Tumor necrosis factor gene polymorphisms in patients with sporadic Parkinson's disease

We studied promoter region polymorphisms in the tumor necrosis factor (TNF) gene at position −1031, −863, and −857, in 172 Japanese patients with sporadic Parkinson's disease (PD). The frequency of the -1031C allele, a high producer of TNF, increased significantly in early onset PD patients compared with controls. In addition, PD patients with the −1031C allele showed a significantly earlier onset than those without −1031C allele, after stratification of the data by an interleukin-1β gene polymorphism. Our findings suggest that TNF might have a toxic effect in PD.