RCAN1 and Dravet syndrome: RCAN1 (previously called DSC1—Down syndrome critical region gene 1) is another gene located on HSA21 and is found to be upregulated in DS patients by up to 1.9-fold in the fetal brain and up to threefold in the adult brain [80, 81] RCAN1 was found to be overexpressed in regions of neural proliferation and differentiation zone [80, 81].