SCN1A and encephalopathy, progressive, early-onset, with brain edema and/or leukoencephalopathy: Following this study, other rare/novel SCN9A variants (Table 1) were reported as putative monogenic causes of disease in individuals and small families with familial febrile seizures [12,13], FS+ and GEFS+ [14–18] and as a modifier of Dravet syndrome, in some cases in the presence of accompanying SCN1A pathogenic variants [7,18] (Table 1).