Search Results (173)

Rett syndrome is a severe neurodevelopmental disorder that occurs primarily in females and is caused by mutations in the methyl-CpG-binding protein 2 (MECP2) gene located on the X chromosome. Though MECP2 acts as a representative transcriptional regulator and affects gene expression both directly and indirectly, a complete understanding of this disease and the treatment mechanism has not been established yet. MECP2 plays a particularly important role in synaptic development, neuronal maturation, and epigenetic regulation in the brain. In this study, we summarize the molecular structure of MECP2, mutation-specific pathogenesis, and the role of MECP2 in regulating chromatin remodeling, RNA splicing, and miRNA processing to provide a comprehensive understanding of Rett syndrome. Additionally, we describe abnormal phenotypes manifested in various brain regions and other tissues owing to MECP2 dysfunction. Finally, we discuss current and future therapeutic approaches, including AAV-based gene therapy, RNA editing, X chromosome reactivation, and pharmacological interventions. Understanding the diverse functions and pathological mechanisms of MECP2 provides an important foundation for developing targeted therapies for Rett syndrome. Full article

Methyl CpG-binding protein 2 (MeCP2) is an epigenetic reader of DNA methylation with high abundance in the brain. While genetic mutations occur across different protein domains of MeCP2, the T158M mutation is amongst the most frequent MeCP2 mutations. MeCP2 is encoded by the MECP2/Mecp2 gene located on the X chromosome. In humans, MECP2 mutations cause Rett Syndrome, a debilitating neurodevelopmental disorder in females, with very rare cases presenting in males. Despite the generation of different transgenic mouse lines with MeCP2 mutations, the sex-dependent phenotypic and molecular impact of common MeCP2 mutations in mouse models of disease remains largely unexplored. Here, we focus on the MeCP2 T158M mutation using Mecp2^tm4.1Bird/J transgenic mice (referred to as Mecp2^T158M), and report that Mecp2^T158M mutant mice display sex-specific molecular, behavioural, and phenotypic characteristics when compared to wild-type controls. Our data indicates sex- and brain-region-dependent impacts on the expression of MeCP2, synaptic proteins, cytoskeletal markers, and autophagy factors. Our findings demonstrate that the phenotypic and molecular characteristics of this mouse model may relate to the clinical manifestation in human patients with Rett Syndrome. Full article

Background/Objectives: Miscarriage is an increasingly common event worldwide arising from various factors, and identifying its etiology is important for planning and managing any future pregnancies. It is estimated that about half of early pregnancy loss cases are caused by genetic abnormalities, while a significantly lower rate is found in late pregnancy loss. Multiplex ligation-dependent probe amplification (MLPA) can detect small changes within a gene with precise breakpoints at the level of a single exon. The aim of our study was to identify the rate of copy number variations (CNVs) in spontaneous pregnancy loss samples after having previously tested them via quantitative fluorescence PCR (QF-PCR), with no abnormal findings. Methods: DNA was extracted from product-of-conception tissue samples, followed by the use of an MLPA kit for the detection of 31 microdeletion/microduplication syndromes (SALSA^® MLPA^® Probemix P245 Microdeletion Syndromes-1A, MRC-Holland, Amsterdam, The Netherlands). Results: A total of 11 (13.1%) out of the 84 successfully tested samples showed CNVs. Duplications accounted for 9.5% of the analyzed samples (eight cases), while heterozygous or hemizygous deletions were present in three cases (3.6%). Among all the detected CNVs, only three were certainly pathogenic (3.6%), with two deletions associated with DiGeorge-2 syndrome and Rett syndrome, respectively, and a 2q23.1 microduplication syndrome, all detected in early pregnancy loss samples. For the remaining cases, additional genetic tests (e.g., aCGH/SNP microarray) are required to establish CNV size and gene content and therefore their pathogenicity. Conclusions: MLPA assays seem to have limited value in detecting supplementary chromosomal abnormalities in miscarriages. Full article

Background/Objectives: Rett syndrome (RTT) is a rare neurodevelopmental disorder that affects movement and communication skills primarily in females. This study aimed to synthesize the research from the last two decades regarding the verbal and nonverbal communication abilities, assessment procedures, and intervention approaches for individuals with RTT. Methods: A structured literature search was conducted using the Embase, Scopus, and PubMed databases. Fifty-seven studies were selected and analyzed based on inclusion criteria. The data were categorized into four domains (verbal communication skills, nonverbal communication skills, assessment procedures, and intervention approaches). Results: The findings indicated a wide variety of communicative behaviors across the RTT population, including prelinguistic signals, regression in verbal output, and preserved nonverbal communicative intent. Moreover, the results highlighted the importance of tailored assessments (Inventory of Potential Communicative Acts, eye tracking tools, and Augmentative and Alternative Communication) to facilitate functional communication. The individualized intervention approaches were found to be the most effective in improving communicative participation. Conclusions: The current review provides an overview of the current evidence with an emphasis on the need for personalized and evidence-based clinical practices. Additionally, it provided guidance for professionals, clinicians, and researchers seeking to improve the quality of life for individuals with RTT. Full article

