SCN1A and epilepsy: Intellectual disability is almost universal in adults with Dravet syndrome, but the severity of impairment can range from borderline to severe,29,56,57 although, rarely, adults and adolescents with Dravet syndrome have near-normal intellect.56–58 Identical SCN1A variants can present with a range of cognitive phenotypes even within families.59 Factors impacting cognitive outcomes in people with Dravet syndrome are debated.11,29,57,60–62 We hypothesized that the common variant load for intelligence would be lower in individuals with Dravet syndrome compared with GEL Epilepsy and GEL controls.