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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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2
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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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3
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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: 14] [Impact Index Per Article: 7.0] [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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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: 13] [Impact Index Per Article: 4.3] [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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5
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Pascual-Alonso A, Blasco L, Vidal S, Gean E, Rubio P, O'Callaghan M, Martínez-Monseny AF, Castells AA, Xiol C, Català V, Brandi N, Pacheco P, Ros C, Del Campo M, Guillén E, Ibañez S, Sánchez MJ, Lapunzina P, Nevado J, Santos F, Lloveras E, Ortigoza-Escobar JD, Tejada MI, Maortua H, Martínez F, Orellana C, Roselló M, Mesas MA, Obón M, Plaja A, Fernández-Ramos JA, Tizzano E, Marín R, Peña-Segura JL, Alcántara S, Armstrong J. Molecular characterization of Spanish patients with MECP2 duplication syndrome. Clin Genet 2020; 97:610-620. [PMID: 32043567 DOI: 10.1111/cge.13718] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2019] [Revised: 02/04/2020] [Accepted: 02/05/2020] [Indexed: 12/16/2022]
Abstract
MECP2 duplication syndrome (MDS) is an X-linked neurodevelopmental disorder characterized by a severe to profound intellectual disability, early onset hypotonia and diverse psycho-motor and behavioural features. To date, fewer than 200 cases have been published. We report the clinical and molecular characterization of a Spanish MDS cohort that included 19 boys and 2 girls. Clinical suspicions were confirmed by array comparative genomic hybridization and multiplex ligation-dependent probe amplification (MLPA). Using, a custom in-house MLPA assay, we performed a thorough study of the minimal duplicated region, from which we concluded a complete duplication of both MECP2 and IRAK1 was necessary for a correct MDS diagnosis, as patients with partial MECP2 duplications lacked some typical clinical traits present in other MDS patients. In addition, the duplication location may be related to phenotypic severity. This observation may provide a new approach for genotype-phenotype correlations, and thus more personalized genetic counselling.
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Affiliation(s)
- Ainhoa Pascual-Alonso
- Fundación San Juan de Dios, Servicio de Medicina Genética y Molecular, Barcelona, Spain
| | - Laura Blasco
- Fundación San Juan de Dios, Servicio de Medicina Genética y Molecular, Barcelona, Spain
| | - Silvia Vidal
- Fundación San Juan de Dios, Servicio de Medicina Genética y Molecular, Barcelona, Spain
| | - Esther Gean
- Departamento de Medicina Genética y Molecular, Hospital Universitario San Juan de Dios, Barcelona, Spain
| | - Patricia Rubio
- Departamento de Medicina Genética y Molecular, Hospital Universitario San Juan de Dios, Barcelona, Spain
| | - Mar O'Callaghan
- Departamento de Neurología Pediátrica, Hospital Universitario San Juan de Dios, Barcelona, Spain
| | - Antonio F Martínez-Monseny
- Departamento de Medicina Genética y Molecular, Hospital Universitario San Juan de Dios, Barcelona, Spain
| | - Alba Aina Castells
- Fundación San Juan de Dios, Servicio de Medicina Genética y Molecular, Barcelona, Spain.,Neural Development Lab, Departament de Patologia i Terapèutica Experimental, Institut de Neurociències, Universitat de Barcelona, IDIBELL, l'Hospitalet de Llobregat, Barcelona, Spain
| | - Clara Xiol
- Fundación San Juan de Dios, Servicio de Medicina Genética y Molecular, Barcelona, Spain
| | - Vicenç Català
- Unitad de Biología Celular y Genética Médica, Departament of BCFyI, Universidad Autónoma de Barcelona, Barcelona, Spain
| | - Nuria Brandi
- Servicio de Medicina Genètica i Molecular, Hospital Universitario San Juan de Dios, Barcelona, Spain
| | - Paola Pacheco
- Servicio de Medicina Genètica i Molecular, Hospital Universitario San Juan de Dios, Barcelona, Spain
| | - Carlota Ros
- Servicio de Medicina Genètica i Molecular, Hospital Universitario San Juan de Dios, Barcelona, Spain
| | - Miguel Del Campo
- Pediatrics, Genetic Epidemiology, Hospital Valle Hebrón, Barcelona, Spain
| | - Encarna Guillén
- Unidad de Genética, Hospital Virgen de la Arrixaca, Murcia, Spain
| | - Salva Ibañez
- Unidad de Genética, Hospital Virgen de la Arrixaca, Murcia, Spain
| | - María J Sánchez
- Unidad de Genética, Hospital Virgen de la Arrixaca, Murcia, Spain
| | - Pablo Lapunzina
- Instituto de Genética Médica y Molecular, Hospital Universitario La Paz, Madrid, Spain.,CIBERER (Biomedical Network Research Center for Rare Diseases), Instituto de Salud Carlos III, Madrid, Spain
| | - Julián Nevado
