PCDH12 belongs to a protocadherin gene cluster at chromosome 5q31 that has been previously implicated in schizophrenia and psychosis in non-AA samples.61, 62PCDH12 encodes a cellular adhesion molecule that has an important role in cell–cell interactions including axonal guidance and synaptic specificity. The gene discussed is PCDH12; the disease is schizophrenia.