cognitive Neuroscience, Division of Developmental Medicine, Boston Children’s Hospital, Harvard Medical School, Boston, MA, United States
| | - Eric D. Marsh
- Division of Neurology and Pediatrics, Children’s Hospital of Philadelphia, Philadelphia, PA, United States,Departments of Neurology and Pediatrics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, United States,*Correspondence: Eric D. Marsh
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71
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Bernardo P, Cobb S, Coppola A, Tomasevic L, Di Lazzaro V, Bravaccio C, Manganelli F, Dubbioso R. Neurophysiological Signatures of Motor Impairment in Patients with Rett Syndrome. Ann Neurol 2020; 87:763-773. [PMID: 32129908 DOI: 10.1002/ana.25712] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2019] [Revised: 03/02/2020] [Accepted: 03/02/2020] [Indexed: 12/15/2022]
Abstract
OBJECTIVE Rett syndrome (RTT) is an X-linked dominant neurodevelopmental disorder due to pathogenic mutations in the MECP2 gene. Motor impairment constitutes the core diagnostic feature of RTT. Preclinical studies have consistently demonstrated alteration of excitation/inhibition (E/I) balance and aberrant synaptic plasticity at the cortical level. We aimed to understand neurobiological mechanisms underlying motor deficit by assessing in vivo synaptic plasticity and E/I balance in the primary motor cortex (M1). METHODS In 14 patients with typical RTT, 9 epilepsy control patients, and 11 healthy controls, we applied paired-pulse transcranial magnetic stimulation (TMS) protocols to evaluate the excitation index, a biomarker reflecting the contribution of inhibitory and facilitatory circuits in M1. Intermittent TMS-theta burst stimulation was used to probe long-term potentiation (LTP)-like plasticity in M1. Motor impairment, assessed by ad hoc clinical scales, was correlated with neurophysiological metrics. RESULTS RTT patients displayed a significant increase of the excitation index (p = 0.003), as demonstrated by the reduction of short-interval intracortical inhibition and increase of intracortical facilitation, suggesting a shift toward cortical excitation likely due to GABAergic dysfunction. Impairment of inhibitory circuits was also confirmed by the reduction of long-interval intracortical inhibition (p = 0.002). LTP-like plasticity in M1 was abolished (p = 0.008) and scaled with motor disability (all p = 0.003). INTERPRETATION TMS is a method that can be used to assess cortical motor function in RTT patients. Our findings support the introduction of TMS measures in clinical and research settings to monitor the progression of motor deficit and response to treatment. ANN NEUROL 2020;87:763-773.
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Affiliation(s)
- Pia Bernardo
- Department of Neuroscience, Child Neuropsychiatry Unit, Santobono-Pausilipon Children's Hospital, Naples, Italy.,Department of Translational Medical Sciences, Child Neuropsychiatry Unit, University of Naples Federico II, Naples, Italy
| | - Stuart Cobb
- Institute of Neuroscience and Psychology, College of Medical, Veterinary, and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Antonietta Coppola
- Department of Neurosciences, Reproductive Sciences and Odontostomatology, University of Naples Federico II, Naples, Italy
| | - Leo Tomasevic
- Danish Research Center for Magnetic Resonance, Copenhagen University Hospital Hvidovre, Hvidovre, Denmark
| | - Vincenzo Di Lazzaro
- Unit of Neurology, Neurophysiology, Neurobiology, Department of Medicine, Campus Bio-Medico University of Rome, Rome, Italy
| | - Carmela Bravaccio
- Department of Translational Medical Sciences, Child Neuropsychiatry Unit, University of Naples Federico II, Naples, Italy
| | - Fiore Manganelli
- Department of Neurosciences, Reproductive Sciences and Odontostomatology, University of Naples Federico II, Naples, Italy
| | - Raffaele Dubbioso
- Department of Neurosciences, Reproductive Sciences and Odontostomatology, University of Naples Federico II, Naples, Italy
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Lavery LA, Ure K, Wan YW, Luo C, Trostle AJ, Wang W, Jin H, Lopez J, Lucero J, Durham MA, Castanon R, Nery JR, Liu Z, Goodell M, Ecker JR, Behrens MM, Zoghbi HY. Losing Dnmt3a dependent methylation in inhibitory neurons impairs neural function by a mechanism impacting Rett syndrome. eLife 2020; 9:e52981. [PMID: 32159514 PMCID: PMC7065908 DOI: 10.7554/elife.52981] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Accepted: 02/20/2020] [Indexed: 12/11/2022] Open
Abstract
Methylated cytosine is an effector of epigenetic gene regulation. In the brain, Dnmt3a is the sole 'writer' of atypical non-CpG methylation (mCH), and MeCP2 is the only known 'reader' for mCH. We asked if MeCP2 is the sole reader for Dnmt3a dependent methylation by comparing mice lacking either protein in GABAergic inhibitory neurons. Loss of either protein causes overlapping and distinct features from the behavioral to molecular level. Loss of Dnmt3a causes global loss of mCH and a subset of mCG sites resulting in more widespread transcriptional alterations and severe neurological dysfunction than MeCP2 loss. These data suggest that MeCP2 is responsible for reading only part of the Dnmt3a dependent methylation in the brain. Importantly, the impact of MeCP2 on genes differentially expressed in both models shows a strong dependence on mCH, but not Dnmt3a dependent mCG, consistent with mCH playing a central role in the pathogenesis of Rett Syndrome.
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Affiliation(s)
- Laura A Lavery
- Jan and Dan Duncan Neurological Research Institute at Texas Children’s HospitalHoustonUnited States
- Department of Molecular and Human Genetics, Baylor College of MedicineHoustonUnited States
| | - Kerstin Ure
- Jan and Dan Duncan Neurological Research Institute at Texas Children’s HospitalHoustonUnited States
- Department of Molecular and Human Genetics, Baylor College of MedicineHoustonUnited States
| | - Ying-Wooi Wan
- Jan and Dan Duncan Neurological Research Institute at Texas Children’s HospitalHoustonUnited States
- Department of Molecular and Human Genetics, Baylor College of MedicineHoustonUnited States
| | - Chongyuan Luo
- Genomic Analysis Laboratory, The Salk Institute for Biological StudiesLa JollaUnited States
- Howard Hughes Medical Institute, The Salk Institute for Biological StudiesLa JollaUnited States
| | - Alexander J Trostle
- Jan and Dan Duncan Neurological Research Institute at Texas Children’s HospitalHoustonUnited States
- Department of Pediatrics, Baylor College of MedicineHoustonUnited States
| | - Wei Wang
- Jan and Dan Duncan Neurological Research Institute at Texas Children’s HospitalHoustonUnited States
- Department of Molecular and Human Genetics, Baylor College of MedicineHoustonUnited States
| | - Haijing Jin
- Graduate Program in Quantitative and Computational Biosciences, Baylor College of MedicineHoustonUnited States
| | - Joanna Lopez
- Jan and Dan Duncan Neurological Research Institute at Texas Children’s HospitalHoustonUnited States
- Department of Molecular and Human Genetics, Baylor College of MedicineHoustonUnited States
| | - Jacinta Lucero
- Computational Neurobiology Laboratory, The Salk Institute for Biological StudiesLa JollaUnited States
| | - Mark A Durham
- Program in Developmental Biology, Baylor College of MedicineHoustonUnited States
- Medical Scientist Training Program, Baylor College of MedicineHoustonUnited States
| | - Rosa Castanon
- Genomic Analysis Laboratory, The Salk Institute for Biological StudiesLa JollaUnited States
| | - Joseph R Nery
- Genomic Analysis Laboratory, The Salk Institute for Biological StudiesLa JollaUnited States
| | - Zhandong Liu
- Jan and Dan Duncan Neurological Research Institute at Texas Children’s HospitalHoustonUnited States
- Department of Molecular and Human Genetics, Baylor College of MedicineHoustonUnited States
- Graduate Program in Quantitative and Computational Biosciences, Baylor College of MedicineHoustonUnited States
| | - Margaret Goodell
- Department of Molecular and Human Genetics, Baylor College of MedicineHoustonUnited States
- Program in Developmental Biology, Baylor College of MedicineHoustonUnited States
- Center for Cell and Gene Therapy, Baylor College of MedicineHoustonUnited States
- Stem Cells and Regenerative Medicine Center, Baylor College of MedicineHoustonUnited States
- Department Molecular and Cellular Biology, Baylor College of MedicineHoustonUnited States
| | - Joseph R Ecker
- Genomic Analysis Laboratory, The Salk Institute for Biological StudiesLa JollaUnited States
- Howard Hughes Medical Institute, The Salk Institute for Biological StudiesLa JollaUnited States
| | - M Margarita Behrens
- Computational Neurobiology Laboratory, The Salk Institute for Biological StudiesLa JollaUnited States
- Department of Psychiatry, University of California San DiegoLa JollaUnited States
| | - Huda Y Zoghbi
- Jan and Dan Duncan Neurological Research Institute at Texas Children’s HospitalHoustonUnited States
- Department of Molecular and Human Genetics, Baylor College of MedicineHoustonUnited States
- Department of Pediatrics, Baylor College of MedicineHoustonUnited States
- Program in Developmental Biology, Baylor College of MedicineHoustonUnited States
- Department of Neuroscience, Baylor College of MedicineHoustonUnited States
- Howard Hughes Medical Institute, Baylor College of MedicineHoustonUnited States
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Aygun D, Bjornsson HT. Clinical epigenetics: a primer for the practitioner. Dev Med Child Neurol 2020; 62:192-200. [PMID: 31749156 DOI: 10.1111/dmcn.14398] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 10/01/2019] [Indexed: 12/12/2022]
Abstract
Disruption of epigenetic modifications and the factors that maintain these modifications is rapidly emerging as a cause of developmental disorders. Here we summarize some of the major principles of epigenetics including how epigenetic modifications are: (1) normally reset in the germ line, (2) form an additional layer of interindividual variation, (3) are environmentally sensitive, and (4) change over time in humans. We also briefly discuss the disruption of growth and intellect associated with the Mendelian disorders of the epigenetic machinery and the classical imprinting disorders (such as Beckwith-Wiedemann syndrome, Silver-Russell syndrome, Prader-Willi syndrome, and Angelman syndrome), as well as suggesting some diagnostic considerations for the clinicians taking care of these patients. Finally, we discuss novel therapeutic strategies targeting epigenetic modifications, which may offer a safe alternative to up and coming genome editing strategies for the treatment of genetic diseases. This review provides a starting point for clinicians interested in epigenetics and the role epigenetic disruption plays in human disease. WHAT THIS PAPER ADDS: Clinicians are introduced to four main principles of epigenetics. Clinical features of imprinting disorders and Mendelian disorders of epigenetic machinery are presented.
