1
|
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.
Collapse
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
| |
Collapse
|
2
|
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.
Collapse
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.
| |
Collapse
|
3
|
Romanowska J, Nustad HE, Page CM, Denault WRP, Lee Y, Magnus MC, Haftorn KL, Gjerdevik M, Novakovic B, Saffery R, Gjessing HK, Lyle R, Magnus P, Håberg SE, Jugessur A. The X-factor in ART: does the use of assisted reproductive technologies influence DNA methylation on the X chromosome? Hum Genomics 2023; 17:35. [PMID: 37085889 PMCID: PMC10122315 DOI: 10.1186/s40246-023-00484-6] [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: 01/09/2023] [Accepted: 04/10/2023] [Indexed: 04/23/2023] Open
Abstract
BACKGROUND Assisted reproductive technologies (ART) may perturb DNA methylation (DNAm) in early embryonic development. Although a handful of epigenome-wide association studies of ART have been published, none have investigated CpGs on the X chromosome. To bridge this knowledge gap, we leveraged one of the largest collections of mother-father-newborn trios of ART and non-ART (natural) conceptions to date to investigate sex-specific DNAm differences on the X chromosome. The discovery cohort consisted of 982 ART and 963 non-ART trios from the Norwegian Mother, Father, and Child Cohort Study (MoBa). To verify our results from the MoBa cohort, we used an external cohort of 149 ART and 58 non-ART neonates from the Australian 'Clinical review of the Health of adults conceived following Assisted Reproductive Technologies' (CHART) study. The Illumina EPIC array was used to measure DNAm in both datasets. In the MoBa cohort, we performed a set of X-chromosome-wide association studies ('XWASs' hereafter) to search for sex-specific DNAm differences between ART and non-ART newborns. We tested several models to investigate the influence of various confounders, including parental DNAm. We also searched for differentially methylated regions (DMRs) and regions of co-methylation flanking the most significant CpGs. Additionally, we ran an analogous model to our main model on the external CHART dataset. RESULTS In the MoBa cohort, we found more differentially methylated CpGs and DMRs in girls than boys. Most of the associations persisted after controlling for parental DNAm and other confounders. Many of the significant CpGs and DMRs were in gene-promoter regions, and several of the genes linked to these CpGs are expressed in tissues relevant for both ART and sex (testis, placenta, and fallopian tube). We found no support for parental DNAm-dependent features as an explanation for the observed associations in the newborns. The most significant CpG in the boys-only analysis was in UBE2DNL, which is expressed in testes but with unknown function. The most significant CpGs in the girls-only analysis were in EIF2S3 and AMOT. These three loci also displayed differential DNAm in the CHART cohort. CONCLUSIONS Genes that co-localized with the significant CpGs and DMRs associated with ART are implicated in several key biological processes (e.g., neurodevelopment) and disorders (e.g., intellectual disability and autism). These connections are particularly compelling in light of previous findings indicating that neurodevelopmental outcomes differ in ART-conceived children compared to those naturally conceived.
Collapse
Affiliation(s)
- Julia Romanowska
- Centre for Fertility and Health, Norwegian Institute of Public Health, Oslo, Norway.
- Department of Global Public Health and Primary Care, University of Bergen, Bergen, Norway.
| | - Haakon E Nustad
- Centre for Fertility and Health, Norwegian Institute of Public Health, Oslo, Norway
- DeepInsight, 0154, Oslo, Norway
| | - Christian M Page
- Centre for Fertility and Health, Norwegian Institute of Public Health, Oslo, Norway
- Department of Mathematics, Faculty of Mathematics and Natural Sciences, University of Oslo, Oslo, Norway
| | - William R P Denault
- Centre for Fertility and Health, Norwegian Institute of Public Health, Oslo, Norway
- Department of Human Genetics, University of Chicago, Chicago, IL, USA
| | - Yunsung Lee
- Centre for Fertility and Health, Norwegian Institute of Public Health, Oslo, Norway
| | - Maria C Magnus
- Centre for Fertility and Health, Norwegian Institute of Public Health, Oslo, Norway
| | - Kristine L Haftorn
- Centre for Fertility and Health, Norwegian Institute of Public Health, Oslo, Norway
| | - Miriam Gjerdevik
- Centre for Fertility and Health, Norwegian Institute of Public Health, Oslo, Norway
- Department of Computer Science, Electrical Engineering and Mathematical Sciences, Western Norway University of Applied Sciences, Bergen, Norway
| | - Boris Novakovic
- Murdoch Children's Research Institute, Melbourne, Australia
- Department of Paediatrics, University of Melbourne, Melbourne, Australia
| | - Richard Saffery
- Murdoch Children's Research Institute, Melbourne, Australia
- Department of Paediatrics, University of Melbourne, Melbourne, Australia
