Both OCD and TS are highly heritable and have long been suspected to share genetic liability, though specific gene variants have been difficult to identify.7–9 Both disorders frequently co-occur in individuals,10 and there is evidence for shared OCD/TS genetic risk from family studies,9,11 with genetic correlation estimates ranging from 41–90%.2,12. In OCD, locus-specific CNV analyses have been reported,13,14 but no prior genome-wide CNV analysis has been performed. In TS, the three previous genome-wide surveys of CNVs have been limited by small sample sizes (<500 cases), and results differ with regard to whether there is an increased CNV burden in TS compared to controls.15–17 No specific CNV region has received strong statistical support across studies, although exonic NRXN1 deletions have been identified in two studies.15,17