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Affiliation(s)
- Deniz Aygun
- School of Arts and Sciences, Tufts University, Medford, MA, USA
| | - Hans T Bjornsson
- McKusick-Nathans Institute of Genetic Medicine, Baltimore, MD, USA.,Department of Pediatrics, Johns Hopkins University, Baltimore, MD, USA.,Department of Genetics and Molecular Medicine, Landspitali University Hospital, Reykjavik, Iceland.,Faculty of Medicine, University of Iceland, Reykjavik, Iceland
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Stahlhut M, Downs J, Wong K, Bisgaard AM, Nordmark E. Feasibility and Effectiveness of an Individualized 12-Week "Uptime" Participation (U-PART) Intervention in Girls and Women With Rett Syndrome. Phys Ther 2020; 100:168-179. [PMID: 31584667 DOI: 10.1093/ptj/pzz138] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/04/2019] [Accepted: 06/12/2019] [Indexed: 11/13/2022]
Abstract
BACKGROUND Girls and women with Rett Syndrome (RTT) have low levels of daily physical activity and high levels of sedentary time. Reducing sedentary time and enhancing "uptime" activities, such as standing and walking, could be an important focus for interventions to address long-term health and quality of life in RTT. OBJECTIVE The aim of the study was to evaluate the feasibility and health-related effects of an individualized 12-week uptime participation (U-PART) intervention in girls and women with RTT. DESIGN The study used a single-group pretest-posttest design with 4 assessments (2 baseline, postintervention, and follow-up). METHODS A participation-based intervention employing a whole-day approach was used. During a 12-week intervention period, individualized programs focused on participation in enjoyable uptime activities in home, school/day center, and community settings. Feasibility was assessed with a study-specific questionnaire. Primary outcome measures were sedentary time and daily step count. Secondary outcomes were gross motor skills, walking capacity, quality of life, and goal attainment scaling. RESULTS Fourteen girls and women who were 5 to 48 years old and had RTT participated. The U-PART intervention was perceived as feasible by caregivers. Similar scores were observed at baseline assessments in all outcomes. Positive effects with small to medium effect sizes (0.27-0.54) were seen in sedentary time (- 4%), daily step count (+ 689 steps/d), walking capacity (+ 18.8 m), quality of life (+ 2.75 points), and goal attainment scaling after the intervention. Positive effects were maintained in sedentary time (- 3.2%) and walking capacity (+ 12.1 m) at short-term follow-up. LIMITATIONS This study was limited by the lack of a control group. However, participants acted as their own control, and the stable baseline period partially mitigated this issue. CONCLUSIONS The U-PART intervention was found to be feasible and effective in the short term in girls and women with RTT.
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Affiliation(s)
- Michelle Stahlhut
- Department of Paediatrics and Adolescent Medicine, Center for Rett Syndrome, Copenhagen, Denmark; and Faculty of Medicine, Health Sciences Center, Lund University, Lund, Sweden
| | - Jenny Downs
- University of Western Australia, Perth, Western Australia, Australia; and School of Physiotherapy and Exercise Science, Curtin University, Perth, Western Australia, Australia
| | | | | | - Eva Nordmark
- Faculty of Medicine, Health Sciences Center, Lund University
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Tang BL. The Expanding Therapeutic Potential of Neuronal KCC2. Cells 2020; 9:E240. [PMID: 31963584 PMCID: PMC7016893 DOI: 10.3390/cells9010240] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Revised: 01/09/2020] [Accepted: 01/16/2020] [Indexed: 02/06/2023] Open
Abstract
Dysfunctions in GABAergic inhibitory neural transmission occur in neuronal injuries and neurological disorders. The potassium-chloride cotransporter 2 (KCC2, SLC12A5) is a key modulator of inhibitory GABAergic inputs in healthy adult neurons, as its chloride (Cl-) extruding activity underlies the hyperpolarizing reversal potential for GABAA receptor Cl- currents (EGABA). Manipulation of KCC2 levels or activity improve symptoms associated with epilepsy and neuropathy. Recent works have now indicated that pharmacological enhancement of KCC2 function could reactivate dormant relay circuits in an injured mouse's spinal cord, leading to functional recovery and the attenuation of neuronal abnormality and disease phenotype associated with a mouse model of Rett syndrome (RTT). KCC2 interacts with Huntingtin and is downregulated in Huntington's disease (HD), which contributed to GABAergic excitation and memory deficits in the R6/2 mouse HD model. Here, these recent advances are highlighted, which attest to KCC2's growing potential as a therapeutic target for neuropathological conditions resulting from dysfunctional inhibitory input.
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Affiliation(s)
- Bor Luen Tang
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117596, Singapore; ; Tel.: +65-6516-1040
- NUS Graduate School for Integrative Sciences and Engineering, National University of Singapore, Singapore 119077, Singapore
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76
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Pereira JLP, Pedroso JL, Barsottini OGP, Meira AT, Teive HAG. Rett syndrome: the Brazilian contribution to the gene discovery. ARQUIVOS DE NEURO-PSIQUIATRIA 2020; 77:896-899. [PMID: 31939587 DOI: 10.1590/0004-282x20190110] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2018] [Accepted: 03/20/2019] [Indexed: 11/21/2022]
Abstract
OBJECTIVE A brief history of the syndrome discovered by Andreas Rett is reported in this paper. METHODS Although having been described in 1966, the syndrome was only recognized by the international community after a report by Hagberg et al. in 1983. Soon, its importance was evident as a relatively frequent cause of severe encephalopathy among girls. CONCLUSION From the beginning it was difficult to explain the absence of male patients and the almost total predominance of sporadic cases (99%), with very few familial cases. For these reasons, it was particularly difficult to investigate this condition until 1997, when a particular Brazilian family greatly helped in the final discovery of the gene, and in the clarification of its genetic mechanism. RESULTS Brief references are made to the importance of the MECP2 gene, 18 years later, as well as to its role in synaptogenesis and future prospects.
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Affiliation(s)
- José Luiz Pinto Pereira
- Prefeitura Municipal de Curitiba, Serviço de Atendimento Móvel de Urgência (SAMU), Curitiba PR, Brasil.,Hospital John Hopkins, Investigações Genéticas (1999-2000), EUA.,Instituto Kennedy Krieger, Investigações Genéticas (1999-2000), EUA
| | - José Luiz Pedroso
- Universidade Federal de São Paulo, Departamento de Neurologia, São Paulo SP, Brasil
| | | | - Alex Tiburtino Meira
- Universidade Federal do Paraná, Departamento de Medicina Interna, Serviço de Neurologia, Curitiba PR, Brasil
| | - Hélio A G Teive
- Universidade Federal do Paraná, Departamento de Medicina Interna, Serviço de Neurologia, Curitiba PR, Brasil
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77
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Comprehensive Analysis of GABA A-A1R Developmental Alterations in Rett Syndrome: Setting the Focus for Therapeutic Targets in the Time Frame of the Disease. Int J Mol Sci 2020; 21:ijms21020518. [PMID: 31947619 PMCID: PMC7014188 DOI: 10.3390/ijms21020518] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2019] [Revised: 01/03/2020] [Accepted: 01/10/2020] [Indexed: 02/08/2023] Open
Abstract
Rett syndrome, a serious neurodevelopmental disorder, has been associated with an altered expression of different synaptic-related proteins and aberrant glutamatergic and γ-aminobutyric acid (GABA)ergic neurotransmission. Despite its severity, it lacks a therapeutic option. Through this work we aimed to define the relationship between MeCP2 and GABAA.-A1 receptor expression, emphasizing the time dependence of such relationship. For this, we analyzed the expression of the ionotropic receptor subunit in different MeCP2 gene-dosage and developmental conditions, in cells lines, and in primary cultured neurons, as well as in different developmental stages of a Rett mouse model. Further, RNAseq and systems biology analysis was performed from post-mortem brain biopsies of Rett patients. We observed that the modulation of the MeCP2 expression in cellular models (both Neuro2a (N2A) cells and primary neuronal cultures) revealed a MeCP2 positive effect on the GABAA.-A1 receptor subunit expression, which did not occur in other proteins such as KCC2 (Potassium-chloride channel, member 5). In the Mecp2+/− mouse brain, both the KCC2 and GABA subunits expression were developmentally regulated, with a decreased expression during the pre-symptomatic stage, while the expression was variable in the adult symptomatic mice. Finally, the expression of the gamma-aminobutyric acid (GABA) receptor-related synaptic proteins from the postmortem brain biopsies of two Rett patients was evaluated, specifically revealing the GABA A1R subunit overexpression. The identification of the molecular changes along with the Rett syndrome prodromic stages strongly endorses the importance of time frame when addressing this disease, supporting the need for a neurotransmission-targeted early therapeutic intervention.
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Yamada J, Jinno S. Promotion of synaptogenesis and neural circuit development by exosomes. ANNALS OF TRANSLATIONAL MEDICINE 2019; 7:S323. [PMID: 32016041 DOI: 10.21037/atm.2019.09.154] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
- Jun Yamada
- Department of Anatomy and Neuroscience, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Shozo Jinno
- Department of Anatomy and Neuroscience, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
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Lavery LA, Zoghbi HY. The distinct methylation landscape of maturing neurons and its role in Rett syndrome pathogenesis. Curr Opin Neurobiol 2019; 59:180-188. [PMID: 31542590 PMCID: PMC6892602 DOI: 10.1016/j.conb.2019.08.001] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2019] [Accepted: 08/21/2019] [Indexed: 02/06/2023]
Abstract
Rett syndrome (RTT) is one of the most common causes of intellectual and developmental disabilities in girls, and is caused by mutations in the gene encoding methyl-CpG binding protein 2 (MECP2). Here we will review our current understanding of RTT, the landscape of pathogenic mutations and function of MeCP2, and culminate with recent advances elucidating the distinct DNA methylation landscape in the brain that may explain why disease symptoms are delayed and selective to the nervous system.
