Association analysis of the tumor necrosis factor gene polymorphisms (TNFA 238 and 302) in the development of schizophrenia: Impact on the antipsychotic treatment response

This study investigated the tumor necrosis factor-α gene (TNFA; -238 G/A and -308 G/A polymorphisms) on the development of schizophrenia, as well as the interaction of the two polymorphisms in relation to symptomatology, family history, onset age and antipsychotic treatment response. Genomic DNA analyses with polymerase chain reaction (PCR) were used for the genotyping. One hundred and fifty-two (152) patients with schizophrenia and 152 normal controls participated in the study. Any associations between the individual polymorphism and schizophrenia were not found. However, marginal association between subjects with TNFA -238 A allele (genotype AA plus AG) and presence of family history was found (p=0.023). No significant interaction effects between TNFA -238 and -308 polymorphisms either on the development of schizophrenia or on clinical variables such as antipsychotics treatment response and psychopathology were found, although a significant interaction effect for subjects carrying TNFA -238 AG and -308 AA genotypes on a positive family history was observed (p=0.017). These results suggest that the interaction effects between TNFA -238 and -308 polymorphisms gives no significant contribution to the susceptibility to schizophrenia, and is not associated with clinical variables, antipsychotic treatment response and psychopathological features, except for family history of disease, at least in Korean population.