Given the evidence for shared genetic underpinnings of OCD and TS and cross-disorder effects of specific neurodevelopmental CNVs, along with the need for large samples when investigating rare events, we chose a cross-disorder design that combined OCD and TS samples into a single case group, with follow-up analyses examining the individual disorders. This study is the first genome-wide CNV analysis in OCD and the largest to date in TS, and addressed three key questions. First, is there an increased burden of large, rare CNVs in OCD/TS? Second, are the recurrent and/or de novo CNVs implicated in other neurodevelopmental disorders also etiologically relevant for OCD/TS? Third, is there evidence of association between any specific genomic region and OCD/TS?