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Affiliation(s)
- Laura A Lavery
- Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, TX 77030, USA; Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Huda Y Zoghbi
- Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, TX 77030, USA; Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA; Program in Developmental Biology, Baylor College of Medicine, Houston, TX 77030, USA; Department of Pediatrics, Baylor College of Medicine, Houston, TX 77030, USA; Department of Neuroscience, Baylor College of Medicine, Houston, TX 77030, USA; Howard Hughes Medical Institute, Baylor College of Medicine, Houston, TX 77030, USA.
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80
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Sysoeva OV, Smirnov K, Stroganova TA. Sensory evoked potentials in patients with Rett syndrome through the lens of animal studies: Systematic review. Clin Neurophysiol 2019; 131:213-224. [PMID: 31812082 DOI: 10.1016/j.clinph.2019.11.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Revised: 11/07/2019] [Accepted: 11/11/2019] [Indexed: 01/04/2023]
Abstract
OBJECTIVE Systematically review the abnormalities in event related potential (ERP) recorded in Rett Syndrome (RTT) patients and animals in search of translational biomarkers of deficits related to the particular neurophysiological processes of known genetic origin (MECP2 mutations). METHODS Pubmed, ISI Web of Knowledge and BIORXIV were searched for the relevant articles according to PRISMA standards. RESULTS ERP components are generally delayed across all sensory modalities both in RTT patients and its animal model, while findings on ERPs amplitude strongly depend on stimulus properties and presentation rate. Studies on RTT animal models uncovered the abnormalities in the excitatory and inhibitory transmission as critical mechanisms underlying the ERPs changes, but showed that even similar ERP alterations in auditory and visual domains have a diverse neural basis. A range of novel approaches has been developed in animal studies bringing along the meaningful neurophysiological interpretation of ERP measures in RTT patients. CONCLUSIONS While there is a clear evidence for sensory ERPs abnormalities in RTT, to further advance the field there is a need in a large-scale ERP studies with the functionally-relevant experimental paradigms. SIGNIFICANCE The review provides insights into domain-specific neural basis of the ERP abnormalities and promotes clinical application of the ERP measures as the non-invasive functional biomarkers of RTT pathophysiology.
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Affiliation(s)
- Olga V Sysoeva
- The Cognitive Neurophysiology Laboratory, Department of Pediatrics, Albert Einstein College of Medicine & Montefiore Medical Center, Bronx, New York, USA; The Cognitive Neurophysiology Laboratory, Ernest J. Del Monte Institute for Neuroscience, Department of Neuroscience, University of Rochester School of Medicine and Dentistry, Rochester, New York, USA; The Laboratory of Human Higher Nervous Activity, Institute of Higher Nervous Activity and Neurophysiology, Russian Academy of Sciences, Moscow, Russia.
| | - Kirill Smirnov
- Department of Neuroontogenesis, Institute of Higher Nervous Activity and Neurophysiology, Russian Academy of Science, Moscow, Russia.
| | - Tatiana A Stroganova
- Center for Neurocognitive Research (MEG-Center), Moscow State University of Psychology and Education (MSUPE), Moscow, Russia; Autism Research Laboratory, Moscow State University of Psychology and Education (MSUPE), Moscow, Russia.
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81
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A New Scale to Evaluate Motor Function in Rett Syndrome: Validation and Psychometric Properties. Pediatr Neurol 2019; 100:80-86. [PMID: 31047758 DOI: 10.1016/j.pediatrneurol.2019.03.005] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/07/2018] [Revised: 03/04/2019] [Accepted: 03/06/2019] [Indexed: 01/18/2023]
Abstract
BACKGROUND We aim to describe and psychometrically validate the Rett Syndrome Motor Evaluation Scale, a 25-item ordinal scale examining (loco-)motor function across six sections: standing, sitting, transitions, walking, running, and walking up or downstairs. METHODS We illustrate the process of item construction and validation, report findings and normative data obtained on a standardization sample of 60 patients with Rett syndrome. We investigate the validity and reliability of the scale and illustrate its psychometric properties using modern multivariate techniques of data analysis. RESULTS Sixty patients with Rett syndrome were included (all female; mean age 12.45 (S.D. 8.75) years). The multidimensional latent structure of the scale was supported by the results of the confirmatory factor analysis. Rett Syndrome Motor Evaluation Scale showed strong internal consistency reliability as well as excellent inter-rater agreement. The Rett Syndrome Motor Evaluation Scale scores were not predicted by age, but were associated with disease severity, degree of spasticity, and hand dysfunction. We also identified three latent classes with different degrees of impairment. CONCLUSIONS Rett Syndrome Motor Evaluation Scale is a new, valid, and reliable scale that can be introduced in clinical practice when assessing (loco-)motor function in Rett syndrome.
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Marano D, Fioriniello S, Fiorillo F, Gibbons RJ, D'Esposito M, Della Ragione F. ATRX Contributes to MeCP2-Mediated Pericentric Heterochromatin Organization during Neural Differentiation. Int J Mol Sci 2019; 20:E5371. [PMID: 31671722 PMCID: PMC6862095 DOI: 10.3390/ijms20215371] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Accepted: 10/24/2019] [Indexed: 11/16/2022] Open
Abstract
Methyl-CpG binding protein 2 (MeCP2) is a multi-function factor involved in locus-specific transcriptional modulation and the regulation of genome architecture, e.g., pericentric heterochromatin (PCH) organization. MECP2 mutations are responsible for Rett syndrome (RTT), a devastating postnatal neurodevelopmental disorder, the pathogenetic mechanisms of which are still unknown. MeCP2, together with Alpha-thalassemia/mental retardation syndrome X-linked protein (ATRX), accumulates at chromocenters, which are repressive PCH domains. As with MECP2, mutations in ATRX cause ATR-X syndrome which is associated with severe intellectual disability. We exploited two murine embryonic stem cell lines, in which the expression of MeCP2 or ATRX is abolished. Through immunostaining, chromatin immunoprecipitation and western blot, we show that MeCP2 and ATRX are reciprocally dependent both for their expression and targeting to chromocenters. Moreover, ATRX plays a role in the accumulation of members of the heterochromatin protein 1 (HP1) family at PCH and, as MeCP2, modulates their expression. Furthermore, ATRX and HP1 targeting to chromocenters depends on an RNA component. 3D-DNA fluorescence in situ hybridization (FISH) highlighted, for the first time, a contribution of ATRX in MeCP2-mediated chromocenter clustering during neural differentiation. Overall, we provide a detailed dissection of the functional interplay between MeCP2 and ATRX in higher-order PCH organization in neurons. Our findings suggest molecular defects common to RTT and ATR-X syndrome, including an alteration in PCH.
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Affiliation(s)
- Domenico Marano
- Institute of Genetics and Biophysics 'A. Buzzati-Traverso', National Research Council (CNR), 80131 Naples, Italy.
| | - Salvatore Fioriniello
- Institute of Genetics and Biophysics 'A. Buzzati-Traverso', National Research Council (CNR), 80131 Naples, Italy.
| | - Francesca Fiorillo
- Institute of Genetics and Biophysics 'A. Buzzati-Traverso', National Research Council (CNR), 80131 Naples, Italy.
| | - Richard J Gibbons
- MRC Molecular Haematology Unit, MRC Weatherall Institute of Molecular Medicine, University of Oxford, Oxford OX3 9DS, UK.
| | - Maurizio D'Esposito
- Institute of Genetics and Biophysics 'A. Buzzati-Traverso', National Research Council (CNR), 80131 Naples, Italy.
| | - Floriana Della Ragione
- Institute of Genetics and Biophysics 'A. Buzzati-Traverso', National Research Council (CNR), 80131 Naples, Italy.
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Cortelazzo A, De Felice C, Guy J, Timperio AM, Zolla L, Guerranti R, Leoncini S, Signorini C, Durand T, Hayek J. Brain protein changes in Mecp2 mouse mutant models: Effects on disease progression of Mecp2 brain specific gene reactivation. J Proteomics 2019; 210:103537. [PMID: 31629059 DOI: 10.1016/j.jprot.2019.103537] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Revised: 09/10/2019] [Accepted: 09/27/2019] [Indexed: 12/29/2022]
Abstract
Rett syndrome (RTT) is a leading cause of severe intellectual disability in females, caused by de novo loss-of function mutations in the X-linked methyl-CpG binding protein 2 (MECP2). To better investigate RTT disease progression/pathogenesis animal models of Mecp2 deficiency have been developed. Here, Mecp2 mouse models are employed to investigate the role of protein patterns in RTT. A proteome analysis was carried out in brain tissue from i) Mecp2 deficient mice at the pre-symptomatic and symptomatic stages and, ii) mice in which the disease phenotype was reversed by Mecp2 reactivation. Several proteins were shown to be differentially expressed in the pre-symptomatic (n = 18) and symptomatic (n = 20) mice. Mecp2 brain reactivated mice showed wild-type comparable levels of expression for twelve proteins, mainly related to proteostasis (n = 4) and energy metabolic pathways (n = 4). The remaining ones were found to be involved in redox homeostasis (n = 2), nitric oxide regulation (n = 1), neurodevelopment (n = 1). Ten out of twelve proteins were newly linked to Mecp2 deficiency. Our study sheds light on the relevance of the protein-regulation of main physiological process in the complex mechanisms leading from Mecp2 mutation to the RTT clinical phenotype. SIGNIFICANCE: We performed a proteomic study of a Mecp2stop/y mouse model for Rett syndrome (RTT) at the pre-symptomatic and symptomatic Mecp2 deficient mice stage and for the brain specific reactivated Mecp2 model. Our results reveal major protein expression changes pointing out to defects in proteostasis or energy metabolic pathways other than, to a lesser extent, in redox homeostasis, nitric oxide regulation or neurodevelopment. The Mecp2 mouse rescued model provides the possibility to select target proteins more susceptible to the Mecp2 gene mutation, potential and promising therapeutical targets.
