<h4>Background</h4>Dravet syndrome (DS) is a severe epileptic encephalopathy mainly caused by haploinsufficiency of the gene <i>SCN1A</i>, which encodes the voltage-gated sodium channel Na<sub>V</sub>1. This evidence concerns the gene SCN1A and encephalopathy, progressive, early-onset, with brain edema and/or leukoencephalopathy.