A Role of Cytokine Gene Polymorphisms in Cognitive Functioning

The changes in cognitive functions that occur with aging and in various pathological conditions are a subject of growing interest. Experimental and clinical data justify the hypothesis about the influence the immune system exerts on cognitive processes. The balance between pro-inflammatory and anti-inflammatory cytokines has been established as a necessary factor for normal cognitive functioning. Cytokine production is under strong genetic control and various single nucleotide polymorphisms (SNPs) in cytokine genes have been described. As cytokine SNPs have been demonstrated to affect the gene expression or the functional activity of the immune protein this logically led to the suggestion about the role of these polymorphisms in cognitive functioning. Studies exploring the association between different genetic variants of cytokine gene polymorphisms and cognitive abilities in healthy subjects and in demented patients show divergent results. The review of relevant literature suggests that SNPs implement their effect on cognition in large interactions with each other, as well as with many other factors, some of which still remain to be identified. This article summarizes the contemporary knowledge about the correlations between SNPs in cytokine genes and cognitive status in humans. Further research is needed to determine the precise role and the molecular mechanisms of action of the SNPs in cognitive processes.