Researchers at Rutgers University analyzing exome sequencing data from nearly 4,000 individuals have identified 36 genes that substantially increase the risk of obsessive-compulsive disorder and chronic tic disorders. Published in Nature Neuroscience, the study reveals biological overlaps with autism and pinpoints critical brain circuits driving these neurodevelopmental conditions.
For decades, clinicians have observed that obsessive-compulsive disorder (OCD) and chronic tic disorders (CTDs)—such as Tourette disorder—frequently overlap in patients. Up to 50 percent of people with CTDs display obsessive-compulsive behaviors, while nearly 30 percent of individuals diagnosed with OCD report a history of tics. Yet, despite this high rate of co-occurrence and strong heritability, science had identified only four high-confidence risk genes for these conditions.
That landscape changed following a comprehensive genetic analysis published in the journal Nature Neuroscience. Led by geneticists and neuroscientists at Rutgers University, a large research team analyzed newly and previously sequenced exome data—the protein-coding regions that make up roughly one percent of the human genome—from nearly 4,000 individuals diagnosed with OCD, CTD, or both. By examining over 2,400 parent-child trios and more than 1,500 singletons, the investigators nearly doubled previous sample sizes, allowing them to isolate 36 genes that substantially increase disease risk.
According to Gary Heiman, a genetic epidemiologist at Rutgers University and senior co-author of the study, the research dramatically expands the catalog of shared risk genes, uncovers biological connections with autism and schizophrenia, and highlights the brain circuits that govern impulse control, movement, and habit formation.
Mapping the Brain’s Neural Blueprint and Circuitry
To understand how these newly identified genes impact neurological function, the research team utilized brain maps from humans, rhesus macaques, and mice. This cross-species approach helped outline a spatial and temporal blueprint for OCD and CTDs, tracking when and where risk-influencing genes are expressed across different developmental stages.
The findings point directly to dysfunction within the cortico-striato-thalamo-cortical circuit. This expansive loop connects brain regions responsible for cognition, voluntary movement, impulse control, and sensory data processing. Risk-associated genes showed heightened expression during both prenatal and postnatal developmental stages within specific regions of this loop, including the cortex, striatum, and thalamus.
The outer cortex governs complex reasoning, learning, and memory. The striatum, positioned deep within the brain, dictates motivation, decision-making, and motor control. Meanwhile, the thalamus acts as the brain’s central relay station, routing incoming sensory signals.
Postnatal gene expression was also heavily concentrated in the cerebellum, a region vital for balance, movement coordination, and timing. At the cellular level, the investigators implicated telencephalic projecting excitatory neurons, which serve as essential conduits for long-range communication between different brain networks.
The Power of Genetic Networks and Magnitude of Risk
Rather than functioning in isolation, these newly discovered risk factors operate collectively. Jay Tischfield, a geneticist at Rutgers University and senior co-author of the research, notes that these genes act in networks, meaning future therapies can be designed to target entire biological pathways rather than individual molecular anomalies.
The statistical impact of these genetic variants is profound. The researchers determined that the identified genes carry very large effects, increasing disease risk by an average of 57-fold, with extreme cases showing up to a 210-fold increase. Furthermore, the data confirms a substantial genetic overlap between conditions, as 30 of the 36 identified risk genes were shared across both OCD and CTD patient cohorts. Additional analysis revealed that several of these risk genes intersect with other neurodevelopmental conditions, including autism.
In Plain English: The Clinical Takeaway
- Expanded Genetic Catalog: Researchers identified 36 high-confidence risk genes for OCD and chronic tic disorders, up from just four previously known genes.
- Network-Based Treatment: Because these genes operate in interconnected biological networks, future pharmaceutical therapies can target entire pathways rather than isolated targets.
- Shared Origins: The findings confirm a substantial biological overlap between OCD, tics, and other neurodevelopmental conditions like autism and schizophrenia.
Contraindications & When to Consult a Doctor
Summary of Genetic and Spatial Findings
| Metric / Region | Clinical or Anatomical Detail |
|---|---|
| Sample Size | Nearly 4,000 individuals (including over 2,400 parent-child trios and 1,500 singletons) |
| Risk Genes Identified | 36 high-confidence genes (30 shared between OCD and CTDs) |
| Risk Magnitude | 57-fold average increase, up to 210-fold at the extreme end |
| Primary Circuit Involved | Cortico-striato-thalamo-cortical circuit |
| Key Brain Regions | Cortex, striatum, thalamus, and cerebellum |
References
- Rutgers University. Exome sequencing identifies multiple OCD and chronic tic disorder risk genes. Published in Nature Neuroscience.
- ScienceAlert. Scientists Uncover Shared Genetic Roots of OCD, Tourette Syndrome, And Autism.
- Inside Precision Medicine. Whole-Exome Sequencing Identifies Multiple OCD, Chronic Tic Disorder Risk Genes.
