Aberrant synaptic network development and maintenance represents a plausible molecular mechanism for psychosis susceptibility and mutations involving other Group I PAKs (PAK2 (the 3q29 microdeletion syndrome locus [MIM 609425]) and PAK3 [MIM:300558]) are known to be associated with neurodevelopmental syndromes characterized by psychosis (32). This evidence concerns the gene PAK3 and psychotic disorder.