The combination of t-α-syn, o-α-syn, and TNF-α discriminated the asymptomatic LRRK2 mutation carriers group from the Ctrl group: low levels of t-α-syn (OR, 0.997; 95% CI, 0.994–0.999), high levels of o-α-syn (OR, 1.029, 95% CI, 0.999–1.060), and high levels of TNF-α (OR, 1.418; 95% CI, 0.998–2.014) indicate that individuals are at higher risk developing PD. This evidence concerns the gene LRRK2 and Parkinson disease.