SCN1A and Cognitive impairment: Together with seizures, Dravet patients display disabling behavioural alterations, including hyperactivity, anxiety, motor delay, social interaction and cognitive impairment.25,26 To test the effect of delayed induction of Scn1a gene haploinsufficiency on those specific behavioural alterations, we subjected P2-, P30- and P60-induced male mice and a mixed group of control male mice, between 2.5 and 3.5 months of age, to a battery of behavioural tests (Supplementary Fig. 6).