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Gomathi M, Dhivya V, Padmavathi V, Pradeepkumar M, Robert Wilson S, Kumar NS, Balachandar V. Genetic Instability and Disease Progression of Indian Rett Syndrome Patients. Mol Neurobiol 2024; 61:4868-4878. [PMID: 38147229 DOI: 10.1007/s12035-023-03882-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2023] [Accepted: 12/08/2023] [Indexed: 12/27/2023]
Abstract
Rett syndrome (RTT) is the rare neurodevelopmental disorder caused by mutations in methyl CpG binding protein 2 (MECP2) gene with a prevalence of 1:10,000 worldwide. The hallmark clinical features of RTT are developmental delay, microcephaly, repetitive behaviours, gait abnormalities, respiratory abnormalities and seizures. Still, the understanding on the diagnosis of RTT among clinicians are less. The aim of our work was to study various clinical manifestations and a spectrum of MECP2 genetic heterogeneity in RTT patients from South Indian population. We screened 208 autistic patients and diagnosed 20 RTT patients, who were further divided into classical RTT (group I; N = 11) and variant RTT (group II; N = 9). The clinical severity of RTT was measured using RSSS, RSBQ, SSI, SSS and RTT gross motor scale. The biochemical analysis showed that thyroid-stimulating hormone (TSH), plasma dopamine and cholesterol levels were higher in group I when compared to group II, whereas the level of blood pressure, calcium, ferritin and high-density lipoprotein levels were significantly decreased in both RTT groups, when compared to the control group. The genetic mutational spectrum of MECP2 mutations were found in 12/20 of RTT patients, which revealed the occurrence of 60% pathogenic mutation and 20% unknown mutation and it was correlated with the clinical finding of respiratory dysfunction, scoliosis and sleeping problems. The significant results of this study provided clinical and genetic aspects of RTT diagnosis and proposed the clinicians to screen abnormal cholesterol, calcium and TSH levels tailed with MECP2 gene mutations for early prognosis of disease severity.
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Affiliation(s)
- Mohan Gomathi
- Centre for Neuroscience, Department of Biotechnology, Karpagam Academy of Higher Education (Deemed to be University), Coimbatore, Tamil Nadu, 641021, India.
- Department of Human Genetics and Molecular Biology, Bharathiar University, Coimbatore, Tamil Nadu, 641 046, India.
| | - Venkatesan Dhivya
- Centre for Neuroscience, Department of Biotechnology, Karpagam Academy of Higher Education (Deemed to be University), Coimbatore, Tamil Nadu, 641021, India
- Department of Human Genetics and Molecular Biology, Bharathiar University, Coimbatore, Tamil Nadu, 641 046, India
| | - Vijayakumar Padmavathi
- Department of Microbiology, Sacred Heart College (Autonomous), Tirupattur, Tamil Nadu, 635601, India
| | - Murugasamy Pradeepkumar
- Department of Medical Genetics, KMCH Institute of Health Sciences and Research, Civil Aerodrome Road, Coimbatore, Tamil Nadu, 641014, India
| | - S Robert Wilson
- SRM Medical College Hospital and Research Centre, Kancheepuram District, Kattankulathur, Tamil Nadu, 603203, India
| | - Nachimuthu Senthil Kumar
- Department of Biotechnology, Mizoram University (A Central University), Aizawl, Mizoram, 796004, India
| | - Vellingiri Balachandar
- Department of Human Genetics and Molecular Biology, Bharathiar University, Coimbatore, Tamil Nadu, 641 046, India
- Human Cytogenetics and Stem Cell Laboratory, Department of Zoology, School of Basic Sciences, Central University of Punjab, Bathinda, Punjab, 151401, India
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Bouzroud W, Tazzite A, Berrada S, Gazzaz B, Dehbi H. R306X Mutation in the MECP2 Gene Causes an Atypical Rett Syndrome in a Moroccan Patient: A Case Report. CLINICAL PATHOLOGY (THOUSAND OAKS, VENTURA COUNTY, CALIF.) 2022; 15:2632010X221124269. [PMID: 36147795 PMCID: PMC9486266 DOI: 10.1177/2632010x221124269] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/14/2022] [Accepted: 08/18/2022] [Indexed: 11/16/2022]
Abstract
Rett syndrome (RTT) is a rare X-linked syndrome that predominantly affects girls.
