Catechol-O-methyltransferase gene Val108/158Met polymorphism in bipolar disorder

Abstract

Backgrounds: Although several studies have tested the association between bipolar disorder (BD) and the Val108 (H, high-activity allele)/158Met (L, low-activity allele) polymorphism of the catechol-O-methyltransferase (COMT) gene, most of the results showed no significant association. However, an association between the H or L allele and bipolar disorder (BD), particularly, between L allele and rapid-cycling form has been reported; it has also been suggested that the variation in the COMT gene modifies the course of BD and there is a tendency for the L allele amongst the female patients. In this study, the researchers aimed to evaluate the association between BD and COMT gene H/L polymorphism considering the influence of gender in a group of Turkish patients. Method: One hundred and thirty-five BD patients (71 male and 64 female) and 171 controls were included. Polymerase chain reaction-based endonuclease digestion method was used. Results: Genotypic distribution in patients and controls were in Hardy-Weinberg equilibrium. No significant difference was found in genotypic and allelic frequencies between patients and controls. However, female patients had H allele more frequently than male patients and female healthy controls. Females had more depressive and less manic episodes than males. Number of total episodes was associated with H allele in all patients. Conclusion: Distribution of COMT genetic polymorphism was not significantly different between the patients and controls. However, it has been found an association of H allele with female patients and number of episodes among all patients. © 2011 Elsevier GmbH. All rights reserved.