Familiar hemiplegic migraine type 3 (FHM3), which is caused by specific missense mutations in the SCN1A gene encoding the α1 subunit of voltage-gated NaV1.1 sodium channels (Dichgans et al., 2005; Tolner et al., 2015), allows the specific interrogation of the role mutant NaV1.1 channels in migraine pathophysiology. Here, SCN1A is linked to migraine, familial hemiplegic, 3.