Interleukin-6 genetic polymorphism and Chinese major depression

Background: It has been reported that serum concentrations of interleukin-6 (IL-6), a pro-inflammatory cytokine, were significantly higher in major depressive disorder (MDD). Objectives: The aim of the present study was to examine whether the IL-6 genetic variant confers susceptibility to MDD. Methods: We genotyped a functional polymorphism in the promoter region ( position - 634) of the IL-6 gene in a sample of 257 MDD patients and 105 normal controls. Results: No significant differences were demonstrated for the genotype or allele frequency of the IL-6 polymorphism when comparing the MDD and control groups. Conclusions: Our findings suggested that the investigated IL-6 polymorphism does not affect MDD susceptibility. We propose that other genetic variations of IL-6, relating either to MDD or to the clinical manifestations of MDD, may need further investigation. Copyright (C) 2005 S. Karger AG, Basel.