Cross-Disorder Comparison of Four Neuropsychiatric CNV Loci

Copy number variants (CNVs) have been identified as a major risk factor in neuropsychiatric disorders. In this review, we describe the phenotypes and syndromic features associated with CNVs at four of the best-characterized risk loci for these disorders: 15q11.2-13.1, 22q11.2, 16p11.2, and 7q11.23. By considering the reported prevalence of these CNVs in autism, intellectual disability, schizophrenia, and controls, we demonstrate a pattern of asymmetric shared risk in which CNVs increase the risk of multiple disorders but to differing degrees. This asymmetric risk sharing is incompatible with a model in which CNVs observed in autism or schizophrenia are secondary to a reduction in IQ, but favors a more complex relationship between individual CNVs and specific neuropsychiatric phenotypes. Finally, we discuss how the lessons learned from CNVs in neuropsychiatric disorders will translate to the expanding list of genes being associated with these disorders through exome sequencing.