Additive effect of glutathione S-transferase T1 active genotype and infection with for increasing the risk of schizophrenia.

PURPOSE

To determine if () infection may play a role in the development of schizophrenia in genetically susceptible persons with regard to genes encoding glutathione S-transferase T1 () and M1 ().

METHODS

A total of 78 cases with psychiatric diagnosis of schizophrenia were compared with 91 healthy controls. For detection of IgG antibodies, enzyme-linked immunosorbent assay was used. Genotyping of and was performed by multiplex PCR. Chi-square and logistic regression were used for statistical analyses.

RESULTS

A higher frequency of the active gene in schizophrenic patients was observed. When risk categories based on the combination of status and GSTs polymorphisms were compared, risk of schizophrenia increased in positive/ absent subjects (OR = 4.75,  = 0.05) compared with negative/ absent group. When positive subjects had the active genotype, the risk increased linearly (OR = 10.20,  < 0.001). Odds ratio in positive groups were almost the same in combination with the active genotype (OR = 4.45,  = 0.003) or null genotype (OR = 4.37,  = 0.006).

CONCLUSIONS

Our results showed an additive effect for and active genotype as risk factors for schizophrenia in Iranian population. This is a small pilot study and replicating the study with larger groups of patients in multinational investigation to clarify these findings is recommended.