Dravet syndrome is a rare form of epilepsy. Between 70% and 80% of patients carry sodium channel α1 subunit gene (SCN1A) loss of function mutations. Truncating mutations (early stop codon) account for about 40% and have a significant correlation with an earlier age of seizures onset. The mutations lead to haploinsufficiency of the voltage-gated sodium channel α subunit NaV1.1 in the of GABAergic inhibitory interneurons in the brain.
Mutations in other genes like KCNA1, CHD2, PCDH19 and STXBP1 can also lead to Dravet syndrome.