BST1 and Parkinson disease: This is supported by the top PD GWAS hit in the BST1 locus, the rs4698412 G allele, which is associated with reduced risk of PD.3 This allele is also associated with reduced expression of BST1 in blood in GTEx (normalized effect size −0.07, p = 1.5e-6), suggesting that reduced expression might be protective.