The cutoff value for predicting cognitive impairment in PD patients were 50.251 pg/ml of Aβ-40, (AUC = 0.697), 30.555 pg/ml of T-tau, (AUC = 0.726) and 0.522 pg/ml of α-synuclein, (AUC = 0.799). This evidence concerns the gene MAPT and Parkinson disease.