| | - Håkon K Gjessing
- Centre for Fertility and Health, Norwegian Institute of Public Health, Oslo, Norway
- Department of Global Public Health and Primary Care, University of Bergen, Bergen, Norway
| | - Robert Lyle
- Centre for Fertility and Health, Norwegian Institute of Public Health, Oslo, Norway
- Department of Medical Genetics, Oslo University Hospital and University of Oslo, Oslo, Norway
| | - Per Magnus
- Centre for Fertility and Health, Norwegian Institute of Public Health, Oslo, Norway
| | - Siri E Håberg
- Centre for Fertility and Health, Norwegian Institute of Public Health, Oslo, Norway
| | - Astanand Jugessur
- Centre for Fertility and Health, Norwegian Institute of Public Health, Oslo, Norway
- Department of Global Public Health and Primary Care, University of Bergen, Bergen, Norway
| |
Collapse
|
4
|
Mariya T, Shichiri Y, Sugimoto T, Kawamura R, Miyai S, Inagaki H, Sugihara E, Ikeda K, Baba T, Ishikawa A, Ammae M, Nakaoka Y, Saito T, Sakurai A, Kurahashi H. Clinical application of long-read nanopore sequencing in a preimplantation genetic testing pre-clinical workup to identify the junction for complex Xq chromosome rearrangement-related disease. Prenat Diagn 2023; 43:304-313. [PMID: 36797813 DOI: 10.1002/pd.6334] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2022] [Revised: 02/08/2023] [Accepted: 02/10/2023] [Indexed: 02/18/2023]
Abstract
OBJECTIVE Xq chromosome duplication with complex rearrangements is generally acknowledged to be associated with neurodevelopmental disorders, such as Pelizaeus-Merzbacher disease (PMD) and MECP2 duplication syndrome. For couples who required a PGT-M (pre-implantation genetic testing for monogenic disease) for these disorders, junction-specific PCR is useful to directly detect pathogenic variants. Therefore, pre-clinical workup for PGT-M requires the identification of the junction of duplicated segments in PMD and MECP2 duplication syndrome, which is generally difficult. METHODS In this report, we used nanopore long-read sequencing targeting the X chromosome using an adaptive sampling method to identify breakpoint junctions in disease-causing triplications. RESULTS By long-read sequencing, we successfully identified breakpoint junctions in one PMD case with PLP1 triplication and in another MECP2 triplication case in a single sequencing run. Surprisingly, the duplicated region involving MECP2 was inserted 45 Mb proximal to the original position. This inserted region was confirmed by FISH analysis. With the help of precise mapping of the pathogenic variant, we successfully re-established STR haplotyping for PGT-M and avoided any potential misinterpretation of the pathogenic allele due to recombination. CONCLUSION Long-read sequencing with adaptive sampling in a PGT-M pre-clinical workup is a beneficial method for identifying junctions of chromosomal complex structural rearrangements.
Collapse
Affiliation(s)
- Tasuku Mariya
- Division of Molecular Genetics, Institute for Comprehensive Medical Science, Fujita Health University, Toyoake, Aichi, Japan.,Departments of Medical Genetics and Genomics, School of Medicine, Sapporo Medical University, Sapporo, Japan.,Department of Obstetrics and Gynecology, School of Medicine, Sapporo Medical University, Sapporo, Japan
| | - Yui Shichiri
- Division of Molecular Genetics, Institute for Comprehensive Medical Science, Fujita Health University, Toyoake, Aichi, Japan
| | - Takeshi Sugimoto
- Division of Molecular Genetics, Institute for Comprehensive Medical Science, Fujita Health University, Toyoake, Aichi, Japan
| | - Rie Kawamura
- Division of Molecular Genetics, Institute for Comprehensive Medical Science, Fujita Health University, Toyoake, Aichi, Japan
| | - Syunsuke Miyai
- Division of Molecular Genetics, Institute for Comprehensive Medical Science, Fujita Health University, Toyoake, Aichi, Japan
| | - Hidehito Inagaki
- Division of Molecular Genetics, Institute for Comprehensive Medical Science, Fujita Health University, Toyoake, Aichi, Japan
| | - Eiji Sugihara
- Open Facility Center, Research Promotion and Support Headquarters, Fujita Health University, Toyoake, Aichi, Japan
| | - Keiko Ikeda
- Department of Obstetrics and Gynecology, School of Medicine, Sapporo Medical University, Sapporo, Japan
| | - Tsuyoshi Baba
- Department of Obstetrics and Gynecology, School of Medicine, Sapporo Medical University, Sapporo, Japan
| | - Aki Ishikawa
- Departments of Medical Genetics and Genomics, School of Medicine, Sapporo Medical University, Sapporo, Japan
| | | | | | - Tsuyoshi Saito
- Department of Obstetrics and Gynecology, School of Medicine, Sapporo Medical University, Sapporo, Japan
| | - Akihiro Sakurai
- Departments of Medical Genetics and Genomics, School of Medicine, Sapporo Medical University, Sapporo, Japan
| | - Hiroki Kurahashi
- Division of Molecular Genetics, Institute for Comprehensive Medical Science, Fujita Health University, Toyoake, Aichi, Japan
| |
Collapse
|
5
|
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.
