| A rare genetic neurological disorder characterized by a phenotypic spectrum comprising severe intellectual disability, developmental delay, and, in the majority of cases, early-onset epilepsy. The most frequent seizure type are epileptic spasms, but a broad spectrum of seizure types has been reported. Motor disturbances include ataxia, hypotonia, dystonia, tremor, spasticity, and dyskinesia. Some patients may also present with autism/autistic-like features. Older patients have been reported to show signs of parkinsonism, including tremor, bradykinesia, and antecollis. |