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Affiliation(s)
- Alessio Cortelazzo
- Child Neuropsychiatry Unit, University Hospital, Azienda Ospedaliera Universitaria Senese (AOUS), Siena, Italy; Department of Medical Biotechnologies, University of Siena, Siena, Italy; Clinical Pathology Laboratory Unit, University Hospital, AOUS, Siena, Italy.
| | - Claudio De Felice
- Neonatal Intensive Care Unit, University Hospital, AOUS, Siena, Italy
| | - Jacky Guy
- Wellcome Centre for Cell Biology, University of Edinburgh, Edinburgh, UK
| | - Anna Maria Timperio
- Department of Ecological and Biological Sciences, University of Tuscia, Viterbo, Italy
| | - Lello Zolla
- Department of Ecological and Biological Sciences, University of Tuscia, Viterbo, Italy
| | - Roberto Guerranti
- Department of Medical Biotechnologies, University of Siena, Siena, Italy; Clinical Pathology Laboratory Unit, University Hospital, AOUS, Siena, Italy
| | - Silvia Leoncini
- Child Neuropsychiatry Unit, University Hospital, Azienda Ospedaliera Universitaria Senese (AOUS), Siena, Italy; Department of Molecular and Developmental Medicine, University of Siena, Siena, Italy
| | - Cinzia Signorini
- Department of Molecular and Developmental Medicine, University of Siena, Siena, Italy
| | - Thierry Durand
- Institut des Biomolécules Max Mousseron, (IBMM), UMR 5247, CNRS, Université de Montpellier, ENSCM, Montpellier, France
| | - Joussef Hayek
- Child Neuropsychiatry Unit, University Hospital, Azienda Ospedaliera Universitaria Senese (AOUS), Siena, Italy
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Balogh R, Leonard H, Bourke J, Brameld K, Downs J, Hansen M, Glasson E, Lin E, Lloyd M, Lunsky Y, O'Donnell M, Shooshtari S, Wong K, Krahn G. Data Linkage: Canadian and Australian Perspectives on a Valuable Methodology for Intellectual and Developmental Disability Research. INTELLECTUAL AND DEVELOPMENTAL DISABILITIES 2019; 57:439-462. [PMID: 31568733 DOI: 10.1352/1934-9556-57.5.439] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Data linkage holds great promise for generating new information about people with intellectual and developmental disabilities (IDD) as a population, yet few centers have developed the infrastructure to utilize this methodology. Two examples, from Canada and Australia, describe their efforts in building data linkage capabilities, and how linked databases can be used to identify persons with IDD and used for population-based research. The value of data linkage is illustrated through new estimates of prevalence of IDD; health service utilization patterns; associations with sociodemographic characteristics, and with physical and mental health conditions (e.g., chronic diseases, injury, fertility, and depression); and findings on equity in medical treatments. Examples are provided of findings used for governmental policy and program planning.
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Affiliation(s)
- Robert Balogh
- Robert Balogh, Ontario Tech University, Oshawa, Ontario, Canada; Helen Leonard and Jenny Bourke, Telethon Kids Institute, The University of Western Australia, Perth; Kate Brameld, Curtin University, Perth, Western Australia; Jenny Downs, Michele Hansen, and Emma Glasson, Telethon Kids Institute, The University of Western Australia, Perth; Elizabeth Lin, Centre for Addiction and Mental Health, Toronto, Ontario, Canada; Meghann Lloyd, Ontario Tech University, Oshawa, Ontario, Canada; Yona Lunsky, Centre for Addiction and Mental Health, Toronto, Ontario, Canada; Melissa O'Donnell, Telethon Kids Institute, The University of Western Australia, Perth; Shahin Shooshtari, University of Manitoba, Winnipeg, Manitoba, Canada; Kingsley Wong, Telethon Kids Institute, The University of Western Australia, Perth; and Gloria Krahn, Oregon State University, Corvallis
| | - Helen Leonard
- Robert Balogh, Ontario Tech University, Oshawa, Ontario, Canada; Helen Leonard and Jenny Bourke, Telethon Kids Institute, The University of Western Australia, Perth; Kate Brameld, Curtin University, Perth, Western Australia; Jenny Downs, Michele Hansen, and Emma Glasson, Telethon Kids Institute, The University of Western Australia, Perth; Elizabeth Lin, Centre for Addiction and Mental Health, Toronto, Ontario, Canada; Meghann Lloyd, Ontario Tech University, Oshawa, Ontario, Canada; Yona Lunsky, Centre for Addiction and Mental Health, Toronto, Ontario, Canada; Melissa O'Donnell, Telethon Kids Institute, The University of Western Australia, Perth; Shahin Shooshtari, University of Manitoba, Winnipeg, Manitoba, Canada; Kingsley Wong, Telethon Kids Institute, The University of Western Australia, Perth; and Gloria Krahn, Oregon State University, Corvallis
| | - Jenny Bourke
- Robert Balogh, Ontario Tech University, Oshawa, Ontario, Canada; Helen Leonard and Jenny Bourke, Telethon Kids Institute, The University of Western Australia, Perth; Kate Brameld, Curtin University, Perth, Western Australia; Jenny Downs, Michele Hansen, and Emma Glasson, Telethon Kids Institute, The University of Western Australia, Perth; Elizabeth Lin, Centre for Addiction and Mental Health, Toronto, Ontario, Canada; Meghann Lloyd, Ontario Tech University, Oshawa, Ontario, Canada; Yona Lunsky, Centre for Addiction and Mental Health, Toronto, Ontario, Canada; Melissa O'Donnell, Telethon Kids Institute, The University of Western Australia, Perth; Shahin Shooshtari, University of Manitoba, Winnipeg, Manitoba, Canada; Kingsley Wong, Telethon Kids Institute, The University of Western Australia, Perth; and Gloria Krahn, Oregon State University, Corvallis
| | - Kate Brameld
- Robert Balogh, Ontario Tech University, Oshawa, Ontario, Canada; Helen Leonard and Jenny Bourke, Telethon Kids Institute, The University of Western Australia, Perth; Kate Brameld, Curtin University, Perth, Western Australia; Jenny Downs, Michele Hansen, and Emma Glasson, Telethon Kids Institute, The University of Western Australia, Perth; Elizabeth Lin, Centre for Addiction and Mental Health, Toronto, Ontario, Canada; Meghann Lloyd, Ontario Tech University, Oshawa, Ontario, Canada; Yona Lunsky, Centre for Addiction and Mental Health, Toronto, Ontario, Canada; Melissa O'Donnell, Telethon Kids Institute, The University of Western Australia, Perth; Shahin Shooshtari, University of Manitoba, Winnipeg, Manitoba, Canada; Kingsley Wong, Telethon Kids Institute, The University of Western Australia, Perth; and Gloria Krahn, Oregon State University, Corvallis
| | - Jenny Downs
- Robert Balogh, Ontario Tech University, Oshawa, Ontario, Canada; Helen Leonard and Jenny Bourke, Telethon Kids Institute, The University of Western Australia, Perth; Kate Brameld, Curtin University, Perth, Western Australia; Jenny Downs, Michele Hansen, and Emma Glasson, Telethon Kids Institute, The University of Western Australia, Perth; Elizabeth Lin, Centre for Addiction and Mental Health, Toronto, Ontario, Canada; Meghann Lloyd, Ontario Tech University, Oshawa, Ontario, Canada; Yona Lunsky, Centre for Addiction and Mental Health, Toronto, Ontario, Canada; Melissa O'Donnell, Telethon Kids Institute, The University of Western Australia, Perth; Shahin Shooshtari, University of Manitoba, Winnipeg, Manitoba, Canada; Kingsley Wong, Telethon Kids Institute, The University of Western Australia, Perth; and Gloria Krahn, Oregon State University, Corvallis
| | - Michele Hansen
- Robert Balogh, Ontario Tech University, Oshawa, Ontario, Canada; Helen Leonard and Jenny Bourke, Telethon Kids Institute, The University of Western Australia, Perth; Kate Brameld, Curtin University, Perth, Western Australia; Jenny Downs, Michele Hansen, and Emma Glasson, Telethon Kids Institute, The University of Western Australia, Perth; Elizabeth Lin, Centre for Addiction and Mental Health, Toronto, Ontario, Canada; Meghann Lloyd, Ontario Tech University, Oshawa, Ontario, Canada; Yona Lunsky, Centre for Addiction and Mental Health, Toronto, Ontario, Canada; Melissa O'Donnell, Telethon Kids Institute, The University of Western Australia, Perth; Shahin Shooshtari, University of Manitoba, Winnipeg, Manitoba, Canada; Kingsley Wong, Telethon Kids Institute, The University of Western Australia, Perth; and Gloria Krahn, Oregon State University, Corvallis
| | - Emma Glasson
- Robert Balogh, Ontario Tech University, Oshawa, Ontario, Canada; Helen Leonard and Jenny Bourke, Telethon Kids Institute, The University of Western Australia, Perth; Kate Brameld, Curtin University, Perth, Western Australia; Jenny Downs, Michele Hansen, and Emma Glasson, Telethon Kids Institute, The University of Western Australia, Perth; Elizabeth Lin, Centre for Addiction and Mental Health, Toronto, Ontario, Canada; Meghann Lloyd, Ontario Tech University, Oshawa, Ontario, Canada; Yona Lunsky, Centre for Addiction and Mental Health, Toronto, Ontario, Canada; Melissa O'Donnell, Telethon Kids Institute, The University of Western Australia, Perth; Shahin Shooshtari, University of Manitoba, Winnipeg, Manitoba, Canada; Kingsley Wong, Telethon Kids Institute, The University of Western Australia, Perth; and Gloria Krahn, Oregon State University, Corvallis
| | - Elizabeth Lin
- Robert Balogh, Ontario Tech University, Oshawa, Ontario, Canada; Helen Leonard and Jenny Bourke, Telethon Kids Institute, The University of Western Australia, Perth; Kate Brameld, Curtin University, Perth, Western Australia; Jenny Downs, Michele Hansen, and Emma Glasson, Telethon Kids Institute, The University of Western Australia, Perth; Elizabeth Lin, Centre for Addiction and Mental Health, Toronto, Ontario, Canada; Meghann Lloyd, Ontario Tech University, Oshawa, Ontario, Canada; Yona Lunsky, Centre for Addiction and Mental Health, Toronto, Ontario, Canada; Melissa O'Donnell, Telethon Kids Institute, The University of Western Australia, Perth; Shahin Shooshtari, University of Manitoba, Winnipeg, Manitoba, Canada; Kingsley Wong, Telethon Kids Institute, The University of Western Australia, Perth; and Gloria Krahn, Oregon State University, Corvallis
| | - Meghann Lloyd
