The executed analyses statistically demonstrated significant data, specifically, (a) the area under the curve (AUC) of the ROC for distinguishing PD from the HCs based on NLR was 0.929 (95% CI, 0.858–1; p < 0.0001); (b) based on hs-CRP, the AUC was 0.9272 (95% CI, 0.853–1.001); (c) based on SDC-1, the AUC was 0.796 (95% CI, 0.686–0.906); (d) based on SDC-2, the AUC was 0.793 (95% CI, 0.682–0.904); (e) based on SDC-3, the AUC was 0.750 (95% CI, 0.623–0.874); (f) based on BDNF, the AUC was 0.923 (95% CI, 0.899–0.993); and (g) based on ELA-32, the AUC was 0.928 (95% CI, 0.861–0.986). This evidence concerns the gene BDNF and Parkinson disease.