Although there are no disease-modifying gene therapies available for use in monogenic epilepsies currently, several are already undergoing clinical trials (e.g. Phase 1/2 open-label trial of an antisense oligonucleotide (STK-001) [128], and a Phase 1/2 trial of an adeno-associated virus-9 based gene therapy (ETX101) [129], both in children with SCN1A-related Dravet syndrome. This evidence concerns the gene SCN1A and encephalopathy, progressive, early-onset, with brain edema and/or leukoencephalopathy.