- Robert Balogh, Ontario Tech University, Oshawa, Ontario, Canada; Helen Leonard and Jenny Bourke, Telethon Kids Institute, The University of Western Australia, Perth; Kate Brameld, Curtin University, Perth, Western Australia; Jenny Downs, Michele Hansen, and Emma Glasson, Telethon Kids Institute, The University of Western Australia, Perth; Elizabeth Lin, Centre for Addiction and Mental Health, Toronto, Ontario, Canada; Meghann Lloyd, Ontario Tech University, Oshawa, Ontario, Canada; Yona Lunsky, Centre for Addiction and Mental Health, Toronto, Ontario, Canada; Melissa O'Donnell, Telethon Kids Institute, The University of Western Australia, Perth; Shahin Shooshtari, University of Manitoba, Winnipeg, Manitoba, Canada; Kingsley Wong, Telethon Kids Institute, The University of Western Australia, Perth; and Gloria Krahn, Oregon State University, Corvallis
| | - Yona Lunsky
- Robert Balogh, Ontario Tech University, Oshawa, Ontario, Canada; Helen Leonard and Jenny Bourke, Telethon Kids Institute, The University of Western Australia, Perth; Kate Brameld, Curtin University, Perth, Western Australia; Jenny Downs, Michele Hansen, and Emma Glasson, Telethon Kids Institute, The University of Western Australia, Perth; Elizabeth Lin, Centre for Addiction and Mental Health, Toronto, Ontario, Canada; Meghann Lloyd, Ontario Tech University, Oshawa, Ontario, Canada; Yona Lunsky, Centre for Addiction and Mental Health, Toronto, Ontario, Canada; Melissa O'Donnell, Telethon Kids Institute, The University of Western Australia, Perth; Shahin Shooshtari, University of Manitoba, Winnipeg, Manitoba, Canada; Kingsley Wong, Telethon Kids Institute, The University of Western Australia, Perth; and Gloria Krahn, Oregon State University, Corvallis
| | - Melissa O'Donnell
- Robert Balogh, Ontario Tech University, Oshawa, Ontario, Canada; Helen Leonard and Jenny Bourke, Telethon Kids Institute, The University of Western Australia, Perth; Kate Brameld, Curtin University, Perth, Western Australia; Jenny Downs, Michele Hansen, and Emma Glasson, Telethon Kids Institute, The University of Western Australia, Perth; Elizabeth Lin, Centre for Addiction and Mental Health, Toronto, Ontario, Canada; Meghann Lloyd, Ontario Tech University, Oshawa, Ontario, Canada; Yona Lunsky, Centre for Addiction and Mental Health, Toronto, Ontario, Canada; Melissa O'Donnell, Telethon Kids Institute, The University of Western Australia, Perth; Shahin Shooshtari, University of Manitoba, Winnipeg, Manitoba, Canada; Kingsley Wong, Telethon Kids Institute, The University of Western Australia, Perth; and Gloria Krahn, Oregon State University, Corvallis
| | - Shahin Shooshtari
- Robert Balogh, Ontario Tech University, Oshawa, Ontario, Canada; Helen Leonard and Jenny Bourke, Telethon Kids Institute, The University of Western Australia, Perth; Kate Brameld, Curtin University, Perth, Western Australia; Jenny Downs, Michele Hansen, and Emma Glasson, Telethon Kids Institute, The University of Western Australia, Perth; Elizabeth Lin, Centre for Addiction and Mental Health, Toronto, Ontario, Canada; Meghann Lloyd, Ontario Tech University, Oshawa, Ontario, Canada; Yona Lunsky, Centre for Addiction and Mental Health, Toronto, Ontario, Canada; Melissa O'Donnell, Telethon Kids Institute, The University of Western Australia, Perth; Shahin Shooshtari, University of Manitoba, Winnipeg, Manitoba, Canada; Kingsley Wong, Telethon Kids Institute, The University of Western Australia, Perth; and Gloria Krahn, Oregon State University, Corvallis
| | - Kingsley Wong
- Robert Balogh, Ontario Tech University, Oshawa, Ontario, Canada; Helen Leonard and Jenny Bourke, Telethon Kids Institute, The University of Western Australia, Perth; Kate Brameld, Curtin University, Perth, Western Australia; Jenny Downs, Michele Hansen, and Emma Glasson, Telethon Kids Institute, The University of Western Australia, Perth; Elizabeth Lin, Centre for Addiction and Mental Health, Toronto, Ontario, Canada; Meghann Lloyd, Ontario Tech University, Oshawa, Ontario, Canada; Yona Lunsky, Centre for Addiction and Mental Health, Toronto, Ontario, Canada; Melissa O'Donnell, Telethon Kids Institute, The University of Western Australia, Perth; Shahin Shooshtari, University of Manitoba, Winnipeg, Manitoba, Canada; Kingsley Wong, Telethon Kids Institute, The University of Western Australia, Perth; and Gloria Krahn, Oregon State University, Corvallis
| | - Gloria Krahn
- Robert Balogh, Ontario Tech University, Oshawa, Ontario, Canada; Helen Leonard and Jenny Bourke, Telethon Kids Institute, The University of Western Australia, Perth; Kate Brameld, Curtin University, Perth, Western Australia; Jenny Downs, Michele Hansen, and Emma Glasson, Telethon Kids Institute, The University of Western Australia, Perth; Elizabeth Lin, Centre for Addiction and Mental Health, Toronto, Ontario, Canada; Meghann Lloyd, Ontario Tech University, Oshawa, Ontario, Canada; Yona Lunsky, Centre for Addiction and Mental Health, Toronto, Ontario, Canada; Melissa O'Donnell, Telethon Kids Institute, The University of Western Australia, Perth; Shahin Shooshtari, University of Manitoba, Winnipeg, Manitoba, Canada; Kingsley Wong, Telethon Kids Institute, The University of Western Australia, Perth; and Gloria Krahn, Oregon State University, Corvallis
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85
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Inui T, Iwama K, Miyabayashi T, Sato R, Okubo Y, Endo W, Togashi N, Kakisaka Y, Kikuchi A, Mizuguchi T, Kure S, Matsumoto N, Haginoya K. Two males with sick sinus syndrome in a family with 0.6 kb deletions involving major domains in MECP2. Eur J Med Genet 2019; 63:103769. [PMID: 31536832 DOI: 10.1016/j.ejmg.2019.103769] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2019] [Revised: 09/05/2019] [Accepted: 09/15/2019] [Indexed: 10/26/2022]
Abstract
Mutations in methyl-CpG-binding protein 2 (MECP2) in males can lead to various phenotypes, ranging from neonatal encephalopathy to intellectual disability. In this study, using Nord's method of next-generation sequencing in three siblings, we identified a 0.6 kb deletion involving the transcriptional repression domain (TRD). Two males and one female had intellectual disability and apnea, but none met the criteria of Rett syndrome. Both males had sick sinus syndrome and severe tracheomalacia that resulted in early death. The mother, with skewed X-inactivation, had no symptoms. Therefore, this mutation is pathological for both males and females, resulting in sick sinus syndrome and severe tracheomalacia with strong reproducibility in males. Deletions involving major domains in MECP2 can result in a severe phenotype, and deletion of the TRD domain can cause severe autonomic nervous system dysregulation in males in these cases.
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Affiliation(s)
- Takehiko Inui
- Department of Pediatric Neurology, Miyagi Children's Hospital, 4-3-17 Ochiai, Aoba-ku, Sendai-shi, Miyagi, 989-3126, Japan.
| | - Kazuhiro Iwama
- Department of Human Genetics, Graduate School of Medicine, Yokohama City University, Yokohama, Japan; Department of Pediatrics, Graduate School of Medicine, Yokohama City University, Yokohama, Japan
| | - Takuya Miyabayashi
- Department of Pediatric Neurology, Miyagi Children's Hospital, 4-3-17 Ochiai, Aoba-ku, Sendai-shi, Miyagi, 989-3126, Japan
| | - Ryo Sato
- Department of Pediatric Neurology, Miyagi Children's Hospital, 4-3-17 Ochiai, Aoba-ku, Sendai-shi, Miyagi, 989-3126, Japan
| | - Yukimune Okubo
- Department of Pediatric Neurology, Miyagi Children's Hospital, 4-3-17 Ochiai, Aoba-ku, Sendai-shi, Miyagi, 989-3126, Japan
| | - Wakaba Endo
- Department of Pediatrics, Tohoku University School of Medicine, Sendai, Japan
| | - Noriko Togashi
- Department of Pediatric Neurology, Miyagi Children's Hospital, 4-3-17 Ochiai, Aoba-ku, Sendai-shi, Miyagi, 989-3126, Japan
| | - Yosuke Kakisaka
- Department of Pediatrics, Tohoku University School of Medicine, Sendai, Japan
| | - Atsuo Kikuchi
- Department of Pediatrics, Tohoku University School of Medicine, Sendai, Japan
| | - Takeshi Mizuguchi
- Department of Human Genetics, Graduate School of Medicine, Yokohama City University, Yokohama, Japan
| | - Shigeo Kure
- Department of Pediatrics, Tohoku University School of Medicine, Sendai, Japan
| | - Naomichi Matsumoto
- Department of Human Genetics, Graduate School of Medicine, Yokohama City University, Yokohama, Japan
| | - Kazuhiro Haginoya
- Department of Pediatric Neurology, Miyagi Children's Hospital, 4-3-17 Ochiai, Aoba-ku, Sendai-shi, Miyagi, 989-3126, Japan; Department of Pediatrics, Tohoku University School of Medicine, Sendai, Japan
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86
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Banerjee A, Miller MT, Li K, Sur M, Kaufmann WE. Towards a better diagnosis and treatment of Rett syndrome: a model synaptic disorder. Brain 2019; 142:239-248. [PMID: 30649225 DOI: 10.1093/brain/awy323] [Citation(s) in RCA: 65] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2018] [Accepted: 10/31/2018] [Indexed: 12/21/2022] Open
Abstract
With the recent 50th anniversary of the first publication on Rett syndrome, and the almost 20 years since the first report on the link between Rett syndrome and MECP2 mutations, it is important to reflect on the tremendous advances in our understanding and their implications for the diagnosis and treatment of this neurodevelopmental disorder. Rett syndrome features an interesting challenge for biologists and clinicians, as the disorder lies at the intersection of molecular mechanisms of epigenetic regulation and neurophysiological alterations in synapses and circuits that together contribute to severe pathophysiological endophenotypes. Genetic, clinical, and neurobiological evidences support the notion that Rett syndrome is primarily a synaptic disorder, and a disease model for both intellectual disability and autism spectrum disorder. This review examines major developments in both recent neurobiological and preclinical findings of Rett syndrome, and to what extent they are beginning to impact our understanding and management of the disorder. It also discusses potential applications of knowledge on synaptic plasticity abnormalities in Rett syndrome to its diagnosis and treatment.
