Catechol-O-methyltransferase gene expression and obsessive-compulsive disorder

Abstract

Objective To explore the association of peripheral catechol-O-methyl-transferase (COMT)gene expression and obsessive-compulsive disorder(OCD)in Han Chinese.Methods Peripheral blood samples were collected from individuals with OCD(n=35)and age-and sex-matched healthy subjects (n=31).Relative COMT gene expression levels were examined with real-time quantitative reverse transcription PCR in peripheral blood of all the subjects.Structured clinical interview for the 4th Edition of Diagnostic and Statistical Manual of Mental Disorder axisⅡ(SCID-Ⅱ)was used to assess the co-morbidity of OCD and obsessive-compulsive personality disorders(OCPD).The Yale-Brown Obsessive-Compulsive Scale(Y-BOCS)was used to evaluate the severity of obsessive compulsive symptoms.Results The COMT gene expression levels were significantly decreased in the OCD group compared with healthy control group (t=2.56,P＜0.05).The OCD patients showed a 32%down-regulation of COMT gene expression.A significant lower COMT gene expression was observed in non-OCPD patients(n=15)in comparison with healthy controls(t=2.41.P＜0.05),while there was,no significant difference between OCPD patients (n=20)and healthy controls(t=1.50,P＞0.05).The rates of COMT gene expression down-regulation in OCD patients with OCPD and ones without OCPD were 14%and 56%respectively.There was no significant correlation between COMT expression level and the Y-BOCS score(r=0.09,P=0.62).Conclusions These results suggest that COMT gene expression down-regulation is associated with OCD,and the OCD patients with and without OCPD may have different genetic background. Key words: Obsessive-compulsive disorder; Compulsive personality disorder; Catechol Omethyl transferase; Gene expression