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Billes A, Pujalte M, Jedraszak G, Amsallem D, Boudry-Labis E, Boute O, Bouquillon S, Brischoux-Boucher E, Callier P, Coutton C, Denizet ALA, Dieterich K, Kuentz P, Lespinasse J, Mazel B, Morin G, Amram F, Pennamen P, Rio M, Piard J, Putoux A, Rama M, Roze-Guillaumey V, Schluth-Bolard C, Till M, Trouvé C, Vieville G, Rooryck C, Sanlaville D, Chatron N. Possible incomplete penetrance of Xq28 int22h-1/int22h-2 duplication. Clin Genet 2024; 106:234-246. [PMID: 38561231 DOI: 10.1111/cge.14525] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2023] [Revised: 03/16/2024] [Accepted: 03/18/2024] [Indexed: 04/04/2024]
Abstract
Xq28 int22h-1/int22h-2 duplication is the result of non-allelic homologous recombination between int22h-1/int22h-2 repeats separated by 0.5 Mb. It is responsible for a syndromic form of intellectual disability (ID), with recurrent infections and atopic diseases. Minor defects, nonspecific facial dysmorphic features, and overweight have also been described. Half of female carriers have been reported with ID, whereas all reported evaluated born males present mild to moderate ID, suggesting complete penetrance. We collected data on 15 families from eight university hospitals. Among them, 40 patients, 21 females (one fetus), and 19 males (two fetuses), were carriers of typical or atypical Xq28 int22h-1/int22h-2 duplication. Twenty-one individuals were considered asymptomatic (16 females and 5 males), without significantly higher rate of recurrent infections, atopia, overweight, or facial dysmorphism. Approximately 67% live-born males and 23% live-born female carriers of the typical duplication did not have obvious signs of intellectual disability, suggesting previously undescribed incomplete penetrance or low expression in certain carriers. The possibility of a second-hit or modifying factors to this possible susceptibility locus is yet to be studied but a possible observational bias should be considered in assessing such challenging X-chromosome copy number gains. Additional segregation studies should help to quantify this newly described incomplete penetrance.
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Affiliation(s)
- Alexis Billes
- CHU Amiens Picardie, Service de Génétique Clinique, Amiens, France
- CHU Amiens Picardie, Laboratoire de Génétique Constitutionnelle, Amiens, France
| | - Mathilde Pujalte
- Service de Génétique, Groupement Hospitalier Est, Hospices Civils de Lyon, Bron, France
| | - Guillaume Jedraszak
- CHU Amiens Picardie, Laboratoire de Génétique Constitutionnelle, Amiens, France
- CHU Amiens Picardie, Département de génétique, UR4666 HEMATIM, CURS, Université Picardie Jules Verne, Amiens, France
| | - Daniel Amsallem
- Service de Neuropédiatrie, CHU de Besançon, Besançon, France
| | - Elise Boudry-Labis
- Institut de Génétique Médicale, Hôpital Jeanne de Flandre, Centre Hospitalier Universitaire de Lille, Lille, France
| | - Odile Boute
- Génétique Clinique, Centre Hospitalier Universitaire de Lille, Hôpital Jeanne de Flandre, Lille, France
| | - Sonia Bouquillon
- Institut de Génétique Médicale, Hôpital Jeanne de Flandre, Centre Hospitalier Universitaire de Lille, Lille, France
| | - Elise Brischoux-Boucher
- Centre de Génétique Humaine - CHU de Besançon, Université de Bourgogne-Franche-Comté, Besançon, France
| | - Patrick Callier
- Inserm UMR 1231 GAD Génétique des Anomalies du Développement, Université de Bourgogne, Dijon, France
- Unité Fonctionnelle Innovation diagnostique dans les maladies rares, laboratoire de génétique chromosomique et moléculaire, Plateau Technique de Biologie, CHU Dijon Bourgogne, Dijon, France
- Fédération Hospitalo-Universitaire Médecine Translationnelle et Anomalies du Développement (FHU TRANSLAD), CHU Dijon Bourgogne et Université de Bourgogne-Franche Comté, Dijon, France
| | - Charles Coutton
- Service de Génétique, Génomique, et Procréation, Centre Hospitalier Universitaire Grenoble Alpes, La Tronche, France
- INSERM 1209, CNRS UMR 5309, Institut pour l'Avancée des Biosciences (IAB), Université Grenoble Alpes, Grenoble, France
| | - Anne-Laude Avice Denizet
- Centre de Génétique Humaine - CHU de Besançon, Université de Bourgogne-Franche-Comté, Besançon, France
| | - Klaus Dieterich
- Université Grenoble Alpes, Inserm, U1216, CHU Grenoble Alpes, Medical Genetics, Grenoble Institute of Neurosciences, Grenoble, France
- CHU Grenoble, UM Génétique Chromosomique, Grenoble, France
| | - Paul Kuentz
- Oncobiologie Génétique Bioinformatique, PCBio, CHU de Besançon, Besançon, France
- UFR Des Sciences de Santé, INSERM-Université de Bourgogne UMR1231 GAD "Génétique des Anomalies du Développement", FHUTRANSLAD, Dijon, France
| | - James Lespinasse
- Centre Hospitalier de Chambéry, Service de Cytogénétique, Chambéry, France
| | - Benoît Mazel
- Centre de Génétique et Centre de Référence Anomalies du Développement et Syndromes Malformatifs, FHUTRANSLAD - CHU Dijon Bourgogne, Dijon, France
| | - Gilles Morin
- CHU Amiens Picardie, Service de Génétique Clinique, Amiens, France
| | - Florence Amram
- CHU Amiens Picardie, Service de Génétique Clinique, Amiens, France
| | - Perrine Pennamen
- CHU Bordeaux, Laboratoire de Génétique Biologique, Bordeaux, France
| | - Marlène Rio
- Université Paris Cité, Institut Imagine, Inserm U1163, Paris, France
- Service de Médecine Génomique des maladies rares, AP-HP, Centre Hôpital Necker-Enfants Malades, Paris, France
| | - Juliette Piard
- Centre de Génétique Humaine - CHU de Besançon, Université de Bourgogne-Franche-Comté, Besançon, France
- UMR 1231 GAD, Inserm, Université de Bourgogne Franche Comté, Dijon, France
| | - Audrey Putoux
- Hospices Civils de Lyon, Service de Génétique, Groupement Hospitalier Est, Bron, France
- Equipe GENDEV, Centre de Recherche en Neurosciences de Lyon, INSERM U1028 CNRS UMR5292, Université Claude Bernard Lyon 1, Lyon, France
| | - Mélanie Rama
- Institut de Génétique Médicale, Hôpital Jeanne de Flandre, Centre Hospitalier Universitaire de Lille, Lille, France
| | | | - Caroline Schluth-Bolard
- Service de Génétique, Groupement Hospitalier Est, Hospices Civils de Lyon, Bron, France
- Institute NeuroMyoGène, Laboratoire Physiopathologie et Génétique du Neurone et du Muscle, CNRS UMR 5261-INSERM U1315, Université de Lyon - Université Claude Bernard Lyon 1, Lyon, France
- Laboratoire de Diagnostic Génétique, Institut de Génétique Médicale d'Alsace, Hôpitaux Universitaires de Strasbourg, Strasbourg, France
| | - Marianne Till
- Service de Génétique, Groupement Hospitalier Est, Hospices Civils de Lyon, Bron, France
| | - Chloé Trouvé
- Centre de Génétique Humaine - CHU de Besançon, Université de Bourgogne-Franche-Comté, Besançon, France
| | - Gaëlle Vieville
- Département de Génétique et Procréation, Hôpital Couple Enfant, CHU Grenoble-Alpes, Grenoble, France
| | - Caroline Rooryck
- CHU de Bordeaux, Service de Génétique Médicale, Bordeaux, France
- Univ. Bordeaux, Maladies Rares: Génétique et Métabolisme (MRGM), U 1211 INSERM, Bordeaux, France
| | - Damien Sanlaville
- Service de Génétique, Groupement Hospitalier Est, Hospices Civils de Lyon, Bron, France
- Institute NeuroMyoGène, Laboratoire Physiopathologie et Génétique du Neurone et du Muscle, CNRS UMR 5261-INSERM U1315, Université de Lyon - Université Claude Bernard Lyon 1, Lyon, France
| | - Nicolas Chatron
- Service de Génétique, Groupement Hospitalier Est, Hospices Civils de Lyon, Bron, France
- Institute NeuroMyoGène, Laboratoire Physiopathologie et Génétique du Neurone et du Muscle, CNRS UMR 5261-INSERM U1315, Université de Lyon - Université Claude Bernard Lyon 1, Lyon, France
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2
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Grochowski CM, Bengtsson JD, Du H, Gandhi M, Lun MY, Mehaffey MG, Park K, Höps W, Benito E, Hasenfeld P, Korbel JO, Mahmoud M, Paulin LF, Jhangiani SN, Hwang JP, Bhamidipati SV, Muzny DM, Fatih JM, Gibbs RA, Pendleton M, Harrington E, Juul S, Lindstrand A, Sedlazeck FJ, Pehlivan D, Lupski JR, Carvalho CMB. Inverted triplications formed by iterative template switches generate structural variant diversity at genomic disorder loci. CELL GENOMICS 2024; 4:100590. [PMID: 38908378 PMCID: PMC11293582 DOI: 10.1016/j.xgen.2024.100590] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/13/2023] [Revised: 12/27/2023] [Accepted: 05/31/2024] [Indexed: 06/24/2024]
Abstract
The duplication-triplication/inverted-duplication (DUP-TRP/INV-DUP) structure is a complex genomic rearrangement (CGR). Although it has been identified as an important pathogenic DNA mutation signature in genomic disorders and cancer genomes, its architecture remains unresolved. Here, we studied the genomic architecture of DUP-TRP/INV-DUP by investigating the DNA of 24 patients identified by array comparative genomic hybridization (aCGH) on whom we found evidence for the existence of 4 out of 4 predicted structural variant (SV) haplotypes. Using a combination of short-read genome sequencing (GS), long-read GS, optical genome mapping, and single-cell DNA template strand sequencing (strand-seq), the haplotype structure was resolved in 18 samples. The point of template switching in 4 samples was shown to be a segment of ∼2.2-5.5 kb of 100% nucleotide similarity within inverted repeat pairs. These data provide experimental evidence that inverted low-copy repeats act as recombinant substrates. This type of CGR can result in multiple conformers generating diverse SV haplotypes in susceptible dosage-sensitive loci.
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Affiliation(s)
| | | | - Haowei Du
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Mira Gandhi
- Pacific Northwest Research Institute, Seattle, WA 98122, USA
| | - Ming Yin Lun
- Pacific Northwest Research Institute, Seattle, WA 98122, USA
| | | | - KyungHee Park
- Pacific Northwest Research Institute, Seattle, WA 98122, USA
| | - Wolfram Höps
- European Molecular Biology Laboratory (EMBL), Genome Biology Unit, Heidelberg, Germany
| | - Eva Benito
- European Molecular Biology Laboratory (EMBL), Genome Biology Unit, Heidelberg, Germany
| | - Patrick Hasenfeld
- European Molecular Biology Laboratory (EMBL), Genome Biology Unit, Heidelberg, Germany
| | - Jan O Korbel
- European Molecular Biology Laboratory (EMBL), Genome Biology Unit, Heidelberg, Germany
| | - Medhat Mahmoud
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA; Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX 77030, USA
| | - Luis F Paulin
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX 77030, USA
| | - Shalini N Jhangiani
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX 77030, USA
| | - James Paul Hwang
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX 77030, USA
| | - Sravya V Bhamidipati
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX 77030, USA
| | - Donna M Muzny
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX 77030, USA
| | - Jawid M Fatih
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Richard A Gibbs
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA; Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX 77030, USA
| | | | | | - Sissel Juul
- Oxford Nanopore Technologies, New York, NY 10013, USA
| | - Anna Lindstrand
- Department of Molecular Medicine and Surgery, Karolinska Institutet, 171 76 Stockholm, Sweden; Department of Clinical Genetics and Genomics, Karolinska University Hospital, 171 76 Stockholm, Sweden
| | - Fritz J Sedlazeck
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA; Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX 77030, USA; Department of Computer Science, Rice University, Houston TX 77030, USA
| | - Davut Pehlivan
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA; Section of Neurology and Developmental Neuroscience, Department of Pediatrics, Baylor College of Medicine, Houston, TX 77030, USA; Department of Pediatrics, Baylor College of Medicine, Houston, TX 77030, USA; Texas Children's Hospital, Houston, TX 77030, USA; Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, TX 77030, USA
| | - James R Lupski
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA; Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX 77030, USA; Department of Pediatrics, Baylor College of Medicine, Houston, TX 77030, USA; Texas Children's Hospital, Houston, TX 77030, USA
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3
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Pascual-Alonso A, Xiol C, Smirnov D, Kopajtich R, Prokisch H, Armstrong J. Multi-omics in MECP2 duplication syndrome patients and carriers. Eur J Neurosci 2024; 60:4004-4018. [PMID: 38746988 DOI: 10.1111/ejn.16389] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2024] [Revised: 04/16/2024] [Accepted: 04/24/2024] [Indexed: 07/21/2024]
Abstract
MECP2 duplication syndrome (MDS) is an X-linked neurodevelopmental disorder caused by the gain of dose of at least the genes MECP2 and IRAK1 and is characterised by intellectual disability (ID), developmental delay, hypotonia, epilepsy and recurrent infections. It mainly affects males, and females can be affected or asymptomatic carriers. Rett syndrome (RTT) is mainly triggered by loss of function mutations in MECP2 and is a well described syndrome that presents ID, epilepsy, lack of purposeful hand use and impaired speech, among others. As a result of implementing omics technology, altered biological pathways in human RTT samples have been reported, but such molecular characterisation has not been performed in patients with MDS. We gathered human skin fibroblasts from 17 patients with MDS, 10 MECP2 duplication carrier mothers and 21 patients with RTT, and performed multi-omics (RNAseq and proteomics) analysis. Here, we provide a thorough description and compare the shared and specific dysregulated biological processes between the cohorts. We also highlight the genes TMOD2, SRGAP1, COPS2, CNPY2, IGF2BP1, MOB2, VASP, FZD7, ECSIT and KIF3B as biomarker and therapeutic target candidates due to their implication in neuronal functions. Defining the RNA and protein profiles has shown that our four cohorts are less alike than expected by their shared phenotypes.
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Affiliation(s)
- Ainhoa Pascual-Alonso
- Fundació per la Recerca Sant Joan de Déu, Esplugues de Llobregat, Spain
- Institut de Recerca Sant Joan de Déu, Esplugues de Llobregat, Spain
| | - Clara Xiol
- Fundació per la Recerca Sant Joan de Déu, Esplugues de Llobregat, Spain
- Institut de Recerca Sant Joan de Déu, Esplugues de Llobregat, Spain
| | - Dmitrii Smirnov
- Institute of Human Genetics, Technical University of Munich, Munich, Germany
- Institute of Neurogenomics, Helmholtz Zentrum München, Munich, Germany
| | - Rober Kopajtich
- Institute of Human Genetics, Technical University of Munich, Munich, Germany
- Institute of Neurogenomics, Helmholtz Zentrum München, Munich, Germany
| | - Holger Prokisch
- Institute of Human Genetics, Technical University of Munich, Munich, Germany
- Institute of Neurogenomics, Helmholtz Zentrum München, Munich, Germany
| | - Judith Armstrong
- Institut de Recerca Sant Joan de Déu, Esplugues de Llobregat, Spain
- Instituto de Salud Carlos III (ISCIII), CIBER-ER (Biomedical Network Research Center for Rare Diseases), Madrid, Spain
- Genomic Unit, Molecular and Genetic Medicine Section, Hospital Sant Joan de Déu, Esplugues de Llobregat, Spain
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4
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Allison K, Maletic-Savatic M, Pehlivan D. MECP2-related disorders while gene-based therapies are on the horizon. Front Genet 2024; 15:1332469. [PMID: 38410154 PMCID: PMC10895005 DOI: 10.3389/fgene.2024.1332469] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2023] [Accepted: 01/23/2024] [Indexed: 02/28/2024] Open
Abstract
The emergence of new genetic tools has led to the discovery of the genetic bases of many intellectual and developmental disabilities. This creates exciting opportunities for research and treatment development, and a few genetic disorders (e.g., spinal muscular atrophy) have recently been treated with gene-based therapies. MECP2 is found on the X chromosome and regulates the transcription of thousands of genes. Loss of MECP2 gene product leads to Rett Syndrome, a disease found primarily in females, and is characterized by developmental regression, motor dysfunction, midline hand stereotypies, autonomic nervous system dysfunction, epilepsy, scoliosis, and autistic-like behavior. Duplication of MECP2 causes MECP2 Duplication Syndrome (MDS). MDS is found mostly in males and presents with developmental delay, hypotonia, autistic features, refractory epilepsy, and recurrent respiratory infections. While these two disorders share several characteristics, their differences (e.g., affected sex, age of onset, genotype/phenotype correlations) are important to distinguish in the light of gene-based therapy because they require opposite solutions. This review explores the clinical features of both disorders and highlights these important clinical differences.