Collapse
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.
| |
Collapse
|
6
|
Medical Comorbidities in MECP2 Duplication Syndrome: Results from the International MECP2 Duplication Database. CHILDREN 2022; 9:children9050633. [PMID: 35626810 PMCID: PMC9139587 DOI: 10.3390/children9050633] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/19/2022] [Revised: 04/14/2022] [Accepted: 04/21/2022] [Indexed: 11/16/2022]
Abstract
Since the discovery of MECP2 duplication syndrome (MDS) in 1999, efforts to characterise this disorder have been limited by a lack of large datasets, with small case series often favouring the reporting of certain conditions over others. This study is the largest to date, featuring 134 males and 20 females, ascertained from the international MECP2 Duplication Database (MDBase). We report a higher frequency of pneumonia, bronchitis, bronchiolitis, gastroesophageal reflux and slow gut motility in males compared to females. We further examine the prevalence of other medical comorbidities such as epilepsy, gastrointestinal problems, feeding difficulties, scoliosis, bone fractures, sleep apnoea, autonomic disturbance and decreased pain sensitivity. A novel feature of urinary retention is reported and requires further investigation. Further research is required to understand the developmental trajectory of this disorder and to examine the context of these medical comorbidities in a quality of life framework.
Collapse
|
7
|
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.
Collapse
|
8
|
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.
Collapse
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
| |
Collapse
|
9
|
Peters SU, Fu C, Marsh ED, Benke TA, Suter B, Skinner SA, Lieberman DN, Standridge S, Jones M, Beisang A, Feyma T, Heydeman P, Ryther R, Glaze DG, Percy AK, Neul JL. Phenotypic features in MECP2 duplication syndrome: Effects of age. Am J Med Genet A 2020; 185:362-369. [PMID: 33170557 DOI: 10.1002/ajmg.a.61956] [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: 08/28/2020] [Revised: 10/09/2020] [Accepted: 10/17/2020] [Indexed: 12/14/2022]
Abstract
BACKGROUND MECP2 Duplication syndrome (MDS) is a rare X-linked genomic disorder that is caused by interstitial chromosomal duplications at Xq28 encompassing the MECP2 gene. Although phenotypic features in MDS have been described, there is a limited understanding of the range of severity of these features, and how they evolve with age. METHODS The cross-sectional results of N = 69 participants (ages 6 months-33 years) enrolled in a natural history study of MDS are presented. Clinical severity was assessed using a clinician-report measure as well as a parent-report measure. Data was also gathered related to the top 3 concerns of parents as selected from the most salient symptoms related to MDS. The Child Health Questionnaire was also utilized to obtain parental reports of each child's quality of life to establish disease burden. RESULTS The results of linear regression from the clinician-reported measure show that overall clinical severity scores, motor dysfunction, and functional skills are significantly worse with increasing age. Top concerns rated by parents included lack of effective communication, abnormal walking/balance issues, constipation, and seizures. Higher levels of clinical severity were also related to lower physical health quality of life scores as reported by parents. CONCLUSIONS The data suggest that increasing levels of clinical severity are noted with older age, and this is primarily attributable to motor dysfunction, and functional skills. The results provide an important foundation for creating an MDS-specific severity scale highlighting the most important domains to target for treatment trials and will help clinicians and researchers define clinically meaningful changes.
Collapse
Affiliation(s)
- Sarika U Peters
- Department of Pediatrics, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Cary Fu
- Department of Pediatrics, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Eric D Marsh
- Children's Hospital of Philadelphia and Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Tim A Benke
- University of Colorado School of Medicine, Aurora, Colorado, USA
| | | | | | | | | | - Mary Jones
- Oakland Children's Hospital, Oakland, California, USA
| | - Arthur Beisang
- Gilette Children's Specialty Healthcare, Saint Paul, Minnesota, USA
| | - Timothy Feyma
- Gilette Children's Specialty Healthcare, Saint Paul, Minnesota, USA
| | | | - Robin Ryther
- Washington University School of Medicine, St. Louis, Missouri, USA
| | | | - Alan K Percy
- University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Jeffrey L Neul
- Department of Pediatrics, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| |
Collapse
|
10
|
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: 23] [Impact Index Per Article: 4.6] [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.
Collapse
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
| |
Collapse
|