Neurodevelopmental Disorder with Hypotonia and Impaired Expressive Language and with or Without Seizures, also known as dyskinesia, seizures, and intellectual developmental disorder, is related to intellectual disability-epilepsy-extrapyramidal syndrome. An important gene associated with Neurodevelopmental Disorder with Hypotonia and Impaired Expressive Language and with or Without Seizures is DEAF1 (DEAF1 Transcription Factor). Affiliated tissues include eye and brain, and related phenotypes are intellectual disability and eeg abnormality