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Affiliation(s)
- Katherine Allison
- Royal College of Surgeons in Ireland, School of Medicine, Dublin, Ireland
| | - Mirjana Maletic-Savatic
- Section of Pediatric Neurology and Developmental Neuroscience, Department of Pediatrics, Baylor College of Medicine, Houston, TX, United States
- Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, TX, United States
| | - Davut Pehlivan
- Section of Pediatric Neurology and Developmental Neuroscience, Department of Pediatrics, Baylor College of Medicine, Houston, TX, United States
- Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, TX, United States
- Blue Bird Circle Rett Center, Texas Children's Hospital, Houston, TX, United States
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Moore JR, Nemera MT, D’Souza RD, Hamagami N, Clemens AW, Beard DC, Urman A, Mendoza VR, Gabel HW. Non-CG DNA methylation and MeCP2 stabilize repeated tuning of long genes that distinguish closely related neuron types. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.01.30.577861. [PMID: 38352532 PMCID: PMC10862856 DOI: 10.1101/2024.01.30.577861] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/23/2024]
Abstract
The extraordinary diversity of neuron types in the mammalian brain is delineated at the highest resolution by subtle gene expression differences that may require specialized molecular mechanisms to be maintained. Neurons uniquely express the longest genes in the genome and utilize neuron-enriched non-CG DNA methylation (mCA) together with the Rett syndrome protein, MeCP2, to control gene expression, but the function of these unique gene structures and machinery in regulating finely resolved neuron type-specific gene programs has not been explored. Here, we employ epigenomic and spatial transcriptomic analyses to discover a major role for mCA and MeCP2 in maintaining neuron type-specific gene programs at the finest scale of cellular resolution. We uncover differential susceptibility to MeCP2 loss in neuronal populations depending on global mCA levels and dissect methylation patterns and intragenic enhancer repression that drive overlapping and distinct gene regulation between neuron types. Strikingly, we show that mCA and MeCP2 regulate genes that are repeatedly tuned to differentiate neuron types at the highest cellular resolution, including spatially resolved, vision-dependent gene programs in the visual cortex. These repeatedly tuned genes display genomic characteristics, including long length, numerous intragenic enhancers, and enrichment for mCA, that predispose them to regulation by MeCP2. Thus, long gene regulation by the MeCP2 pathway maintains differential gene expression between closely-related neurons to facilitate the exceptional cellular diversity in the complex mammalian brain.
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Affiliation(s)
- J. Russell Moore
- Department of Neuroscience, Washington University School of Medicine, St. Louis, MO 63110-1093, USA
| | - Mati T. Nemera
- Department of Neuroscience, Washington University School of Medicine, St. Louis, MO 63110-1093, USA
| | - Rinaldo D. D’Souza
- Department of Neuroscience, Washington University School of Medicine, St. Louis, MO 63110-1093, USA
| | - Nicole Hamagami
- Department of Neuroscience, Washington University School of Medicine, St. Louis, MO 63110-1093, USA
| | - Adam W. Clemens
- Department of Neuroscience, Washington University School of Medicine, St. Louis, MO 63110-1093, USA
| | - Diana C. Beard
- Department of Neuroscience, Washington University School of Medicine, St. Louis, MO 63110-1093, USA
| | - Alaina Urman
- Department of Neuroscience, Washington University School of Medicine, St. Louis, MO 63110-1093, USA
| | - Victoria Rodriguez Mendoza
- Opportunities in Genomic Research Program, McDonnell Genome Institute, Washington University School of Medicine, St. Louis, MO 63110-1093, USA
| | - Harrison W. Gabel
- Department of Neuroscience, Washington University School of Medicine, St. Louis, MO 63110-1093, USA
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6
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Lockman S, Genung M, Sheikholeslami K, Sher AA, Kroft D, Buist M, Olson CO, Toor B, Rastegar M. Transcriptional Inhibition of the Mecp2 Promoter by MeCP2E1 and MeCP2E2 Isoforms Suggests Negative Auto-Regulatory Feedback that can be Moderated by Metformin. J Mol Neurosci 2024; 74:14. [PMID: 38277073 DOI: 10.1007/s12031-023-02177-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2023] [Accepted: 12/29/2023] [Indexed: 01/27/2024]
Abstract
The epigenetic factor Methyl-CpG-Binding Protein 2 (MeCP2) is a nuclear protein that binds methylated DNA molecules (both 5-methylcytosine and 5-hydroxymethylcytosine) and controls gene transcription. MeCP2 is an important transcription factor that acts in a dose-dependent manner in the brain; thus, its optimal expression level in brain cells is important. As such, its deregulated expression, as well as gain- or loss-of-function mutation, lead to impaired neurodevelopment, and compromised structure and function of brain cells, particularly in neurons. Studies from others and us have characterized two well-recognized MeCP2 isoforms: MeCP2E1 and MeCP2E2. We have reported that in Daoy medulloblastoma brain cells, MeCP2E2 overexpression leads to MeCP2E1 protein degradation. Whether MeCP2 isoforms regulate the Mecp2 promoter regulatory elements remains unexplored. We previously showed that in Daoy cells, metformin (an anti-diabetic drug) induces MECP2E1 transcripts. However, possible impact of metformin on the Mecp2 promoter activity was not studied. Here, we generated stably transduced Daoy cell reporters to express EGFP driven by the Mecp2 promoter. Transduced cells were sorted into four EGFP-expressing groups (R4-to-R7) with different intensities of EGFP expression. Our results confirm that the Mecp2 promoter is active in Daoy cells, and that overexpression of either isoform inhibits the Mecp2 promoter activity, as detected by flow cytometry and luciferase reporter assays. Interestingly, metformin partially relieved the inhibitory effect of MeCP2E1 on the Mecp2 promoter, detected by flow cytometry. Taken together, our data provide important insight towards the regulation of MeCP2 isoforms at the promoter level, which might have biological relevance to the neurobiology of the brain.
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Affiliation(s)
- Sandhini Lockman
- Department of Biochemistry and Medical Genetics, Max Rady College of Medicine, Faculty of Health Sciences, University of Manitoba, Winnipeg, MB, Canada
| | - Matthew Genung
- Department of Biochemistry and Medical Genetics, Max Rady College of Medicine, Faculty of Health Sciences, University of Manitoba, Winnipeg, MB, Canada
| | - Kimia Sheikholeslami
- Department of Biochemistry and Medical Genetics, Max Rady College of Medicine, Faculty of Health Sciences, University of Manitoba, Winnipeg, MB, Canada
- Faculty of Medicine, University of Toronto, Toronto, ON, Canada
| | - Annan Ali Sher
- Department of Biochemistry and Medical Genetics, Max Rady College of Medicine, Faculty of Health Sciences, University of Manitoba, Winnipeg, MB, Canada
| | - Daniel Kroft
- Department of Biochemistry and Medical Genetics, Max Rady College of Medicine, Faculty of Health Sciences, University of Manitoba, Winnipeg, MB, Canada
| | - Marjorie Buist
- Department of Biochemistry and Medical Genetics, Max Rady College of Medicine, Faculty of Health Sciences, University of Manitoba, Winnipeg, MB, Canada
| | - Carl O Olson
- Department of Biochemistry and Medical Genetics, Max Rady College of Medicine, Faculty of Health Sciences, University of Manitoba, Winnipeg, MB, Canada
| | - Brian Toor
- Department of Biochemistry and Medical Genetics, Max Rady College of Medicine, Faculty of Health Sciences, University of Manitoba, Winnipeg, MB, Canada
| | - Mojgan Rastegar
- Department of Biochemistry and Medical Genetics, Max Rady College of Medicine, Faculty of Health Sciences, University of Manitoba, Winnipeg, MB, Canada.
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7
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Smolka M, Paulin LF, Grochowski CM, Horner DW, Mahmoud M, Behera S, Kalef-Ezra E, Gandhi M, Hong K, Pehlivan D, Scholz SW, Carvalho CMB, Proukakis C, Sedlazeck FJ. Detection of mosaic and population-level structural variants with Sniffles2. Nat Biotechnol 2024:10.1038/s41587-023-02024-y. [PMID: 38168980 PMCID: PMC11217151 DOI: 10.1038/s41587-023-02024-y] [Citation(s) in RCA: 25] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2022] [Accepted: 10/11/2023] [Indexed: 01/05/2024]
Abstract
Calling structural variations (SVs) is technically challenging, but using long reads remains the most accurate way to identify complex genomic alterations. Here we present Sniffles2, which improves over current methods by implementing a repeat aware clustering coupled with a fast consensus sequence and coverage-adaptive filtering. Sniffles2 is 11.8 times faster and 29% more accurate than state-of-the-art SV callers across different coverages (5-50×), sequencing technologies (ONT and HiFi) and SV types. Furthermore, Sniffles2 solves the problem of family-level to population-level SV calling to produce fully genotyped VCF files. Across 11 probands, we accurately identified causative SVs around MECP2, including highly complex alleles with three overlapping SVs. Sniffles2 also enables the detection of mosaic SVs in bulk long-read data. As a result, we identified multiple mosaic SVs in brain tissue from a patient with multiple system atrophy. The identified SV showed a remarkable diversity within the cingulate cortex, impacting both genes involved in neuron function and repetitive elements.
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Affiliation(s)
- Moritz Smolka
- Human Genome Sequencing Center Baylor College of Medicine, Houston, TX, USA
| | - Luis F Paulin
- Human Genome Sequencing Center Baylor College of Medicine, Houston, TX, USA
| | | | - Dominic W Horner
- Department of Clinical and Movement Neurosciences, Royal Free Campus, Queen Square Institute of Neurology, University College London, London, UK
- Aligning Science Across Parkinson's (ASAP) Collaborative Research Network, Chevy Chase, MD, USA
| | - Medhat Mahmoud
- Human Genome Sequencing Center Baylor College of Medicine, Houston, TX, USA
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
| | - Sairam Behera
- Human Genome Sequencing Center Baylor College of Medicine, Houston, TX, USA
| | - Ester Kalef-Ezra
- Department of Clinical and Movement Neurosciences, Royal Free Campus, Queen Square Institute of Neurology, University College London, London, UK
- Aligning Science Across Parkinson's (ASAP) Collaborative Research Network, Chevy Chase, MD, USA
| | - Mira Gandhi
- Pacific Northwest Research Institute (PNRI), Seattle, WA, USA
| | - Karl Hong
- Bionano Genomics, San Diego, CA, USA
| | - Davut Pehlivan
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
- Division of Neurology and Developmental Neuroscience, Department of Pediatrics, Baylor College of Medicine, Houston, TX, USA
| | - Sonja W Scholz
- Neurodegenerative Diseases Research Unit, National Institute of Neurological Disorders and Stroke, Bethesda, MD, USA
- Department of Neurology, Johns Hopkins University Medical Center, Baltimore, MD, USA
| | - Claudia M B Carvalho
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
- Pacific Northwest Research Institute (PNRI), Seattle, WA, USA
| | - Christos Proukakis
- Department of Clinical and Movement Neurosciences, Royal Free Campus, Queen Square Institute of Neurology, University College London, London, UK
- Aligning Science Across Parkinson's (ASAP) Collaborative Research Network, Chevy Chase, MD, USA
| | - Fritz J Sedlazeck
- Human Genome Sequencing Center Baylor College of Medicine, Houston, TX, USA.
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA.
- Aligning Science Across Parkinson's (ASAP) Collaborative Research Network, Chevy Chase, MD, USA.
- Department of Computer Science, Rice University, Houston, TX, USA.
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8
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Grochowski CM, Bengtsson JD, Du H, Gandhi M, Lun MY, Mehaffey MG, Park K, Höps W, Benito-Garagorri E, Hasenfeld P, Korbel JO, Mahmoud M, Paulin LF, Jhangiani SN, Muzny DM, Fatih JM, Gibbs RA, Pendleton M, Harrington E, Juul S, Lindstrand A, Sedlazeck FJ, Pehlivan D, Lupski JR, Carvalho CMB. Break-induced replication underlies formation of inverted triplications and generates unexpected diversity in haplotype structures. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.10.02.560172. [PMID: 37873367 PMCID: PMC10592851 DOI: 10.1101/2023.10.02.560172] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/25/2023]
Abstract
Background The duplication-triplication/inverted-duplication (DUP-TRP/INV-DUP) structure is a type of complex genomic rearrangement (CGR) hypothesized to result from replicative repair of DNA due to replication fork collapse. It is often mediated by a pair of inverted low-copy repeats (LCR) followed by iterative template switches resulting in at least two breakpoint junctions in cis . Although it has been identified as an important mutation signature of pathogenicity for genomic disorders and cancer genomes, its architecture remains unresolved and is predicted to display at least four structural variation (SV) haplotypes. Results Here we studied the genomic architecture of DUP-TRP/INV-DUP by investigating the genomic DNA of 24 patients with neurodevelopmental disorders identified by array comparative genomic hybridization (aCGH) on whom we found evidence for the existence of 4 out of 4 predicted SV haplotypes. Using a combination of short-read genome sequencing (GS), long- read GS, optical genome mapping and StrandSeq the haplotype structure was resolved in 18 samples. This approach refined the point of template switching between inverted LCRs in 4 samples revealing a DNA segment of ∼2.2-5.5 kb of 100% nucleotide similarity. A prediction model was developed to infer the LCR used to mediate the non-allelic homology repair. Conclusions These data provide experimental evidence supporting the hypothesis that inverted LCRs act as a recombinant substrate in replication-based repair mechanisms. Such inverted repeats are particularly relevant for formation of copy-number associated inversions, including the DUP-TRP/INV-DUP structures. Moreover, this type of CGR can result in multiple conformers which contributes to generate diverse SV haplotypes in susceptible loci .
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9
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Xing XH, Takam R, Bao XY, Ba-alwi NA, Ji H. Methyl-CpG-Binding protein 2 duplication syndrome in a Chinese patient: A case report and review of the literature. World J Clin Cases 2023; 11:6505-6514. [PMID: 37900250 PMCID: PMC10600989 DOI: 10.12998/wjcc.v11.i27.6505] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/07/2023] [Revised: 08/08/2023] [Accepted: 08/29/2023] [Indexed: 09/20/2023] Open
Abstract
BACKGROUND Chromosomal Xq28 region duplication encompassing methyl-CpG-binding protein 2 (MECP2) results in an identifiable phenotype and global developmental delay known as MECP2 duplication syndrome (MDS). This syndrome has a wide range of clinical manifestations, including abnormalities in appearance, neurodevelopment, and gastrointestinal motility; recurrent infections; and spasticity. Here, we report a case of confirmed MDS at our institution. CASE SUMMARY A 12-year-old Chinese boy presented with intellectual disability (poor intellectual [reasoning, judgment, abstract thinking, and learning] and adaptive [lack of communication and absent social skills, apraxia, and ataxia] functioning) and dysmorphism. He had no history of recurrent infections, seizures, or bowel dysfunction, which is different from that in reported cases. Microarray comparative genomic hybridization confirmed MECP2 duplication in the patient and his mother who is a carrier. The duplication size was the same in the patient and his mother. No prophylactic antibiotic or anti-seizure therapy was offered to the patient or his mother before or after the consultation. CONCLUSION MDS is rare and has various clinical presentations. Clinical suspicion is critical in patients presenting with developmental delays.
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Affiliation(s)
- Xu-Hang Xing
- Department of Pediatrics, The First Part of The First Affiliated Hospital of Dalian Medical University, Dalian 116011, Liaoning Province, China
| | - Russel Takam
- Department of Pediatrics, The First Part of The First Affiliated Hospital of Dalian Medical University, Dalian 116011, Liaoning Province, China
| | - Xiu-Ying Bao
- Department of Pediatrics, The First Part of The First Affiliated Hospital of Dalian Medical University, Dalian 116011, Liaoning Province, China
| | - Nour Abdallah Ba-alwi
- Department of Pediatrics, The First Part of The First Affiliated Hospital of Dalian Medical University, Dalian 116011, Liaoning Province, China
| | - Hong Ji
- Department of Pediatrics, The First Part of The First Affiliated Hospital of Dalian Medical University, Dalian 116011, Liaoning Province, China
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10
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Powers S, Likhite S, Gadalla KK, Miranda CJ, Huffenberger AJ, Dennys C, Foust KD, Morales P, Pierson CR, Rinaldi F, Perry S, Bolon B, Wein N, Cobb S, Kaspar BK, Meyer KC. Novel MECP2 gene therapy is effective in a multicenter study using two mouse models of Rett syndrome and is safe in non-human primates. Mol Ther 2023; 31:2767-2782. [PMID: 37481701 PMCID: PMC10492029 DOI: 10.1016/j.ymthe.2023.07.013] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2022] [Revised: 04/10/2023] [Accepted: 07/19/2023] [Indexed: 07/24/2023] Open
Abstract
The AAV9 gene therapy vector presented in this study is safe in mice and non-human primates and highly efficacious without causing overexpression toxicity, a major challenge for clinical translation of Rett syndrome gene therapy vectors to date. Our team designed a new truncated methyl-CpG-binding protein 2 (MECP2) promoter allowing widespread expression of MECP2 in mice and non-human primates after a single injection into the cerebrospinal fluid without causing overexpression symptoms up to 18 months after injection. Additionally, this new vector is highly efficacious at lower doses compared with previous constructs as demonstrated in extensive efficacy studies performed by two independent laboratories in two different Rett syndrome mouse models carrying either a knockout or one of the most frequent human mutations of Mecp2. Overall, data from this multicenter study highlight the efficacy and safety of this gene therapy construct, making it a promising candidate for first-in-human studies to treat Rett syndrome.
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Affiliation(s)
- Samantha Powers
- Center for Gene Therapy, Abigail Wexner Research Institute, Nationwide Children's Hospital, Columbus, OH 43205, USA; Neuroscience Graduate Program, The Ohio State University, Columbus, OH 43210, USA.
| | - Shibi Likhite
- Center for Gene Therapy, Abigail Wexner Research Institute, Nationwide Children's Hospital, Columbus, OH 43205, USA
| | - Kamal K Gadalla
- Simons Initiative for the Developing Brain, Centre for Discovery Brain Sciences, University of Edinburgh, EH8 9XD Edinburgh, UK
| | - Carlos J Miranda
- Center for Gene Therapy, Abigail Wexner Research Institute, Nationwide Children's Hospital, Columbus, OH 43205, USA
| | - Amy J Huffenberger
- Center for Gene Therapy, Abigail Wexner Research Institute, Nationwide Children's Hospital, Columbus, OH 43205, USA
| | - Cassandra Dennys
- Center for Gene Therapy, Abigail Wexner Research Institute, Nationwide Children's Hospital, Columbus, OH 43205, USA
| | - Kevin D Foust
- Neuroscience Graduate Program, The Ohio State University, Columbus, OH 43210, USA
| | - Pablo Morales
- The Mannheimer Foundation Inc, Homestead, FL 33034, USA
| | - Christopher R Pierson
- The Department of Pathology & Laboratory Medicine, Nationwide Children's Hospital, Columbus, OH 43205, USA; Department of Pathology and the Department of Biomedical Education & Anatomy, The Ohio State University, Columbus, OH 43210, USA
| | - Federica Rinaldi
- Center for Gene Therapy, Abigail Wexner Research Institute, Nationwide Children's Hospital, Columbus, OH 43205, USA
| | - Stephanie Perry
- Center for Gene Therapy, Abigail Wexner Research Institute, Nationwide Children's Hospital, Columbus, OH 43205, USA
| | | | - Nicolas Wein
- Center for Gene Therapy, Abigail Wexner Research Institute, Nationwide Children's Hospital, Columbus, OH 43205, USA; Department of Pediatrics, The Ohio State University, Columbus, OH 43210, USA
| | - Stuart Cobb
- Simons Initiative for the Developing Brain, Centre for Discovery Brain Sciences, University of Edinburgh, EH8 9XD Edinburgh, UK
| | - Brian K Kaspar
- Center for Gene Therapy, Abigail Wexner Research Institute, Nationwide Children's Hospital, Columbus, OH 43205, USA; Department of Pediatrics, The Ohio State University, Columbus, OH 43210, USA
| | - Kathrin C Meyer
- Center for Gene Therapy, Abigail Wexner Research Institute, Nationwide Children's Hospital, Columbus, OH 43205, USA; Neuroscience Graduate Program, The Ohio State University, Columbus, OH 43210, USA; Department of Pediatrics, The Ohio State University, Columbus, OH 43210, USA.