It is characterized by a severe and progressive neurodevelopmental disorder with
neurological regression and autism spectrum features. The Rett syndrome is
associated with a broad phenotypic spectrum. It ranges from a classical Rett
syndrome defined by well-established criteria to atypical cases with symptoms
similar to other syndromes, such as Angelman syndrome. The first case of a
Moroccan female child carrying a R306X mutation in the MECP2
(Methyl-CpG-Binding Protein 2) gene, with an unusual manifestation of Rett
syndrome, is presented here. She showed autistic regression, behavioral
stagnation, epilepsy, unmotivated laughter, and craniofacial dysmorphia. Whole
exome sequencing revealed a nonsense mutation (R306X), resulting in a truncated,
nonfunctional MECP2 protein. The overlapping phenotypic spectrums between Rett
and Angelman syndromes have been described, and an interaction between the
MECP2 gene and the UBE3A (Ubiquitin
Protein Ligase E3A) gene pathways is possible but has not yet been proven. An
extensive genetic analysis is highly recommended in atypical cases to ensure an
accurate diagnosis and to improve patient management and genetic counseling.
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Affiliation(s)
- Wafaa Bouzroud
- Medical Genetics Laboratory, Ibn Rochd University Hospital, Casablanca, Morocco
| | - Amal Tazzite
- Laboratory of Cellular and Molecular Pathology, Faculty of Medicine and Pharmacy, Hassan II University, Casablanca, Morocco
| | - Sarah Berrada
- Medical Genetics Laboratory, Ibn Rochd University Hospital, Casablanca, Morocco
| | - Bouchaïb Gazzaz
- Laboratory of Cellular and Molecular Pathology, Faculty of Medicine and Pharmacy, Hassan II University, Casablanca, Morocco.,Genetics Analysis Institute, Royal Gendarmerie, Rabat, Morocco
| | - Hind Dehbi
- Medical Genetics Laboratory, Ibn Rochd University Hospital, Casablanca, Morocco.,Laboratory of Cellular and Molecular Pathology, Faculty of Medicine and Pharmacy, Hassan II University, Casablanca, Morocco
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Singh J, Lanzarini E, Nardocci N, Santosh P. Movement disorders in patients with Rett syndrome: A systematic review of evidence and associated clinical considerations. Psychiatry Clin Neurosci 2021; 75:369-393. [PMID: 34472659 PMCID: PMC9298304 DOI: 10.1111/pcn.13299] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/09/2021] [Revised: 07/28/2021] [Accepted: 08/20/2021] [Indexed: 12/18/2022]
Abstract
AIM This systematic review identified and thematically appraised clinical evidence of movement disorders in patients with Rett syndrome (RTT). METHOD Using PRISMA criteria, six electronic databases were searched from inception to April 2021. A thematic analysis was then undertaken on the extracted data to identify potential themes. RESULTS Following the thematic analysis, six themes emerged: (i) clinical features of abnormal movement behaviors; (ii) mutational profile and its impact on movement disorders; (iii) symptoms and stressors that impact on movement disorders; (iv) possible underlying neurobiological mechanisms; (v) quality of life and movement disorders; and (vi) treatment of movement disorders. Current guidelines for managing movement disorders in general were then reviewed to provide possible treatment recommendations for RTT. CONCLUSION Our study offers an enriched data set for clinical investigations and treatment of fine and gross motor issues in RTT. A detailed understanding of genotype-phenotype relationships of movement disorders allows for more robust genetic counseling for families but can also assist healthcare professionals in terms of monitoring disease progression in RTT. The synthesis also showed that environmental enrichment would be beneficial for improving some aspects of movement disorders. The cerebellum, basal ganglia, alongside dysregulation of the cortico-basal ganglia-thalamo-cortical loop, are likely anatomical targets. A review of treatments for movement disorders also helped to provide recommendations for treating and managing movement disorders in patients with RTT.