Background/Objectives: This exploratory study examined the potential effectiveness of cognitive enhancement interventions targeting basic cognitive prerequisites and communicative abilities in girls with Rett syndrome. Special attention was given to evaluating telerehabilitation as a feasible alternative to traditional in-person therapy, particularly for individuals with severe impairments and limited access to care. Methods: Twenty-four girls diagnosed with Rett syndrome (mean age = 13.7 years, SD = 7.1), all meeting the basic cognitive prerequisites defined by the GAIRS scale, were randomly assigned to two groups: a telerehabilitation group (n = 12) and an in-person rehabilitation group (n = 12). Interventions were delivered in school settings and focused on two core areas: basic cognitive skills (e.g., object recognition, spatial and temporal concepts, form and color discrimination, and cause–effect reasoning) and communication skills (e.g., comprehension and expression through gestures, images, or verbal output). Results: Both groups showed significant improvements in the cognitive and communicative domains, with generally comparable outcomes. Notably, the telerehabilitation group demonstrated relatively greater gains in verbal expression and cause–effect understanding. Correlational analyses indicated positive associations between the cognitive and communicative improvements, particularly between spatial understanding and expressive abilities. However, these findings should be interpreted with caution due to the sample size and study design limitations. Conclusions: These preliminary findings suggest that cognitive enhancement programs may support developmental gains in girls with Rett syndrome and that telerehabilitation could represent a viable alternative for those unable to access in-person care. Given the limited sample size and absence of qualitative measures, further research is necessary to validate its effectiveness and understand its role within comprehensive care models. Full article

Rett syndrome (RTT) is an X-linked neurodevelopmental disorder marked by neurological regression, autonomic dysfunction, seizures, and significant sleep and breathing abnormalities. About 80% of affected individuals, especially young children, experience sleep disturbances such as insomnia, sleep-disordered breathing, nocturnal vocalizations, bruxism, and seizures. Breathing irregularities during sleep—like apnea, alternating hyperventilation, and hypoventilation—are common, with both obstructive and central sleep apnea identified through polysomnography. This review focuses on the prevalent sleep disorders in children with Rett syndrome and highlights current recommendations for the management of sleep disorders. Full article

Background/Objectives: Rett Syndrome (RTT) is a rare neurodevelopmental disorder that affects girls and is characterized by severe motor and cognitive impairments, the loss of purposeful hand use, and communication difficulties. Children with RTT, especially those aged 5 to 9 years, often struggle to develop the foundational skills necessary for adaptive functioning, such as eye contact, object tracking, functional gestures, turn-taking, and basic communication. These abilities are essential for cognitive, social, and motor development and contribute to greater autonomy in daily life. This study aimed to explore the feasibility of a structured telerehabilitation program and to provide preliminary observations of its potential utility for young girls with RTT, addressing the presumed challenge of engaging this population in video-based interactive training. Methods: The intervention consisted of 30 remotely delivered sessions (each lasting 90 min), with assessments at baseline (A), after 5 weeks (B1), and after 10 weeks (B2). Quantitative outcome measures focused on changes in eye contact, object tracking, functional gestures, social engagement, and responsiveness to visual stimulus. Results: The findings indicate that the program was feasible and well-tolerated. Improvements were observed across all measured domains, and participants showed high levels of engagement and participation throughout the intervention. While these results are preliminary, they suggest that interactive digital formats may be promising for supporting foundational learning processes in children with RTT. Conclusions: This study provides initial evidence that telerehabilitation is a feasible approach for engaging young girls with RTT and supporting adaptive skill development. These findings may inform future research and the design of controlled studies to evaluate the efficacy of technology-assisted interventions in this population. Full article

Rett syndrome (RTT) is a multisystem neurological disorder. Pathogenic changes in the MECP2 gene that codes for methyl-CpG-binding protein 2 (MeCP2) in RTT lead to a loss of previously established motor and cognitive skills. Unravelling the mechanisms of neurological regression in RTT is complex, due to multiple components of the neural epigenome being affected. Most evidence has primarily focused on deciphering the complexity of transcriptional machinery at the molecular level. Little attention has been paid to how epigenetic changes across the neural epigenome in RTT lead to neurological regression. In this narrative review, we examine how pathogenic changes in MECP2 can disrupt the balance of the RTT neural epigenome and lead to neurological regression. Environmental and genetic factors can disturb the balance of the neural epigenome in RTT, modifying the onset of neurological regression. Methylation changes across the RTT neural epigenome and the consequent genotoxic stress cause neurons to regress into a senescent state. These changes influence the brain as it matures and lead to the emergence of specific symptoms at different developmental periods. Future work could focus on epidrugs or epi-editing approaches that may theoretically help to restore the epigenetic imbalance and thereby minimise the impact of genotoxic stress on the RTT neural epigenome. Full article

