Cathryn M. Lewis, James Rucker, Jouke-Jan Hottenga, Johannes H. Smit, Peter McGuffin, Ole Mors, Eco J. C. de Geus, Martin Preisig, Myrna M. Weissman, Gerome Breen, A. Abdellaoui, Alan R. Sanders, James A. Knowles, Dorret I. Boomsma, Xianglong Zhang, Brenda W.J.H. Penninx, Pablo V. Gejman, Carlos N. Pato, Nicholas John Craddock, Jianxin Shi, Simone de Jong, Rudolf Uher, James B. Potash, Michael John Owen, Marcella Rietschel, Janet L. Sobell, Douglas F. Levinson, Lisa Jones, Margarita Rivera, John P. Rice, Henriette N. Buttenschøn, Ian Jones, Michele T. Pato, Biological Psychology, APH - Health Behaviors & Chronic Diseases, APH - Personalized Medicine, APH - Mental Health, APH - Methodology, Amsterdam Neuroscience - Mood, Anxiety, Psychosis, Stress & Sleep, Psychiatry, and APH - Digital Health
BACKGROUND: Major depressive disorder (MDD) is moderately heritable, with a high prevalence and a presumed high heterogeneity. Copy number variants (CNVs) could contribute to the heritable component of risk, but the two previous genome-wide association studies of rare CNVs did not report significant findings. METHODS: In this meta-analysis of four cohorts (5780 patients and 6626 control subjects), we analyzed the association of MDD to 1) genome-wide burden of rare deletions and duplications, partitioned by length (,100 kb or .100 kb) and other characteristics, and 2) individual rare exonic CNVs and CNV regions. RESULTS: Patients with MDD carried significantly more short deletions than control subjects (p = .0059) but not long deletions or short or long duplications. The confidence interval for long deletions overlapped with that for short deletions, but long deletions were 70% less frequent genome-wide, reducing the power to detect increased burden. The increased burden of short deletions was primarily in intergenic regions. Short deletions in cases were also modestly enriched for high-confidence enhancer regions. No individual CNV achieved thresholds for suggestive or significant association after genome-wide correction. p values , .01 were observed for 15q11.2 duplications (TUBGCP5, CYFIP1, NIPA1, and NIPA2), deletions in or near PRKN or MSR1, and exonic duplications of ATG5. CONCLUSIONS: The increased burden of short deletions in patients with MDD suggests that rare CNVs increase the risk of MDD by disrupting regulatory regions. Results for longer deletions were less clear, but no large effects were observed for long multigenic CNVs (as seen in schizophrenia and autism). Further studies with larger sample sizes are warranted., This work was supported by a joint grant from the United Kingdom Medical Research Council and GlaxoSmithKline (Grant No. G0701420) and the National Institute for Health Research (NIHR) Biomedical Research Centre for Mental Health at South London and Maudsley National Health Service (NHS) Foundation Trust and Institute of Psychiatry, King’s College London. This work presents independent research in part funded by the NIHR. The views expressed are those of the authors and not necessarily those of the NHS, the NIHR, or the Department of Health. This work was also supported by the Wellcome Trust Grant No. 086635 (JJHR); NIHR Specialist Biomedical Research Centre for Mental Health at the South London and Maudsley NHS Foundation Trust and the Institute of Psychiatry, King’s College London (SC-W); a Marie Curie Intra-European Fellowship within the 7th European Community Framework Programme; European Commission Grant Agreement No. 115008); and Canada Research Chairs program