Gain of function mutations of SCN1A are associated with migraine (Dichgans et al., 2005), while loss of function mutations are associated with a broad range of epilepsy syndromes, ranging from the more mild GEFS+ to severe epileptic encephalopathies, including DS (Scheffer and Nabbout, 2019). The gene discussed is SCN1A; the disease is epilepsy syndrome.