biostudies-literatureHalvorsen MWNIMH NIH HHS1510-1517https://www.ebi.ac.uk/biostudies/studies/S-EPMC11919692biostudies-literatureUnknown30(4)Current genetic research on obsessive-compulsive disorder (OCD) supports contributions to risk specifically from common single nucleotide variants (SNVs), along with rare coding SNVs and small insertion-deletions (indels). The contribution to OCD risk from rare copy number variants (CNVs), however, has not been formally assessed at a similar scale. Here we describe an analysis of rare CNVs called from genotype array data in 2248 deeply phenotyped OCD cases and 3608 unaffected controls from Sweden and Norway. Cases carry an elevated burden of CNVs ≥30 kb in size (OR = 1.12, P = 1.77 × 10^-3). The excess rate of these CNVs in cases versus controls was around 0.07 (95% CI 0.02-0.11, P = 2.58 × 10^-3). This signal was largely driven by CNVs overlapping protein-coding regionMolecular psychiatryA burden of rare copy number variants in obsessive-compulsive disorder.PMC11919692R01 MH119084R01 MH110427R01 MH120170U01 MH109528de Schipper EChen LLKvale GDjurfeldt DRLindblad-Toh KMattheisen MMorrill KPedersen NLLanden MCrowley JJEide TOHaavik JBackman JFundin BRuck CHagen KWallert JHansen BBulik CMLichtenstein PStrom NIZayats THoffler KDKarlsson EKNordic OCD and Related Disorders Consortium (NORDiC)Kahler AKHalvorsen MWMataix-Cols DNoh HJfalseA burden of rare copy number variants in obsessive-compulsive disorder.Current genetic research on obsessive-compulsive disorder (OCD) supports contributions to risk specifically from common single nucleotide variants (SNVs), along with rare coding SNVs and small insertion-deletions (indels). The contribution to OCD risk from rare copy number variants (CNVs), however, has not been formally assessed at a similar scale. Here we describe an analysis of rare CNVs called from genotype array data in 2248 deeply phenotyped OCD cases and 3608 unaffected controls from Sweden and Norway. Cases carry an elevated burden of CNVs ≥30 kb in size (OR = 1.12, P = 1.77 × 10^-3). The excess rate of these CNVs in cases versus controls was around 0.07 (95% CI 0.02-0.11, P = 2.58 × 10^-3). This signal was largely driven by CNVs overlapping protein-coding region2025-01-01T00:00:00Z2025 Apr2025-04-04T00:32:07.712Z2025-04-04T00:32:07.712ZS-EPMC119196923946344810.1038/s41380-024-02763-7