SCN1A and encephalopathy, progressive, early-onset, with brain edema and/or leukoencephalopathy: Dravet syndrome (DS) is one of the most common monogenic epilepsies, presenting as a developmental and epileptic encephalopathy resulting in cognitive, behavioural and motor impairments.1,2 DS is caused by loss-of-function (LoF) mutations in the SCN1A gene3 and children typically experience seizure exacerbation following sodium channel blocker (SCB) use.