Thirty-six genes link OCD and tic disorders to shared brain pathways

Whole-exome sequencing has identified dozens of genes associated with obsessive-compulsive disorder and chronic tic disorders, revealing substantial genetic overlap and possible shared biological mechanisms.

Scientists have identified 36 genes that appear to substantially raise the risk of obsessive-compulsive disorder and chronic tic disorders, including Tourette syndrome, in a finding that sharply expands the known genetic basis of both conditions. The study, published in Nature Neuroscience, suggests that many of the same genes are involved in each disorder and that some also overlap with genes previously tied to autism and schizophrenia, pointing to shared biological pathways across a wider group of neurodevelopmental conditions.

Until now, researchers had only a small handful of strong genetic leads. According to the report, the new analysis used whole-exome sequencing, which examines the protein-coding part of the genome, from 3,964 people affected by obsessive-compulsive disorder, chronic tic disorders, or both, including 2,418 parent-child trios. The data showed an excess of de novo mutations, meaning changes present in a child but not in either parent, as well as other rare protein-damaging variants.

The team, led by genetic epidemiologist Gary Heiman at Rutgers University, found that 30 of the 36 genes were linked to both obsessive-compulsive disorder and chronic tic disorders. Research materials released by Rutgers said the discovery offers a more detailed picture of the brain circuits involved in impulse control, movement and habit formation. Those shared networks may help explain why the disorders so often appear together in the same patient.

The researchers stressed that the findings do not amount to a treatment yet, but they may eventually help direct drug development towards more precise targets. They also cautioned that genes increase susceptibility rather than determine outcome on their own, with environment and developmental chance still playing a role. The result marks a significant step forward in understanding why these conditions emerge and why they frequently overlap.