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Affiliation(s)
- Abhishek Banerjee
- Laboratory of Neural Circuit Dynamics, Brain Research Institute, University of Zürich, Zürich, Switzerland
| | - Meghan T Miller
- Roche Pharma Research and Early Development, Roche Innovation Center, F. Hoffman-La Roche, Basel, Switzerland
| | - Keji Li
- Department of Brain and Cognitive Sciences, Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge MA, USA
| | - Mriganka Sur
- Department of Brain and Cognitive Sciences, Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge MA, USA
| | - Walter E Kaufmann
- Department of Human Genetics, Emory University School of Medicine, Atlanta GA, USA
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87
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Epstein A, Williams K, Reddihough D, Murphy N, Leonard H, Whitehouse A, Jacoby P, Downs J. Content validation of the Quality of Life Inventory-Disability. Child Care Health Dev 2019; 45:654-659. [PMID: 31163096 DOI: 10.1111/cch.12691] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/11/2019] [Accepted: 05/30/2019] [Indexed: 12/14/2022]
Abstract
BACKGROUND Focus is shifting to better understand the lived experiences of children with intellectual disability in relation to their quality of life (QOL). Yet no available QOL measures are grounded in the domains important for this population. We previously conducted qualitative parent caregiver interviews identifying QOL domains in children with intellectual disability to constitute a new measure of QOL. This study describes the content validity of the Quality of Life Inventory-Disability (QI-Disability), a parent-report measure developed for children with intellectual disability. METHODS AND RESULTS Questionnaire items were extracted from a qualitative dataset of 77 parent caregiver interviews. To establish content validation, a draft of QI-Disability was administered to 16 parent caregivers of children with intellectual disability (Down syndrome, Rett syndrome, cerebral palsy, or autism spectrum disorder). Parents participated in a cognitive interviewing procedure known as the "think-aloud" method. The process of item generation, cognitive debriefing, and refinement of QI-Disability prior to its pilot testing are described. A conceptual framework is presented. CONCLUSIONS Satisfactory content validity is reported, where ongoing consumer feedback shaped the dataset from which the final items were selected. Use of QI-Disability for children with intellectual disability will allow for greater insight into service utility and targeted intervention.
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Affiliation(s)
- Amy Epstein
- Telethon Kids Institute, The University of Western Australia, Perth, Australia
| | - Katrina Williams
- Developmental Disability and Rehabilitation Research, Murdoch Children's Research Institute, Melbourne, Australia.,Department of Paediatrics, Monash University, Melbourne, Australia
| | - Dinah Reddihough
- Developmental Disability and Rehabilitation Research, Murdoch Children's Research Institute, Melbourne, Australia.,Department of Paediatrics, University of Melbourne, Melbourne, Australia
| | - Nada Murphy
- Telethon Kids Institute, The University of Western Australia, Perth, Australia
| | - Helen Leonard
- Telethon Kids Institute, The University of Western Australia, Perth, Australia
| | - Andrew Whitehouse
- Telethon Kids Institute, The University of Western Australia, Perth, Australia
| | - Peter Jacoby
- Telethon Kids Institute, The University of Western Australia, Perth, Australia
| | - Jenny Downs
- Telethon Kids Institute, The University of Western Australia, Perth, Australia.,School of Physiotherapy and Exercise Science, Curtin University, Perth, Australia
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88
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Abstract
Rett syndrome (RTT) is a severe neurological disorder caused by mutations in the gene encoding methyl-CpG-binding protein 2 (MeCP2). Almost two decades of research into RTT have greatly advanced our understanding of the function and regulation of the multifunctional protein MeCP2. Here, we review recent advances in understanding how loss of MeCP2 impacts different stages of brain development, discuss recent findings demonstrating the molecular role of MeCP2 as a transcriptional repressor, assess primary and secondary effects of MeCP2 loss and examine how loss of MeCP2 can result in an imbalance of neuronal excitation and inhibition at the circuit level along with dysregulation of activity-dependent mechanisms. These factors present challenges to the search for mechanism-based therapeutics for RTT and suggest specific approaches that may be more effective than others.
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89
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Xiol C, Vidal S, Pascual-Alonso A, Blasco L, Brandi N, Pacheco P, Gerotina E, O'Callaghan M, Pineda M, Armstrong J. X chromosome inactivation does not necessarily determine the severity of the phenotype in Rett syndrome patients. Sci Rep 2019; 9:11983. [PMID: 31427717 PMCID: PMC6700087 DOI: 10.1038/s41598-019-48385-w] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Accepted: 08/05/2019] [Indexed: 11/24/2022] Open
Abstract
Rett syndrome (RTT) is a severe neurological disorder usually caused by mutations in the MECP2 gene. Since the MECP2 gene is located on the X chromosome, X chromosome inactivation (XCI) could play a role in the wide range of phenotypic variation of RTT patients; however, classical methylation-based protocols to evaluate XCI could not determine whether the preferentially inactivated X chromosome carried the mutant or the wild-type allele. Therefore, we developed an allele-specific methylation-based assay to evaluate methylation at the loci of several recurrent MECP2 mutations. We analyzed the XCI patterns in the blood of 174 RTT patients, but we did not find a clear correlation between XCI and the clinical presentation. We also compared XCI in blood and brain cortex samples of two patients and found differences between XCI patterns in these tissues. However, RTT mainly being a neurological disease complicates the establishment of a correlation between the XCI in blood and the clinical presentation of the patients. Furthermore, we analyzed MECP2 transcript levels and found differences from the expected levels according to XCI. Many factors other than XCI could affect the RTT phenotype, which in combination could influence the clinical presentation of RTT patients to a greater extent than slight variations in the XCI pattern.
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Affiliation(s)
- Clara Xiol
- Molecular and Genetics Medicine Section, Hospital Sant Joan de Déu, Barcelona, Spain
| | - Silvia Vidal
- Molecular and Genetics Medicine Section, Hospital Sant Joan de Déu, Barcelona, Spain
| | - Ainhoa Pascual-Alonso
- Molecular and Genetics Medicine Section, Hospital Sant Joan de Déu, Barcelona, Spain
| | - Laura Blasco
- Molecular and Genetics Medicine Section, Hospital Sant Joan de Déu, Barcelona, Spain
| | - Núria Brandi
- Facultat de Medicina, Universitat de Barcelona, Barcelona, Spain
| | - Paola Pacheco
- Molecular and Genetics Medicine Section, Hospital Sant Joan de Déu, Barcelona, Spain
| | - Edgar Gerotina
- Molecular and Genetics Medicine Section, Hospital Sant Joan de Déu, Barcelona, Spain
| | - Mar O'Callaghan
- Neurology Service, Hospital Sant Joan de Déu, Barcelona, Spain
| | - Mercè Pineda
- Institut de Recerca Pediàtrica, Hospital Sant Joan de Déu, Barcelona, Spain
| | - Judith Armstrong
- Molecular and Genetics Medicine Section, Hospital Sant Joan de Déu, Barcelona, Spain. .,Institut de Recerca Pediàtrica, Hospital Sant Joan de Déu, Barcelona, Spain. .,CIBER-ER (Biomedical Network Research Center for Rare Diseases), Instituto de Salud Carlos III, Madrid, Spain.
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90
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Deep learning of spontaneous arousal fluctuations detects early cholinergic defects across neurodevelopmental mouse models and patients. Proc Natl Acad Sci U S A 2019; 117:23298-23303. [PMID: 31332003 DOI: 10.1073/pnas.1820847116] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Neurodevelopmental spectrum disorders like autism (ASD) are diagnosed, on average, beyond age 4 y, after multiple critical periods of brain development close and behavioral intervention becomes less effective. This raises the urgent need for quantitative, noninvasive, and translational biomarkers for their early detection and tracking. We found that both idiopathic (BTBR) and genetic (CDKL5- and MeCP2-deficient) mouse models of ASD display an early, impaired cholinergic neuromodulation as reflected in altered spontaneous pupil fluctuations. Abnormalities were already present before the onset of symptoms and were rescued by the selective expression of MeCP2 in cholinergic circuits. Hence, we trained a neural network (ConvNetACh) to recognize, with 97% accuracy, patterns of these arousal fluctuations in mice with enhanced cholinergic sensitivity (LYNX1-deficient). ConvNetACh then successfully detected impairments in all ASD mouse models tested except in MeCP2-rescued mice. By retraining only the last layers of ConvNetACh with heart rate variation data (a similar proxy of arousal) directly from Rett syndrome patients, we generated ConvNetPatients, a neural network capable of distinguishing them from typically developing subjects. Even with small cohorts of rare patients, our approach exhibited significant accuracy before (80% in the first and second year of life) and into regression (88% in stage III patients). Thus, transfer learning across species and modalities establishes spontaneous arousal fluctuations combined with deep learning as a robust noninvasive, quantitative, and sensitive translational biomarker for the rapid and early detection of neurodevelopmental disorders before major symptom onset.
