Silver Russell Syndrome (SRS) is a rare imprinting disorder (about 1/16000). Parental imprinting is an epigenetic regulation phenomenon leading to the monoallelic expression of some genes. Its establishment takes place in the gametes and its maintenance is important at the early embryonic stage. Increase in the prevalence of conception by assisted reproductive technology (ART) has already been found in patients with imprinted disorder such as Angelman, Beckwith-Wiedemann or Prader Willi Syndromes, and more recently with SRS; ART is associated with an increase in the frequency of SRS. Several hypotheses are formulated to explain this increase. The first one is the involvement of the infertility etiology in the imprinting disorder genesis. The second one is the involvement of ART technics in the genesis of abnormal gamete imprinting during their manipulation or during imprinting maintenance at early embryonic stages.

Our main objective is to estimate ART conceptions prevalence in children followed for a SRS. The secondary objectives are to estimate infertility prevalence among parents of patients with SRS, to estimate factors frequency possibly responsible for the genesis of imprinting anomalies among parents of patients with SRS, to describe the infertility causes and to detail ART technics used (stimulation protocols, type of fertilization used, modality of embryonic culture and transfer, embryonic characteristics).

A transversal pilote study will be firstly conducted in parents of patients followed in Silver Russell Syndrome Reference Center (Pediatric Endocrine department, in Trousseau Hospital, Paris).

Data collection will be done by phone, after collecting the non-opposition of the parents, in order to complete a questionnaire concerning their fertility and conception mode of their child. If ART was used to conceive, a questionnaire concerning the details of the ART technics used will be sent to the doctor and:or the ART biologist, who performed the ART. The data will be anonymized and collected on a REDCap database.

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 purpose of this study is to evaluate the efficacy and safety of ION582 in children and adults with Angelman syndrome caused by a deletion or mutation of the UBE3A gene.

The primary objective of this study is to evaluate the effect of GTX-102 in cognitive function in participants with deletion-type Angelman Syndrome (AS).

The primary objective of the study is to evaluate the long-term safety profile of GTX-102 in participants with Angelman Syndrome (AS)

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)