Robust statistical, genetic and functional evidence supports a role for in the aetiology of major mental illness. Furthermore, many of its protein-binding partners show evidence for involvement in the pathophysiology of a range of neurodevelopmental and psychiatric disorders. Copy number variants (CNVs) are suspected to play an important causal role in these disorders. In this study, CNV analysis of and its binding partners and in Scottish and Northern Swedish population-based samples was carried out using multiplex amplicon quantification. Here, we report the finding of rare CNVs in (together with adjacent genes within the 16p13.11 duplication), (including the overlapping gene) and . Our findings provide further evidence for involvement of and its interaction partners in neuropsychiatric disorders and also for a role of structural variants in the aetiology of these devastating diseases.