Examples of such syndromes include Phelan-McDermid’s syndrome, which is often associated with a SHANK3 mutation; Rett’s syndrome and MecP2 duplication syndrome, which are associated with MECP2 mutations; Fragile-X syndrome, which is associated with FMR1 mutations, Tuberous sclerosis complex, which is associated with TSC1/2 mutations, Angelman’s syndrome, which is associated with UBE3A mutations, Prader-Willi’s syndrome, which is associated with chromosome 15q11-q13 deletion, and CACNA1C mutations [431]. The gene discussed is MECP2; the disease is fragile X syndrome.