Preliminary investigation of two promoter region polymorphisms of the TNFA gene in patients with recurrent depressive disorder

Immune system dysregulation plays a role in the pathogenesis of complex human diseases, including psychiatric disorders. In addition, elevated levels of pro-inflammatory cytokines, including tumor necrosis factor alpha (TNF-alpha) may be conditioned by the presence of specific polymorphic variants. The present case-controlled preliminary study evaluated the prevalence of TNFA gene single nucleotide polymorphisms (SNPs) G-308A (rs1800629) and T-1031C (rs1799964) in 83 Polish patients with depression by restriction fragment length polymorphism analysis. The results were compared with the frequencies of genotypes in a geographically- and ethnically-matched group of individuals without depression. No statistically significant difference in genotype/allele frequency was observed for either SNP between the two groups. No association was found between the particular genotypes and selected demographic/clinical features, including sex, age at diagnosis or severity of depressive symptoms beforefafter pharmacotherapy. Thus, there does not appear to be any connection between the studied SNPs and the development and progression of depression; however, further studies are required with larger cohorts to better understand this aspect of depression.