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11
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Akahoshi K, Nakagawa E, Goto YI, Inoue K. Duplication within two regions distal to MECP2: clinical similarity with MECP2 duplication syndrome. BMC Med Genomics 2023; 16:43. [PMID: 36879246 PMCID: PMC9987063 DOI: 10.1186/s12920-023-01465-3] [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: 11/25/2022] [Accepted: 02/21/2023] [Indexed: 03/08/2023] Open
Abstract
BACKGROUND X-linked methyl-CpG-binding protein 2 (MECP2) duplication syndrome is prevalent in approximately 1% of X-linked intellectual disabilities. Accumulating evidence has suggested that MECP2 is the causative gene of MECP2 duplication syndrome. We report a case of a 17-year-old boy with a 1.2 Mb duplication distal to MECP2 on chromosome Xq28. Although this region does not contain MECP2, the clinical features and course of the boy are remarkably similar to those observed in MECP2 duplication syndrome. Recently, case reports have described duplication in the region distal to, and not containing, MECP2. These regions have been classified as the K/L-mediated Xq28 duplication region and int22h1/int22h2-mediated Xq28 duplication region. The case reports also described signs similar to those of MECP2 duplication syndrome. To the best of our knowledge, ours is the first case to include these two regions. CASE PRESENTATION The boy presented with a mild to moderate regressive intellectual disability and progressive neurological disorder. He developed epilepsy at the age of 6 years and underwent a bilateral equinus foot surgery at 14 years of age because of the increasing spasticity in lower extremities since the age of 11. Intracranial findings showed hypoplasia of the corpus callosum, cerebellum, and brain stem; linear hyperintensity in the deep white matter; and decreased white matter capacity. During his childhood, he suffered from recurrent infection. However, genital problems, skin abnormalities and gastrointestinal manifestations (gastroesophageal reflux) were not observed. CONCLUSIONS Cases in which duplication was observed in the region of Xq28 that does not include MECP2 also showed symptoms similar to those of MECP2 duplication syndrome. We compared four pathologies: MECP2 duplication syndrome with minimal regions, duplication within the two distal regions without MECP2, and our case including both regions. Our results suggest that MECP2 alone may not explain all symptoms of duplication in the distal part of Xq28.
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Affiliation(s)
- Keiko Akahoshi
- Department of Pediatrics, Tokyo Children's Rehabilitation Hospital, 4-10-1 Gakuen, Musashi-Murayama, Tokyo, 208-0011, Japan.
| | - Eiji Nakagawa
- Department of Child Neurology, National Center of Neurology and Psychiatry, Tokyo, 187-8551, Japan
| | - Yu-Ichi Goto
- Department of Mental Retardation and Birth Defect Research, National Institute of Neuroscience, Tokyo, 187-8502, Japan.,Medical Genome Center, National Center of Neurology and Psychiatry, Tokyo, 187-8551, Japan
| | - Ken Inoue
- Department of Mental Retardation and Birth Defect Research, National Institute of Neuroscience, Tokyo, 187-8502, Japan
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12
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Hamagami N, Wu DY, Clemens AW, Nettles SA, Gabel HW. NSD1 deposits histone H3 lysine 36 dimethylation to pattern non-CG DNA methylation in neurons. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.02.17.528965. [PMID: 36824816 PMCID: PMC9949142 DOI: 10.1101/2023.02.17.528965] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/19/2023]
Abstract
During postnatal development the DNA methyltransferase DNMT3A deposits high levels of non-CG cytosine methylation in neurons. This unique methylation is critical for transcriptional regulation in the mature mammalian brain, and loss of this mark is implicated in DNMT3A-associated neurodevelopmental disorders (NDDs). The mechanisms determining genomic non-CG methylation profiles are not well defined however, and it is unknown if this pathway is disrupted in additional NDDs. Here we show that genome topology and gene expression converge to shape histone H3 lysine 36 dimethylation (H3K36me2) profiles, which in turn recruit DNMT3A and pattern neuronal non-CG methylation. We show that NSD1, the H3K36 methyltransferase mutated in the NDD, Sotos syndrome, is required for megabase-scale patterning of H3K36me2 and non-CG methylation in neurons. We find that brain-specific deletion of NSD1 causes alterations in DNA methylation that overlap with models of DNMT3A disorders and define convergent disruption in the expression of key neuronal genes in these models that may contribute to shared phenotypes in NSD1- and DNMT3A-associated NDD. Our findings indicate that H3K36me2 deposited by NSD1 is an important determinant of neuronal non-CG DNA methylation and implicates disruption of this methylation in Sotos syndrome. Highlights Topology-associated DNA methylation and gene expression independently contribute to neuronal gene body and enhancer non-CG DNA methylation patterns.Topology-associated H3K36me2 patterns and local enrichment of H3K4 methylation impact deposition of non-CG methylation by DNMT3A. Disruption of NSD1 in vivo leads to alterations in H3K36me2, DNA methylation, and gene expression that overlap with models of DNMT3A disorders.
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Affiliation(s)
- Nicole Hamagami
- Department of Neuroscience, Washington University School of Medicine, St Louis MO 63110-1093, USA
- These authors contributed equally
| | - Dennis Y Wu
- Department of Neuroscience, Washington University School of Medicine, St Louis MO 63110-1093, USA
- These authors contributed equally
| | - Adam W Clemens
- Department of Neuroscience, Washington University School of Medicine, St Louis MO 63110-1093, USA
| | - Sabin A Nettles
- Department of Neuroscience, Washington University School of Medicine, St Louis MO 63110-1093, USA
| | - Harrison W Gabel
- Department of Neuroscience, Washington University School of Medicine, St Louis MO 63110-1093, USA
- Lead contact
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13
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Gottschalk I, Kölsch U, Wagner DL, Kath J, Martini S, Krüger R, Puel A, Casanova JL, Jezela-Stanek A, Rossi R, Chehadeh SE, Van Esch H, von Bernuth H. IRAK1 Duplication in MECP2 Duplication Syndrome Does Not Increase Canonical NF-κB-Induced Inflammation. J Clin Immunol 2023; 43:421-439. [PMID: 36319802 PMCID: PMC9628328 DOI: 10.1007/s10875-022-01390-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Accepted: 10/20/2022] [Indexed: 01/24/2023]
Abstract
PURPOSE Besides their developmental and neurological phenotype, most patients with MECP2/IRAK1 duplication syndrome present with recurrent and severe infections, accompanied by strong inflammation. Respiratory infections are the most common cause of death. Standardized pneumological diagnostics, targeted anti-infectious treatment, and knowledge of the underlying pathomechanism that triggers strong inflammation are unmet clinical needs. We investigated the influence of IRAK1 overexpression on the canonical NF-κB signaling as a possible cause for excessive inflammation in these patients. METHODS NF-κB signaling was examined by measuring the production of proinflammatory cytokines and evaluating the IRAK1 phosphorylation and degradation as well as the IκBα degradation upon stimulation with IL-1β and TLR agonists in SV40-immortalized fibroblasts, PBMCs, and whole blood of 9 patients with MECP2/IRAK1 duplication syndrome, respectively. RESULTS Both, MECP2/IRAK1-duplicated patients and healthy controls, showed similar production of IL-6 and IL-8 upon activation with IL-1β and TLR2/6 agonists in immortalized fibroblasts. In PBMCs and whole blood, both patients and controls had a similar response of cytokine production after stimulation with IL-1β and TLR4/2/6 agonists. Patients and controls had equivalent patterns of IRAK1 phosphorylation and degradation as well as IκBα degradation upon stimulation with IL-1β. CONCLUSION Patients with MECP2/IRAK1 duplication syndrome do not show increased canonical NF-κB signaling in immortalized fibroblasts, PBMCs, and whole blood. Therefore, we assume that these patients do not benefit from a therapeutic suppression of this pathway.
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Affiliation(s)
- Ilona Gottschalk
- Department of Pediatric Respiratory Medicine, Immunology and Critical Care Medicine, Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health (BIH), Berlin, Germany
- Berlin-Brandenburg Center for Regenerative Therapies (BCRT), Berlin Institute of Health (BIH), Charité-Universitätsmedizin Berlin, Augustenburger Platz 1, 13353, Berlin, Germany
| | - Uwe Kölsch
- Labor Berlin GmbH, Department of Immunology, Berlin, Germany
| | - Dimitrios L Wagner
- Berlin-Brandenburg Center for Regenerative Therapies (BCRT), Berlin Institute of Health (BIH), Charité-Universitätsmedizin Berlin, Augustenburger Platz 1, 13353, Berlin, Germany
- Berlin Center for Advanced Therapies (BeCAT), Charité-Universitätsmedizin Berlin, Corporate Member of Freie Universität, Berlin, Humboldt-Universität Zu Berlin, and Berlin Institute of Health (BIH), Berlin, Germany
- Institute of Transfusion Medicine, Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health (BIH), Berlin, Germany
- Institute of Medical Immunology, Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health (BIH), Campus Virchow-Klinikum, Berlin, Germany
| | - Jonas Kath
- Berlin-Brandenburg Center for Regenerative Therapies (BCRT), Berlin Institute of Health (BIH), Charité-Universitätsmedizin Berlin, Augustenburger Platz 1, 13353, Berlin, Germany
- Berlin Center for Advanced Therapies (BeCAT), Charité-Universitätsmedizin Berlin, Corporate Member of Freie Universität, Berlin, Humboldt-Universität Zu Berlin, and Berlin Institute of Health (BIH), Berlin, Germany
| | - Stefania Martini
- Berlin-Brandenburg Center for Regenerative Therapies (BCRT), Berlin Institute of Health (BIH), Charité-Universitätsmedizin Berlin, Augustenburger Platz 1, 13353, Berlin, Germany
| | - Renate Krüger
- Department of Pediatric Respiratory Medicine, Immunology and Critical Care Medicine, Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health (BIH), Berlin, Germany
| | - Anne Puel
- Laboratory of Human Genetics of Infectious Diseases, Necker Branch, INSERM U1163, Necker Hospital for Sick Children, Paris, France
- Imagine Institute, University of Paris, Paris, France
| | - Jean-Laurent Casanova
- Laboratory of Human Genetics of Infectious Diseases, Necker Branch, INSERM U1163, Necker Hospital for Sick Children, Paris, France
- Imagine Institute, University of Paris, Paris, France
- St. Giles Laboratory of Human Genetics of Infectious Diseases, Rockefeller Branch, The Rockefeller University, New York, NY, USA
- Howard Hughes Medical Institute, New York, NY, USA
- Pediatric Hematology and Immunology Unit, Necker Hospital for Sick Children, AP-HP, Paris, France
| | - Aleksandra Jezela-Stanek
- Department of Genetics and Clinical Immunology, National Institute of Tuberculosis and Lung Diseases, Warsaw, Poland
| | - Rainer Rossi
- Childrens' Hospital Neukölln, Vivantes GmbH, Berlin, Germany
| | | | - Hilde Van Esch
- Center for Human Genetics, University Hospitals Leuven, Louvain, Belgium
| | - Horst von Bernuth
- Department of Pediatric Respiratory Medicine, Immunology and Critical Care Medicine, Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health (BIH), Berlin, Germany.
- Berlin-Brandenburg Center for Regenerative Therapies (BCRT), Berlin Institute of Health (BIH), Charité-Universitätsmedizin Berlin, Augustenburger Platz 1, 13353, Berlin, Germany.
- Labor Berlin GmbH, Department of Immunology, Berlin, Germany.
- Berlin Institute of Health, Charité-Universitätsmedizin Berlin, Berlin, Germany.
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14
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Leffler M, Christie L, Hackett A, Bennetts B, Goel H, Amor DJ, Peters GB, Field M, Dudding-Byth T. Further delineation of dosage-sensitive K/L mediated Xq28 duplication syndrome includes incomplete penetrance. Clin Genet 2023; 103:681-687. [PMID: 36688272 DOI: 10.1111/cge.14303] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2022] [Revised: 01/07/2023] [Accepted: 01/17/2023] [Indexed: 01/24/2023]
Abstract
The low copy tandem repeat area at Xq28 is prone to recurrent copy number gains, including the K/L mediated duplications of 300 kb size (herein described as the K/L mediated Xq28 duplication syndrome). We describe five families, including nine males with K/L mediated Xq28 duplications, some with regions of greater copy number variation (CNV). We summarise findings in 25 affected males reported to date. Within the five families, males were variably affected by seizures, intellectual disability, and neurological features; however, one male with a familial K/L mediated Xq28 duplication has normal intelligence, suggesting that this CNV is not 100% penetrant. Including our five families, 13 carrier females have been identified, with nine presenting phenotypically normal. Three carrier females reported mild learning difficulties, and all of them had duplications containing regions with at least four copies. Delineation of the spectrum of K/L mediated Xq28 duplication syndrome highlights GDI1 as the most likely candidate gene contributing to the phenotype. For patients identified with CNVs in this region, high-resolution microarray is required to define copy number gains and provide families with accurate information.
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Affiliation(s)
- Melanie Leffler
- NSW Genetics of Learning Disability (GOLD) Service, Hunter New England Local Health District, Waratah, New South Wales, Australia
| | - Louise Christie
- NSW Genetics of Learning Disability (GOLD) Service, Hunter New England Local Health District, Waratah, New South Wales, Australia
| | - Anna Hackett
- NSW Genetics of Learning Disability (GOLD) Service, Hunter New England Local Health District, Waratah, New South Wales, Australia
| | - Bruce Bennetts
- Department of Molecular Genetics, Sydney Genome Diagnostics, Western Sydney Genetics Program, The Children's Hospital at Westmead, Sydney, New South Wales, Australia.,Specialty of Genomic Medicine, Faculty of Medicine and Health, University of Sydney, Sydney, New South Wales, Australia
| | - Himanshu Goel
- Hunter Genetics, Hunter New England Local Health District, Waratah, New South Wales, Australia.,University of Newcastle, Callaghan, New South Wales, Australia
| | - David J Amor
- Murdoch Children's Research Institute, Parkville, Victoria, Australia.,Faculty of Medicine, Dentistry and Health Sciences, University of Melbourne, Parkville, Victoria, Australia.,Department of Paediatrics, Royal Children's Hospital, Parkville, Victoria, Australia
| | - Greg B Peters
- Formerly of Sydney Genome Diagnostics, The Children's Hospital at Westmead, Sydney, New South Wales, Australia
| | - Michael Field
- NSW Genetics of Learning Disability (GOLD) Service, Hunter New England Local Health District, Waratah, New South Wales, Australia
| | - Tracy Dudding-Byth
- NSW Genetics of Learning Disability (GOLD) Service, Hunter New England Local Health District, Waratah, New South Wales, Australia.,Hunter Genetics, Hunter New England Local Health District, Waratah, New South Wales, Australia.,University of Newcastle, Callaghan, New South Wales, Australia
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15
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Differential Sensitivity of the Protein Translation Initiation Machinery and mTOR Signaling to MECP2 Gain- and Loss-of-Function Involves MeCP2 Isoform-Specific Homeostasis in the Brain. Cells 2022; 11:cells11091442. [PMID: 35563748 PMCID: PMC9105805 DOI: 10.3390/cells11091442] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Revised: 04/15/2022] [Accepted: 04/19/2022] [Indexed: 12/25/2022] Open
Abstract
Eukaryotic gene expression is controlled at multiple levels, including gene transcription and protein translation initiation. One molecule with key roles in both regulatory mechanisms is methyl CpG binding protein 2 (MeCP2). MECP2 gain- and loss-of-function mutations lead to Rett Syndrome and MECP2 Duplication Syndrome, respectively. To study MECP2 gain-of-function, we generated stably transduced human brain cells using lentiviral vectors for both MECP2E1 and MECP2E2 isoforms. Stable overexpression was confirmed by Western blot and immunofluorescence. We assessed the impact of MeCP2E1-E2 gain-of-function on the MeCP2 homeostasis regulatory network (MECP2E1/E2-BDNF/BDNF-miR-132), mTOR-AKT signaling, ribosome biogenesis, markers of chromatin structure, and protein translation initiation. We observed that combined co-transduction of MeCP2 isoforms led to protein degradation of MeCP2E1. Proteosome inhibition by MG132 treatment recovered MeCP2E1 protein within an hour, suggesting its induced degradation through the proteosome pathway. No significant change was detected for translation initiation factors as a result of MeCP2E1, MeCP2E2, or combined overexpression of both isoforms. In contrast, analysis of human Rett Syndrome brains tissues compared with controls indicated impaired protein translation initiation, suggesting that such mechanisms may have differential sensitivity to MECP2 gain- and loss-of-function. Collectively, our results provide further insight towards the dose-dependent functional role of MeCP2 isoforms in the human brain.