Kleefstra syndrome (KS) is a rare neurodevelopmental disorder associated with disruptions in the EHMT1 gene, often leading to intellectual disability, autism spectrum behaviors and epilepsy. The electroencephalogram (EEG) serves as a non-invasive tool to explore brain function in KS; yet, systematic characterizations of EEG features remain extremely limited. This review synthesizes current evidence on EEG findings in KS, highlighting the high prevalence of nonspecific abnormalities and seizures, but the absence of a consistent electrophysiological biomarker. Given the growing role of machine learning (ML) in extracting patterns from EEG data in related disorders—such as Angelman, Rett and Fragile X syndromes—this review explores how similar approaches could be adapted for KS. Despite promising perspectives, a lack of large-scale, publicly available EEG datasets hinders the application of ML methodologies in KS research. Future directions are proposed to address these gaps, including standardized EEG data collection, adoption of quantitative EEG analyses and integration of ML techniques adapted for small datasets. This multidisciplinary strategy holds potential for improving early diagnosis, monitoring and personalized interventions in Kleefstra syndrome. Full article

Classical Rett syndrome (RTT) is a neurodevelopmental disorder caused by mutations in the MECP2 gene, resulting in a devastating phenotype associated with a lack of gene expression control. Mouse models lacking Mecp2 expression with an RTT-like phenotype have been developed to advance therapeutic alternatives. Environmental enrichment (EE) attenuates RTT symptoms in patients and mouse models. However, the mechanisms underlying the effects of EE on RTT have not been fully elucidated. We housed male hemizygous Mecp2-null (Mecp2^-/y) and wild-type mice in specially conditioned cages to enhance sensory, cognitive, social, and motor stimulation. EE attenuated the progression of the RTT phenotype by preserving neuronal cytoarchitecture and neural plasticity markers. Furthermore, EE ameliorated defects in neuromuscular junction organization and restored the motor deficit of Mecp2^-/y mice. Treatment with plasma from young WT mice was used to assess whether the increased activity could modify plasma components, mimicking the benefits of EE in Mecp2^-/y. Plasma treatment attenuated the RTT phenotype by improving neurological markers, suggesting that peripheral signals of mice with normal motor function have the potential to reactivate dormant neurodevelopment in RTT mice. These findings demonstrate how EE and treatment with young plasma ameliorate RTT-like phenotype in mice, opening new therapeutical approaches for RTT patients. Full article

Rett syndrome (RTT) is a rare X-linked dominant neurodevelopmental disorder caused by pathogenic variants in the methyl-CpG-binding protein 2 (MECP2) gene, which encodes a methyl-CpG-binding protein (MeCP2) that acts as a repressor of gene expression, crucial in neurons. Dysfunction of MeCP2 due to its pathogenic variants explains the clinical features of RTT. Here, we performed histological and RNA analyses on a post-mortem brain sample from an RTT patient carrying the p.Arg106Trp missense mutation. This patient is part of a cohort of 56 genetically and clinically characterized RTT patients, for whom we provide an overview of the mutation landscape. In the RTT brain specimen, RT-PCR analysis detected preferential transcription of the mutated mRNA. X-inactivation studies revealed a skewed X-chromosome inactivation ratio (95:5), supporting the transcriptional findings. We also mapped the MECP2 transcript in control human brain regions (temporal cortex and cerebellum) using the RNAscope assay, confirming its high expression. This study reports the MECP2 transcript representation in a post-mortem RTT brain and, for the first time, the in situ MECP2 transcript localization in a human control brain, offering insights into how specific MECP2 mutations may differentially impact neuronal functions. We suggest these findings are crucial for developing RNA-based therapies for Rett syndrome. Full article