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Affiliation(s)
- Jatinder Singh
- Department of Child and Adolescent Psychiatry, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK.,Centre for Interventional Paediatric Psychopharmacology and Rare Diseases, South London and Maudsley NHS Foundation Trust, London, UK.,Centre for Personalised Medicine in Rett Syndrome, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
| | - Evamaria Lanzarini
- Child and Adolescent Neuropsychiatry Unit, Infermi Hospital, Rimini, Italy
| | - Nardo Nardocci
- Department of Paediatric Neurology, Fondazione IRCCS Istituto Neurologico "Carlo Besta", Milan, Italy
| | - Paramala Santosh
- Department of Child and Adolescent Psychiatry, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK.,Centre for Interventional Paediatric Psychopharmacology and Rare Diseases, South London and Maudsley NHS Foundation Trust, London, UK.,Centre for Personalised Medicine in Rett Syndrome, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
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Rett Syndrome as a movement and motor disorder - A narrative review. Eur J Paediatr Neurol 2020; 28:29-37. [PMID: 32807681 DOI: 10.1016/j.ejpn.2020.06.020] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/04/2019] [Revised: 06/16/2020] [Accepted: 06/30/2020] [Indexed: 11/24/2022]
Abstract
UNLABELLED Rett syndrome (RTT) is neurodevelopmental disorder affecting approximately 1:10000-15000 live female births, commonly associated with MECP2 gene mutations. Hand stereotypies and gait disturbance, as well as spasticity and dystonia, were noted in RTT since first descriptions. This review aimed to explore the prevalence of reported movement disorders in RTT. DATA SOURCES AND EXTRACTION Pubmed and Embase databases for papers describing features of movement disorders in RTT. Papers were selected if included description of case report, cohort or case-series of patients with RTT including descriptions of clinical features of their movement disorder. Papers were divided into 3 epochs - i) Pre-1999,ii) 2000-2009, and iii) 2010 onwards. RESULTS 32 studies (13 in the first, 10 in the second and 9 in the third epochs) reported on movement disorders in RTT. Hand stereotypies were almost universal, diminishing but not disappearing over time. Gait disturbance and ataxia/tremor were also very common (>50% cases). Hypertonia was also often reported, increasing with age. In earlier descriptions spasticity was commonly described, with greater reference to dystonia/rigidity in more recent reports. Myoclonus and choreoathetosis were uncommonly reported. CONCLUSIONS Movement disorders beyond hand stereotypies are common in RTT, most notably tremor. Hypertonia is frequently seen in RTT, increasing in prevalence with age, with apparent changes in nomenclature over time, (i.e early epoch spasticity, late epoch dystonia). Dystonia was specifically reported in 229/417 cases. Further work is required to explore the relative contribution of dystonia and rigidity to hypertonia in RTT, as well as the impact of these impairments when present.
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Aldosary M, Al-Bakheet A, Al-Dhalaan H, Almass R, Alsagob M, Al-Younes B, AlQuait L, Mustafa OM, Bulbul M, Rahbeeni Z, Alfadhel M, Chedrawi A, Al-Hassnan Z, AlDosari M, Al-Zaidan H, Al-Muhaizea MA, AlSayed MD, Salih MA, AlShammari M, Faiyaz-Ul-Haque M, Chishti MA, Al-Harazi O, Al-Odaib A, Kaya N, Colak D. Rett Syndrome, a Neurodevelopmental Disorder, Whole-Transcriptome, and Mitochondrial Genome Multiomics Analyses Identify Novel Variations and Disease Pathways. OMICS-A JOURNAL OF INTEGRATIVE BIOLOGY 2020; 24:160-171. [PMID: 32105570 DOI: 10.1089/omi.2019.0192] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Rett syndrome (RTT) is a severe neurodevelopmental disorder reported worldwide in diverse populations. RTT is diagnosed primarily in females, with clinical findings manifesting early in life. Despite the variable rates across populations, RTT has an estimated prevalence of ∼1 in 10,000 live female births. Among 215 Saudi Arabian patients with neurodevelopmental and autism spectrum disorders, we identified 33 patients with RTT who were subsequently examined by genome-wide