SCN1B and encephalopathy, progressive, early-onset, with brain edema and/or leukoencephalopathy: The epileptic encephalopathy Dravet syndrome is linked to heterozygous variants in SCN1A leading to haploinsufficiency in most patients, however, a subset of patients has SCN1B homozygous loss-of-function variants (Patino et al., 2009).