A number of genes causing mental retardation, for example MECP2 (OMIM +300005) [18], NDP (OMIM+310600) [23], FMR2 (OMIM +309548) [24], or SLC6A8 (OMIM *300036) (this work) have already been reported to have elevated expression in these brain regions compared to other areas of the brain (see table 1). Here, MECP2 is linked to Intellectual disability.