- Instituto de Genética Médica y Molecular, Hospital Universitario La Paz, Madrid, Spain.,CIBERER (Biomedical Network Research Center for Rare Diseases), Instituto de Salud Carlos III, Madrid, Spain
| | - Fernando Santos
- Instituto de Genética Médica y Molecular, Hospital Universitario La Paz, Madrid, Spain
| | | | - Juan D Ortigoza-Escobar
- Departamento de Neurología Pediátrica, Hospital Universitario San Juan de Dios, Barcelona, Spain
| | - María I Tejada
- CIBERER (Biomedical Network Research Center for Rare Diseases), Instituto de Salud Carlos III, Madrid, Spain.,Laboratorio de Genética Molecular, Servicio de Genética, Instituto de Investigación Sanitaria Biocruces, Hospital Universitario de Cruces, Barakaldo, Spain
| | - Hiart Maortua
- CIBERER (Biomedical Network Research Center for Rare Diseases), Instituto de Salud Carlos III, Madrid, Spain.,Laboratorio de Genética Molecular, Servicio de Genética, Instituto de Investigación Sanitaria Biocruces, Hospital Universitario de Cruces, Barakaldo, Spain
| | - Francisco Martínez
- Unidad de Genética, Hospital Universitario y Politécnico La Fe, Valencia, Spain
| | - Carmen Orellana
- Unidad de Genética, Hospital Universitario y Politécnico La Fe, Valencia, Spain
| | - Mónica Roselló
- Unidad de Genética, Hospital Universitario y Politécnico La Fe, Valencia, Spain
| | | | - María Obón
- Area de Genètica Clínica i Consell Genètic, Laboratoris ICS, Girona, Spain
| | - Alberto Plaja
- Institut de Recerca (VHIR), Universitat Autònoma de Barcelona, Hospital Universitari Vall d'Hebron, Barcelona, Spain
| | | | - Eduardo Tizzano
- Area Genética Clínica y Molecular, Hospital Universitari Vall d'Hebron, Barcelona, Spain
| | - Rosario Marín
- Hospital Universitario Puerta del Mar Unidad de Genética, Cádiz, Spain
| | - José L Peña-Segura
- Unidad de Neuropediatría, Hospital Universitario Miguel Servet, Zaragoza, Spain
| | - Soledad Alcántara
- Neural Development Lab, Departament de Patologia i Terapèutica Experimental, Institut de Neurociències, Universitat de Barcelona, IDIBELL, l'Hospitalet de Llobregat, Barcelona, Spain
| | - Judith Armstrong
- Servicio de Medicina Genètica i Molecular, Hospital Universitario San Juan de Dios, Barcelona, Spain.,CIBERER (Biomedical Network Research Center for Rare Diseases), Instituto de Salud Carlos III, Madrid, Spain.,Institut de Recerca Pediàtrica, Hospital Sant Joan de Déu, Barcelona, Spain
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6
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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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7
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Yon DK, Park JE, Kim SJ, Shim SH, Chae KY. A sibship with duplication of Xq28 inherited from the mother; genomic characterization and clinical outcomes. BMC MEDICAL GENETICS 2017; 18:30. [PMID: 28302064 PMCID: PMC5356410 DOI: 10.1186/s12881-017-0394-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/09/2016] [Accepted: 03/07/2017] [Indexed: 12/17/2022]
Abstract
BACKGROUND Loss-of-function mutations in methyl-CpG-binding protein 2 (MECP2; MIM *300005) results in the Rett syndrome, whereas gain-of-function mutations are associated with the MECP2 duplication syndrome. METHODS We did research on a family with two brothers showing Xq28 duplication syndrome using various molecular cytogenetic techniques such as multiplex ligation-dependent probe amplification and array-based genomic hybridization. RESULTS The duplicated region had several genes including MECP2 and interleukin-1 receptor associated kinase 1 (IRAK1; MIM *300283). MECP2 and IRAK1 were associated with the neurological phenotypes in dose-sensitive and dose-critical manner. The brothers demonstrated severe intellectual disability, autistic features, generalized hypotonia, recurrent infections, epilepsy, choreiform movements such as hand-wringing movement, and moderate increased spasticity with the lower limbs. The X-inactivation test showed a complete skewed X inactivation pattern of mother. In this reason, the mother had the same loci duplication but showed significantly little neurological manifestation compared to the two sons. CONCLUSIONS MECP2/IRAK1 duplication at Xq28 is inherited as an X-linked recessive trait and male-specific disorder associated with severe intellectual disability. We tried to analyze the information of the relationship between neuropsychiatric phenotype and the extent of duplication at Xq28 by comparing with previous reports.
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Affiliation(s)
- Dong Keon Yon
- Department of Pediatrics, CHA Bundang Medical Center, School of Medicine, CHA University, 351 Yatap-dong, Bundang-gu, Seongnam, 463-712 Republic of Korea
| | - Ji Eun Park
- Genetics Laboratory, Fertility Center, CHA Gangnam Medical Center, School of Medicine, CHA University, 606-13 Yeoksam-dong, Gangnam-gu, Seoul, 06135 Republic of Korea
| | - Seung Jun Kim
- GenoLifeCare Division, BioCore, Seoul, Republic of Korea
| | - Sung Han Shim
