Only the SNP rs1126680 in the butyrylcholinesterase gene (BCHE) showed significant association with PD per se (Table 4; minor allele (G) frequency 0.140 in controls, 0.060 in PD; P = 0.007, OR = 0.38, 95% confidence interval: 0.20–0.70). The gene discussed is BCHE; the disease is Parkinson disease.