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91
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Abstract
Exosomes have been implicated in intercellular communication in cancer and neurodegenerative disorders. We explored their function in brain development. Proteomic analysis demonstrated that exosomes from isogenic control cultures contain neurodevelopmental signaling proteins, which are lacking in exosomes from MECP2 loss-of-function (MECP2LOF) cultures. Treating MECP2LOF neural cultures with control exosomes rescues neurodevelopmental deficits, increasing neurogenesis, synaptogenesis, and network activity. Exosomes function similarly in vivo: injecting purified exosomes into the lateral ventricles of P4 mouse brains increased hippocampal neurogenesis. These findings significantly advance the field by demonstrating that neural exosomes contain diverse protein cargo predicted to affect multiple outcome measures of neural development and that exosomes signal between cells in developing neural circuits to promote neural circuit development and function. Exosomes are thought to be released by all cells in the body and to be involved in intercellular communication. We tested whether neural exosomes can regulate the development of neural circuits. We show that exosome treatment increases proliferation in developing neural cultures and in vivo in dentate gyrus of P4 mouse brain. We compared the protein cargo and signaling bioactivity of exosomes released by hiPSC-derived neural cultures lacking MECP2, a model of the neurodevelopmental disorder Rett syndrome, with exosomes released by isogenic rescue control neural cultures. Quantitative proteomic analysis indicates that control exosomes contain multiple functional signaling networks known to be important for neuronal circuit development. Treating MECP2-knockdown human primary neural cultures with control exosomes rescues deficits in neuronal proliferation, differentiation, synaptogenesis, and synchronized firing, whereas exosomes from MECP2-deficient hiPSC neural cultures lack this capability. These data indicate that exosomes carry signaling information required to regulate neural circuit development.
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92
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Faundez V, Wynne M, Crocker A, Tarquinio D. Molecular Systems Biology of Neurodevelopmental Disorders, Rett Syndrome as an Archetype. Front Integr Neurosci 2019; 13:30. [PMID: 31379529 PMCID: PMC6650571 DOI: 10.3389/fnint.2019.00030] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2019] [Accepted: 07/02/2019] [Indexed: 12/17/2022] Open
Abstract
Neurodevelopmental disorders represent a challenging biological and medical problem due to their genetic and phenotypic complexity. In many cases, we lack the comprehensive understanding of disease mechanisms necessary for targeted therapeutic development. One key component that could improve both mechanistic understanding and clinical trial design is reliable molecular biomarkers. Presently, no objective biological markers exist to evaluate most neurodevelopmental disorders. Here, we discuss how systems biology and "omic" approaches can address the mechanistic and biomarker limitations in these afflictions. We present heuristic principles for testing the potential of systems biology to identify mechanisms and biomarkers of disease in the example of Rett syndrome, a neurodevelopmental disorder caused by a well-defined monogenic defect in methyl-CpG-binding protein 2 (MECP2). We propose that such an approach can not only aid in monitoring clinical disease severity but also provide a measure of target engagement in clinical trials. By deepening our understanding of the "big picture" of systems biology, this approach could even help generate hypotheses for drug development programs, hopefully resulting in new treatments for these devastating conditions.
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Affiliation(s)
- Victor Faundez
- Department of Cell Biology, Emory University, Atlanta, GA, United States
| | - Meghan Wynne
- Department of Cell Biology, Emory University, Atlanta, GA, United States
| | - Amanda Crocker
- Program in Neuroscience, Middlebury College, Middlebury, VT, United States
| | - Daniel Tarquinio
- Rare Neurological Diseases (Private Research Institution), Atlanta, GA, United States
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93
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Sun Y, Gao Y, Tidei JJ, Shen M, Hoang JT, Wagner DF, Zhao X. Loss of MeCP2 in immature neurons leads to impaired network integration. Hum Mol Genet 2019; 28:245-257. [PMID: 30277526 DOI: 10.1093/hmg/ddy338] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2018] [Accepted: 09/18/2018] [Indexed: 12/12/2022] Open
Abstract
Rett syndrome (RTT) is a neurodevelopmental disorder caused by mutations or deletions in Methyl-CpG-binding Protein 2 (MeCP2), a brain-enriched transcriptional regulator. MeCP2 is highly expressed during neuronal maturation and its deficiency results in impaired dendritic morphogenesis and reduced dendritic spine numbers in developing neurons. However, whether MeCP2 deficiency impacts the integration of new neurons has not been directly assessed. In this study, we developed a modified rabies virus-mediated monosynaptic retrograde tracing method to interrogate presynaptic integration of MeCP2-deficient new neurons born in the adult hippocampus, a region with lifelong neurogenesis and plasticity. We found that selective deletion of MeCP2 in adult-born new neurons impaired their long-range connectivity to the cortex, whereas their connectivity within the local hippocampal circuits or with subcortical regions was not significantly affected. We further showed that knockdown of MeCP2 in primary hippocampal neurons also resulted in reduced network integration. Interestingly, (1-3) insulin-like growth factor-1 (IGF-1), a small peptide under clinical trial testing for RTT, rescued neuronal integration deficits of MeCP2-deficient neurons in vitro but not in vivo. In addition, (1-3) IGF-1 treatment corrected aberrant excitability and network synchrony of MeCP2-deficient hippocampal neurons. Our results indicate that MeCP2 is essential for immature neurons to establish appropriate network connectivity.
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Affiliation(s)
- Yi Sun
- National Key Research Laboratory of Natural and Biomimetic Drugs.,Department of Molecular and Cellular Pharmacology, School of Pharmaceutical Sciences, Peking University, Beijing, PR China.,Waisman Center
| | - Yu Gao
- Waisman Center.,Department of Neuroscience
| | | | | | | | | | - Xinyu Zhao
- Waisman Center.,Department of Neuroscience.,Cellular and Molecular Biology Program, University of Wisconsin-Madison, Madison, WI, USA
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94
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Strugnell A, Leonard H, Epstein A, Downs J. Using directed-content analysis to identify a framework for understanding quality of life in adults with Rett syndrome. Disabil Rehabil 2019; 42:3800-3807. [PMID: 31074665 DOI: 10.1080/09638288.2019.1610801] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Purpose: Rett syndrome (RTT) is a rare neurodevelopmental disorder mainly affecting females and is caused by a mutation in the MECP2 gene. Recent research identified the domains of quality of life (QOL) important for children with RTT but there has been no investigation of domains important for adults. This qualitative study explored QOL in adults with RTT and compared domains with those previously identified for children.Methods: The sample comprised parents and/or primary caregivers of 20 adults, aged 18-38 years, who were registered with the Australian Rett Syndrome Database. Semi-structured telephone interviews were conducted to investigate aspects of life that were observed to be satisfying or challenging. Data were analyzed using directed content analysis, based on existing QOL domains for children with RTT that related to health and wellbeing, daily activities, and community immersion and services.Results: Each of the domains identified for children with RTT was represented in the adult dataset, with no new domains emerging.Conclusion: This is the first study to identify QOL domains important for adults with RTT. Health and therapy needs are ongoing during adulthood but services may be limited. Findings will guide choice of an appropriate QOL measure for this group.IMPLICATIONS FOR REHABILITATIONKnowing the important domains of quality of life enables clinicians and service providers to systematically review and address key management issues.Despite a high level of dependency and sometimes poor health, parent caregivers perceive potential for strong quality of life in adulthood.Services that maintain functional skills and health throughout the lifespan are valued for their support of quality of life in adults with Rett syndrome.
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Affiliation(s)
- Aleisha Strugnell
- School of Physiotherapy and Exercise Science, Curtin University, Perth, Australia
| | - Helen Leonard
- Telethon Kids Institute, The University of Western Australia, Nedlands, Australia
| | - Amy Epstein
- Telethon Kids Institute, The University of Western Australia, Nedlands, Australia
| | - Jenny Downs
- School of Physiotherapy and Exercise Science, Curtin University, Perth, Australia.,Telethon Kids Institute, The University of Western Australia, Nedlands, Australia
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95
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Rodocanachi Roidi ML, Grange F, Cozzi F, Pari E, Toshimori K, Ripamonti E. Parents' perception of health care services for girls with Rett syndrome. Child Care Health Dev 2019; 45:417-422. [PMID: 30870585 DOI: 10.1111/cch.12660] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Revised: 03/09/2019] [Accepted: 03/09/2019] [Indexed: 11/27/2022]
Abstract
BACKGROUND Rett syndrome (RTT) is a severe neurodevelopmental disorder, implying impairment and disability across several domains. METHOD We investigated parents' perception of the caregiving process in a sample of 55 mothers and fathers of girls with RTT using the MPOC-20 questionnaire. The association of parents' satisfaction with clinical variables has also been explored. RESULTS We obtained intermediate levels of satisfaction on the MPOC-20 Coordinated and Comprehensive Care and Respectful and Supportive Care scales. The performance was lower on the scales Providing General Information and Providing Specific Information. Mothers' assessment was not associated with clinical variables such as walking disability, presence of scoliosis, or epilepsy. For children with greater degree of walking impairment, fathers expressed the need of having more information available. CONCLUSIONS Although parents seemed satisfied of the caregiving process, clinicians should put more emphasis on their need of receiving general and specific information on RTT along the entire rehabilitation program.
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Affiliation(s)
| | | | | | - Elisa Pari
- IRCCS Fondazione Don Carlo Gnocchi, Milano, Italy
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96
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Hor CHH, Tang BL. Beta-propeller protein-associated neurodegeneration (BPAN) as a genetically simple model of multifaceted neuropathology resulting from defects in autophagy. Rev Neurosci 2019; 30:261-277. [DOI: 10.1515/revneuro-2018-0045] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2018] [Accepted: 07/07/2018] [Indexed: 12/13/2022]
Abstract
AbstractAutophagy is an essential and conserved cellular homeostatic process. Defects in the core and accessory components of the autophagic machinery would most severely impact terminally differentiated cells, such as neurons. The neurodevelopmental/neurodegenerative disorder β-propeller protein-associated neurodegeneration (BPAN) resulted from heterozygous or hemizygous germline mutations/pathogenic variant of the X chromosome geneWDR45, encoding WD40 repeat protein interacting with phosphoinositides 4 (WIPI4). This most recently identified subtype of the spectrum of neurodegeneration with brain iron accumulation diseases is characterized by a biphasic mode of disease manifestation and progression. The first phase involves early-onset of epileptic seizures, global developmental delay, intellectual disability and autistic syndrome. Subsequently, Parkinsonism and dystonia, as well as dementia, emerge in a subacute manner in adolescence or early adulthood. BPAN disease phenotypes are thus complex and linked to a wide range of other neuropathological disorders. WIPI4/WDR45 has an essential role in autophagy, acting as a phosphatidylinositol 3-phosphate binding effector that participates in autophagosome biogenesis and size control. Here, we discuss recent updates on WIPI4’s mechanistic role in autophagy and link the neuropathological manifestations of BPAN’s biphasic infantile onset (epilepsy, autism) and adolescent onset (dystonic, Parkinsonism, dementia) phenotypes to neurological consequences of autophagy impairment that are now known or emerging in many other neurodevelopmental and neurodegenerative disorders. As monogenicWDR45mutations in BPAN result in a large spectrum of disease phenotypes that stem from autophagic dysfunctions, it could potentially serve as a simple and unique genetic model to investigate disease pathology and therapeutics for a wider range of neuropathological conditions with autophagy defects.
