SCN1A and encephalopathy, progressive, early-onset, with brain edema and/or leukoencephalopathy: The heterozygous knockout (KO) Scn1a+/− mouse model with Dravet syndrome (DS) showed a reduced level of NaV1.1 to 50% of the normal levels and spontaneous seizures, hypothermia-induced seizures, and a high mortality rate within one month of birth while the homozygous KOs of the same mutation died within 15 days of birth [26,203].