transcriptome and mitochondrial genome variations. To the best of our knowledge, this is the first in-depth molecular and multiomics analyses of a large cohort of Saudi RTT cases with a view to informing the underlying mechanisms of this disease that impact many patients and families worldwide. The patients were unrelated, except for 2 affected sisters, and comprised of 25 classic and eight atypical RTT cases. The cases were screened for methyl-CpG binding protein 2 (MECP2), CDKL5, FOXG1, NTNG1, and mitochondrial DNA (mtDNA) variants, as well as copy number variations (CNVs) using a genome-wide experimental strategy. We found that 15 patients (13 classic and two atypical RTT) have MECP2 mutations, 2 of which were novel variants. Two patients had novel FOXG1 and CDKL5 variants (both atypical RTT). Whole mtDNA sequencing of the patients who were MECP2 negative revealed two novel mtDNA variants in two classic RTT patients. Importantly, the whole-transcriptome analysis of our RTT patients' blood and further comparison with previous expression profiling of brain tissue from patients with RTT revealed 77 significantly dysregulated genes. The gene ontology and interaction network analysis indicated potentially critical roles of MAPK9, NDUFA5, ATR, SMARCA5, RPL23, SRSF3, and mitochondrial dysfunction, oxidative stress response and MAPK signaling pathways in the pathogenesis of RTT genes. This study expands our knowledge on RTT disease networks and pathways as well as presents novel mutations and mtDNA alterations in RTT in a population sample that was not previously studied.
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Affiliation(s)
- Mazhor Aldosary
- Department of Genetics, King Faisal Specialist Hospital & Research Center, Riyadh, Saudi Arabia
| | - AlBandary Al-Bakheet
- Department of Genetics, King Faisal Specialist Hospital & Research Center, Riyadh, Saudi Arabia
| | - Hesham Al-Dhalaan
- Department of Neuroscience, and King Faisal Specialist Hospital & Research Center, Riyadh, Saudi Arabia
| | - Rawan Almass
- Department of Genetics, King Faisal Specialist Hospital & Research Center, Riyadh, Saudi Arabia
| | - Maysoon Alsagob
- Department of Genetics, King Faisal Specialist Hospital & Research Center, Riyadh, Saudi Arabia
| | - Banan Al-Younes
- Department of Genetics, King Faisal Specialist Hospital & Research Center, Riyadh, Saudi Arabia
| | - Laila AlQuait
- Department of Genetics, King Faisal Specialist Hospital & Research Center, Riyadh, Saudi Arabia
| | - Osama Mufid Mustafa
- Department of Genetics, King Faisal Specialist Hospital & Research Center, Riyadh, Saudi Arabia
| | - Mustafa Bulbul
- Department of Genetics, King Faisal Specialist Hospital & Research Center, Riyadh, Saudi Arabia
| | - Zuhair Rahbeeni
- Department of Medical Genetics, King Faisal Specialist Hospital & Research Center, Riyadh, Saudi Arabia
| | - Majid Alfadhel
- King Abdullah International Medical Research Centre, King Saud bin Abdulaziz University for Health Sciences, Genetics Division, Department of Pediatrics, King Abdullah Specialized Children Hospital, Riyadh, Saudi Arabia
| | - Aziza Chedrawi
- Department of Neuroscience, and King Faisal Specialist Hospital & Research Center, Riyadh, Saudi Arabia
| | - Zuhair Al-Hassnan
- Department of Medical Genetics, King Faisal Specialist Hospital & Research Center, Riyadh, Saudi Arabia
| | - Mohammed AlDosari
- Center for Pediatric Neurosciences, Cleveland Clinic, Cleveland, Ohio
| | - Hamad Al-Zaidan
- Department of Medical Genetics, King Faisal Specialist Hospital & Research Center, Riyadh, Saudi Arabia
| | - Mohammad A Al-Muhaizea
- Department of Neuroscience, and King Faisal Specialist Hospital & Research Center, Riyadh, Saudi Arabia
| | - Moeenaldeen D AlSayed
- Department of Medical Genetics, King Faisal Specialist Hospital & Research Center, Riyadh, Saudi Arabia
| | - Mustafa A Salih
- Division of Pediatric Neurology, College of Medicine, King Saud University, Riyadh, Saudi Arabia
| | - Mai AlShammari
- Department of Genetics, King Faisal Specialist Hospital & Research Center, Riyadh, Saudi Arabia
| | | | - Mohammad Azhar Chishti
- Department of Biochemistry, King Khalid Hospital, King Saud University, Riyadh, Saudi Arabia
| | - Olfat Al-Harazi
