Some of the above behavioral and histological abnormalities in Zic2kd/+mice are reminiscent of schizophrenia symptoms in humans. We therefore set out to examine whether ZIC2 mutations contribute to the onset of schizophrenia, in at least a subset of patients. As a first step to address this possibility, we searched ZIC2 for nonsynonymous mutations in patients with schizophrenia. Many nonsynonymous mutations are reported in patients with HPE623; however, there are no reports of an association of ZIC2 mutations with psychiatric illnesses.