Consistent with previous studies in humans with DS and trisomic mice1,4,18,19, we found that Brwd1 mRNA was significantly elevated in both embryonic (E17.5) and adult (6-week) male and female Ts65Dn brain tissues, including the prefrontal cortex (PFC), hippocampus and cerebellum—with no significant difference between the sexes in adult euploid animals (Fig. 1a and Supplementary Fig. 2a, b). This evidence concerns the gene BRWD1 and Dravet syndrome.