No significant difference in the ratio of o-α-syn to t-α-syn was found in the LRRK2-PD relative to controls (mean ± SEM = 24.08 ± 7.359, n = 13) (P = 0.5297, Mann-Whitney U test), possibly because of the small number of individuals in this group (n = 13 vs. n = 42). This evidence concerns the gene LRRK2 and Parkinson disease.