In conclusion, although our study did not identify 15q11-q13 and 22q11 microdeletions in patients with OCD, further search of CNVs in OCD is warranted using genome-wide approaches in large samples. The recently created OCD International Genetics Consortium will perform such studies with a sufficiently large number of individuals, by pooling DNA from different sites [1,38]. Recent whole genome association studies and CNV analyses using microarray technologies in other neurodevelopmental disorders such as autism and schizophrenia suggest that CNVs are more promising to identify regions of the genome with high probability of harboring candidate genes, than the results of the association study itself [39-42]. The identification of multiple, individually rare structural genomic variants throughout the genome playing a causal role or significantly increasing the risk in neuropsychiatric disorders has resulted in a shift from the 'common disease-common variant' perspective to the 'multiple rare variants' perspective in the conceptualization of these disorders. Similar advances are expected in OCD with the use of genome-wide approaches to identify CNVs conferring an increased risk for the disorder.
