Subanalysis of PD and DLB stratified by GBA1 variant severity (GBAWT, GBArisk, GBAmild, GBAsevere) revealed no significant differences in levels of sphingolipid species in pmol/ml (Cer: 3.76 vs. 4.18 vs. 3.86 vs. 3.65; GlcCer: 0.90 vs. 0.94 vs. 0.92 vs. 0.86; GlcSph: 0.013 vs. 0.014 vs. 0.015 vs. 0.014; GalSph: 0.15 vs. 0.16 vs. 0.15 vs. 0.13; SphM: 333 vs. 346 vs. 346 vs. 324; p > 0.05 respectively); Supplemental Fig. 1. This evidence concerns the gene GBA1 and Parkinson disease.