SCN1A and genetic developmental and epileptic encephalopathy: A Japanese group has previously described a single case of infantile epileptic encephalopathy with a hyperkinetic movement disorder and hand stereotypies associated with a different novel SCN1A mutation.12,13 This Japanese child's presentation sounds like early infantile SCN1A encephalopathy in terms of seizure onset age of 8 weeks; seizure types included epileptic spasms, hemiclonic seizures, myoclonic seizures, generalized tonic-clonic seizures, and status epilepticus, with profound impairment.