Some mutations in the glucosylceramidase-beta (GBA) gene encoding the lysosomal hydrolase glucocerebrosidase (GCase) involved in membrane lipid composition represent high risk factors for PD and dementia with Lewy bodies (Barkhuizen et al., 2016; Gan-Or et al., 2018). The gene discussed is GBA1; the disease is Parkinson disease.