Polymorphism of Tumor Necrosis Factor-beta Gene in Bipolar I disorder

Jun, Tae Youn; Lee, Kyoung Uk; Pae, Chi Un; Kim, Won; Woo, Young Sup; Chae, Jeong Ho; Bahk, Won Myong

Abstract

OBJECTIVES
Bipolar disorder is known to have a high genetic predisposition. Recently, the main focus of etiologic studies in bipolar disorder has been concentrated on molecular genetic approach including gene polymorphism analysis. The present study was conducted to investigate whether TNFB polymorphism is associated with bipolar I disorder in the Korean population.
METHODS
89 bipolar I disorder patients diagnosed by DSM-IV criteria were assigned as the patient group and 202 normal population, matched on age and sex from Catholic hemopoietic stem cell bank (Seoul, Korea), were enrolled as the control group in this study. Genotyping was performed by a polymerase chain reaction-restriction fragment length polymorphism method. All data was analyzed by chi2 test.
RESULTS
There were no significant differences in frequency of TNFB*1/1, TNFB*1/2 and TNFB*2/2 between bipolar I disorder patient group and normal control group. The frequency of TNFB*2 and TNFB*1 was not statistically different between bipolar I disorder patient group and normal control group.
CONCLUSION
The difference of frequency in TNFB*1/TNFB*2 gene between the bipolar I disorder gropup and the normal control could not be verified. The present result suggested that the gene polymorphism of TNFB may not play a significant role in susceptibility to bipolar I disorder. Studies with a larger number of subjects from different ethnic backgrounds, considering clinical phenotype and controlling various factors, should be launched to further determine the role of TNFB in bipolar I disorder.