Gene Polymorphism of Tumor Necrosis Factor Beta in Major Depressive Disorder

Jun, Taeyoun; Pae, Chi Un; Kim, Young Ho; Jang, Giu Ho; Lee, Chung Tai; Bahk, Won Myong; Kim, Kwang Soo

Abstract

OBJECTIVE
Major depressive disorder is known to have high genetic predisposition and the main focus of recent genetic studies in major depressive disorder has been concentrated on association studies between genetic polymorphism and disease, since molecular genetic methods have been developed. This study was designed to investigate the relationship between major depressive disorder and immunogenetic influences by analyzing polymorphism of TNFB gene, which is involved in interaction of immune system and CNS. METHOD: 95 persons who had been diagnosed of major depressive disorder were assigned as patient group and, 202 data obtained from Catholic hemopoietic stem cell bank, College of medicine, the Catholic University of Korea, were used as normal controls in this study. DNA was extracted from whole blood, thereafter amplified by polymerase chain reaction, and digested by NcoI. After that procedure, we obtained and assessd restriction fragment length polymorphism of two alleles, TNFB*1 which has 555bp and 185bp fragments and carries the NcoI restriction site, and TNFB*2 of 740 bp fragment lacks the NcoI restriction site. All data were analyzed by x2 test with two-tailed Fisher's exact test.
RESULTS
1) The frequencies of TNFB*1/1, TNFB*1/2, and TNFB*2/2 were not statistically different between major depressive disorder patients and control group. 2) The frequencies of TNFB*2 and TNFB*1 were not statistically different between major depressive disorder patient group and normal control group.
CONCLUSION
We did not verified the differences of frequency in TNFB*1/TNFB*2 gene between the major depressive disorder and normal controls, respectively. Consequently, there is no genetic relationship between major depressive disorder and gene polymorphism of TNFB. We do suggest that further systematic studies including various clinical variables should be conducted.