Dravet syndrome is a severe infantile-onset epileptic encephalopathy associated 
with mutations in the sodium channel alpha-1 subunit gene SCN1A. We aimed to 
describe the incidence of Dravet syndrome in the Danish population. Based on a 
6-year birth cohort from 2004 to 2009, we propose an incidence of 1:22,000, 
which is higher than what has been established earlier. We identified 17 cases 
with SCN1A mutation-positive Dravet syndrome. Fifteen patients were found, by 
conventional Sanger sequencing. Two additional patients with clinical Dravet 
syndrome, but without a detectable SCN1A mutation by Sanger sequencing, were 
diagnosed with a SCN1A mutation after using a targeted next-generation 
sequencing gene panel.