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16
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Fang X, Butler KM, Abidi F, Gass J, Beisang A, Feyma T, Ryther RC, Standridge S, Heydemann P, Jones M, Haas R, Lieberman DN, Marsh E, Benke TA, Skinner S, Neul JL, Percy AK, Friez MJ, Caylor RC. Analysis of X-inactivation status in a Rett syndrome natural history study cohort. Mol Genet Genomic Med 2022; 10:e1917. [PMID: 35318820 PMCID: PMC9034674 DOI: 10.1002/mgg3.1917] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2021] [Revised: 02/15/2022] [Accepted: 02/17/2022] [Indexed: 12/04/2022] Open
Abstract
BACKGROUND Rett syndrome (RTT) is a rare neurodevelopmental disorder associated with pathogenic MECP2 variants. Because the MECP2 gene is subject to X-chromosome inactivation (XCI), factors including MECP2 genotypic variation, tissue differences in XCI, and skewing of XCI all likely contribute to the clinical severity of individuals with RTT. METHODS We analyzed the XCI patterns from blood samples of 320 individuals and their mothers. It includes individuals with RTT (n = 287) and other syndromes sharing overlapping phenotypes with RTT (such as CDKL5 Deficiency Disorder [CDD, n = 16]). XCI status in each proband/mother duo and the parental origin of the preferentially inactivated X chromosome were analyzed. RESULTS The average XCI ratio in probands was slightly increased compared to their unaffected mothers (73% vs. 69%, p = .0006). Among the duos with informative XCI data, the majority of individuals with classic RTT had their paternal allele preferentially inactivated (n = 180/220, 82%). In sharp contrast, individuals with CDD had their maternal allele preferentially inactivated (n = 10/12, 83%). Our data indicate a weak positive correlation between XCI skewing ratio and clinical severity scale (CSS) scores in classic RTT patients with maternal allele preferentially inactivated XCI (rs = 0.35, n = 40), but not in those with paternal allele preferentially inactivated XCI (rs = -0.06, n = 180). The most frequent MECP2 pathogenic variants were enriched in individuals with highly/moderately skewed XCI patterns, suggesting an association with higher levels of XCI skewing. CONCLUSION These results extend our understanding of the pathogenesis of RTT and other syndromes with overlapping clinical features by providing insight into the both XCI and the preferential XCI of parental alleles.
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Affiliation(s)
- Xiaolan Fang
- Greenwood Genetic CenterGreenwoodSouth CarolinaUSA
| | | | - Fatima Abidi
- Greenwood Genetic CenterGreenwoodSouth CarolinaUSA
| | - Jennifer Gass
- Florida Cancer Specialists & Research InstituteFort MyersFLUSA,Present address:
Florida Cancer Specialists & Research InstituteFort MyersFloridaUSA
| | - Arthur Beisang
- Gillette Children’s Specialty HealthcareSt. PaulMinnesotaUSA
| | - Timothy Feyma
- Gillette Children’s Specialty HealthcareSt. PaulMinnesotaUSA
| | - Robin C. Ryther
- Department of NeurologyWashington University School of MedicineSt. LouisMissouriUSA
| | - Shannon Standridge
- Division of NeurologyCincinnati Children’s Hospital Medical CenterCincinnatiOhioUSA,Department of Pediatrics, College of MedicineUniversity of CincinnatiCincinnatiOhioUSA
| | | | - Mary Jones
- Oakland Children’s Hospital, UCSFOaklandCaliforniaUSA
| | - Richard Haas
- University of California San DiegoSan DiegoCaliforniaUSA
| | - David N Lieberman
- Department of NeurologyBoston Children’s HospitalBostonMassachusettsUSA
| | - Eric D. Marsh
- Children’s Hospital of Philadelphia and University of PennsylvaniaPhiladelphiaPennsylvaniaUSA
| | - Tim A. Benke
- University of Colorado School of Medicine, Children’s Hospital Colorado‐AuroraDenverColoradoUSA
| | | | - Jeffrey L. Neul
- Vanderbilt Kennedy CenterVanderbilt University Medical CenterNashville TN
| | - Alan K. Percy
- The University of Alabama at BirminghamBirminghamAlabamaUSA
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17
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A brief history of MECP2 duplication syndrome: 20-years of clinical understanding. Orphanet J Rare Dis 2022; 17:131. [PMID: 35313898 PMCID: PMC8939085 DOI: 10.1186/s13023-022-02278-w] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Accepted: 03/07/2022] [Indexed: 11/10/2022] Open
Abstract
MECP2 duplication syndrome (MDS) is a rare, X-linked, neurodevelopmental disorder caused by a duplication of the methyl-CpG-binding protein 2 (MECP2) gene-a gene in which loss-of-function mutations lead to Rett syndrome (RTT). MDS has an estimated live birth prevalence in males of 1/150,000. The key features of MDS include intellectual disability, developmental delay, hypotonia, seizures, recurrent respiratory infections, gastrointestinal problems, behavioural features of autism and dysmorphic features-although these comorbidities are not yet understood with sufficient granularity. This review has covered the past two decades of MDS case studies and series since the discovery of the disorder in 1999. After comprehensively reviewing the reported characteristics, this review has identified areas of limited knowledge that we recommend may be addressed by better phenotyping this disorder through an international data collection. This endeavour would also serve to delineate the clinical overlap between MDS and RTT.
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18
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Bassuk AG. Gene therapy for Rett syndrome. GENES, BRAIN, AND BEHAVIOR 2022; 21:e12754. [PMID: 34053173 PMCID: PMC9744469 DOI: 10.1111/gbb.12754] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Accepted: 05/26/2021] [Indexed: 11/29/2022]
Affiliation(s)
- Alexander G Bassuk
- Pediatrics Child Neurology, Neurology, Neurology, Genetics, Molecular and Cellular Biology, The Iowa Neuroscience Institute (INI), The Medical Scientist Training Program, The University of Iowa, Iowa City, Iowa, USA
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19
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Abdala BB, Gonçalves AP, Dos Santos JM, Boy R, de Carvalho CMB, Grochowski CM, Krepischi ACV, Rosenberg C, Gusmão L, Pehlivan D, Pimentel MMG, Santos-Rebouças CB. Molecular and clinical insights into complex genomic rearrangements related to MECP2 duplication syndrome. Eur J Med Genet 2021; 64:104367. [PMID: 34678473 DOI: 10.1016/j.ejmg.2021.104367] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2021] [Revised: 10/04/2021] [Accepted: 10/16/2021] [Indexed: 10/20/2022]
Abstract
MECP2 duplication syndrome (MDS) is caused by copy number variation (CNV) spanning the MECP2 gene at Xq28 and is a major cause of intellectual disability (ID) in males. Herein, we describe two unrelated males harboring non-recurrent complex Xq28 rearrangements associated with MDS. Copy number gains were initially detected by quantitative real-time polymerase chain reaction and further delineated by high-resolution array comparative genomic hybridization, familial segregation, expression analysis and X-chromosome inactivation (XCI) evaluation in a carrier mother. SNVs within the rearrangements and/or fluorescent in situ hybridization (FISH) were used to assess the parental origin of the rearrangements. Patient 1 exhibited an intrachromosomal rearrangement, whose structure is consistent with a triplicated segment presumably embedded in an inverted orientation between two duplicated sequences (DUP-TRP/INV-DUP). The rearrangement was inherited from the carrier mother, who exhibits extreme XCI skewing and subtle psychiatric symptoms. Patient 2 presented a de novo (X;Y) unbalanced translocation resulting in duplication of Xq28 and deletion of Yp, originated in the paternal gametogenesis. Neurodevelopmental trajectory and non-neurological symptoms were consistent with previous reports, with the exception of cerebellar vermis hypoplasia in patient 2. Although both patients share the core MDS phenotype, patient 1 showed MECP2 transcript levels in blood similar to controls. Understanding the molecular mechanisms related to MDS is essential for designing targeted therapeutic strategies.
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Affiliation(s)
- Bianca Barbosa Abdala
- Department of Genetics, Institute of Biology Roberto Alcantara Gomes, State University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Andressa Pereira Gonçalves
- Department of Genetics, Institute of Biology Roberto Alcantara Gomes, State University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Jussara Mendonça Dos Santos
- Department of Genetics, Institute of Biology Roberto Alcantara Gomes, State University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Raquel Boy
- Pedro Ernesto University Hospital, State University of Rio de Janeiro, Rio de Janeiro, Brazil
| | | | | | | | - Carla Rosenberg
- Department of Genetics and Evolutionary Biology, Institute of Biosciences, University of São Paulo, São Paulo, Brazil
| | - Leonor Gusmão
- DNA Diagnostic Laboratory (LDD), State University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Davut Pehlivan
- Department of Molecular and Human Genetics, Baylor College of Medicine, Texas, USA; Section of Neurology, Department of Pediatrics, Baylor College of Medicine, Texas, USA
| | - Márcia Mattos Gonçalves Pimentel
- Department of Genetics, Institute of Biology Roberto Alcantara Gomes, State University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Cíntia Barros Santos-Rebouças
- Department of Genetics, Institute of Biology Roberto Alcantara Gomes, State University of Rio de Janeiro, Rio de Janeiro, Brazil.
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20
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Abstract
OBJECTIVE MECP2 duplication syndrome (MECP2DS) is an x-linked recessive syndrome characterized by infantile hypotonia, severe neurodevelopmental delay, intellectual disability, progressive spasticity, recurrent infections, and seizures. More than 50% of cases have been associated with epilepsy. Seizure semiology and electroencephalogram (EEG) findings in these patients are poorly described. METHODS In this case series, the authors describe the electroclinical features of children with MECP2DS presenting to their institution. In addition, they reviewed seizure types and therapies used. RESULTS Eight out of 9 patients with MECP2DS developed epilepsy, with 56% having normal initial EEG. Generalized slowing with generalized and focal/multifocal discharges was the most common EEG pattern which is consistent with prior studies. Atonic seizure was the most common semiology. Majority were pharmacoresistant (63%). CONCLUSION The goal of this case series is to better define the clinical and electrophysiological aspects of the epilepsy associated with MECP2 duplication syndrome and provide practical guidance regarding management.
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Affiliation(s)
- Jocelyn Lorenzo
- University of Texas Southwestern Medical Center, Dallas, TX, USA
- Children's Medical Center, Dallas, TX, USA
| | - Alison Dolce
- University of Texas Southwestern Medical Center, Dallas, TX, USA
- Children's Medical Center, Dallas, TX, USA
| | - Andrea Lowden
- University of Texas Southwestern Medical Center, Dallas, TX, USA
- Children's Medical Center, Dallas, TX, USA
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21
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Pascual-Alonso A, Martínez-Monseny AF, Xiol C, Armstrong J. MECP2-Related Disorders in Males. Int J Mol Sci 2021; 22:9610. [PMID: 34502518 PMCID: PMC8431762 DOI: 10.3390/ijms22179610] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Revised: 08/25/2021] [Accepted: 09/01/2021] [Indexed: 12/23/2022] Open
Abstract
Methyl CpG binding protein 2 (MECP2) is located at Xq28 and is a multifunctional gene with ubiquitous expression. Loss-of-function mutations in MECP2 are associated with Rett syndrome (RTT), which is a well-characterized disorder that affects mainly females. In boys, however, mutations in MECP2 can generate a wide spectrum of clinical presentations that range from mild intellectual impairment to severe neonatal encephalopathy and premature death. Thus, males can be more difficult to classify and diagnose than classical RTT females. In addition, there are some variants of unknown significance in MECP2, which further complicate the diagnosis of these children. Conversely, the entire duplication of the MECP2 gene is related to MECP2 duplication syndrome (MDS). Unlike in RTT, in MDS, males are predominantly affected. Usually, the duplication is inherited from an apparently asymptomatic carrier mother. Both syndromes share some characteristics, but also differ in some aspects regarding the clinical picture and evolution. In the following review, we present a thorough description of the different types of MECP2 variants and alterations that can be found in males, and explore several genotype-phenotype correlations, although there is still a lot to understand.
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Affiliation(s)
- Ainhoa Pascual-Alonso
- Fundació Per la Recerca Sant Joan de Déu, Santa Rosa 39-57, 08950 Esplugues de Llobregat, Spain; (A.P.-A.); (C.X.)
- Institut de Recerca Sant Joan de Déu, Santa Rosa 39-57, 08950 Esplugues de Llobregat, Spain;
| | - Antonio F. Martínez-Monseny
- Institut de Recerca Sant Joan de Déu, Santa Rosa 39-57, 08950 Esplugues de Llobregat, Spain;
- Clinical Genetics, Molecular and Genetic Medicine Section, Hospital Sant Joan de Déu, 08950 Esplugues de Llobregat, Spain
| | - Clara Xiol
- Fundació Per la Recerca Sant Joan de Déu, Santa Rosa 39-57, 08950 Esplugues de Llobregat, Spain; (A.P.-A.); (C.X.)
- Institut de Recerca Sant Joan de Déu, Santa Rosa 39-57, 08950 Esplugues de Llobregat, Spain;
| | - Judith Armstrong
- Institut de Recerca Sant Joan de Déu, Santa Rosa 39-57, 08950 Esplugues de Llobregat, Spain;
- Clinical Genetics, Molecular and Genetic Medicine Section, Hospital Sant Joan de Déu, 08950 Esplugues de Llobregat, Spain
- CIBER-ER (Biomedical Network Research Center for Rare Diseases), Instituto de Salud Carlos III (ISCIII), 28029 Madrid, Spain
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22
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Collins BE, Merritt JK, Erickson KR, Neul JL. Safety and efficacy of genetic MECP2 supplementation in the R294X mouse model of Rett syndrome. GENES, BRAIN, AND BEHAVIOR 2021; 21:e12739. [PMID: 33942492 PMCID: PMC8563491 DOI: 10.1111/gbb.12739] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Revised: 04/29/2021] [Accepted: 05/01/2021] [Indexed: 01/03/2023]
Abstract
Rett syndrome is a neurodevelopmental disorder caused predominantly by loss-of-function mutations in MECP2, encoding transcriptional modulator methyl-CpG-binding protein 2 (MeCP2). Although no disease-modifying therapies exist at this time, some proposed therapeutic strategies aim to supplement the mutant allele with a wild-type allele producing typical levels of functional MeCP2, such as gene therapy. Because MECP2 is a dosage-sensitive gene, with both loss and gain of function causing disease, these approaches must achieve a narrow therapeutic window to be both safe and effective. While MeCP2 supplementation rescues RTT-like phenotypes in mouse models, the tolerable threshold of MeCP2 is not clear, particularly for partial loss-of-function mutations. We assessed the safety of genetically supplementing full-length human MeCP2 in the context of the R294X allele, a common partial loss-of-function mutation retaining DNA-binding capacity. We assessed the potential for adverse effects from MeCP2 supplementation of a partial loss-of-function mutant and the potential for dominant negative interactions between mutant and full-length MeCP2. In male hemizygous R294X mice, MeCP2 supplementation rescued RTT-like behavioral phenotypes and did not elicit behavioral evidence of excess MeCP2. In female heterozygous R294X mice, RTT-specific phenotypes were similarly rescued. However, MeCP2 supplementation led to evidence of excess MeCP2 activity in a motor coordination assay, suggesting that the underlying motor circuitry is particularly sensitive to MeCP2 dosage in females. These results show that genetic supplementation of full-length MeCP2 is safe in males and largely so females. However, careful consideration of risk for adverse motor effects may be warranted for girls and women with RTT.
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Affiliation(s)
| | - Jonathan K. Merritt
- Department of PediatricsVanderbilt University Medical CenterNashvilleTennesseeUSA
| | - Kirsty R. Erickson
- Department of PediatricsVanderbilt University Medical CenterNashvilleTennesseeUSA
| | - Jeffrey L. Neul
- Vanderbilt Kennedy Center, Departments of Pediatrics, Pharmacology, and Special EducationVanderbilt University Medical Center and Vanderbilt UniversityNashvilleTennesseeUSA
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23
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Sharifi O, Yasui DH. The Molecular Functions of MeCP2 in Rett Syndrome Pathology. Front Genet 2021; 12:624290. [PMID: 33968128 PMCID: PMC8102816 DOI: 10.3389/fgene.2021.624290] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2020] [Accepted: 02/08/2021] [Indexed: 12/13/2022] Open
Abstract
MeCP2 protein, encoded by the MECP2 gene, binds to DNA and affects transcription. Outside of this activity the true range of MeCP2 function is still not entirely clear. As MECP2 gene mutations cause the neurodevelopmental disorder Rett syndrome in 1 in 10,000 female births, much of what is known about the biologic function of MeCP2 comes from studying human cell culture models and rodent models with Mecp2 gene mutations. In this review, the full scope of MeCP2 research available in the NIH Pubmed (https://pubmed.ncbi.nlm.nih.gov/) data base to date is considered. While not all original research can be mentioned due to space limitations, the main aspects of MeCP2 and Rett syndrome research are discussed while highlighting the work of individual researchers and research groups. First, the primary functions of MeCP2 relevant to Rett syndrome are summarized and explored. Second, the conflicting evidence and controversies surrounding emerging aspects of MeCP2 biology are examined. Next, the most obvious gaps in MeCP2 research studies are noted. Finally, the most recent discoveries in MeCP2 and Rett syndrome research are explored with a focus on the potential and pitfalls of novel treatments and therapies.