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97
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Mori Y, Downs J, Wong K, Leonard H. Longitudinal effects of caregiving on parental well-being: the example of Rett syndrome, a severe neurological disorder. Eur Child Adolesc Psychiatry 2019; 28:505-520. [PMID: 30151799 DOI: 10.1007/s00787-018-1214-0] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/14/2018] [Accepted: 08/13/2018] [Indexed: 01/14/2023]
Abstract
Little longitudinal research has examined parental well-being in those with a child with specific genetic developmental disorder although the associated severe neurological impairments and multiple physical comorbidities likely place substantial burden of caregiving on the parent. We aimed to examine longitudinally the well-being of parents of individuals included in the Australian Rett Syndrome Database over the period from 2002 to 2011 using the Short Form 12 Health Survey. Residential remoteness, the child being a teenager at baseline, having frequent sleep disturbances or behavioural problems, and the type of MECP2 gene mutation were each associated with later poorer parental physical well-being scores. Being a single parent or on a low income was also associated with later poorer physical well-being, while the child having enteral feeding was associated with later poorer emotional well-being. Both the physical and emotional well-being of the parent improved if the child was living in out-of-home care. Our findings suggest that some opportunities do exist for clinicians to help optimise parental well-being. Being alert to the possibility and need for management of a child's sleep or emotional disturbance is important as is awareness of the additional likely parental burden as the child moves through adolescence into early adulthood and their need for additional support at that time. However, the findings also highlight the complex nature of parental well-being over time in parents of children with a severe neurological disorder and how they may be affected by a range of inter-related family and child factors.
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Affiliation(s)
- Yuka Mori
- Telethon Kids Institute, 100 Roberts Road, Subiaco, WA, 6008, Australia.,The University of Western Australia, 35 Stirling Highway, Crawley, WA, 6009, Australia.,Department of Home Medical Treatment and Pediatrics, Osaka Developmental Rehabilitation Center, 5-11-21 Yamasaka Higashi-Sumiyoshi-ku, Osaka, 546-0035, Japan
| | - Jenny Downs
- Telethon Kids Institute, 100 Roberts Road, Subiaco, WA, 6008, Australia.,The University of Western Australia, 35 Stirling Highway, Crawley, WA, 6009, Australia.,School of Physiotherapy and Exercise Science, Curtin University, Building 408, Brand Drive, Bentley, WA, 6102, Australia
| | - Kingsley Wong
- Telethon Kids Institute, 100 Roberts Road, Subiaco, WA, 6008, Australia.,The University of Western Australia, 35 Stirling Highway, Crawley, WA, 6009, Australia
| | - Helen Leonard
- Telethon Kids Institute, 100 Roberts Road, Subiaco, WA, 6008, Australia. .,The University of Western Australia, 35 Stirling Highway, Crawley, WA, 6009, Australia.
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98
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Brown M, Ashcraft P, Arning E, Bottiglieri T, McClintock W, Giancola F, Lieberman D, Hauser NS, Miller R, Roullet JB, Pearl P, Gibson KM. Rett syndrome (MECP2) and succinic semialdehyde dehydrogenase (ALDH5A1) deficiency in a developmentally delayed female. Mol Genet Genomic Med 2019; 7:e629. [PMID: 30829465 PMCID: PMC6503008 DOI: 10.1002/mgg3.629] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2019] [Revised: 02/06/2019] [Accepted: 02/10/2019] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND We present a patient with Rett syndrome (RTT; MECP2) and autosomal-recessive succinic semialdehyde dehydrogenase deficiency (SSADHD; ALDH5A1 (aldehyde dehydrogenase 5a1 = SSADH), in whom the current phenotype exhibits features of SSADHD (hypotonia, global developmental delay) and RTT (hand stereotypies, gait anomalies). METHODS γ-Hydroxybutyric acid (GHB) was quantified by UPLC-tandem mass spectrometry, while mutation analysis followed standard methodology of whole-exome sequencing. RESULTS The biochemical hallmark of SSADHD, GHB was increased in the proband's dried bloodspot (DBS; 673 µM; previous SSADHD DBSs (n = 7), range 124-4851 µM); control range (n = 2,831), 0-78 µM. The proband was compound heterozygous for pathogenic ALDH5A1 mutations (p.(Asn418IlefsTer39); maternal; p.(Gly409Asp); paternal) and a de novo RTT nonsense mutation in MECP2 (p.Arg255*). CONCLUSION The major inhibitory neurotransmitter, γ-aminobutyric acid (GABA), is increased in SSADHD but normal in RTT, although there are likely regional changes in GABA receptor distribution. GABAergic anomalies occur in both disorders, each featuring an autism spectrum phenotype. What effect the SSADHD biochemical anomalies (elevated GABA, GHB) might play in the neurodevelopmental/epileptic phenotype of our patient is currently unknown.
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Affiliation(s)
- Madalyn Brown
- Department of Pharmacotherapy, College of Pharmacy and Pharmaceutical Sciences, Washington State University, Spokane, Washington
| | - Paula Ashcraft
- Baylor Scott & White Research Institute, Institute of Metabolic Disease, Dallas, Texas
| | - Erland Arning
- Baylor Scott & White Research Institute, Institute of Metabolic Disease, Dallas, Texas
| | - Teodoro Bottiglieri
- Baylor Scott & White Research Institute, Institute of Metabolic Disease, Dallas, Texas
| | | | | | - David Lieberman
- Department of Neurology, Boston Children's Hospital, Harvard School of Medicine, Boston, Massachusetts
| | | | | | - Jean-Baptiste Roullet
- Department of Pharmacotherapy, College of Pharmacy and Pharmaceutical Sciences, Washington State University, Spokane, Washington
| | - Phillip Pearl
- Department of Neurology, Boston Children's Hospital, Harvard School of Medicine, Boston, Massachusetts
| | - K Michael Gibson
- Department of Pharmacotherapy, College of Pharmacy and Pharmaceutical Sciences, Washington State University, Spokane, Washington
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99
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Stahlhut M, Esbensen BA, Larsen JL, Bisgaard AM, Downs J, Nordmark E. Facilitators and Barriers of Participation in "Uptime" Activities in Girls and Women With Rett Syndrome: Perspectives From Parents and Professionals. QUALITATIVE HEALTH RESEARCH 2019; 29:609-619. [PMID: 30304998 DOI: 10.1177/1049732318803358] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Rett syndrome (RTT) is a rare neurodevelopmental disorder usually affecting females. It is associated with intellectual and multiple disabilities leading to a high level of dependency in all aspects of daily living including participation in physical activities. This study explored facilitators and barriers to "uptime" (non-sedentary) activities in Danish girls and women with RTT as perceived by parents and professionals using focus groups. Through thematic analysis, one central theme emerged: a constant balance to do the best thing for the girl or woman. Within the central theme, five subthemes of facilitators and barriers were identified relating to the individual and the physical, organizational, social, and attitudinal environments. Environmental barriers can be reduced through policy and management-level changes in health promotion and strong advocacy of physical activity by health professionals. Targeting both facilitators and barriers of "uptime" activities enables the planning and implementing of health-promoting interventions in individuals with RTT.
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Affiliation(s)
- Michelle Stahlhut
- 1 Center for Rett Syndrome, Rigshospitalet, Glostrup, Denmark
- 2 Health Sciences Center, Lund University, Lund, Sweden
| | - Bente Appel Esbensen
- 3 Copenhagen Center for Arthritis Research, Rigshospitalet, Glostrup, Denmark
- 4 Department of Clinical Medicine, University of Copenhagen, Copenhagen, Denmark
| | | | | | - Jenny Downs
- 4 Department of Clinical Medicine, University of Copenhagen, Copenhagen, Denmark
- 5 Telethon Kids Institute, University of Western Australia, Perth, Australia
| | - Eva Nordmark
- 2 Health Sciences Center, Lund University, Lund, Sweden
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100
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Sernheim ÅS, Hemmingsson H, Lidström H, Witt Engerström I, Liedberg GM. Rett syndrome: Teenagers' and young adults' activities, usage of time and responses during an ordinary week - a diary study. Scand J Occup Ther 2019; 27:323-335. [PMID: 30663472 DOI: 10.1080/11038128.2018.1545046] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Background: Little is known about the everyday life of individuals with Rett syndrome.Aim/Objective: To describe ten participants' (teenagers/young adults) activities during a period of seven days, the time-use, where and with whom the activities were performed and the participants' responses in the form of visible/audible reactions during activities.Material and method: A time-geographic self-administered diary was filled in by 63 informants (parents/support staff) and analysed using the software, DAILY LIFE 2011.Results/Findings: The most frequently reported activities were hygiene/toilet, moving around indoors, eating and getting dressed. Most time was spent in sleeping, daily care, medical health care and travel/transportation. Little time remained for receptive activities, daytime rest, physical, social/creative, communication, school/daily work and domestic chore activities, especially for the young adults. Most time was spent with staff, thereafter with families and the least time was spent with friends. The most reported response was "interested", and "opposed" was the least reported.Conclusions: Daily and medical health care activities were time consuming. Improved communication between all parties may increase participation and well-being and provide solutions for handling unpleasant activities and sedentary time.Significance: A more varied range of activities may improve the everyday life for individuals with Rett syndrome.
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Affiliation(s)
- Åsa-Sara Sernheim
- Department of Social and Welfare Studies, Linköping University, Norrköping, Sweden.,The Swedish National Center for Rett syndrome & related disorders, Frösön, Sweden*
| | - Helena Hemmingsson
- Department of Social and Welfare Studies, Linköping University, Norrköping, Sweden.,Department of Special Education, Stockholm University, Stockholm, Sweden
| | - Helene Lidström
- Department of Social and Welfare Studies, Linköping University, Norrköping, Sweden
| | - I Witt Engerström
- The Swedish National Center for Rett syndrome & related disorders, Frösön, Sweden*
| | - G M Liedberg
- Department of Social and Welfare Studies, Linköping University, Norrköping, Sweden
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