- Genetics Laboratory, Fertility Center, CHA Gangnam Medical Center, School of Medicine, CHA University, 606-13 Yeoksam-dong, Gangnam-gu, Seoul, 06135 Republic of Korea
- Department of Biomedical Science, College of Life Science, CHA University, 335 Pankyo-ro, Bundang-gu, Seongnam, 13488 Republic of Korea
| | - Kyu Young Chae
- Department of Pediatrics, CHA Bundang Medical Center, School of Medicine, CHA University, 351 Yatap-dong, Bundang-gu, Seongnam, 463-712 Republic of Korea
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8
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El Chehadeh S, Touraine R, Prieur F, Reardon W, Bienvenu T, Chantot-Bastaraud S, Doco-Fenzy M, Landais E, Philippe C, Marle N, Callier P, Mosca-Boidron AL, Mugneret F, Le Meur N, Goldenberg A, Guerrot AM, Chambon P, Satre V, Coutton C, Jouk PS, Devillard F, Dieterich K, Afenjar A, Burglen L, Moutard ML, Addor MC, Lebon S, Martinet D, Alessandri JL, Doray B, Miguet M, Devys D, Saugier-Veber P, Drunat S, Aral B, Kremer V, Rondeau S, Tabet AC, Thevenon J, Thauvin-Robinet C, Perreton N, Des Portes V, Faivre L. Xq28 duplication includingMECP2in six unreported affected females: what can we learn for diagnosis and genetic counselling? Clin Genet 2017; 91:576-588. [DOI: 10.1111/cge.12898] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2016] [Revised: 10/14/2016] [Accepted: 10/17/2016] [Indexed: 11/27/2022]
Affiliation(s)
- S. El Chehadeh
- FHU TRANSLAD, Centre de Référence Maladies Rares «Anomalies du Développement et Syndromes Malformatifs» de l'Est; Centre de Génétique, CHU de Dijon; Dijon France
- Service de Génétique Médicale, Institut de Génétique Médicale d'Alsace (IGMA), Centre de Référence Maladies Rares «Anomalies du Développement et Syndromes Malformatifs» de l'Est; Hôpitaux Universitaires de Strasbourg, Hôpital de Hautepierre; Strasbourg France
| | - R. Touraine
- Service de Génétique Clinique Chromosomique et Moléculaire; CHU de Saint-Etienne; Saint-Étienne France
| | - F. Prieur
- Service de Génétique Clinique Chromosomique et Moléculaire; CHU de Saint-Etienne; Saint-Étienne France
| | - W. Reardon
- Clinical Genetics, Division National Centre for Medical Genetics; Our Lady's Children's Hospital; Dublin Ireland
| | - T. Bienvenu
- AP-HP, Laboratoire de Génétique et Biologie Moléculaires, HU Paris Centre, Site Cochin, France; Université Paris Descartes; Institut Cochin, INSERM U1016; Paris France
| | - S. Chantot-Bastaraud
- Service de Génétique et Embryologie Médicales; CHU Paris Est - Hôpital d'Enfants Armand-Trousseau; Paris France
| | - M. Doco-Fenzy
- Service de Génétique, EA3801; SFR-CAP Santé, CHU de Reims; Reims France
| | - E. Landais
- PRBI, Pôle de Biologie Médicale; CHU de Reims; Reims France
| | - C. Philippe
- Laboratoire de Génétique Médicale; Hôpitaux de Brabois CHRU; Vandoeuvre les Nancy France
| | - N. Marle
- Service de Cytogénétique; CHU de Dijon; Dijon France
| | - P. Callier
- Service de Cytogénétique; CHU de Dijon; Dijon France
| | | | - F. Mugneret
- Service de Cytogénétique; CHU de Dijon; Dijon France
| | - N. Le Meur
- Etablissement Français du Sang; CHU de Rouen; Rouen France
| | - A. Goldenberg
- Service de Génétique et Inserm U1079, Centre Normand de Génomique Médicale et Médecine Personnalisée, CHU de Rouen; Inserm et Université de Rouen; Rouen France
| | - A.-M. Guerrot
- Service de Génétique et Inserm U1079, Centre Normand de Génomique Médicale et Médecine Personnalisée, CHU de Rouen; Inserm et Université de Rouen; Rouen France
| | - P. Chambon
- Laboratoire D'histologie, Cytogénétique et Biologie de la Reproduction; CHU de Rouen; Rouen France
| | - V. Satre
- Département de Génétique et Procréation, CHU Grenoble Alpes; Université Grenoble Alpes; Grenoble France
| | - C. Coutton
- Département de Génétique et Procréation, CHU Grenoble Alpes; Université Grenoble Alpes; Grenoble France
| | - P.-S. Jouk
- Département de Génétique et Procréation, CHU Grenoble Alpes; Université Grenoble Alpes; Grenoble France
| | - F. Devillard
- Département de Génétique et Procréation, CHU Grenoble Alpes; Université Grenoble Alpes; Grenoble France
| | - K. Dieterich
- Département de Génétique et Procréation, CHU Grenoble Alpes; Université Grenoble Alpes; Grenoble France
| | - A. Afenjar
- Service de Génétique; CHU Paris Est - Hôpital d'Enfants Armand-Trousseau; Paris France
| | - L. Burglen
- Service de Génétique; CHU Paris Est - Hôpital d'Enfants Armand-Trousseau; Paris France
| | - M.-L. Moutard
- Unité de neuropédiatrie et pathologie du développement; CHU Paris Est - Hôpital d'Enfants Armand-Trousseau; Paris France
| | - M.-C. Addor
- Service de Génétique Médicale; Centre Hospitalier Universitaire Vaudois CHUV; Lausanne Switzerland
| | - S. Lebon
- Unité de Neuropédiatrie; Centre Hospitalier Universitaire Vaudois CHUV; Lausanne Switzerland
| | - D. Martinet
- Laboratoire de Cytogénétique Constitutionnelle et Prénatale; Centre Hospitalier Universitaire Vaudois CHUV; Lausanne Switzerland
| | - J.-L. Alessandri
- Pôle Enfants; CHU de la Réunion - Hôpital Félix Guyon; Saint-Denis France