- Department of Biostatistics, Epidemiology, and Scientific Computing, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Ali Al-Odaib
- Department of Genetics, King Faisal Specialist Hospital & Research Center, Riyadh, Saudi Arabia
| | - Namik Kaya
- Department of Genetics, King Faisal Specialist Hospital & Research Center, Riyadh, Saudi Arabia
| | - Dilek Colak
- Department of Biostatistics, Epidemiology, and Scientific Computing, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
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Hettiarachchi D, Neththikumara NF, Pathirana BAPS, Dissanayake VHW. Variant Profile of MECP2 Gene in Sri Lankan Patients with Rett Syndrome. J Autism Dev Disord 2019; 50:118-126. [DOI: 10.1007/s10803-019-04230-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Munde V, Vlaskamp C, Ter Haar A. Social-emotional instability in individuals with Rett syndrome: parents' experiences with second stage behaviour. JOURNAL OF INTELLECTUAL DISABILITY RESEARCH : JIDR 2016; 60:43-53. [PMID: 26497300 DOI: 10.1111/jir.12233] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2014] [Revised: 08/18/2015] [Accepted: 09/08/2015] [Indexed: 06/05/2023]
Abstract
BACKGROUND While the medical profession often terms behaviours in individuals with Rett syndrome (RTT) in the second stage as 'autistic-like', parents disagree with this description. The present study focuses on a comparison of parents' experiences with the social-emotional behaviour of the child with RTT in the second and subsequent stages. METHOD In collaboration with the Dutch Rett Syndrome Organization, 51 parents of children with RTT in the Netherlands took part in the present study. Parents completed an online questionnaire to clarify their experiences of the social-emotional behaviour of their children during and after the second stage of RTT. Both quantitative and qualitative analysis techniques have been used. RESULTS The results of the paired-samples t-test show that parents see significantly less social-emotional behaviour in the children during the second stage of RTT than in the subsequent stages. Parents reported that their children did not seek as much interaction. From the parents' descriptions, it would seem that the children are willing but unable to interact with their environment. CONCLUSIONS Like previous research, our study leads to doubts about the appropriateness of the label 'autistic-like' for the behaviour of individuals in the second stage of RTT. While behaviours of individuals with autism and individuals with RTT may resemble each other, quality and intentions may differ. Still, future studies are needed for further clarification.
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Affiliation(s)
- V Munde
- Department of Special Needs Education and Child Care, University of Groningen, Groningen, The Netherlands
| | - C Vlaskamp
- Department of Special Needs Education and Child Care, University of Groningen, Groningen, The Netherlands
| | - A Ter Haar
- Department of Special Needs Education and Child Care, University of Groningen, Groningen, The Netherlands
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Wang F, Fischhaber PL, Guo C, Tang TS. Epigenetic modifications as novel therapeutic targets for Huntington’s disease. Epigenomics 2014; 6:287-97. [DOI: 10.2217/epi.14.19] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Huntington’s disease is a late-onset, autosomal dominant neurodegenerative disorder characterized by motor, cognitive and psychiatric symptomatology. The earliest stage of Huntington’s disease is marked by alterations in gene expression, which partially results from dysregulated epigenetic modifications. In past decades, altered epigenetic markers including histone modifications (acetylation, methylation, ubiquitylation and phosphorylation) and DNA modifications (cytosine methylation and hydroxymethylation) have been reported as important epigenetic features in patients and multiple animal models of Huntington’s disease. Drugs aimed to correct some of those alterations have shown promise in treating Huntington’s disease. This article discusses the field of epigenetics for potential Huntington’s disease interventions and presents the most recent findings in this area.