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Affiliation(s)
- Osman Sharifi
- LaSalle Laboratory, Department of Medical Microbiology and Immunology, UC Davis School of Medicine, Davis, CA, United States
| | - Dag H Yasui
- LaSalle Laboratory, Department of Medical Microbiology and Immunology, UC Davis School of Medicine, Davis, CA, United States
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24
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Gomes AR, Fernandes TG, Cabral JM, Diogo MM. Modeling Rett Syndrome with Human Pluripotent Stem Cells: Mechanistic Outcomes and Future Clinical Perspectives. Int J Mol Sci 2021; 22:3751. [PMID: 33916879 PMCID: PMC8038474 DOI: 10.3390/ijms22073751] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2021] [Revised: 03/23/2021] [Accepted: 04/02/2021] [Indexed: 12/19/2022] Open
Abstract
Rett syndrome (RTT) is a neurodevelopmental disorder caused by mutations in the gene encoding the methyl-CpG-binding protein 2 (MeCP2). Among many different roles, MeCP2 has a high phenotypic impact during the different stages of brain development. Thus, it is essential to intensively investigate the function of MeCP2, and its regulated targets, to better understand the mechanisms of the disease and inspire the development of possible therapeutic strategies. Several animal models have greatly contributed to these studies, but more recently human pluripotent stem cells (hPSCs) have been providing a promising alternative for the study of RTT. The rapid evolution in the field of hPSC culture allowed first the development of 2D-based neuronal differentiation protocols, and more recently the generation of 3D human brain organoid models, a more complex approach that better recapitulates human neurodevelopment in vitro. Modeling RTT using these culture platforms, either with patient-specific human induced pluripotent stem cells (hiPSCs) or genetically-modified hPSCs, has certainly contributed to a better understanding of the onset of RTT and the disease phenotype, ultimately allowing the development of high throughput drugs screening tests for potential clinical translation. In this review, we first provide a brief summary of the main neurological features of RTT and the impact of MeCP2 mutations in the neuropathophysiology of this disease. Then, we provide a thorough revision of the more recent advances and future prospects of RTT modeling with human neural cells derived from hPSCs, obtained using both 2D and organoids culture systems, and its contribution for the current and future clinical trials for RTT.
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Affiliation(s)
- Ana Rita Gomes
- Department of Bioengineering and IBB-Institute for Bioengineering and Biosciences, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa, Portugal; (A.R.G.); (T.G.F.); (J.M.S.C.)
- Associate Laboratory i4HB-Institute for Health and Bioeconomy, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa, Portugal
- Instituto de Medicina Molecular-João Lobo Antunes, Faculdade de Medicina da Universidade de Lisboa, 1649-028 Lisboa, Portugal
| | - Tiago G. Fernandes
- Department of Bioengineering and IBB-Institute for Bioengineering and Biosciences, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa, Portugal; (A.R.G.); (T.G.F.); (J.M.S.C.)
- Associate Laboratory i4HB-Institute for Health and Bioeconomy, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa, Portugal
| | - Joaquim M.S. Cabral
- Department of Bioengineering and IBB-Institute for Bioengineering and Biosciences, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa, Portugal; (A.R.G.); (T.G.F.); (J.M.S.C.)
- Associate Laboratory i4HB-Institute for Health and Bioeconomy, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa, Portugal
| | - Maria Margarida Diogo
- Department of Bioengineering and IBB-Institute for Bioengineering and Biosciences, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa, Portugal; (A.R.G.); (T.G.F.); (J.M.S.C.)
- Associate Laboratory i4HB-Institute for Health and Bioeconomy, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa, Portugal
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25
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Shao Y, Sztainberg Y, Wang Q, Bajikar SS, Trostle AJ, Wan YW, Jafar-Nejad P, Rigo F, Liu Z, Tang J, Zoghbi HY. Antisense oligonucleotide therapy in a humanized mouse model of MECP2 duplication syndrome. Sci Transl Med 2021; 13:eaaz7785. [PMID: 33658357 PMCID: PMC8976688 DOI: 10.1126/scitranslmed.aaz7785] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2019] [Revised: 05/26/2020] [Accepted: 10/01/2020] [Indexed: 12/14/2022]
Abstract
Many intellectual disability disorders are due to copy number variations, and, to date, there have been no treatment options tested for this class of diseases. MECP2 duplication syndrome (MDS) is one of the most common genomic rearrangements in males and results from duplications spanning the methyl-CpG binding protein 2 (MECP2) gene locus. We previously showed that antisense oligonucleotide (ASO) therapy can reduce MeCP2 protein amount in an MDS mouse model and reverse its disease features. This MDS mouse model, however, carried one transgenic human allele and one mouse allele, with the latter being protected from human-specific MECP2-ASO targeting. Because MeCP2 is a dosage-sensitive protein, the ASO must be titrated such that the amount of MeCP2 is not reduced too far, which would cause Rett syndrome. Therefore, we generated an "MECP2 humanized" MDS model that carries two human MECP2 alleles and no mouse endogenous allele. Intracerebroventricular injection of the MECP2-ASO efficiently down-regulated MeCP2 expression throughout the brain in these mice. Moreover, MECP2-ASO mitigated several behavioral deficits and restored expression of selected MeCP2-regulated genes in a dose-dependent manner without any toxicity. Central nervous system administration of MECP2-ASO is therefore well tolerated and beneficial in this mouse model and provides a translatable approach that could be feasible for treating MDS.
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Affiliation(s)
- Yingyao Shao
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
- Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, TX 77030, USA
- Program in Developmental Biology, Baylor College of Medicine, Houston, TX 77030, USA
| | - Yehezkel Sztainberg
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
- Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, TX 77030, USA
| | - Qi Wang
- Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, TX 77030, USA
- Department of Pediatrics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Sameer S Bajikar
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
- Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, TX 77030, USA
| | - Alexander J Trostle
- Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, TX 77030, USA
- Department of Pediatrics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Ying-Wooi Wan
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
- Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, TX 77030, USA
| | | | - Frank Rigo
- Ionis Pharmaceuticals, 2855 Gazelle Court, Carlsbad, CA 92010, USA
| | - Zhandong Liu
- Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, TX 77030, USA
- Department of Pediatrics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Jianrong Tang
- Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, TX 77030, USA
- Department of Pediatrics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Huda Y Zoghbi
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA.
- Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, 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
- Howard Hughes Medical Institute, Baylor College of Medicine, Houston, TX 77030, USA
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26
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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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Pejhan S, Siu VM, Ang LC, Del Bigio MR, Rastegar M. Differential brain region-specific expression of MeCP2 and BDNF in Rett Syndrome patients: a distinct grey-white matter variation. Neuropathol Appl Neurobiol 2020; 46:735-750. [PMID: 32246495 DOI: 10.1111/nan.12619] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2019] [Revised: 01/03/2020] [Accepted: 03/23/2020] [Indexed: 12/18/2022]
Abstract
INTRODUCTION AND OBJECTIVES Rett Syndrome (RTT) is a neurodevelopmental disorder caused by Methyl CpG Binding Protein 2 (MECP2) gene mutations. Previous studies of MeCP2 in the human brain showed variable and inconsistent mosaic-pattern immunolabelling, which has been interpreted as a reflection of activation-state variability. We aimed to study post mortem MeCP2 and BDNF (MeCP2 target) degradation and brain region-specific detection in relation to RTT pathophysiology. METHODS We investigated MeCP2 and BDNF stabilities in non-RTT human brains by immunohistochemical labelling and compared them in three brain regions of RTT and controls. RESULTS In surgically excised samples of human hippocampus and cerebellum, MeCP2 was universally detected. There was no significantly obvious difference between males and females. However, post mortem delay in autopsy samples had substantial influence on MeCP2 detection. Immunohistochemistry studies in RTT patients showed lower MeCP2 detection in glial cells of the white matter. Glial fibrillary acidic protein (GFAP) expression was also reduced in RTT brain samples without obvious change in myelin basic protein (MBP). Neurons did not show any noticeable decrease in MeCP2 detection. BDNF immunohistochemical detection showed an astroglial/endothelial pattern without noticeable difference between RTT and controls. CONCLUSIONS Our findings indicate that MeCP2 protein is widely expressed in mature human brain cells at all ages. However, our data points towards a possible white matter abnormality in RTT and highlights the importance of studying human RTT brain tissues in parallel with research on animal and cell models of RTT.
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Affiliation(s)
- S Pejhan
- Regenerative Medicine Program, and Department of Biochemistry and Medical Genetics, Max Rady College of Medicine, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, MB, Canada
| | - V M Siu
- Division of Medical Genetics, Department of Paediatrics, Schulich School of Medicine and Dentistry, Western University, London, ON, Canada
| | - L C Ang
- Department of Pathology, Schulich School of Medicine and Dentistry, Western University, London, ON, Canada
| | - M R Del Bigio
- Department of Pathology, Max Rady College of Medicine, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, MB, Canada
| | - M Rastegar
- Regenerative Medicine Program, and Department of Biochemistry and Medical Genetics, Max Rady College of Medicine, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, MB, Canada
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Yu B, Yuan B, Dai JK, Cheng TL, Xia SN, He LJ, Yuan YT, Zhang YF, Xu HT, Xu FQ, Liang ZF, Qiu ZL. Reversal of Social Recognition Deficit in Adult Mice with MECP2 Duplication via Normalization of MeCP2 in the Medial Prefrontal Cortex. Neurosci Bull 2020; 36:570-584. [PMID: 32144612 DOI: 10.1007/s12264-020-00467-w] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2019] [Accepted: 11/16/2019] [Indexed: 01/05/2023] Open
Abstract
Methyl-CpG binding protein 2 (MeCP2) is a basic nuclear protein involved in the regulation of gene expression and microRNA processing. Duplication of MECP2-containing genomic segments causes MECP2 duplication syndrome, a severe neurodevelopmental disorder characterized by intellectual disability, motor dysfunction, heightened anxiety, epilepsy, autistic phenotypes, and early death. Reversal of the abnormal phenotypes in adult mice with MECP2 duplication (MECP2-TG) by normalizing the MeCP2 levels across the whole brain has been demonstrated. However, whether different brain areas or neural circuits contribute to different aspects of the behavioral deficits is still unknown. Here, we found that MECP2-TG mice showed a significant social recognition deficit, and were prone to display aversive-like behaviors, including heightened anxiety-like behaviors and a fear generalization phenotype. In addition, reduced locomotor activity was observed in MECP2-TG mice. However, appetitive behaviors and learning and memory were comparable in MECP2-TG and wild-type mice. Functional magnetic resonance imaging illustrated that the differences between MECP2-TG and wild-type mice were mainly concentrated in brain areas regulating emotion and social behaviors. We used the CRISPR-Cas9 method to restore normal MeCP2 levels in the medial prefrontal cortex (mPFC) and bed nuclei of the stria terminalis (BST) of adult MECP2-TG mice, and found that normalization of MeCP2 levels in the mPFC but not in the BST reversed the social recognition deficit. These data indicate that the mPFC is responsible for the social recognition deficit in the transgenic mice, and provide new insight into potential therapies for MECP2 duplication syndrome.
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Affiliation(s)
- Bin Yu
- Institute of Neuroscience, State Key Laboratory of Neuroscience, Chinese Academy of Sciences Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, 200031, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Bo Yuan
- Institute of Neuroscience, State Key Laboratory of Neuroscience, Chinese Academy of Sciences Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, 200031, China
| | - Jian-Kun Dai
- Institute of Neuroscience, State Key Laboratory of Neuroscience, Chinese Academy of Sciences Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, 200031, China
| | - Tian-Lin Cheng
- Institute of Neuroscience, State Key Laboratory of Neuroscience, Chinese Academy of Sciences Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, 200031, China
| | - Sheng-Nan Xia
- Institute of Neuroscience, State Key Laboratory of Neuroscience, Chinese Academy of Sciences Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, 200031, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Ling-Jie He
- Department of Molecular and Human Genetics, Howard Hughes Medical Institute, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Yi-Ting Yuan
- Institute of Neuroscience, State Key Laboratory of Neuroscience, Chinese Academy of Sciences Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, 200031, China
| | - Yue-Fang Zhang
- Institute of Neuroscience, State Key Laboratory of Neuroscience, Chinese Academy of Sciences Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, 200031, China
| | - Hua-Tai Xu
- Institute of Neuroscience, State Key Laboratory of Neuroscience, Chinese Academy of Sciences Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, 200031, China
| | - Fu-Qiang Xu
- Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan, 430071, China
| | - Zhi-Feng Liang
- Institute of Neuroscience, State Key Laboratory of Neuroscience, Chinese Academy of Sciences Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, 200031, China
| | - Zi-Long Qiu
- Institute of Neuroscience, State Key Laboratory of Neuroscience, Chinese Academy of Sciences Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, 200031, China.
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Distinct patterns of complex rearrangements and a mutational signature of microhomeology are frequently observed in PLP1 copy number gain structural variants. Genome Med 2019; 11:80. [PMID: 31818324 PMCID: PMC6902434 DOI: 10.1186/s13073-019-0676-0] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2019] [Accepted: 10/10/2019] [Indexed: 01/05/2023] Open
Abstract
BACKGROUND We investigated the features of the genomic rearrangements in a cohort of 50 male individuals with proteolipid protein 1 (PLP1) copy number gain events who were ascertained with Pelizaeus-Merzbacher disease (PMD; MIM: 312080). We then compared our new data to previous structural variant mutagenesis studies involving the Xq22 region of the human genome. The aggregate data from 159 sequenced join-points (discontinuous sequences in the reference genome that are joined during the rearrangement process) were studied. Analysis of these data from 150 individuals enabled the spectrum and relative distribution of the underlying genomic mutational signatures to be delineated. METHODS Genomic rearrangements in PMD individuals with PLP1 copy number gain events were investigated by high-density customized array or clinical chromosomal microarray analysis and breakpoint junction sequence analysis. RESULTS High-density customized array showed that the majority of cases (33/50; ~ 66%) present with single duplications, although complex genomic rearrangements (CGRs) are also frequent (17/50; ~ 34%). Breakpoint mapping to nucleotide resolution revealed further previously unknown structural and sequence complexities, even in single duplications. Meta-analysis of all studied rearrangements that occur at the PLP1 locus showed that single duplications were found in ~ 54% of individuals and that, among all CGR cases, triplication flanked by duplications is the most frequent CGR array CGH pattern observed. Importantly, in ~ 32% of join-points, there is evidence for a mutational signature of microhomeology (highly similar yet imperfect sequence matches). CONCLUSIONS These data reveal a high frequency of CGRs at the PLP1 locus and support the assertion that replication-based mechanisms are prominent contributors to the formation of CGRs at Xq22. We propose that microhomeology can facilitate template switching, by stabilizing strand annealing of the primer using W-C base complementarity, and is a mutational signature for replicative repair.
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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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31
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Yang H, Li K, Han S, Zhou A, Zhou ZJ. Leveraging the genetic basis of Rett syndrome to ascertain pathophysiology. Neurobiol Learn Mem 2019; 165:106961. [PMID: 30447288 PMCID: PMC6635128 DOI: 10.1016/j.nlm.2018.11.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2018] [Revised: 09/18/2018] [Accepted: 11/14/2018] [Indexed: 10/27/2022]
Abstract
Mutations in the methyl-CpG binding protein 2 (MECP2) gene cause Rett syndrome (RTT), a progressive X-linked neurological disorder characterized by loss of developmental milestones, intellectual disability and breathing abnormality. Despite being a monogenic disorder, the pathogenic mechanisms by which mutations in MeCP2 impair neuronal function and underlie the RTT symptoms have been challenging to elucidate. The seemingly simple genetic root and the availability of genetic data from RTT patients have led to the generation and characterization of a series of mouse models recapitulating RTT-associated genetic mutations. This review focuses on the studies of RTT mouse models and describe newly obtained pathogenic insights from these studies. We also highlight the potential of studying pathophysiology using genetics-based modeling approaches in rodents and suggest a future direction to tackle the pathophysiology of intellectual disability with known or complex genetic causes.
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Affiliation(s)
- Hua Yang
- Qingdao Jiaozhou Central Hospital, Jiaozhou City, Shandong Province 266300, China
| | - Kequan Li
- Qingdao Jiaozhou Central Hospital, Jiaozhou City, Shandong Province 266300, China
| | - Song Han
- Jiaozhou People's Hospital, Jiaozhou City, Shandong Province 266300, China
| | - Ailing Zhou
- Jiaozhou People's Hospital, Jiaozhou City, Shandong Province 266300, China
| | - Zhaolan Joe Zhou
- Department of Genetics, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA.
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Giudice-Nairn P, Downs J, Wong K, Wilson D, Ta D, Gattas M, Amor D, Thompson E, Kirrali-Borri C, Ellaway C, Leonard H. The incidence, prevalence and clinical features of MECP2 duplication syndrome in Australian children. J Paediatr Child Health 2019; 55:1315-1322. [PMID: 30756435 DOI: 10.1111/jpc.14399] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/02/2018] [Accepted: 01/20/2019] [Indexed: 12/22/2022]
Abstract
AIM The aim of this study was to assess the incidence and prevalence of MECP2 duplication syndrome in Australian children and further define its phenotype. METHODS The Australian Paediatric Surveillance Unit was used to identify children with MECP2 duplication syndrome between June 2014 and November 2017. Reporting clinicians were invited to complete a questionnaire. Clinician data (n = 20) were supplemented with information from the International Rett Syndrome Phenotype Database and from caregivers (n = 7). Birth prevalence and diagnostic incidence were calculated. RESULTS The birth prevalence of MECP2 duplication syndrome in Australia was 0.65/100 000 for all live births and 1/100 000 for males. Diagnostic incidence was 0.07/100 000 person-years overall and 0.12/100 000 person-years for males. The median age at diagnosis was 23.5 months (range 0 months-13 years). A history of pneumonia was documented in three quarters of the clinical cases, half of whom had more than nine episodes. Cardiovascular abnormalities were reported in three cases. A clinical vignette is presented for one child who died due to severe idiopathic pulmonary hypertension. The majority (13/15) of males had inherited the duplication from their mothers, and two had an unbalanced translocation. CONCLUSIONS MECP2 duplication syndrome is a rare but important diagnosis in children because of the burden of respiratory illness and recurrence risk. Pulmonary hypertension is a rare life-threatening complication. Array comparative genomic hybridisation testing is recommended for children with undiagnosed intellectual disability or global developmental delay. Early cardiac assessment and ongoing monitoring is recommended for MECP2 duplication syndrome.
