The SNCA-PD group (2.43 pg/mL per year) showed the highest estimated change in NfL, while there was no difference in the longitudinal change of NfL between iPD (1.10 pg/mL per year) and GBA-PD (0.98 pg/mL per year) groups (p = 0.823). This evidence concerns the gene NEFL and Parkinson disease.