NRG3 and schizophrenia: Genome-wide linkage and fine mapping studies demonstrate that structural and polymorphic variation in one such gene, Neuregulin 3 (NRG3), is associated with increased risk for a range of neurodevelopmental disorders including schizophrenia, and atypical neurocognitive and behavioral disorders in humans, including speech delay, delusion severity, attention sustainability and scholastic disorganization [7]–[14].