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Affiliation(s)
- Peter Giudice-Nairn
- Telethon Kids Institute, University of Western Australia, Perth, Western Australia, Australia
| | - Jenny Downs
- Telethon Kids Institute, University of Western Australia, Perth, Western Australia, Australia.,School of Physiotherapy and Exercise Science, Curtin University, Perth, Western Australia, Australia
| | - Kingsley Wong
- Telethon Kids Institute, University of Western Australia, Perth, Western Australia, Australia
| | - Dylan Wilson
- Leading Steps Paediatric Clinic, Gold Coast, Queensland, Australia
| | - Daniel Ta
- Telethon Kids Institute, University of Western Australia, Perth, Western Australia, Australia
| | | | - David Amor
- Murdoch Children's Research Institute, Melbourne, Victoria, Australia.,Royal Children's Hospital, Melbourne, Victoria, Australia.,Department of Paediatrics, University of Melbourne, Melbourne, Victoria, Australia
| | - Elizabeth Thompson
- SA Clinical Genetics Service, Women's and Children's Hospital, Adelaide, South Australia, Australia.,Faculty of Health and Medical Sciences, University of Adelaide, Adelaide, South Australia, Australia
| | - Cathy Kirrali-Borri
- Genetic Metabolic Disorders Service, Sydney Children's Hospital Network, Sydney, New South Wales, Australia
| | - Carolyn Ellaway
- Genetic Medicine, and Child and Adolescent Health, University of Sydney, Sydney, New South Wales, Australia
| | - Helen Leonard
- Telethon Kids Institute, University of Western Australia, Perth, Western Australia, Australia
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33
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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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Zhou C, Yan S, Qian S, Wang Z, Shi Z, Xiong Y, Zhou Y. Atypical Response Properties of the Auditory Cortex of Awake MECP2-Overexpressing Mice. Front Neurosci 2019; 13:439. [PMID: 31133783 PMCID: PMC6515258 DOI: 10.3389/fnins.2019.00439] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2018] [Accepted: 04/16/2019] [Indexed: 11/13/2022] Open
Abstract
Methyl-CpG binding protein 2 (MECP2) is a gene associated with DNA methylation and has been found to be important for maintaining brain function. In humans, overexpression of MECP2 can cause a severe developmental disorder known as MECP2 duplication syndrome. However, it is still unclear whether MECP2 overexpression also causes auditory abnormalities, which are common in people with autism. MECP2-TG is a mouse model of MECP2 duplication syndrome and has been widely used for research on social difficulty and other autism-like disorders. In this study, we used a combination of multiple electrophysiological techniques to document the response properties of the auditory cortex of awake MECP2-TG mice. Our results showed that while the auditory brainstem responses are similar, cortical activity patterns including local field potentials (LFPs), multiunit activity (MUA), and single-neuron responses differ between MECP2-TG and wild-type (WT) mice. At the single-neuron level, the spike waveform of fast-spiking (FS) neurons from MECP2-TG mice is different from that of WT mice, as reflected by reduced peak/trough ratios in the transgenic mice. Both regular-spiking (RS) and FS neurons exhibited atypical response properties in MECP2-TG mice compared with WT mice, such as prolonged latency and an elevated intensity threshold; furthermore, regarding the response strength to different stimuli, MECP2-TG mice exhibited stronger responses to noise than to pure tone, while this pattern was not observed in WT mice. Our findings suggest that MECP2 overexpression can cause the auditory cortex to have atypical response properties, an implication that could be helpful for further understanding the nature of auditory deficits in autism.
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Affiliation(s)
- Chang Zhou
- Department of Neurobiology, School of Basic Medical Sciences, Army Medical University, Chongqing, China
| | - Sumei Yan
- Department of Neurobiology, School of Basic Medical Sciences, Army Medical University, Chongqing, China
| | - Shaowen Qian
- Department of Neurobiology, School of Basic Medical Sciences, Army Medical University, Chongqing, China
| | - Zhaoqun Wang
- Department of Neurobiology, School of Basic Medical Sciences, Army Medical University, Chongqing, China
| | - Zhiyue Shi
- Department of Neurobiology, School of Basic Medical Sciences, Army Medical University, Chongqing, China
| | - Ying Xiong
- Department of Neurobiology, School of Basic Medical Sciences, Army Medical University, Chongqing, China
| | - Yi Zhou
- Department of Neurobiology, School of Basic Medical Sciences, Army Medical University, Chongqing, China
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35
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Carvalho CMB, Coban-Akdemir Z, Hijazi H, Yuan B, Pendleton M, Harrington E, Beaulaurier J, Juul S, Turner DJ, Kanchi RS, Jhangiani SN, Muzny DM, Gibbs RA, Stankiewicz P, Belmont JW, Shaw CA, Cheung SW, Hanchard NA, Sutton VR, Bader PI, Lupski JR. Interchromosomal template-switching as a novel molecular mechanism for imprinting perturbations associated with Temple syndrome. Genome Med 2019; 11:25. [PMID: 31014393 PMCID: PMC6480824 DOI: 10.1186/s13073-019-0633-y] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2018] [Accepted: 04/02/2019] [Indexed: 12/13/2022] Open
Abstract
Background Intrachromosomal triplications (TRP) can contribute to disease etiology via gene dosage effects, gene disruption, position effects, or fusion gene formation. Recently, post-zygotic de novo triplications adjacent to copy-number neutral genomic intervals with runs of homozygosity (ROH) have been shown to result in uniparental isodisomy (UPD). The genomic structure of these complex genomic rearrangements (CGRs) shows a consistent pattern of an inverted triplication flanked by duplications (DUP-TRP/INV-DUP) formed by an iterative DNA replisome template-switching mechanism during replicative repair of a single-ended, double-stranded DNA (seDNA), the ROH results from an interhomolog or nonsister chromatid template switch. It has been postulated that these CGRs may lead to genetic abnormalities in carriers due to dosage-sensitive genes mapping within the copy-number variant regions, homozygosity for alleles at a locus causing an autosomal recessive (AR) disease trait within the ROH region, or imprinting-associated diseases. Methods Here, we report a family wherein the affected subject carries a de novo 2.2-Mb TRP followed by 42.2 Mb of ROH and manifests clinical features overlapping with those observed in association with chromosome 14 maternal UPD (UPD(14)mat). UPD(14)mat can cause clinical phenotypic features enabling a diagnosis of Temple syndrome. This CGR was then molecularly characterized by high-density custom aCGH, genome-wide single-nucleotide polymorphism (SNP) and methylation arrays, exome sequencing (ES), and the Oxford Nanopore long-read sequencing technology. Results We confirmed the postulated DUP-TRP/INV-DUP structure by multiple orthogonal genomic technologies in the proband. The methylation status of known differentially methylated regions (DMRs) on chromosome 14 revealed that the subject shows the typical methylation pattern of UPD(14)mat. Consistent with these molecular findings, the clinical features overlap with those observed in Temple syndrome, including speech delay. Conclusions These data provide experimental evidence that, in humans, triplication can lead to segmental UPD and imprinting disease. Importantly, genotype/phenotype analyses further reveal how a post-zygotically generated complex structural variant, resulting from a replication-based mutational mechanism, contributes to expanding the clinical phenotype of known genetic syndromes. Mechanistically, such events can distort transmission genetics resulting in homozygosity at a locus for which only one parent is a carrier as well as cause imprinting diseases. Electronic supplementary material The online version of this article (10.1186/s13073-019-0633-y) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Claudia M B Carvalho
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, Room 604B, Houston, TX, 77030-3498, USA.
| | - Zeynep Coban-Akdemir
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, Room 604B, Houston, TX, 77030-3498, USA
| | - Hadia Hijazi
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, Room 604B, Houston, TX, 77030-3498, USA
| | - Bo Yuan
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, Room 604B, Houston, TX, 77030-3498, USA
| | | | | | | | - Sissel Juul
- Oxford Nanopore Technologies Inc, New York, NY, USA.,Oxford Nanopore Technologies Inc, San Francisco, CA, USA
| | | | | | - Shalini N Jhangiani
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Donna M Muzny
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Richard A Gibbs
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, Room 604B, Houston, TX, 77030-3498, USA.,Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX, 77030, USA
| | | | - Pawel Stankiewicz
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, Room 604B, Houston, TX, 77030-3498, USA
| | - John W Belmont
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, Room 604B, Houston, TX, 77030-3498, USA.,Department of Pediatrics, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Chad A Shaw
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, Room 604B, Houston, TX, 77030-3498, USA
| | - Sau Wai Cheung
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, Room 604B, Houston, TX, 77030-3498, USA
| | - Neil A Hanchard
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, Room 604B, Houston, TX, 77030-3498, USA
| | - V Reid Sutton
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, Room 604B, Houston, TX, 77030-3498, USA.,Texas Children's Hospital, Houston, TX, USA
| | | | - James R Lupski
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, Room 604B, Houston, TX, 77030-3498, USA.,Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX, 77030, USA.,Department of Pediatrics, Baylor College of Medicine, Houston, TX, 77030, USA.,Texas Children's Hospital, Houston, TX, USA
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36
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Peters SU, Fu C, Suter B, Marsh E, Benke TA, Skinner SA, Lieberman DN, Standridge S, Jones M, Beisang A, Feyma T, Heydeman P, Ryther R, Kaufmann WE, Glaze DG, Neul JL, Percy AK. Characterizing the phenotypic effect of Xq28 duplication size in MECP2 duplication syndrome. Clin Genet 2019; 95:575-581. [PMID: 30788845 DOI: 10.1111/cge.13521] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2018] [Revised: 02/01/2019] [Accepted: 02/05/2019] [Indexed: 12/11/2022]
Abstract
Individuals with methyl CpG binding protein 2 (MECP2) duplication syndrome (MDS) have varying degrees of severity in their mobility, hand use, developmental skills, and susceptibility to infections. In the present study, we examine the relationship between duplication size, gene content, and overall phenotype in MDS using a clinical severity scale. Other genes typically duplicated within Xq28 (eg, GDI1, RAB39B, FLNA) are associated with distinct clinical features independent of MECP2. We additionally compare the phenotype of this cohort (n = 48) to other reported cohorts with MDS. Utilizing existing indices of clinical severity in Rett syndrome, we found that larger duplication size correlates with higher severity in total clinical severity scores (r = 0.36; P = 0.02), and in total motor behavioral assessment inventory scores (r = 0.31; P = 0.05). Greater severity was associated with having the RAB39B gene duplicated, although most of these participants also had large duplications. Results suggest that developmental delays in the first 6 months of life, hypotonia, vasomotor disturbances, constipation, drooling, and bruxism are common in MDS. This is the first study to show that duplication size is related to clinical severity. Future studies should examine whether large duplications which do not encompass RAB39B also contribute to clinical severity. Results also suggest the need for creating an MDS specific severity scale.
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Affiliation(s)
- Sarika U Peters
- Department of Pediatrics, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Cary Fu
- Department of Pediatrics, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Bernhard Suter
- Department of Pediatrics, Baylor College of Medicine, Houston, Texas
| | - Eric Marsh
- Division of Neurology and Pediatrics, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania
| | - Timothy A Benke
- Department of Pediatrics, University of Colorado School of Medicine, Aurora, Colorado
| | | | - David N Lieberman
- Department of Pediatrics, Boston Children's Hospital, Boston, Massachusetts
| | - Shannon Standridge
- Department of Pediatrics, Cincinnati Children's Hospital, Cincinnati, Ohio
| | - Mary Jones
- Department of Pediatrics, UCSF Benioff Children's Hospital, Oakland, California
| | - Arthur Beisang
- Department of Pediatrics, Gilette Children's Specialty Healthcare, Saint Paul, Minnesota
| | - Timothy Feyma
- Department of Pediatrics, Gilette Children's Specialty Healthcare, Saint Paul, Minnesota
| | - Peter Heydeman
- Department of Pediatrics, Rush University Medical Center, Chicago, Illinois
| | - Robin Ryther
- Department of Neurology, Washington University School of Medicine, St. Louis, Missouri
| | | | - Daniel G Glaze
- Department of Pediatrics, Baylor College of Medicine, Houston, Texas
| | - Jeffrey L Neul
- Department of Pediatrics, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Alan K Percy
- Department of Pediatrics, University of Alabama at Birmingham, Birmingham, Alabama
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Sex Differences in the Effects of Prenatal Bisphenol A Exposure on Genes Associated with Autism Spectrum Disorder in the Hippocampus. Sci Rep 2019; 9:3038. [PMID: 30816183 PMCID: PMC6395584 DOI: 10.1038/s41598-019-39386-w] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2018] [Accepted: 01/21/2019] [Indexed: 11/30/2022] Open
Abstract
Autism spectrum disorder (ASD) is a neurodevelopmental disorder inexplicably biased towards males. Although prenatal exposure to bisphenol A (BPA) has recently been associated with the ASD risk, whether BPA dysregulates ASD-related genes in the developing brain remains unclear. In this study, transcriptome profiling by RNA-seq analysis of hippocampi isolated from neonatal pups prenatally exposed to BPA was conducted and revealed a list of differentially expressed genes (DEGs) associated with ASD. Among the DEGs, several ASD candidate genes, including Auts2 and Foxp2, were dysregulated and showed sex differences in response to BPA exposure. The interactome and pathway analyses of DEGs using Ingenuity Pathway Analysis software revealed significant associations between the DEGs in males and neurological functions/disorders associated with ASD. Moreover, the reanalysis of transcriptome profiling data from previously published BPA studies consistently showed that BPA-responsive genes were significantly associated with ASD-related genes. The findings from this study indicate that prenatal BPA exposure alters the expression of ASD-linked genes in the hippocampus and suggest that maternal BPA exposure may increase ASD susceptibility by dysregulating genes associated with neurological functions known to be negatively impacted in ASD, which deserves further investigations.
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38
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Kim JJ, Savas JN, Miller MT, Hu X, Carromeu C, Lavallée-Adam M, Freitas BCG, Muotri AR, Yates JR, Ghosh A. Proteomic analyses reveal misregulation of LIN28 expression and delayed timing of glial differentiation in human iPS cells with MECP2 loss-of-function. PLoS One 2019; 14:e0212553. [PMID: 30789962 PMCID: PMC6383942 DOI: 10.1371/journal.pone.0212553] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2018] [Accepted: 02/05/2019] [Indexed: 12/14/2022] Open
Abstract
Rett syndrome (RTT) is a pervasive developmental disorder caused by mutations in MECP2. Complete loss of MECP2 function in males causes congenital encephalopathy, neurodevelopmental arrest, and early lethality. Induced pluripotent stem cell (iPSC) lines from male patients harboring mutations in MECP2, along with control lines from their unaffected fathers, give us an opportunity to identify some of the earliest cellular and molecular changes associated with MECP2 loss-of-function (LOF). We differentiated iPSC-derived neural progenitor cells (NPCs) using retinoic acid (RA) and found that astrocyte differentiation is perturbed in iPSC lines derived from two different patients. Using highly stringent quantitative proteomic analyses, we found that LIN28, a gene important for cell fate regulation and developmental timing, is upregulated in mutant NPCs compared to WT controls. Overexpression of LIN28 protein in control NPCs suppressed astrocyte differentiation and reduced neuronal synapse density, whereas downregulation of LIN28 expression in mutant NPCs partially rescued this synaptic deficiency. These results indicate that the pathophysiology of RTT may be caused in part by misregulation of developmental timing in neural progenitors, and the subsequent consequences of this disruption on neuronal and glial differentiation.
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Affiliation(s)
- Jean J. Kim
- Section of Neurobiology, Division of Biological Sciences, University of California San Diego, La Jolla, California, United States of America
- Department of Pediatrics, University of California San Diego, La Jolla, California, United States of America
- * E-mail: (JJK); (JNS)
| | - Jeffrey N. Savas
- Department of Chemical Physiology, The Scripps Research Institute, La Jolla, California, United States of America
- * E-mail: (JJK); (JNS)
| | - Meghan T. Miller
- Pharma Research and Early Development (pRED), Roche Innovation Center Basel, F. Hoffmann-La Roche, Basel, Switzerland
| | - Xindao Hu
- Section of Neurobiology, Division of Biological Sciences, University of California San Diego, La Jolla, California, United States of America
- Department of Pediatrics, University of California San Diego, La Jolla, California, United States of America
| | - Cassiano Carromeu
- Department of Pediatrics, University of California San Diego, La Jolla, California, United States of America
| | - Mathieu Lavallée-Adam
- Department of Chemical Physiology, The Scripps Research Institute, La Jolla, California, United States of America
| | - Beatriz C. G. Freitas
- Department of Pediatrics, University of California San Diego, La Jolla, California, United States of America
| | - Alysson R. Muotri
- Department of Pediatrics, University of California San Diego, La Jolla, California, United States of America
| | - John R. Yates
- Department of Chemical Physiology, The Scripps Research Institute, La Jolla, California, United States of America
| | - Anirvan Ghosh
- Section of Neurobiology, Division of Biological Sciences, University of California San Diego, La Jolla, California, United States of America
- Pharma Research and Early Development (pRED), Roche Innovation Center Basel, F. Hoffmann-La Roche, Basel, Switzerland
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39
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FOXG1 Regulates PRKAR2B Transcriptionally and Posttranscriptionally via miR200 in the Adult Hippocampus. Mol Neurobiol 2018; 56:5188-5201. [PMID: 30539330 PMCID: PMC6647430 DOI: 10.1007/s12035-018-1444-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2018] [Accepted: 11/30/2018] [Indexed: 02/04/2023]
Abstract
Rett syndrome is a complex neurodevelopmental disorder that is mainly caused by mutations in MECP2. However, mutations in FOXG1 cause a less frequent form of atypical Rett syndrome, called FOXG1 syndrome. FOXG1 is a key transcription factor crucial for forebrain development, where it maintains the balance between progenitor proliferation and neuronal differentiation. Using genome-wide small RNA sequencing and quantitative proteomics, we identified that FOXG1 affects the biogenesis of miR200b/a/429 and interacts with the ATP-dependent RNA helicase, DDX5/p68. Both FOXG1 and DDX5 associate with the microprocessor complex, whereby DDX5 recruits FOXG1 to DROSHA. RNA-Seq analyses of Foxg1cre/+ hippocampi and N2a cells overexpressing miR200 family members identified cAMP-dependent protein kinase type II-beta regulatory subunit (PRKAR2B) as a target of miR200 in neural cells. PRKAR2B inhibits postsynaptic functions by attenuating protein kinase A (PKA) activity; thus, increased PRKAR2B levels may contribute to neuronal dysfunctions in FOXG1 syndrome. Our data suggest that FOXG1 regulates PRKAR2B expression both on transcriptional and posttranscriptional levels.
