While the role of genetic factors in the development of OCD has been emphasized through research, more attention is needed to identify specific risk factors and underlying biological pathways. Past OCD genomic studies focused on single categories of genetic variation, but data suggests that a combination of genetic changes may impact an individual’s likelihood of developing OCD. Past genomic studies in OCD have a vast variety of factors, yet these all require different analysis techniques.

This study examined rare, common, sequence, and structural genetic variations simultaneously within the same individuals with OCD using family samples. With the help of a whole-exome DNA sequencing study of families where the child has a primary OCD diagnosis that demonstrated the role of rare sequence variation, this study added genome-wide array data to examine the role of rare and common variants.

The study found evidence for a higher rate of copy number deletions in children with OCD, which is especially significant if they occur de novo, or are not inherited from parents and arise on its own. It also found that inherited common genetic risk for OCD does not appear to be higher in children with OCD than their parents, but that females with pediatric OCD may have inherited a higher common genetic risk than males. By integrating different categories of genetic variation, this study aimed to advance our understanding of the genomic landscape of pediatric OCD and related conditions, provide insight into how variants impact risk of developing OCD, and inform future interventions.   

Resulting Publication:

Abdallah, S. B., Olfson, E., Cappi, C., Greenspun, S., Zai, G., Rosário, M. C., Willsey, A. J., Shavitt, R. G., Miguel, E. C., Kennedy, J. L., Richter, M. A., & Fernandez, T. V. (2026). Characterizing Rare DNA Copy-Number Variants in Pediatric Obsessive-Compulsive Disorder. Journal of the American Academy of Child and Adolescent Psychiatry, 65(7), 955–964. https://doi.org/10.1016/j.jaac.2025.03.014