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Affiliation(s)
- Fengli Wang
- State Key Laboratory of Biomembrane & Membrane Biotechnology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Paula L Fischhaber
- Department of Chemistry & Biochemistry, California State University Northridge, Northridge, CA 91330–8262, USA
| | - Caixia Guo
- Center for Genome Variations & Precision Biomedicine, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing 100029, China
| | - Tie-Shan Tang
- State Key Laboratory of Biomembrane & Membrane Biotechnology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China
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Tzagkaraki E, Sofocleous C, Fryssira-Kanioura H, Dinopoulos A, Goulielmos G, Mavrou A, Kitsiou-Tzeli S, Kanavakis E, Sofia KT, Kanavakis E. Screening of UBE3A gene in patients referred for Angelman Syndrome. Eur J Paediatr Neurol 2013; 17:366-73. [PMID: 23416059 DOI: 10.1016/j.ejpn.2012.12.010] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/17/2012] [Revised: 12/27/2012] [Accepted: 12/30/2012] [Indexed: 01/05/2023]
Abstract
Angelman Syndrome (AS) is a neurodevelopmental disorder characterized by severe developmental delay, speech impairment and unique behaviors including inappropriate laughter and happy disposition. AS is related to deficient maternal UBE3A gene expression caused either by chromosomal deletions, uniparental disomy, molecular defects of the imprinted 15q11-q13 critical region or by loss of function mutations in the maternally inherited UBE3A. In the present study, screening UBE3A was performed in 43 patients who were referred for AS but whom previous molecular diagnostic tests failed to provide a diagnosis. Two causative mutations--one of them novel--and four polymorphic variants one of which is also novel were revealed. Further investigation of 7 patients disclosed defects in other genes involved in clinical phenotypes mimicking AS. A typical EEG pattern and microcephaly in patients with developmental delay prompt for AS investigation while wide genetic screening should be applied to help resolution of the complex phenotypes characterized by developmental delay.
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Affiliation(s)
- Evmorfia Tzagkaraki
- Department of Medical Genetics, University of Athens School of Medicine, Choremeio Research Laboratory, Aghia Sophia Children's Hospital, Thivon and Levadeias str, 11527 Goudi, Athens, Greece.
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Maortua H, Martínez-Bouzas C, García-Ribes A, Martínez MJ, Guillen E, Domingo MR, Calvo MT, Guitart M, Gabau E, Botella MP, Gener B, Rubio I, López-Aríztegui MA, Tejada MI. MECP2 gene study in a large cohort: testing of 240 female patients and 861 healthy controls (519 females and 342 males). J Mol Diagn 2013; 15:723-9. [PMID: 23810759 DOI: 10.1016/j.jmoldx.2013.05.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2012] [Revised: 05/08/2013] [Accepted: 05/15/2013] [Indexed: 11/24/2022] Open
Abstract
The MECP2 gene located on Xq28 is one of the most important genes contributing to the spectrum of neurodevelopmental disorders. Therefore, we present our experience in the molecular study of this gene. MECP2 was thoroughly tested for the presence of mutations (sequencing of four exons and rearrangements) in 120 female patients: 28 with classic Rett syndrome, five with atypical Rett syndrome, and 87 with heterogeneous phenotypes with some Rett-like features. Another 120 female patients with intellectual disability of unknown origin were also studied, but in these cases we only tested exons 3 and 4. Finally, 861 healthy controls (519 females and 342 males) were also studied for exon 3 and 4. Eighteen different pathological mutations were found, five of them previously undescribed, and four large deletions detected by multiplex ligation-dependent probe amplification. All were de novo mutations not present in the parents. In conclusion, i) MECP2 is one of the most important genes in the diagnosis of genetic intellectual disability in females; ii) MECP2 must be studied not only in patients with classical/atypical Rett syndrome but also in patients with other phenotypes related to Rett syndrome; and iii) for the new variants, it is important to perform complementary studies, including the analysis of large populations of healthy individuals and the use of in silico programs.