| | - B. Doray
- Service de Génétique; CHU de la Réunion - Hôpital Félix Guyon; Saint-Denis France
| | - M. Miguet
- Service de Génétique Médicale, Institut de Génétique Médicale d'Alsace (IGMA), Centre de Référence Maladies Rares «Anomalies du Développement et Syndromes Malformatifs» de l'Est; Hôpitaux Universitaires de Strasbourg, Hôpital de Hautepierre; Strasbourg France
| | - D. Devys
- Laboratoire de Diagnostic Génétique; CHU de Strasbourg - Hôpital Civil; Strasbourg France
| | - P. Saugier-Veber
- Laboratoire de Génétique Moléculaire; Faculté de Médecine et de Pharmacie; Rouen France
| | - S. Drunat
- Laboratoire de Biologie Moléculaire; Hôpital Robert Debré; Paris France
| | - B. Aral
- Service de Biologie Moléculaire; CHU de Dijon; Dijon France
| | - V. Kremer
- Laboratoire de Cytogénétique, Hôpitaux Universitaires de Strasbourg; Hôpital de Hautepierre; Strasbourg France
| | - S. Rondeau
- Service de Pédiatrie Néonatale et Réanimation; CHU de Rouen; Rouen France
| | - A.-C. Tabet
- Laboratoire de Cytogénétique; Hôpital Robert Debré; Paris France
| | - J. Thevenon
- FHU TRANSLAD, Centre de Référence Maladies Rares «Anomalies du Développement et Syndromes Malformatifs» de l'Est; Centre de Génétique, CHU de Dijon; Dijon France
- GAD, EA4271, Génétique et Anomalies du Développement; Université de Bourgogne; Dijon France
| | - C. Thauvin-Robinet
- FHU TRANSLAD, Centre de Référence Maladies Rares «Anomalies du Développement et Syndromes Malformatifs» de l'Est; Centre de Génétique, CHU de Dijon; Dijon France
- GAD, EA4271, Génétique et Anomalies du Développement; Université de Bourgogne; Dijon France
| | - N. Perreton
- EPICIME-CIC 1407 de Lyon, Inserm; Service de Pharmacologie Clinique, CHU-Lyon; Bron France
| | - V. Des Portes
- Service de Neurologie Pédiatrique; CHU de Lyon-GH Est; Bron France
| | - L. Faivre
- FHU TRANSLAD, Centre de Référence Maladies Rares «Anomalies du Développement et Syndromes Malformatifs» de l'Est; Centre de Génétique, CHU de Dijon; Dijon France
- GAD, EA4271, Génétique et Anomalies du Développement; Université de Bourgogne; Dijon France
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9
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Ha K, Shen Y, Graves T, Kim CH, Kim HG. The presence of two rare genomic syndromes, 1q21 deletion and Xq28 duplication, segregating independently in a family with intellectual disability. Mol Cytogenet 2016; 9:74. [PMID: 27708714 PMCID: PMC5041540 DOI: 10.1186/s13039-016-0286-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2016] [Accepted: 09/22/2016] [Indexed: 01/21/2023] Open
Abstract
Background 1q21 microdeletion syndrome is a rare contiguous gene deletion disorder with de novo or autosomal dominant inheritance patterns and its phenotypic features include intellectual disability, distinctive facial dysmorphism, microcephaly, cardiac abnormalities, and cataracts. MECP2 duplication syndrome is an X-linked recessive neurodevelopmental disorder characterized by intellectual disability, global developmental delay, and other neurological complications including late-onset seizures. Previously, these two different genetic syndromes have not been reported segregating independently in a same family. Case presentation Here we describe two siblings carrying either a chromosome 1q21 microdeletion or a chromosome Xq28 duplication. Using a comparative genomic hybridization (CGH) array, we identified a 1.24 Mb heterozygous deletion at 1q21 resulting in the loss of 9 genes in a girl with learning disability, hypothyroidism, short stature, sensory integration disorder, and soft dysmorphic features including cupped ears and a unilateral ear pit. We also characterized a 508 kb Xq28 duplication encompassing MECP2 in her younger brother with hypotonia, poor speech, cognitive and motor impairment. The parental CGH and quantitative PCR (qPCR) analyses revealed that the 1q21 deletion in the elder sister is de novo, but the Xq28 duplication in the younger brother was originally inherited from the maternal grandmother through the mother, both of whom are asymptomatic carriers. RT-qPCR assays revealed that the affected brother has almost double the amount of MECP2 mRNA expression compared to other family members of both genders including maternal grandmother and mother who have the same Xq28 duplication with no phenotype. This suggests the X chromosome with an Xq28 duplication in the carrier females is preferentially silenced. Conclusion From our understanding, this would be the first report showing the independent segregation of two genetically unrelated syndromes, 1q21 microdeletion and Xq28 duplication, in a same family, especially in siblings. Although these two chromosomal abnormalities share some similar phenotypes such as intellectual disability, mild dysmorphic features, and cardiac abnormalities, the presence of two unrelated and rare syndromes in siblings is very unusual. Therefore, further comprehensive investigations in similar cases are required for future studies.
