FMR1 and fragile X syndrome: Mutations in the mTOR inhibitor genes tuberous sclerosis complex 1/2 (TSC1/TSC2), neurofibromatosis type 1 (NF1), phosphatase and tensin homolog deleted on chromosome ten (PTEN), and fragile X mental retardation 1 (FMR1) lead to tuberous sclerosis complex (TSC), neurofibromatosis, Lhermitte-Duclos disease (LDD), and Fragile X syndrome (FXS), respectively [100, 101], Figure 2.