In schizophrenia, a large (3Mb) deletion at chromosome 22q11.21 has long been known as a significant risk factor for schizophrenia (Karayiorgou et al., 1995). Approximately 25% of 22q11.2 deletion carriers manifest symptoms of psychosis. Recent genome-wide studies have found strong evidence of association for other loci including deletions at chr1q21.1, deletions at chr3q29, duplications of chr16p11.2, deletions at chr15q13.3, exonic deletions at chr2p16.3 (NRXN1) and duplications at chr7q36.3 (VIPR2), with schizophrenia (Table 1; Supplemental Information).
