Clinical Research Directory

Inclusion Criteria * Molecular diagnosis of a genetic disorder associated with DEE, as confirmed by the study investigators * A neurological phenotype such as epilepsy or developmental delay as confirmed by the study investigators. * English Speaking (Arms 1, 2, 4, 5). The registries may be completed by people who speak any language. ARM 1 (In person cohort) * MEF2C * Age 0 to 15 at the time of study enrollment. * Willingness to travel to New York City four times over two years ARM 2 (Virtual cohort) * MEF2C * Any age at the time of study enrollment * Sufficient internet connectivity to support video teleconferencing * Commitment to fill out all survey instruments ARM 3 (Registry) * MEF2C * Any age at the time of study enrollment * Commitment to fill out one on-line instrument ARM 4 (In person cohort) * Any DEE * Any age at the time of study enrollment * Willingness to travel to New York City four times over two years ARM 5 (Virtual cohort) * Any DEE * Any age at the time of study enrollment * Sufficient internet connectivity to support video teleconferencing * Commitment to fill out all survey instruments ARM 6 (Registry) * Any DEE * Any age at the time of study enrollment * Commitment to fill out one on-line instrument Exclusion Criteria * Presence of a significant non-DEE-related central nervous impairment/behavioral disturbance that would confound the scientific rigor or interpretation of results of the study * History of prematurity (defined as gestational age \<35 weeks), interventricular hemorrhage, structural brain deficit, or congenital heart disease * Presence of a clinical comorbidity deemed by the investigator to potentially confound the typical presentation of DEE