We analyzed a total of 851 individuals without pathogenic variants in LRRK2, PINK1, PRKN, or SNCA, including 449 PD patients (87 EOPD, 354 LOPD, and 8 with unknown age at onset), 144 prodromal subjects, 63 SWEDD cases (clinically diagnosed with PD but exhibiting normal DAT SPECT imaging), and 195 healthy controls. Here, SNCA is linked to Parkinson disease.