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Affiliation(s)
- Kyungsoo Ha
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX 77030 USA ; Section of Reproductive Endocrinology, Infertility & Genetics, Department of Obstetrics & Gynecology, Augusta University, Augusta, GA 30912 USA
| | - Yiping Shen
- Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114 USA
| | - Tyler Graves
- Section of Reproductive Endocrinology, Infertility & Genetics, Department of Obstetrics & Gynecology, Augusta University, Augusta, GA 30912 USA
| | - Cheol-Hee Kim
- Department of Biology, Chungnam National University, Daejeon, 34134 South Korea
| | - Hyung-Goo Kim
- Section of Reproductive Endocrinology, Infertility & Genetics, Department of Obstetrics & Gynecology, Augusta University, Augusta, GA 30912 USA ; Department of Neuroscience and Regenerative Medicine, Augusta University, 1120 15th Street, Augusta, GA 30912 USA
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10
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Abolhassani H, Aghamohammadi A, Hammarström L. Monogenic mutations associated with IgA deficiency. Expert Rev Clin Immunol 2016; 12:1321-1335. [DOI: 10.1080/1744666x.2016.1198696] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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11
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Yi Z, Pan H, Li L, Wu H, Wang S, Ma Y, Qi Y. Chromosome Xq28 duplication encompassing MECP2: Clinical and molecular analysis of 16 new patients from 10 families in China. Eur J Med Genet 2016; 59:347-53. [PMID: 27180140 DOI: 10.1016/j.ejmg.2016.05.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2016] [Revised: 04/08/2016] [Accepted: 05/09/2016] [Indexed: 02/08/2023]
Abstract
INTRODUCTION Chromosome Xq28 duplications encompassing methyl-CpG-binding protein 2 gene (MECP2) are observed most in males with a severe neurodevelopmental disorder associated with hypotonia, spasticity, severe learning disability, delayed psychomotor development, and recurrent pulmonary infections. Most female carriers are asymptomatic due to extremely or completely skewed X-inactivation. METHODS A retrospective clinical and molecular study was conducted to examine 16 patients and two fetuses from 10 families who were identified among patients with Xq28 duplications who presented at genetic clinics. RESULTS Of all 16 patients, 10 had a family history. Only one patient was female. All of the patients had no relevant pre-natal history. All of the patients exhibited severe psychomotor developmental delay, infantile hypotonia and recurrent infections. Some of the patients exhibited cardiac abnormalities, gastrointestinal mobility problems, hydrocele of tunica vaginalis, cryptorchidism, and autistic phenotypes. Additionally, neonatal kidney calculus, premature closure of the fontanel and pulmonary sequestration were found in the patients. Duplication sizes in these patients range from 0.21 to 14.391 Mb (most were smaller than 1 Mb), and all the duplications included host cell factor C1 (HCFC1), interleukin-1 receptor-associated kinase 1 (IRAK1), and MECP2. Bioinformatics analysis revealed that approximately half of the distal breakpoints were located within the low-copy repeats (LCRs), which may be involved in the recombination. The two fetuses were found to be healthy in the prenatal diagnosis. CONCLUSION This is the first large cohort of patients with MECP2 duplication syndrome, including a female, reported in China. Interestingly, neonatal kidney calculus, premature closure of the fontanel and pulmonary sequestration were first reported in this syndrome. However, it was difficult to distinguish if these patients represented unique cases or if these phenotypes can be considered as part of the syndrome. The correlation between the infrequent phenotypes and duplications/genes in the duplication region needs further systematic delineation. In conclusion, our study suggested that it is important to emphasize molecular genetic analysis in patients with developmental delay/intellectual disability and recurrent infections and that it is especially important for familial female carriers to accept prenatal diagnosis.
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Affiliation(s)
- Zhi Yi
- Department of Central Laboratory, Peking University First Hospital, Beijing, China
| | - Hong Pan
- Department of Central Laboratory, Peking University First Hospital, Beijing, China.
| | - Lin Li
- Department of Central Laboratory, Peking University First Hospital, Beijing, China
| | - Hairong Wu
- Department of Central Laboratory, Peking University First Hospital, Beijing, China
| | - Songtao Wang
- Department of Central Laboratory, Peking University First Hospital, Beijing, China
| | - Yinan Ma
- Department of Central Laboratory, Peking University First Hospital, Beijing, China
| | - Yu Qi
- Department of Central Laboratory, Peking University First Hospital, Beijing, China
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San Antonio-Arce V, Fenollar-Cortés M, Oancea Ionescu R, DeSantos-Moreno T, Gallego-Merlo J, Illana Cámara FJ, Cotarelo Pérez MC. MECP2 Duplications in Symptomatic Females: Report on 3 Patients Showing the Broad Phenotypic Spectrum. Child Neurol Open 2016; 3:2329048X16630673. [PMID: 28503606 PMCID: PMC5417292 DOI: 10.1177/2329048x16630673] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2015] [Revised: 11/28/2015] [Accepted: 01/11/2016] [Indexed: 12/22/2022] Open
Abstract
Xq28 microduplications including the MECP2 gene constitute a 100% penetrant X-linked syndrome in males caused by overexpression of normal MeCP2 protein. A small number of cases of affected females have been reported. This can be due to the location of the duplicated material into an autosome, but it can also be due to the location of the duplicated material into one of the X chromosomes and random or unfavorable skewed X chromosome inactivation, which is much more likely to occur but may be underdiagnosed because of the resulting broad phenotypic spectrum. In order to contribute to the phenotypic delineation of Xq28 microduplications including MECP2 in symptomatic females, the authors present clinical and molecular data on 3 patients illustrating the broad phenotypic spectrum. Our finding underlines the importance of quantitative analysis of MECP2 in females with intellectual disability and raises the question of the indication in females with borderline intellectual performances or learning difficulties.
