In Dp1Tyb mice, hippocampal DYRK1A levels were upregulated by ~1.7-fold, similarly to that seen in human DS brain samples and as would be expected for a gene on Hsa21 that is present in 3 copies in both DS and the Dp1Tyb mouse strain (Dowjat et al., 2007). This evidence concerns the gene DYRK1A and Dravet syndrome.