Association Study of Tumor Necrosis Factor-Alpha Gene Polymorphism in Schizophrenia and Bipolar Disorder / 신경정신의학

ABSTRACT

OBJECTIVES: The role of cytokines has been one of the focal points of etiologic research in major psychiatric disorders. This study was designed to analyze the polymorphism of TNF-alpha and to investigate its relationship with schizophrenia and bipolar disorder. METHODS: 241 schizophrenic patients and 89 bipolar patients diagnosed by DSM-IV criteria were included as patient groups and 125 normal poplulation from the Catholic Hemopoietic Stem Cell Information Bank (Seoul, Korea) were used as a control group. DNA was extracted from the whole blood, amplified by polymerase chain reaction, and digested by NcoI. Then the obtained RFLP of two alleles, TNFA*1 with 87 bp and 20 bp, and TNFA*2 with 107 bp were assessed. All data were analyzed by chi2 test. RESULTS: The genotype and allele distributions in patients with bipolar disorder were significantly different from those in the controls. There were no significant differences in genotype frequencies of TNFA*1/1, TNFA*1/2, and allelic frequencies of TNFA*1 and TNFA*2 between the schizophrenic patients and the controls. CONCLUSION: In the present study we observed a significant association between the TNFA*2 allele with bipolar disorder, with negative result on the association of the polymorphism of TNF-alpha gene with schizophrenia. Consecutive further studies including diverse clinical variables would be required.