BST1 rs11724635 interacts with environmental factors to increase the risk of Parkinson's disease in a Taiwanese population

A recently published genome-wide association study in Caucasian and Asian populations showed a significant association between the bone marrow stromal cell antigen 1 (BST1) SNP rs11724635 and increased risk for Parkinson's disease (PD). To investigate whether BST1 rs11724635 increases the risk of PD, either by itself or in combination with environmental factors, we performed an association analysis of BST1 rs11724635 in a large cohort of Taiwanese patients with PD and age matched controls. The study used TaqMan genotyping, logistic regression, and haplotype methods. The genotype distribution of rs11724635 in PD patients (N = 468; p = 0.50) and control subjects (N = 487; p = 0.44) was consistent with Hardy-Weinberg equilibrium. Compared with the AA genotype, the frequency of both CA and CC genotypes was not significantly different between the patient and control groups. The adjusted odd ratios (ORs) for CA and CC were not statistically significant (CA: OR = 0.962, 95% CI = 0.643-1.439, p = 0.850; CC: OR = 0.992, 95% CI = 0.654-1.503, p = 0.969). Of note, ever use of well water before the onset of PD symptoms had an impact on the occurrence of PD through interactions with BST1 rs11724635 AC (OR = 1.453, p = 0.024) and CC (OR = 1.623, p = 0.008). Our results show that the BST1 rs11724635 polymorphism alone is not associated with the development of PD, but it can interact with well water drinking to increase the risk of PD in this Taiwanese population.