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In Pursuit of New Imprinting Syndromes by Epimutation Screening in Idiopathic Neurodevelopmental Disorder Patients. BIOMED RESEARCH INTERNATIONAL 2015; 2015:341986. [PMID: 26106604 PMCID: PMC4461700 DOI: 10.1155/2015/341986] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/21/2014] [Revised: 05/04/2015] [Accepted: 05/11/2015] [Indexed: 12/19/2022]
Abstract
Alterations of epigenetic mechanisms, and more specifically imprinting modifications, could be responsible of neurodevelopmental disorders such as intellectual disability (ID) or autism together with other associated clinical features in many cases. Currently only eight imprinting syndromes are defined in spite of the fact that more than 200 genes are known or predicted to be imprinted. Recent publications point out that some epimutations which cause imprinting disorders may affect simultaneously different imprinted loci, suggesting that DNA-methylation may have been altered more globally. Therefore, we hypothesised that the detection of altered methylation patterns in known imprinting loci will indirectly allow identifying new syndromes due to epimutations among patients with unexplained ID. In a screening for imprinting alterations in 412 patients with syndromic ID/autism we found five patients with altered methylation in the four genes studied: MEG3, H19, KCNQ1OT1, and SNRPN. Remarkably, the cases with partial loss of methylation in KCNQ1OT1 and SNRPN present clinical features different to those associated with the corresponding imprinting syndromes, suggesting a multilocus methylation defect in accordance with our initial hypothesis. Consequently, our results are a proof of concept that the identification of epimutations in known loci in patients with clinical features different from those associated with known syndromes will eventually lead to the definition of new imprinting disorders.
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Bauer M, Kölsch U, Krüger R, Unterwalder N, Hameister K, Kaiser FM, Vignoli A, Rossi R, Botella MP, Budisteanu M, Rosello M, Orellana C, Tejada MI, Papuc SM, Patat O, Julia S, Touraine R, Gomes T, Wenner K, Xu X, Afenjar A, Toutain A, Philip N, Jezela-Stanek A, Gortner L, Martinez F, Echenne B, Wahn V, Meisel C, Wieczorek D, El-Chehadeh S, Van Esch H, von Bernuth H. Infectious and immunologic phenotype of MECP2 duplication syndrome. J Clin Immunol 2015; 35:168-81. [PMID: 25721700 PMCID: PMC7101860 DOI: 10.1007/s10875-015-0129-5] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2013] [Accepted: 01/12/2015] [Indexed: 12/02/2022]
Abstract
MECP2 (methyl CpG binding protein 2) duplication causes syndromic intellectual disability. Patients often suffer from life-threatening infections, suggesting an additional immunodeficiency. We describe for the first time the detailed infectious and immunological phenotype of MECP2 duplication syndrome. 17/27 analyzed patients suffered from pneumonia, 5/27 from at least one episode of sepsis. Encapsulated bacteria (S.pneumoniae, H.influenzae) were frequently isolated. T-cell immunity showed no gross abnormalities in 14/14 patients and IFNy-secretion upon ConA-stimulation was not decreased in 6/7 patients. In 6/21 patients IgG2-deficiency was detected – in 4/21 patients accompanied by IgA-deficiency, 10/21 patients showed low antibody titers against pneumococci. Supra-normal IgG1-levels were detected in 11/21 patients and supra-normal IgG3-levels were seen in 8/21 patients – in 6 of the patients as combined elevation of IgG1 and IgG3. Three of the four patients with IgA/IgG2-deficiency developed multiple severe infections. Upon infections pronounced acute-phase responses were common: 7/10 patients showed CRP values above 200 mg/l. Our data for the first time show systematically that increased susceptibility to infections in MECP2 duplication syndrome is associated with IgA/IgG2-deficiency, low antibody titers against pneumococci and elevated acute-phase responses. So patients with MECP2 duplication syndrome and low IgA/IgG2 may benefit from prophylactic substitution of sIgA and IgG.
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Affiliation(s)
- Michael Bauer
- Pediatric Pneumology and Immunology, Charité University Medicine, Berlin, Germany,
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15
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Clinical impacts of genomic copy number gains at Xq28. Hum Genome Var 2014; 1:14001. [PMID: 27081496 PMCID: PMC4785515 DOI: 10.1038/hgv.2014.1] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2014] [Revised: 05/23/2014] [Accepted: 05/26/2014] [Indexed: 11/09/2022] Open
Abstract
Duplications of the Xq28 region are the most frequent chromosomal aberrations observed in patients with intellectual disability (ID), especially in males. These duplications occur by variable mechanisms, including interstitial duplications mediated by segmental duplications in this region and terminal duplications (functional disomy) derived from translocation with other chromosomes. The most commonly duplicated region includes methyl CpG-binding protein 2 gene (MECP2), which has a minimal duplicated size of 0.2 Mb. Patients with MECP2 duplications show severe ID, intractable seizures and recurrent infections. Duplications in the telomeric neighboring regions, which include GDP dissociation inhibitor 1 gene (GDI1) and ras-associated protein RAB39B gene (RAB39B), are independently associated with ID, and many segmental duplications located in this region could mediate these frequently observed interstitial duplications. In addition, large duplications, including MECP2 and GDI1, induce hypoplasia of the corpus callosum. Abnormalities observed in the white matter, revealed by brain magnetic resonance imaging, are a common finding in patients with MECP2 duplications. As primary sequence analysis cannot be used to determine the region responsible for chromosomal duplication syndrome, finding this region relies on the collection of genotype-phenotype data from patients.
