NOS2 and Dravet syndrome: The genes CD40LG, Il6 and NOS2 where down-regulated in our study and in study by Letourneau et al. [11], and the gene CD19 was found significant down-regulated in our study and in Li et al. [9] when neonate and child groups were combined, a finding that confirms previous studies of lymphocyte subpopulations in fetuses [32] and in children with DS [33].