Association between the COMT Gene and Obsessive Compulsive Disorder: A Case-Control Study

This study aimed to find out the genetic variations in Catechol O Methyl transferase (COMT) gene and association of these genes with obsessive compulsive disorder (OCD) in the Pakistani Patients. We selected OCD patients (n=100) following the Diagnostic Statistical Manual-IV (DSM-IV) criteria and controls (n=120) from Sir Ganga Ram Hospital and Panjab Institute of Mental Health, Lahore from August 2011 to January 2014. During the sample collection the factors like age/period, employment status and marital status were considered after informed consent. We found one single base change G>C at c.745 resulting in a nonsynonymous change p.E249Q in the COMT gene. In-silico analysis predicted it to be damaging and disease causing. Screening of case and control group data showed no deviation from Hardy-Weinberg equilibrium with p-value 0.879 and 0.32, respectively. There was no significant difference in age (p-value 0.081), employment status (p-value 0.34) and matrimonial status (p-value 0.28) but there was a significant difference in their education (p-value 0.0002). The prevalence of C allele was 13.5% in disease, 5.83% in controls and found significant with p-value 0.007. These findings suggest that c.G745C in COMT gene has a significant association and a possible role in the OCD development in Pakistani patients.