SHANK3 and fragile X syndrome: Numerous studies have indicated that synaptic-associated gene mutations may cause ASD, including fragile X mental retardation 1 (FMR1) (Fragile X syndrome), tuberous sclerosis gene (TSC) (tuberous sclerosis), SH3, and multiple ankyrin repeat domains 3 (SHANK3) [Phelan–McDermid syndrome (PMS)] (Zoghbi and Bear, 2012).