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Fisher NM, Gogliotti RG, Vermudez SAD, Stansley BJ, Conn PJ, Niswender CM. Genetic Reduction or Negative Modulation of mGlu 7 Does Not Impact Anxiety and Fear Learning Phenotypes in a Mouse Model of MECP2 Duplication Syndrome. ACS Chem Neurosci 2018; 9:2210-2217. [PMID: 29227625 DOI: 10.1021/acschemneuro.7b00414] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Rett syndrome and MECP2 Duplication syndrome are neurodevelopmental disorders attributed to loss-of-function mutations in, or duplication of, the gene encoding methyl-CpG-binding protein 2 (MeCP2), respectively. We recently reported decreased expression and function of the metabotropic glutamate receptor 7 (mGlu7) in a mouse model of Rett syndrome. Positive allosteric modulation of mGlu7 activity was sufficient to improve several disease phenotypes including cognition. Here, we tested the hypothesis that mGlu7 expression would be reciprocally regulated in a mouse model of MECP2 Duplication syndrome, such that negative modulation of mGlu7 activity would exert therapeutic benefit. To the contrary, we report that mGlu7 is not functionally increased in mice overexpressing MeCP2 and that neither genetic nor pharmacological reduction of mGlu7 activity impacts phenotypes that are antiparallel to those observed in Rett syndrome model mice. These data expand our understanding of how mGlu7 expression and function is affected by changes in MeCP2 dosage and have important implications for the therapeutic development of mGlu7 modulators.
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Affiliation(s)
- Nicole M. Fisher
- Department of Pharmacology, Vanderbilt University, Nashville, Tennessee 37232, United States
- Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University, Nashville, Tennessee 37232, United States
| | - Rocco G. Gogliotti
- Department of Pharmacology, Vanderbilt University, Nashville, Tennessee 37232, United States
- Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University, Nashville, Tennessee 37232, United States
| | - Sheryl Anne D. Vermudez
- Department of Pharmacology, Vanderbilt University, Nashville, Tennessee 37232, United States
- Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University, Nashville, Tennessee 37232, United States
| | - Branden J. Stansley
- Department of Pharmacology, Vanderbilt University, Nashville, Tennessee 37232, United States
- Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University, Nashville, Tennessee 37232, United States
| | - P. Jeffrey Conn
- Department of Pharmacology, Vanderbilt University, Nashville, Tennessee 37232, United States
- Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University, Nashville, Tennessee 37232, United States
- Vanderbilt Kennedy Center, Vanderbilt University Medical Center, Nashville, Tennessee 37232, United States
| | - Colleen M. Niswender
- Department of Pharmacology, Vanderbilt University, Nashville, Tennessee 37232, United States
- Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University, Nashville, Tennessee 37232, United States
- Vanderbilt Kennedy Center, Vanderbilt University Medical Center, Nashville, Tennessee 37232, United States
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41
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Tan Q, Zoghbi HY. Mouse models as a tool for discovering new neurological diseases. Neurobiol Learn Mem 2018; 165:106902. [PMID: 30030131 DOI: 10.1016/j.nlm.2018.07.006] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2018] [Revised: 05/11/2018] [Accepted: 07/17/2018] [Indexed: 02/08/2023]
Abstract
Animal models have been the mainstay of biological and medical research. Although there are drawbacks to any research tool, we argue that mice have been under-utilized as a tool for predicting human diseases. Here we review four examples from our research group where studying the consequences of altered gene dosage in a mouse led to the discovery of previously unrecognized human syndromes: MECP2 duplication syndrome, SHANK3 duplication syndrome, CIC haploinsufficiency syndrome, and PUM1-related disorders. We also describe the clinical phenotypes of two individuals with CIC haploinsufficiency syndrome who have not been reported previously. To help bring biological insights gained from model systems a step closer to disease gene discovery, we discuss tools and resources that will facilitate this process. Moving back and forth between the lab and the clinic, between studies of mouse models and human patients, will continue to drive disease gene discovery and lead to better understanding of gene functions and disease mechanisms, laying the groundwork for future therapeutic interventions.
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Affiliation(s)
- Qiumin Tan
- 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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42
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Tordjman S, Cohen D, Anderson G, Botbol M, Canitano R, Coulon N, Roubertoux P. Repint of “Reframing autism as a behavioral syndrome and not a specific mental disorder: Implications of genetic and phenotypic heterogeneity”. Neurosci Biobehav Rev 2018; 89:132-150. [DOI: 10.1016/j.neubiorev.2018.01.014] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2016] [Revised: 12/18/2016] [Accepted: 01/23/2017] [Indexed: 12/22/2022]
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43
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Cheung SW, Bi W. Novel applications of array comparative genomic hybridization in molecular diagnostics. Expert Rev Mol Diagn 2018; 18:531-542. [PMID: 29848116 DOI: 10.1080/14737159.2018.1479253] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
INTRODUCTION In 2004, the implementation of array comparative genomic hybridization (array comparative genome hybridization [CGH]) into clinical practice marked a new milestone for genetic diagnosis. Array CGH and single-nucleotide polymorphism (SNP) arrays enable genome-wide detection of copy number changes in a high resolution, and therefore microarray has been recognized as the first-tier test for patients with intellectual disability or multiple congenital anomalies, and has also been applied prenatally for detection of clinically relevant copy number variations in the fetus. Area covered: In this review, the authors summarize the evolution of array CGH technology from their diagnostic laboratory, highlighting exonic SNP arrays developed in the past decade which detect small intragenic copy number changes as well as large DNA segments for the region of heterozygosity. The applications of array CGH to human diseases with different modes of inheritance with the emphasis on autosomal recessive disorders are discussed. Expert commentary: An exonic array is a powerful and most efficient clinical tool in detecting genome wide small copy number variants in both dominant and recessive disorders. However, whole-genome sequencing may become the single integrated platform for detection of copy number changes, single-nucleotide changes as well as balanced chromosomal rearrangements in the near future.
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Affiliation(s)
- Sau W Cheung
- a Department of Molecular and Human Genetics , Baylor College of Medicine , Houston , TX , USA
| | - Weimin Bi
- a Department of Molecular and Human Genetics , Baylor College of Medicine , Houston , TX , USA.,b Baylor Genetics , Houston , TX , USA
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44
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Lombardi LM, Zaghlula M, Sztainberg Y, Baker SA, Klisch TJ, Tang AA, Huang EJ, Zoghbi HY. An RNA interference screen identifies druggable regulators of MeCP2 stability. Sci Transl Med 2018; 9:9/404/eaaf7588. [PMID: 28835516 DOI: 10.1126/scitranslmed.aaf7588] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2016] [Revised: 04/14/2016] [Accepted: 06/13/2017] [Indexed: 12/14/2022]
Abstract
Alterations in gene dosage due to copy number variation are associated with autism spectrum disorder, intellectual disability (ID), and other psychiatric disorders. The nervous system is so acutely sensitive to the dose of methyl-CpG-binding protein 2 (MeCP2) that even a twofold change in MeCP2 protein-either increased or decreased-results in distinct disorders with overlapping features including ID, autistic behavior, and severe motor dysfunction. Rett syndrome is caused by loss-of-function mutations in MECP2, whereas duplications spanning the MECP2 locus result in MECP2 duplication syndrome (MDS), which accounts for ~1% of X-linked ID. Despite evidence from mouse models that restoring MeCP2 can reverse the course of disease, there are currently no U.S. Food and Drug Administration-approved therapies available to clinically modulate MeCP2 abundance. We used a forward genetic screen against all known human kinases and phosphatases to identify druggable regulators of MeCP2 stability. Two putative modulators of MeCP2, HIPK2 (homeodomain-interacting protein kinase 2) and PP2A (protein phosphatase 2A), were validated as stabilizers of MeCP2 in vivo. Further, pharmacological inhibition of PP2A in vivo reduced MeCP2 in the nervous system and rescued both overexpression and motor abnormalities in a mouse model of MDS. Our findings reveal potential therapeutic targets for treating disorders of altered MECP2 dosage.
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Affiliation(s)
- Laura M Lombardi
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA.,Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, TX 77030, USA.,Howard Hughes Medical Institute, Baylor College of Medicine, Houston, TX 77030, USA
| | - Manar Zaghlula
- Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, TX 77030, USA.,Graduate Program in Translational Biology and Molecular Medicine, Baylor College of Medicine, Houston, TX 77030, USA
| | - Yehezkel Sztainberg
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA.,Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, TX 77030, USA
| | - Steven A Baker
- Department of Pathology, Stanford University School of Medicine, Palo Alto, CA 94305, USA
| | - Tiemo J Klisch
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA.,Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, TX 77030, USA
| | - Amy A Tang
- Department of Pathology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Eric J Huang
- Department of Pathology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Huda Y Zoghbi
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA. .,Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, TX 77030, USA.,Howard Hughes Medical Institute, Baylor College of Medicine, Houston, TX 77030, USA.,Graduate Program in Translational Biology and Molecular Medicine, Baylor College of Medicine, Houston, TX 77030, USA.,Department of Neuroscience, Baylor College of Medicine, Houston, TX 77030, USA.,Department of Pediatrics, Baylor College of Medicine, Houston, TX 77030, USA
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45
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Ali Rodriguez R, Joya C, Hines RM. Common Ribs of Inhibitory Synaptic Dysfunction in the Umbrella of Neurodevelopmental Disorders. Front Mol Neurosci 2018; 11:132. [PMID: 29740280 PMCID: PMC5928253 DOI: 10.3389/fnmol.2018.00132] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2018] [Accepted: 04/03/2018] [Indexed: 01/06/2023] Open
Abstract
The term neurodevelopmental disorder (NDD) is an umbrella term used to group together a heterogeneous class of disorders characterized by disruption in cognition, emotion, and behavior, early in the developmental timescale. These disorders are heterogeneous, yet they share common behavioral symptomatology as well as overlapping genetic contributors, including proteins involved in the formation, specialization, and function of synaptic connections. Advances may arise from bridging the current knowledge on synapse related factors indicated from both human studies in NDD populations, and in animal models. Mounting evidence has shown a link to inhibitory synapse formation, specialization, and function among Autism, Angelman, Rett and Dravet syndromes. Inhibitory signaling is diverse, with numerous subtypes of inhibitory interneurons, phasic and tonic modes of inhibition, and the molecular and subcellular diversity of GABAA receptors. We discuss common ribs of inhibitory synapse dysfunction in the umbrella of NDD, highlighting alterations in the developmental switch to inhibitory GABA, dysregulation of neuronal activity patterns by parvalbumin-positive interneurons, and impaired tonic inhibition. Increasing our basic understanding of inhibitory synapses, and their role in NDDs is likely to produce significant therapeutic advances in behavioral symptom alleviation for interrelated NDDs.
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Affiliation(s)
- Rachel Ali Rodriguez
- Neuroscience Emphasis, Department of Psychology, University of Nevada, Las Vegas, Las Vegas, NV, United States
| | - Christina Joya
- Neuroscience Emphasis, Department of Psychology, University of Nevada, Las Vegas, Las Vegas, NV, United States
| | - Rochelle M Hines
- Neuroscience Emphasis, Department of Psychology, University of Nevada, Las Vegas, Las Vegas, NV, United States
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46
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Miguet M, Faivre L, Amiel J, Nizon M, Touraine R, Prieur F, Pasquier L, Lefebvre M, Thevenon J, Dubourg C, Julia S, Sarret C, Remerand G, Francannet C, Laffargue F, Boespflug-Tanguy O, David A, Isidor B, Vigneron J, Leheup B, Lambert L, Philippe C, Béri-Dexheimer M, Cuisset JM, Andrieux J, Plessis G, Toutain A, Guibaud L, Cormier-Daire V, Rio M, Bonnefont JP, Echenne B, Journel H, Burglen L, Chantot-Bastaraud S, Bienvenu T, Baumann C, Perrin L, Drunat S, Jouk PS, Dieterich K, Devillard F, Lacombe D, Philip N, Sigaudy S, Moncla A, Missirian C, Badens C, Perreton N, Thauvin-Robinet C, AChro-Puce R, Pedespan JM, Rooryck C, Goizet C, Vincent-Delorme C, Duban-Bedu B, Bahi-Buisson N, Afenjar A, Maincent K, Héron D, Alessandri JL, Martin-Coignard D, Lesca G, Rossi M, Raynaud M, Callier P, Mosca-Boidron AL, Marle N, Coutton C, Satre V, Caignec CL, Malan V, Romana S, Keren B, Tabet AC, Kremer V, Scheidecker S, Vigouroux A, Lackmy-Port-Lis M, Sanlaville D, Till M, Carneiro M, Gilbert-Dussardier B, Willems M, Van Esch H, Portes VD, El Chehadeh S. Further delineation of the MECP2 duplication syndrome phenotype in 59 French male patients, with a particular focus on morphological and neurological features. J Med Genet 2018; 55:359-371. [PMID: 29618507 DOI: 10.1136/jmedgenet-2017-104956] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2017] [Revised: 02/04/2018] [Accepted: 02/15/2018] [Indexed: 12/22/2022]
Abstract
The Xq28 duplication involving the MECP2 gene (MECP2 duplication) has been mainly described in male patients with severe developmental delay (DD) associated with spasticity, stereotypic movements and recurrent infections. Nevertheless, only a few series have been published. We aimed to better describe the phenotype of this condition, with a focus on morphological and neurological features. Through a national collaborative study, we report a large French series of 59 affected males with interstitial MECP2 duplication. Most of the patients (93%) shared similar facial features, which evolved with age (midface hypoplasia, narrow and prominent nasal bridge, thick lower lip, large prominent ears), thick hair, livedo of the limbs, tapered fingers, small feet and vasomotor troubles. Early hypotonia and global DD were constant, with 21% of patients unable to walk. In patients able to stand, lower limbs weakness and spasticity led to a singular standing habitus: flexion of the knees, broad-based stance with pseudo-ataxic gait. Scoliosis was frequent (53%), such as divergent strabismus (76%) and hypermetropia (54%), stereotypic movements (89%), without obvious social withdrawal and decreased pain sensitivity (78%). Most of the patients did not develop expressive language, 35% saying few words. Epilepsy was frequent (59%), with a mean onset around 7.4 years of age, and often (62%) drug-resistant. Other medical issues were frequent: constipation (78%), and recurrent infections (89%), mainly lung. We delineate the clinical phenotype of MECP2 duplication syndrome in a large series of 59 males. Pulmonary hypertension appeared as a cause of early death in these patients, advocating its screening early in life.
