| Main clinical features
|
severe infantile form, with congenital microcephaly, intractable seizures (showing a limited response to standard anti-epileptic drugs) and severe psychomotor retardation
also classical West syndrome or a wide variation of clinical seizures such as tonic-clonic seizures, tonic seizures, atonic seizures, gelastic seizures and myoclonic seizures; EEG patterns also vary as both hypsarithmia and multifocal seizure activity evolving towards Lennox–Gastaux syndrome; on MRI, hypomyelination and a severe lack of white matter |