SCN1A and encephalopathy, progressive, early-onset, with brain edema and/or leukoencephalopathy: Phenotypic variability has been reported within single families in which different individuals may present with either ADNFLE or EIMFS.10 Such intrafamilial variation in phenotype is also described in SCN1A kindreds; Dravet syndrome, febrile seizures, and a variety of other generalized epilepsies may be reported in the same family.33 Furthermore, while the majority of variants in our cohort occurred de novo, 2 patients inherited variants from an unaffected parent.