Dysregulation of the mammalian or mechanistic target of rapamycin (mTORC1) pathway has been identified in numerous syndromes, such as fragile X syndrome, tuberous sclerosis, PTEN (phosphatase and tensin homolog deleted on chromosome 10) hamartoma tumor syndrome, a set of syndromes named RASopathy (includes type 1 neurofibromatosis and other mutations in the RAS/MAPK pathway genes with a very similar manifestation), Angelman syndrome, Rett syndrome, and Phelan–McDermid syndrome (see reviews [2,3]). Here, MTOR is linked to tuberous sclerosis.