Thus far, the growing list of mixed variants in NaV1.1 have been part of the epileptic spectrum, ranging from less severe generalized epilepsy with febrile seizures (GEFS+) to severe infantile epileptic encephalopathies (Escayg et al., 2001; Lossin et al., 2002; Peters et al., 2016; Volkers et al., 2017; Brunklaus and Lal, 2020). Here, SCN1A is linked to idiopathic generalized epilepsy.