Tumor necrosis factor-alpha gene is not associated with obsessive-compulsive disorder.

Dysregulation of the immune system has been suggested to play a role in the complex etiology of obsessive-compulsive disorder. In this context, tumor necrosis factor-alpha is considered an interesting candidate for genetic studies as overproduction of tumor necrosis factor-alpha, which may be genetically modulated, can exert neurotoxic effects and influence neural cell growth and proliferation. Moreover, the tumor necrosis factor-alpha gene is located on chromosome 6p21.3, a region that has been found to be weakly associated with obsessive-compulsive disorder in linkage studies. One functional polymorphism, G-308A, has been found within the gene.