Comparing patient samples with sporadic (combination of PD early and late groups) against genetic PD (Analysis 4 in Fig. 1E, see Table 1, including double mutation carriers, PD recessive, PD GBA, and PD LRRK2 individuals’ samples; LRRK2 – leucine-rich repeat kinase 2) with two non-PD control groups (age- and sex-matched control group and group with subset of female participants due to age and sex matching; see Supplementary Table 2 for main statistics output), we were able to determine lowered histidine and methionine levels (Fig. 3). This evidence concerns the gene LRRK2 and Parkinson disease.