a biomarker and a method for evaluating a risk for parkinson &# 39 ; s disease are disclosed . the method comprises : obtaining a sample from a tester , analyzing the polymorphic biomarker of the sample , wherein the biomarker is substrate - specifying subunit of scf e3 ubiquitin ligase complex - fbxo7 gene ; and when the cdna sequence in position 155 of the biomarker is g or the amino acid sequence in position 52 of the biomarker is cysteine , it represents that the tester has a lower risk for parkinson &# 39 ; s disease .