Tumor necrosis factor-α promoter polymorphism is associated with the risk of Parkinson's disease

Inflammatory events may contribute to the pathogenesis of Parkinson's disease (PD). We conducted a case-control study in a cohort of 369 PD cases and another cohort of 326 ethnically matched controls to investigate the association of tumor necrosis factor-alpha (TNF-alpha) promoter single nucleotide polymorphisms (SNPs) with the risk of PD. The overall genotype distribution at T-1031C and C-857T sites showed significant difference between PD cases and controls (P = 0.0062 and 0.0035, respectively). However, only the more frequent -1031 CC genotype was evidently associated with PD (P = 0.0085, odds ratio: 2.96; 95% CI: 1.38-7.09). Pairwise SNP linkage disequilibrium showed -1031 and -863 sites are in strong linkage disequilibrium (D' = 0.93, Delta(2) = 0.80). Pairwise haplotype analysis among the four sites showed that -1031C-863A may act as a risk haplotype among PD cases (P = 0.0028, odds ratio: 2.18; 95% CI: 1.33-3.69).