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Fieremans N, Bauters M, Belet S, Verbeeck J, Jansen AC, Seneca S, Roelens F, De Baere E, Marynen P, Froyen G. De novo MECP2 duplications in two females with intellectual disability and unfavorable complete skewed X-inactivation. Hum Genet 2014; 133:1359-67. [DOI: 10.1007/s00439-014-1469-6] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2014] [Accepted: 07/09/2014] [Indexed: 12/11/2022]
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17
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Fu F, Liu HL, Li R, Han J, Yang X, Min P, Zhen L, Zhang YL, Xie GE, Lei TY, Li Y, Li J, Li DZ, Liao C. Prenatal diagnosis of foetuses with congenital abnormalities and duplication of the MECP2 region. Gene 2014; 546:222-5. [PMID: 24914495 DOI: 10.1016/j.gene.2014.06.012] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2014] [Revised: 05/19/2014] [Accepted: 06/06/2014] [Indexed: 10/25/2022]
Abstract
MECP2 duplication results in a well-recognised syndrome in 100% of affected male children; this syndrome is characterised by severe neurodevelopmental disabilities and recurrent infections. However, no sonographic findings have been reported for affected foetuses, and prenatal molecular diagnosis has not been possible for this disease due to lack of prenatal clinical presentation. In this study, we identified a small duplication comprising the MECP2 and L1CAM genes in the Xq28 region in a patient from a family with severe X-linked mental retardation and in a prenatal foetus with brain structural abnormalities. Using high-resolution chromosome microarray analysis (CMA) to screen 108 foetuses with congenital structural abnormalities, we identified additional three foetuses with the MECP2 duplication. Our study indicates that ventriculomegaly, hydrocephalus, agenesis of the corpus callosum, choroid plexus cysts, foetal growth restriction and hydronephrosis might be common ultrasound findings in prenatal foetuses with the MECP2 duplication and provides the first set of prenatal cases with MECP2 duplication, the ultrasonographic phenotype described in these patients will help to recognise the foetuses with possible MECP2 duplication and prompt the appropriate molecular testing.
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Affiliation(s)
- Fang Fu
- Department of Prenatal Diagnostic Centre, Guangzhou Women and Children's Medical Centre, Guangzhou Medical University, Guangdong 510623, China
| | - Huan-ling Liu
- Ultrasonic Department of Panyu Central Hospital, Guangzhou, Guangdong 511400, China
| | - Ru Li
- Department of Prenatal Diagnostic Centre, Guangzhou Women and Children's Medical Centre, Guangzhou Medical University, Guangdong 510623, China
| | - Jin Han
- Department of Prenatal Diagnostic Centre, Guangzhou Women and Children's Medical Centre, Guangzhou Medical University, Guangdong 510623, China
| | - Xin Yang
- Department of Prenatal Diagnostic Centre, Guangzhou Women and Children's Medical Centre, Guangzhou Medical University, Guangdong 510623, China
| | - Pan Min
- Department of Prenatal Diagnostic Centre, Guangzhou Women and Children's Medical Centre, Guangzhou Medical University, Guangdong 510623, China
| | - Li Zhen
- Department of Prenatal Diagnostic Centre, Guangzhou Women and Children's Medical Centre, Guangzhou Medical University, Guangdong 510623, China
| | - Yong-ling Zhang
- Department of Prenatal Diagnostic Centre, Guangzhou Women and Children's Medical Centre, Guangzhou Medical University, Guangdong 510623, China
| | - Gui-e Xie
- Department of Prenatal Diagnostic Centre, Guangzhou Women and Children's Medical Centre, Guangzhou Medical University, Guangdong 510623, China
| | - Ting-ying Lei
- Department of Prenatal Diagnostic Centre, Guangzhou Women and Children's Medical Centre, Guangzhou Medical University, Guangdong 510623, China
| | - Yan Li
- Department of Prenatal Diagnostic Centre, Guangzhou Women and Children's Medical Centre, Guangzhou Medical University, Guangdong 510623, China
| | - Jian Li
- Department of Prenatal Diagnostic Centre, Guangzhou Women and Children's Medical Centre, Guangzhou Medical University, Guangdong 510623, China
| | - Dong-zhi Li
- Department of Prenatal Diagnostic Centre, Guangzhou Women and Children's Medical Centre, Guangzhou Medical University, Guangdong 510623, China
| | - Can Liao
- Department of Prenatal Diagnostic Centre, Guangzhou Women and Children's Medical Centre, Guangzhou Medical University, Guangdong 510623, China.
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Wax JR, Pinette MG, Smith R, Chard R, Cartin A. Second-trimester prenasal and prefrontal skin thickening - association with MECP2 triplication syndrome. JOURNAL OF CLINICAL ULTRASOUND : JCU 2013; 41:434-437. [PMID: 23744515 DOI: 10.1002/jcu.22065] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/26/2012] [Revised: 04/02/2013] [Accepted: 04/24/2013] [Indexed: 06/02/2023]
Abstract
MECP2 triplication syndrome is a rare and usually lethal genetic disorder characterized by progressive neurologic and cognitive regression. None of the four reported cases describe prenatal sonographic features of affected offspring. We report a second-trimester fetus with marked prefrontal and prenasal skin thickening, retrognathia, and later, third-trimester mild cerebral ventriculomegaly. Amniocyte karyotype was normal male, but newborn whole-genome oligonucleotide microarray showed duplication and triplication of chromosome Xq28 containing the MECP2 gene. Comparative genomic hybridization may be diagnostic in fetuses with prefrontal and prenasal skin thickening, additional sonographic findings, and normal karyotype.