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Affiliation(s)
- Hiart Maortua
- Molecular Genetics Laboratory, Genetics Service, BioCruces Health Research Institute, Cruces University Hospital, Barakaldo-Bizkaia, Spain
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Wang F, Yang Y, Lin X, Wang JQ, Wu YS, Xie W, Wang D, Zhu S, Liao YQ, Sun Q, Yang YG, Luo HR, Guo C, Han C, Tang TS. Genome-wide loss of 5-hmC is a novel epigenetic feature of Huntington's disease. Hum Mol Genet 2013; 22:3641-53. [PMID: 23669348 DOI: 10.1093/hmg/ddt214] [Citation(s) in RCA: 101] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
5-Hydroxymethylcytosine (5-hmC) may represent a new epigenetic modification of cytosine. While the dynamics of 5-hmC during neurodevelopment have recently been reported, little is known about its genomic distribution and function(s) in neurodegenerative diseases such as Huntington's disease (HD). We here observed a marked reduction of the 5-hmC signal in YAC128 (yeast artificial chromosome transgene with 128 CAG repeats) HD mouse brain tissues when compared with age-matched wild-type (WT) mice, suggesting a deficiency of 5-hmC reconstruction in HD brains during postnatal development. Genome-wide distribution analysis of 5-hmC further confirmed the diminishment of the 5-hmC signal in striatum and cortex in YAC128 HD mice. General genomic features of 5-hmC are highly conserved, not being affected by either disease or brain regions. Intriguingly, we have identified disease-specific (YAC128 versus WT) differentially hydroxymethylated regions (DhMRs), and found that acquisition of DhmRs in gene body is a positive epigenetic regulator for gene expression. Ingenuity pathway analysis (IPA) of genotype-specific DhMR-annotated genes revealed that alternation of a number of canonical pathways involving neuronal development/differentiation (Wnt/β-catenin/Sox pathway, axonal guidance signaling pathway) and neuronal function/survival (glutamate receptor/calcium/CREB, GABA receptor signaling, dopamine-DARPP32 feedback pathway, etc.) could be important for the onset of HD. Our results indicate that loss of the 5-hmC marker is a novel epigenetic feature in HD, and that this aberrant epigenetic regulation may impair the neurogenesis, neuronal function and survival in HD brain. Our study also opens a new avenue for HD treatment; re-establishing the native 5-hmC landscape may have the potential to slow/halt the progression of HD.
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Affiliation(s)
- Fengli Wang
- State Key Laboratory of Biomembrane and Membrane Biotechnology, Institute of Zoology, Chinese Academy of Sciences, 1 Beichen West Road, Chaoyang District, Beijing, China
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12
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Miao CG, Yang YY, He X, Li J. New advances of DNA methylation and histone modifications in rheumatoid arthritis, with special emphasis on MeCP2. Cell Signal 2013; 25:875-82. [DOI: 10.1016/j.cellsig.2012.12.017] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2012] [Accepted: 12/21/2012] [Indexed: 01/04/2023]
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13
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Millichap JG. Growth Failure and Outcome in Rett Syndrome. Pediatr Neurol Briefs 2012. [DOI: 10.15844/pedneurbriefs-26-12-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
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14
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Zhang X, Bao X, Zhang J, Zhao Y, Cao G, Pan H, Zhang J, Wei L, Wu X. Molecular characteristics of Chinese patients with Rett syndrome. Eur J Med Genet 2012; 55:677-81. [DOI: 10.1016/j.ejmg.2012.08.009] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2012] [Accepted: 08/20/2012] [Indexed: 10/27/2022]
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Irier HA, Jin P. Dynamics of DNA methylation in aging and Alzheimer's disease. DNA Cell Biol 2012; 31 Suppl 1:S42-8. [PMID: 22313030 DOI: 10.1089/dna.2011.1565] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Gene expression is modulated by epigenetic factors that come in varying forms, such as DNA methylation, histone modifications, microRNAs, and long noncoding RNAs. Recent studies reveal that these epigenetic marks are important regulatory factors in brain function. In particular, DNA methylation dynamics are found to be essential components of epigenetic regulation in the mammalian central nervous system. In this review, we provide an overview of the literature on DNA methylation in neurodegenerative diseases, with a special focus on methylation of 5-position of cytosine base (5mC) and hydroxymethylation of 5-position of cytosine base (5hmC) in the context of neurodegeneration associated with aging and Alzheimer's disease.
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Affiliation(s)
- Hasan A Irier
- Department of Human Genetics, Emory University School of Medicine, Atlanta, Georgia 30322, USA
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