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Affiliation(s)
- Marguerite Miguet
- Service de génétique médicale, Institut de Génétique Médicale d'Alsace (IGMA), Centre de Référence Maladies Rares "Anomalies du développement et syndromes malformatifs", Centre de Référence Maladies Rares "Des déficiences intellectuelles de causes rares", Hôpitaux Universitaires de Strasbourg, Hôpital de Hautepierre, Strasbourg, France
| | - Laurence Faivre
- FHU TRANSLAD, Centre de Référence Maladies Rares «Anomalies du développement et syndromes malformatifs», Centre de Génétique, CHU de Dijon, Dijon, France
| | - Jeanne Amiel
- Service de Génétique Clinique, Hôpital Necker Enfants Malades, APHP, Paris, France
| | - Mathilde Nizon
- Service de Génétique Clinique, Hôpital Necker Enfants Malades, APHP, Paris, France
| | - Renaud Touraine
- Service de Génétique Clinique, CHU de Saint-Etienne, Saint-Etienne, France
| | - Fabienne Prieur
- Service de Génétique Clinique, CHU de Saint-Etienne, Saint-Etienne, France
| | - Laurent Pasquier
- Service de Génétique Clinique, CLAD Ouest, CHU de Rennes, Rennes, France
| | - Mathilde Lefebvre
- FHU TRANSLAD, Centre de Référence Maladies Rares «Anomalies du développement et syndromes malformatifs», Centre de Génétique, CHU de Dijon, Dijon, France
| | - Julien Thevenon
- FHU TRANSLAD, Centre de Référence Maladies Rares «Anomalies du développement et syndromes malformatifs», Centre de Génétique, CHU de Dijon, Dijon, France
| | | | - Sophie Julia
- Service de Génétique Médicale, CHU de Toulouse, Toulouse, France
| | - Catherine Sarret
- Service de Neuropédiatrie, CHU de Clermont-Ferrand, Clermont-Ferrand, France
| | - Ganaëlle Remerand
- Service de Neuropédiatrie, CHU de Clermont-Ferrand, Clermont-Ferrand, France
| | - Christine Francannet
- Service de Génétique Médicale, CHU de Clermont-Ferrand, Clermont-Ferrand, France
| | - Fanny Laffargue
- Service de Génétique Médicale, CHU de Clermont-Ferrand, Clermont-Ferrand, France
| | - Odile Boespflug-Tanguy
- Service de Neuropédiatrie et Maladies Métaboliques, Hôpital Robert Debré, APHP, Paris, France
| | - Albert David
- Service de Génétique Médicale, CHU de Nantes, Nantes, France
| | - Bertrand Isidor
- Service de Génétique Médicale, CHU de Nantes, Nantes, France
| | | | - Bruno Leheup
- Service de Génétique Médicale, CHU de Nancy, Nancy, France
| | | | | | | | | | - Joris Andrieux
- Laboratoire de Génétique Médicale, Hôpital Jeanne de Flandre, CHRU de Lille, Lille, France
| | | | | | - Laurent Guibaud
- Service de Radiologie, Hôpital Femme Mère Enfant, Bron, France
| | | | - Marlene Rio
- Service de Génétique Clinique, Hôpital Necker Enfants Malades, APHP, Paris, France
| | - Jean-Paul Bonnefont
- Laboratoire de Biologie Moléculaire, Hôpital Necker Enfants Malades, APHP, Paris, France
| | - Bernard Echenne
- Service de Neurologie pédiatrique, CHU de Montpellier, Montpellier, France
| | - Hubert Journel
- Service de Génétique, Centre Hospitalier de Vannes, Vannes, France
| | - Lydie Burglen
- Service de Génétique, Hôpital Armand Trousseau, APHP, Paris, France
| | | | - Thierry Bienvenu
- Laboratoire de Génétique Moléculaire, GH Cochin-Broca Hôtel Dieu, APHP, Paris, France
| | - Clarisse Baumann
- Service de Génétique Clinique, Hôpital Robert Debré, APHP, Paris, France
| | - Laurence Perrin
- Service de Génétique Clinique, Hôpital Robert Debré, APHP, Paris, France
| | - Séverine Drunat
- Laboratoire de Biologie Moléculaire, Hôpital Robert Debré, APHP, Paris, France
| | - Pierre-Simon Jouk
- Département de Génétique et Procréation - UMR CNRS 5525 TIMC-IMAG - équipe DYCTIM, CHU Grenoble, Grenoble, France
| | - Klaus Dieterich
- Département de Génétique et Procréation - UMR CNRS 5525 TIMC-IMAG - équipe DYCTIM, CHU Grenoble, Grenoble, France
| | - Françoise Devillard
- Département de Génétique et Procréation - UMR CNRS 5525 TIMC-IMAG - équipe DYCTIM, CHU Grenoble, Grenoble, France
| | - Didier Lacombe
- Université de Bordeaux, Laboratoire MRGM, INSERM U1211 and Service de Génétique Médicale, CHU de Bordeaux, Bordeaux, France
| | - Nicole Philip
- Département de Génétique Médicale, Hôpital de la Timone, Marseille, France
| | - Sabine Sigaudy
- Département de Génétique Médicale, Hôpital de la Timone, Marseille, France
| | - Anne Moncla
- Laboratoire de Génétique Chromosomique, Hôpital de la Timone, Marseille, France
| | - Chantal Missirian
- Laboratoire de Génétique Chromosomique, Hôpital de la Timone, Marseille, France
| | - Catherine Badens
- Laboratoire de Biologie Moléculaire, Hôpital de la Timone, Marseille, France
| | | | - Christel Thauvin-Robinet
- FHU TRANSLAD, Centre de Référence Maladies Rares «Anomalies du développement et syndromes malformatifs», Centre de Génétique, CHU de Dijon, Dijon, France
| | | | | | - Caroline Rooryck
- Université de Bordeaux, Laboratoire MRGM, INSERM U1211 and Service de Génétique Médicale, CHU de Bordeaux, Bordeaux, France
| | - Cyril Goizet
- Université de Bordeaux, Laboratoire MRGM, INSERM U1211 and Service de Génétique Médicale, CHU de Bordeaux, Bordeaux, France
| | | | - Bénédicte Duban-Bedu
- Centre de Génétique Chromosomique, GH de l'Institut Catholique de Lille, Hôpital Saint-Vincent-de-Paul, Lille, France
| | - Nadia Bahi-Buisson
- Service de Neuropédiatrie, Hôpital Necker Enfants Malades, APHP, Paris, France
| | - Alexandra Afenjar
- Département de Génétique Médicale, Centre de Référence "Malformations et maladies congénitales du cervelet", APHP, Hôpital Armand Trousseau, APHP, Paris, France
| | - Kim Maincent
- Département de Génétique Médicale, Centre de Référence "Malformations et maladies congénitales du cervelet", APHP, Hôpital Armand Trousseau, APHP, Paris, France
| | - Delphine Héron
- Service de Génétique Clinique, Hôpital Pitié-Salpêtrière, APHP, Paris, France
| | | | | | - Gaëtan Lesca
- Service de génétique, Hospices Civils de Lyon, Lyon, France.,INSERM U1028, CNRS UMR5292, Centre de Recherche en Neurosciences de Lyon, GENDEV Team, Université Claude Bernard Lyon 1, Lyon, France
| | - Massimiliano Rossi
- Service de génétique, Hospices Civils de Lyon, Lyon, France.,INSERM U1028, CNRS UMR5292, Centre de Recherche en Neurosciences de Lyon, GENDEV Team, Université Claude Bernard Lyon 1, Lyon, France
| | - Martine Raynaud
- Laboratoire de Génétique Moléculaire, CHRU de Tours, Tours, France
| | | | | | - Nathalie Marle
- Laboratoire de Cytogénétique, CHU de Dijon, Dijon, France
| | - Charles Coutton
- Laboratoire de Cytogénétique, CHU de Grenoble, Grenoble, France
| | - Véronique Satre
- Laboratoire de Cytogénétique, CHU de Grenoble, Grenoble, France
| | - Cédric Le Caignec
- Laboratoire de Cytogénétique, CHU de Nantes, Nantes, France.,Sarcomes osseux et remodelage des tissus calcifiés, Université Bretagne Loire, INSERM, UMR1238, Nantes, France
| | - Valérie Malan
- Laboratoire de Cytogénétique, Hôpital Necker Enfants Malades, APHP, Paris, France
| | - Serge Romana
- Laboratoire de Cytogénétique, Hôpital Necker Enfants Malades, APHP, Paris, France
| | - Boris Keren
- Laboratoire de Cytogénétique, Hôpital Pitié-Salpêtrière, APHP, Paris, France
| | - Anne-Claude Tabet
- Laboratoire de Cytogénétique, Hôpital Robert Debré, APHP, Paris, France
| | - Valérie Kremer
- Laboratoire de Cytogénétique, CHU de Strasbourg, Hôpital de Hautepierre, Strasbourg, France
| | - Sophie Scheidecker
- Laboratoire de Cytogénétique, CHU de Strasbourg, Hôpital de Hautepierre, Strasbourg, France
| | | | | | | | - Marianne Till
- Laboratoire de Cytogénétique, CHU de Lyon, Lyon, France
| | - Maryline Carneiro
- Service de Neuropédiatrie, CHU de Lyon, Hôpital Femme-Mère-Enfant, Lyon, France
| | | | | | - Hilde Van Esch
- Laboratory for Genetics of Cognition, Center for Human Genetics, University Hospitals Leuven, Leuven, Belgium
| | - Vincent Des Portes
- Centre de Référence Maladies Rares «Des déficiences intellectuelles de causes rares», HFME, Hospices Civils de Lyon and Université de Lyon, Lyon, France.,Institut des Sciences Cognitives, CNRS UMR 5304, Bron, France
| | - Salima El Chehadeh
- Service de génétique médicale, Institut de Génétique Médicale d'Alsace (IGMA), Centre de Référence Maladies Rares "Anomalies du développement et syndromes malformatifs", Centre de Référence Maladies Rares "Des déficiences intellectuelles de causes rares", Hôpitaux Universitaires de Strasbourg, Hôpital de Hautepierre, Strasbourg, France.,FHU TRANSLAD, Centre de Référence Maladies Rares «Anomalies du développement et syndromes malformatifs», Centre de Génétique, CHU de Dijon, Dijon, France
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Mellios N, Feldman DA, Sheridan SD, Ip JP, Kwok S, Amoah SK, Rosen B, Rodriguez BA, Crawford B, Swaminathan R, Chou S, Li Y, Ziats M, Ernst C, Jaenisch R, Haggarty SJ, Sur M. MeCP2-regulated miRNAs control early human neurogenesis through differential effects on ERK and AKT signaling. Mol Psychiatry 2018; 23:1051-1065. [PMID: 28439102 PMCID: PMC5815944 DOI: 10.1038/mp.2017.86] [Citation(s) in RCA: 178] [Impact Index Per Article: 29.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/25/2016] [Revised: 02/12/2017] [Accepted: 02/28/2017] [Indexed: 12/15/2022]
Abstract
Rett syndrome (RTT) is an X-linked, neurodevelopmental disorder caused primarily by mutations in the methyl-CpG-binding protein 2 (MECP2) gene, which encodes a multifunctional epigenetic regulator with known links to a wide spectrum of neuropsychiatric disorders. Although postnatal functions of MeCP2 have been thoroughly investigated, its role in prenatal brain development remains poorly understood. Given the well-established importance of microRNAs (miRNAs) in neurogenesis, we employed isogenic human RTT patient-derived induced pluripotent stem cell (iPSC) and MeCP2 short hairpin RNA knockdown approaches to identify novel MeCP2-regulated miRNAs enriched during early human neuronal development. Focusing on the most dysregulated miRNAs, we found miR-199 and miR-214 to be increased during early brain development and to differentially regulate extracellular signal-regulated kinase (ERK)/mitogen-activated protein kinase and protein kinase B (PKB/AKT) signaling. In parallel, we characterized the effects on human neurogenesis and neuronal differentiation brought about by MeCP2 deficiency using both monolayer and three-dimensional (cerebral organoid) patient-derived and MeCP2-deficient neuronal culture models. Inhibiting miR-199 or miR-214 expression in iPSC-derived neural progenitors deficient in MeCP2 restored AKT and ERK activation, respectively, and ameliorated the observed alterations in neuronal differentiation. Moreover, overexpression of miR-199 or miR-214 in the wild-type mouse embryonic brains was sufficient to disturb neurogenesis and neuronal migration in a similar manner to Mecp2 knockdown. Taken together, our data support a novel miRNA-mediated pathway downstream of MeCP2 that influences neurogenesis via interactions with central molecular hubs linked to autism spectrum disorders.
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Affiliation(s)
- Nikolaos Mellios
- Department of Neurosciences, University of New Mexico School of Medicine, Albuquerque, NM, 87131,Department of Brain and Cognitive Sciences, Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, MA 02139,Correspondence to and
| | - Danielle A. Feldman
- Department of Brain and Cognitive Sciences, Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, MA 02139
| | - Steven D. Sheridan
- Department of Brain and Cognitive Sciences, Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, MA 02139,Chemical Neurobiology Laboratory, Center for Human Genetic Research, Departments of Neurology & Psychiatry, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114
| | - Jacque P.K. Ip
- Department of Brain and Cognitive Sciences, Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, MA 02139
| | - Showming Kwok
- Department of Brain and Cognitive Sciences, Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, MA 02139
| | - Stephen K. Amoah
- Department of Neurosciences, University of New Mexico School of Medicine, Albuquerque, NM, 87131
| | - Bess Rosen
- Department of Brain and Cognitive Sciences, Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, MA 02139
| | - Brian A. Rodriguez
- Department of Neurosciences, University of New Mexico School of Medicine, Albuquerque, NM, 87131
| | - Benjamin Crawford
- Department of Brain and Cognitive Sciences, Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, MA 02139
| | - Radha Swaminathan
- Department of Neurosciences, University of New Mexico School of Medicine, Albuquerque, NM, 87131
| | - Stephanie Chou
- Department of Brain and Cognitive Sciences, Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, MA 02139
| | - Yun Li
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142
| | - Mark Ziats
- National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, 20892
| | - Carl Ernst
- Department of Psychiatry, McGill University, Montreal, QC Canada
| | - Rudolf Jaenisch
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142
| | - Stephen J. Haggarty
- Chemical Neurobiology Laboratory, Center for Human Genetic Research, Departments of Neurology & Psychiatry, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114
| | - Mriganka Sur
- Department of Brain and Cognitive Sciences, Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, MA 02139,Correspondence to and
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Ward DI, Buckley BA, Leon E, Diaz J, Galegos MF, Hofherr S, Lewanda AF. Intellectual disability and epilepsy due to the K/L-mediated Xq28 duplication: Further evidence of a distinct, dosage-dependent phenotype. Am J Med Genet A 2018; 176:551-559. [PMID: 29341460 DOI: 10.1002/ajmg.a.38524] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2017] [Revised: 09/27/2017] [Accepted: 10/08/2017] [Indexed: 12/30/2022]
Abstract
Copy number variants of the X-chromosome are a common cause of X-linked intellectual disability in males. Duplication of the Xq28 band has been known for over a decade to be the cause of the Lubs X-linked Mental Retardation Syndrome (OMIM 300620) in males and this duplication has been narrowed to a critical region containing only the genes MECP2 and IRAK1. In 2009, four families with a distal duplication of Xq28 not including MECP2 and mediated by low-copy repeats (LCRs) designated "K" and "L" were reported with intellectual disability and epilepsy. Duplication of a second more distal region has been described as the cause of the Int22h-1/Int22h-2 Mediated Xq28 Duplication Syndrome, characterized by intellectual disability, psychiatric problems, and recurrent infections. We report two additional families possessing the K/L-mediated Xq28 duplication with affected males having intellectual disability and epilepsy similar to the previously reported phenotype. To our knowledge, this is the second cohort of individuals to be reported with this duplication and therefore supports K/L-mediated Xq28 duplications as a distinct syndrome.
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Affiliation(s)
- David Isum Ward
- McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University, Baltimore, Maryland
| | - Bethany A Buckley
- McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University, Baltimore, Maryland
| | - Eyby Leon
- Rare Disease Institute Genetics and Metabolism, Children's National Health System, Washington, District of Columbia
| | - Jullianne Diaz
- Rare Disease Institute Genetics and Metabolism, Children's National Health System, Washington, District of Columbia
| | - Margaret Faust Galegos
- Rare Disease Institute Genetics and Metabolism, Children's National Health System, Washington, District of Columbia
| | - Sean Hofherr
- Rare Disease Institute Genetics and Metabolism, Children's National Health System, Washington, District of Columbia
| | - Amy Feldman Lewanda
- McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University, Baltimore, Maryland.,Rare Disease Institute Genetics and Metabolism, Children's National Health System, Washington, District of Columbia
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49
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Li X, Xie H, Chen Q, Yu X, Yi Z, Li E, Zhang T, Wang J, Zhong J, Chen X. Clinical and molecular genetic characterization of familial MECP2 duplication syndrome in a Chinese family. BMC MEDICAL GENETICS 2017; 18:131. [PMID: 29141583 PMCID: PMC5688748 DOI: 10.1186/s12881-017-0486-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/17/2016] [Accepted: 10/24/2017] [Indexed: 01/09/2023]
Abstract
Background Chromosomal duplication at the Xq28 region including the MECP2 gene, share consistent clinical phenotypes and a distinct facial phenotype known as MECP2 duplication syndrome. The typical clinical features include infantile hypotonia, mild dysmorphic features, a broad range of neurodevelopmental disorders, recurrent infections, and progressive spasticity. Methods This Chinese MECP2 duplication syndrome family includes six patients (five males and one female), and four asymptomatic female carriers. Two kinds of chips including 4x180K CNV + SNP chip and custom 8x60K CNV chip were used to detect MECP2 duplication, and then fluorescent in situ hybridization (FISH) analysis was performed to identify the exact copy number of MECP2. X-chromosome inactivation (XCI) analysis on AR gene was detected for all female family members, and the microsatellite analysis on MECP2 was used to validate the recombination event on MECP2 region. Results The affected male subjects presented with a broad range of neurodevelopmental symptoms (severe intellectual disability, developmental delay, seizure, language deficit, and autism spectrum disorder) as well as facial dysmorphism and other symptoms which were consistent with that of Western patients previous reported. Seizure is reported in Chinese patients for the first time. In addition, we validated three recombination events for the MECP2-duplication allele during maternal transmission due to X homologous recombination. Conclusions We provided the largest known Chinese pedigree with MECP2 duplication syndrome. The detailed clinical description and molecular genetic characterization in all affected family members further delineate the typical phenotype of this genomic disorder in Chinese population. Electronic supplementary material The online version of this article (10.1186/s12881-017-0486-4) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Xiaoyan Li
- Department of Neurology, Jiangxi Children's Hospital, Yangming Road, Donghu District, Nanchang, 330006, China.,Beijing Municipal Key Laboratory of Child Development and Nutriomics, Capital Institute of Pediatrics, Room 616, NO. 2, Yabao Road, Chaoyang District, Beijing, 100020, China
| | - Hua Xie
- Beijing Municipal Key Laboratory of Child Development and Nutriomics, Capital Institute of Pediatrics, Room 616, NO. 2, Yabao Road, Chaoyang District, Beijing, 100020, China.,Department of Medical Genetics, Capital Institute of Pediatrics, Beijing, China
| | - Qian Chen
- Department of Neurology, Affiliated Children's Hospital of Capital Institute of Pediatrics, Beijing, China
| | - Xiongying Yu
- Department of Neurology, Jiangxi Children's Hospital, Yangming Road, Donghu District, Nanchang, 330006, China
| | - Zhaoshi Yi
- Department of Neurology, Jiangxi Children's Hospital, Yangming Road, Donghu District, Nanchang, 330006, China
| | - Erzhen Li
- Department of Neurology, Affiliated Children's Hospital of Capital Institute of Pediatrics, Beijing, China
| | - Ting Zhang
- Beijing Municipal Key Laboratory of Child Development and Nutriomics, Capital Institute of Pediatrics, Room 616, NO. 2, Yabao Road, Chaoyang District, Beijing, 100020, China
| | - Jian Wang
- Department of Laboratory Medicine, Shanghai Children's Medical Center, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Jianmin Zhong
- Department of Neurology, Jiangxi Children's Hospital, Yangming Road, Donghu District, Nanchang, 330006, China.
| | - Xiaoli Chen
- Beijing Municipal Key Laboratory of Child Development and Nutriomics, Capital Institute of Pediatrics, Room 616, NO. 2, Yabao Road, Chaoyang District, Beijing, 100020, China. .,Department of Medical Genetics, Capital Institute of Pediatrics, Beijing, China.
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50
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Sztainberg Y, Zoghbi HY. Lessons learned from studying syndromic autism spectrum disorders. Nat Neurosci 2017; 19:1408-1417. [PMID: 27786181 DOI: 10.1038/nn.4420] [Citation(s) in RCA: 148] [Impact Index Per Article: 21.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Syndromic autism spectrum disorders represent a group of childhood neurological conditions, typically associated with chromosomal abnormalities or mutations in a single gene. The discovery of their genetic causes has increased our understanding of the molecular pathways critical for normal cognitive and social development. Human studies have revealed that the brain is particularly sensitive to changes in dosage of various proteins from transcriptional and translational regulators to synaptic proteins. Investigations of these disorders in animals have shed light on previously unknown pathogenic mechanisms leading to the identification of potential targets for therapeutic intervention. The demonstration of reversibility of several phenotypes in adult mice is encouraging, and brings hope that with novel therapies, skills and functionality might improve in affected children and young adults. As new research reveals points of convergence between syndromic and nonsyndromic autism spectrum disorders, we believe there will be opportunities for shared therapeutics for this class of conditions.
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Affiliation(s)
- Yehezkel Sztainberg
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, USA.,Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, Texas, USA
| | - Huda Y Zoghbi
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, USA.,Department of Neuroscience, Baylor College of Medicine, Houston, Texas, USA.,Howard Hughes Medical Institute, Baylor College of Medicine, Houston, Texas, USA
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