Angelman Syndrome

The goal of this observational study is to learn about the natural progression of Angelman syndrome (AS) in children and adults with a confirmed genetic diagnosis of AS. The main questions it aims to answer are: * How do developmental skills, such as communication, motor abilities, and adaptive behaviors, change over a 1-year period in people with AS? * Are there specific patterns in brain activity or sleep that are associated with changes in AS symptoms over time? Participants will: * Attend 3 in-person and 2 virtual study visits over 1 year for assessments. * Complete tests and questionnaires about development, behaviors, and sleep with the help of their caregivers. * Undergo electroencephalograms (EEGs) to measure brain activity and wear a sleep-monitoring device at home (to collect actigraphy data).

The purpose of this study is to evaluate the efficacy and safety of obudanersen in children and adults with Angelman syndrome caused by a deletion or mutation of the UBE3A gene.

The main goal of the study is to evaluate the safety and efficacy of GTX-102 in participants with Angelman syndrome.

Purpose of the study is to evaluate the efficacy and safety of intrathecally administered rugonersen in pediatric and adult participants with Angelman syndrome.

The purpose of this study is to evaluate the safety and efficacy of MVX-220 gene therapy in children and adults with Angelman syndrome with UBE3A gene deletion, uniparental disomy, or imprinting center defect genotypes.

Angelman syndrome (AS) is a rare neurogenetic disorder that affects approximately 1 in 15,000 children - approximately 500,000 people worldwide. It is a major neurodevelopmental disorder characterized by severe developmental delay with significant intellectual disability, lack of oral language, motor, balance, and sensory impairments. While basic research and clinical trials are progressing, the scientific community is still searching for key biomarkers to assess significant improvements in individuals participating in clinical trials. Eye tracking has been widely used in the diagnosis of social perception abnormalities in children with autism spectrum disorder, as has already been the case for other rare neurodevelopmental diseases. However, few studies have highlighted the usefulness of eye tracking as a diagnostic tool for social behavioral disorders in individuals with Angelman syndrome. Given the prevalence of autistic-like symptoms in patients with AS, if eye-tracking can identify abnormalities in social perception in children with Angelman syndrome, these measurements could become a biomarker for therapeutic studies in these patients.

The goal of this observational study is to describe the natural history of imprinting disorders (IDs) according to their metabolic profile in all patients (adults and children) affected with an ID regardless of the severity of the disease, with a molecular characterization, with a signed informed consent for all subjects, followed in one partner's center. The main questions it aims to answer are: * Can we identify common metabolic profiles for all imprinted diseases? * Which imprinting disorders have an impact on the metabolic profiles of IDs? * Which are the metabolic risks associated to IDs? * Can we use the metabolic profiles for the clinical classification and prognosis of IDs? * Are there common therapeutic approaches for all IDs?

For a patient to be considered for this EAP, they must have consented to participate in the TANGELO Optional Open-label Extension (OOE), and continue to meet the inclusion/ exclusion criteria and have not received any other investigational drug for the treatment of AS between the last dose of the TANGELO OOE and the first dose in the EAP. The Physician making the request for expanded access considers continued treatment via the EAP with rugonersen to be a suitable treatment option for the patient under consideration.

This study is a 9-year natural history study for patients with Angelman syndrome in Belgium (a genetic neurodevelopmental disorder, affecting 500,000 individuals in the world). It includes a 3-year recruitment phase, a 5 year follow-up and a year to analyze the collected data. The investigators plan to include 30 patients with a semi-annual follow-up for 4 years. The investigators will collect relevant retrospective and prospective data using age-standardized scales and questionnaires for functional motor assessments and global developmental assessment.

The goal of this study is to conduct a prospective, longitudinal natural history study of children and adults with Angelman Syndrome using investigator-observed and parent-reported outcome measures to obtain data that will be useful for future clinical trials.

Recent studies have shown that the aperiodic part of the signal (neuronal avalanches) of electroencephalography (EEG) contains important information about the dynamics of neuronal networks. Indeed, this has helped to identify functionally altered areas in patients with temporal epilepsy by simply using the resting EEG signal. Furthermore, it has been seen that the propagation of neuronal avalanches (VNs) correlates with the morphological organization of the cerebral cortex. Therefore, NAs represent a measure with direct utility for studying functional reorganization pre and post drug/surgical treatment. In addition, the aperiodic portion of the signal may represent a noninvasive measure of the excitation/inhibition relationship, which is known of being altered both in epilepsy and in some rare neurodevelopmental syndromes (example: Angelman and Dup15q)

The Global Angelman Syndrome Registry is an online patient organisation driven registry to collect information about the natural history of children and adults with Angelman Syndrome. The registry will facilitate 1) recruitment for clinical trials into therapies and interventions to benefit participants with Angelman Syndrome and their families, and 2) advancement of research and best standards of care for Angelman Syndrome. The registry is currently available in English, Spanish, Traditional Chinese, Italian, Polish, Hindi, and Brazilian Portuguese.