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Affiliation(s)
- Joseph R Wax
- Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, Maine Medical Center, Portland, ME 04102, USA
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Shimada S, Okamoto N, Ito M, Arai Y, Momosaki K, Togawa M, Maegaki Y, Sugawara M, Shimojima K, Osawa M, Yamamoto T. MECP2 duplication syndrome in both genders. Brain Dev 2013; 35:411-9. [PMID: 22877836 DOI: 10.1016/j.braindev.2012.07.010] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/25/2012] [Revised: 07/07/2012] [Accepted: 07/15/2012] [Indexed: 12/21/2022]
Abstract
BACKGROUND Duplications involving the methyl-CpG-binding protein 2 gene (MECP2) locus at Xq28 have been frequently identified in male patients who exhibit a phenotype unique from that of Rett syndrome, which is mainly characterized by severe mental retardation, recurrent infections, and epilepsy. This combination of features is recognized as MECP2 duplication syndrome. METHODS Genomic copy number was investigated for patients with unexplained mental retardation, and phenotypic features of the patients having interstitial duplications including MECP2 were analyzed. RESULTS Three male and one female patients with MECP2 duplication were identified. The phenotypic features of all the four patients were compatible with MECP2 duplication syndrome. The X-chromosome inactivation (XCI) pattern was analyzed in the female patient, identifying a skewed XCI that activated the X-chromosome containing the MECP2 duplication. Her mother possessed the same MECP2 duplication and a random XCI pattern but exhibited no phenotypic features, indicating a nonsymptomatic carrier. The brain magnetic resonance imaging revealed periventricular cystic lesions in all four patients, including the female patient. CONCLUSION This study suggested clinical implications of the MECP2 duplication syndrome not only in the male but also in female patients with unexplained mental retardation.
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Affiliation(s)
- Shino Shimada
- Tokyo Women's Medical University Institute for Integrated Medical Sciences, Tokyo, Japan
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Hanchard NA, Carvalho CMB, Bader P, Thome A, Omo-Griffith L, del Gaudio D, Pehlivan D, Fang P, Schaaf CP, Ramocki MB, Lupski JR, Cheung SW. A partial MECP2 duplication in a mildly affected adult male: a putative role for the 3' untranslated region in the MECP2 duplication phenotype. BMC MEDICAL GENETICS 2012; 13:71. [PMID: 22883432 PMCID: PMC3575261 DOI: 10.1186/1471-2350-13-71] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/24/2012] [Accepted: 07/23/2012] [Indexed: 11/17/2022]
Abstract
Background Duplications of the X-linked MECP2 gene are associated with moderate to severe intellectual disability, epilepsy, and neuropsychiatric illness in males, while triplications are associated with a more severe phenotype. Most carrier females show complete skewing of X-inactivation in peripheral blood and an apparent susceptibility to specific personality traits or neuropsychiatric symptoms. Methods We describe the clinical phenotype of a pedigree segregating a duplication of MECP2 found on clinical array comparative genomic hybridization. The position, size, and extent of the duplication were delineated in peripheral blood samples from affected individuals using multiplex ligation-dependent probe amplification and fluorescence in situ hybridization, as well as targeted high-resolution oligonucleotide microarray analysis and long-range PCR. The molecular consequences of the rearrangement were studied in lymphoblast cell lines using quantitative real-time PCR, reverse transcriptase PCR, and western blot analysis. Results We observed a partial MECP2 duplication in an adult male with epilepsy and mild neurocognitive impairment who was able to function independently; this phenotype has not previously been reported among males harboring gains in MECP2 copy number. The same duplication was inherited by this individual’s daughter who was also affected with neurocognitive impairment and epilepsy and carried an additional copy-number variant. The duplicated segment involved all four exons of MECP2, but excluded almost the entire 3' untranslated region (UTR), and the genomic rearrangement resulted in a MECP2-TEX28 fusion gene mRNA transcript. Increased expression of MECP2 and the resulting fusion gene were both confirmed; however, western blot analysis of lysates from lymphoblast cells demonstrated increased MeCP2 protein without evidence of a stable fusion gene protein product. Conclusion The observations of a mildly affected adult male with a MECP2 duplication and paternal transmission of this duplication are unique among reported cases with a duplication of MECP2. The clinical and molecular findings imply a minimal critical region for the full neurocognitive expression of the MECP2 duplication syndrome, and suggest a role for the 3′ UTR in mitigating the severity of the disease phenotype.
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Affiliation(s)
- Neil A Hanchard
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA
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Bijlsma EK, Collins A, Papa FT, Tejada MI, Wheeler P, Peeters EAJ, Gijsbers ACJ, van de Kamp JM, Kriek M, Losekoot M, Broekma AJ, Crolla JA, Pollazzon M, Mucciolo M, Katzaki E, Disciglio V, Ferreri MI, Marozza A, Mencarelli MA, Castagnini C, Dosa L, Ariani F, Mari F, Canitano R, Hayek G, Botella MP, Gener B, Mínguez M, Renieri A, Ruivenkamp CAL. Xq28 duplications including MECP2 in five females: Expanding the phenotype to severe mental retardation. Eur J Med Genet 2012; 55:404-13. [PMID: 22522176 PMCID: PMC3383992 DOI: 10.1016/j.ejmg.2012.02.009] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2011] [Accepted: 02/20/2012] [Indexed: 01/05/2023]
Abstract
Duplications leading to functional disomy of chromosome Xq28, including MECP2 as the critical dosage-sensitive gene, are associated with a distinct clinical phenotype in males, characterized by severe mental retardation, infantile hypotonia, progressive neurologic impairment, recurrent infections, bladder dysfunction, and absent speech. Female patients with Xq duplications including MECP2 are rare. Only recently submicroscopic duplications of this region on Xq28 have been recognized in four females, and a triplication in a fifth, all in combination with random X-chromosome inactivation (XCI). Based on this small series, it was concluded that in females with MECP2 duplication and random XCI, the typical symptoms of affected boys are not present. We present clinical and molecular data on a series of five females with an Xq28 duplication including the MECP2 gene, both isolated and as the result of a translocation, and compare them with the previously reported cases of small duplications in females. The collected data indicate that the associated phenotype in females is distinct from males with similar duplications, but the clinical effects may be as severe as seen in males.
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Affiliation(s)
- E K Bijlsma
- Center for Human and Clinical Genetics, Leiden University Medical Center, Leiden, The Netherlands.
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