In this study we seek to understand how rare genetic variation in all protein coding genes (the exome) influences the risk of developing obsessive-compulsive disorder (OCD). OCD is of major public health importance owing to its profound personal and societal costs. Little is known for certain about its etiology, and treatment, detection and prevention strategies are not optimal or directed by knowledge of pathophysiology. In other psychiatric disorders (e.g., autism, intellectual disability, schizophrenia, ADHD), whole exome sequencing (WES) in large numbers of subjects has begun to deliver fundamental knowledge about genetic architecture, identify specific loci for biological follow-up and localize pathways altered in disease. We intend to realize these same advances for OCD by markedly increasing the worldwide number of OCD subjects with WES data, in a first step toward elucidating the fundamental biology of this condition. Three overlapping areas will be investigated in this project. First, we will produce WES data from 5,100 OCD subjects and 3,000 ancestry-matched controls, all from Sweden and Norway. Sequencing individuals from these countries provides the substantial advantage of knowing about co-morbid conditions. We will call rare genetic variation from the sequencing data. Second, we will combine these new data with existing WES data for ~1,400 OCD cases and ~8,000 controls. This will increase power to identify OCD risk genes, which we will do using a combination of existing and novel analytical methods. Third, we will further refine our understanding of the genetic architecture of OCD, focusing on the relationship of OCD risk to risk for other neurodevelopmental disorders, including tic disorders, autism, ADHD, schizophrenia and bipolar disorder. Combining WES data from multiple large studies will enhance power to identify shared loci and begin to identify loci with greater specificity for OCD. Overall, we believe this study will improve our understanding of genetic risk factors for OCD, with a view towards improving clinical outcomes and reducing chronicity and societal costs.
Obsessive-compulsive disorder (OCD) is a neuropsychiatric condition that causes enormous human suffering and is thought to result from a complex interplay of genetic and the environmental factors. Our goal in this study is to learn more about what precise genetic factors influence an individuals risk for OCD. We propose to do this by resequencing the protein coding portion of the genome in a large number of OCD subjects and matched controls.