Association Study of Val158Met Polymorphism of Catechol-O-Methyltransferase Gene and Cognitive Markers in Schizophrenia

Park, Hae Jung; Park, Dong Yeon; Cho, Eun Young; Kim, Na Ra; Jeun, Hyun Ok; Lee, Yu Sang; Lee, Dongsoo; Hong, Kyung Sue

Abstract

OBJECTIVES
Catechol-O-methyltransferase (COMT) gene has been identified as a positional and functional candidate gene of schizophrenia. Although specific mechanism of increasing schizophrenia susceptibility by this gene has not been well described yet, recent studies suggest that the valine allele of COMT Val158Met polymorphism may contribute to cognitive decline in schizophrenia. The present study investigated the association between this polymorphism of COMT gene and cognitive markers related to schizophrenia in both schizophrenia patients and normal controls.
METHODS
The subjects were 78 patients with schizophrenia diagnosed by DSM-IV and 97 normal controls. Comprehensive neurocognitive tests for which performance deficits have been reported in schizophrenia were administered. Genotyping for COMT Val158Met polymorphism was done with SNapShot method. Association analyses between genotype and cognitive functions were performed using ANCOVA and MANCOVA.
RESULTS
In the comparison of allele frequencies between patient and control groups, no significant association between the polymorphism and schizophrenia was observed. Significant differences of cognitive performance among genotype groups were not identified in control group. This trend was also observed in the patient group. In the combined analysis of both patient and control groups, there was no significant genotype or genotype-by group effect on any cognitive function measure.
CONCLUSION
These findings do not support a major role of COMT gene in the regulation of the cognitive processes of schizophrenia.