BRWD1 and Dravet syndrome: Next, in order to explore potential mechanistic roles for BRWD1 in mediating trisomy 21-related phenotypes, we measured Brwd1 expression in brain tissues of Ts65Dn mice, a well characterized model of DS with segmental trisomy 16 and a corresponding copy number triplication for approximately half of the homologous HSA21 genes, including BRWD116–18.