Study elucidates the role of genomics in obsessive-compulsive disorder

According to recent research carried out by the researchers from the Icahn School of Medicine at Mount Sinai, both rare and commonly seen differences in the DNA letters threaded along an individual’s chromosomes can elucidate about a third of the risk for being diagnosed with obsessive-compulsive disorder (OCD).

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The scientists examined the genomic data of over 2,000 Swedish-born people diagnosed with OCD. The findings might change how researchers perceive the role that genomics plays in OCD. It can also provide insight into how novel treatments can be developed. The findings were published in the American Journal of Psychiatry.

The research was headed by researchers from the lab of Dorothy Grice MD, Professor of Psychiatry at Icahn Mount Sinai.

OCD affects around 2% of Americans and exhibits a set of likely life-long and debilitating symptoms—particularly intense and distressing recurring actions and thoughts.

Even though researchers have not identified the exact reason for OCD, numerous researches show that multiple genomic and environmental factors could play a role in the disease. For example, it was evaluated that around 25%–50% of the risk for OCD behaviors might be due to genomic differences between people in a population.

The study was headed by Behrang Mahjani PhD, a researcher in Dr Grice’s laboratory. The scientists compared the single nucleotide polymorphisms (SNPs)—the small DNA spelling differences commonly seen in an individual’s chromosomes—of 2,090 Swedish-born OCD patients with that of 4,567 controls. This makes it the largest research of its kind until today.

The primary results obtained supported earlier researches. Around 29% of the OCD risk was credited to SNPs difference between patients and control subjects and around 90% of these differences are generally seen throughout the normal population. The scientist also observed that around 10% of the risk can be associated with rare genomic differences, not observed in earlier studies.

Additional examination revealed that the OCD-related SNPs were spread across patients’ chromosomes, indicating that multiple genomic differences unite to influence risk. In general, the observations endorse the idea that OCD risk might, in part, be induced by randomly happening changes to the entire genome instead of a few naturally selected “hot spots.”

The scientists remark that this new view of OCD emphasizes the vital role of rare genomic differences in the risk of OCD. The observations might also alter the analysis of the disorder by researchers to create new treatments for patients.