Pathogenic variants in the KAT6A gene cause KAT6A syndrome, a neurodevelopmental disorder characterised by intellectual disability (ID), developmental delay, speech and language challenges, feeding difficulties, and skeletal abnormalities. This scoping review synthesises current knowledge on KAT6A syndrome, identifies key research themes, and supports the mission of advocacy groups like the KAT6 Foundation. A systematic search of five databases (Ovid MEDLINE, Ovid EMBASE, PubMed, Web of Science, and Scopus) was conducted from 1990 to 2024, including peer-reviewed articles, preprints, and conference abstracts published from 2022 onward. Of 771 citations retrieved, 111 full-text articles were reviewed, with 62 meeting the inclusion criteria. Data were synthesised into six themes: (1) the genotype and phenotype map, revealing a broad phenotypic spectrum with common features like ID, absent speech, and craniofacial dysmorphism, as well as rare features such as severe aplastic anaemia and pancraniosynostosis; (2) the neurodevelopmental profile, detailing communication deficits, sleep disturbances, and impaired adaptive functioning; (3) the epigenetic and developmental roles of KAT6A, highlighting its critical function in histone acetylation, chromatin remodelling, and gene regulation; (4) molecular biomarkers, identifying distinct DNA methylation episignatures and dysregulated cellular pathways; (5) drug discovery, with preliminary studies suggesting that pantothenate and L-carnitine may mitigate mitochondrial dysfunction and histone acetylation deficits, while RSPO2 overexpression reverses cognitive impairment in animal models; (6) phenotypic overlap with Rett syndrome and KAT6B-related disorders. This review underscores the complexity and variability of KAT6A syndrome, highlighting the need for multidisciplinary approaches to improving diagnosis, management, and development of therapies. Future research should focus on longitudinal studies, underrepresented phenotypes, biomarker identification, and robust therapeutic trials to enhance outcomes for affected individuals and their families. Full article

Background/Objectives: Rett Syndrome (RTT) is a rare neurodevelopmental disorder that causes the loss of motor, communicative, and cognitive skills. While no cure exists, rehabilitation plays a crucial role in improving quality of life. Virtual Reality (VR) has shown promise in enhancing motor function and reducing stereotypic behaviors in RTT. This study aims to assess the impact of VR training on upper limb motor skills in RTT patients, focusing on reaching and hand-opening tasks, as well as examining its role in motivation and engagement during rehabilitation. Methods: Twenty RTT patients (aged 5–33) were randomly assigned to an experimental group (VR training) and a control group (standard rehabilitation). Pre- and post-tests evaluated motor skills and motivation in both VR and real-world contexts. The VR training involved 40 sessions over 8 weeks, focusing on fine motor tasks. Non-parametric statistical methods were used to analyze the data. Results: Results indicated significant improvements in the experimental group for motor parameters, including reduced stereotypy intensity and frequency, faster response times, and increased correct performance. These improvements were consistent across VR and ecological conditions. Moreover, attention time increased, while the number of aids required decreased, highlighting enhanced engagement and independence. However, motivation levels remained stable throughout the sessions. Conclusions: This study demonstrates the potential of VR as a tool for RTT rehabilitation, addressing both motor and engagement challenges. Future research should explore the customization of VR environments to maximize the generalization of skills and sustain motivation over extended training periods. Full article

Alternative splicing is one of the processes that contributes to producing a vast protein diversity from the limited number of protein-coding genes in higher eukaryotes. The Methyl CpG Binding Protein 2 (Mecp2) gene, whose mutations cause Rett syndrome, generates two protein isoforms, MeCP2E1 and MeCP2E2, by alternative splicing. These isoforms likely possess non-redundant functions. However, the molecular mechanism for Mecp2 pre-mRNA alternative splicing remains to be understood. Here, we analyzed the alternative splicing mechanism of MeCP2 pre-mRNA and found that exon 2 is efficiently recognized through adjacent strong splice sites. In addition, exonic splicing enhancer (ESE) in exon 2 plays an important role in exon 2 inclusion, which is highly likely to be mediated by SRSF9. Full article

Background/Objectives: Scoliosis is a prevalent comorbidity in Rett syndrome (RTT), often necessitating surgical intervention. This study investigated the impact of a 10-month individualized home exercise program (HEP) on scoliosis progression and gross motor function in girls aged six to 16 years with RTT. Methods: A multiple-baseline single-case design (AABA) was employed with 20 participants. A remotely supervised HEP, based on established principles focused on posture and physical activity, was implemented daily for at least one hour. The primary outcome was the rate of scoliosis progression assessed through the Cobb angle change measured via spinal radiographs at baseline, pre-intervention, and post-intervention. The secondary outcome was the gross motor function. Results: The HEP did not significantly reduce the rate of scoliosis progression. However, individual responses varied, with three participants showing scoliosis reduction. Significant improvements were observed in gross motor function, particularly in standing, walking, and stair-climbing abilities. Conclusions: The HEP did not significantly impact overall scoliosis progression, but a significant improvement was found in gross motor function. Further research into larger sample sizes is needed to confirm the effectiveness of exercise interventions in people with RTT. Full article