GBA1 and Parkinson disease: Several genetic risk factors, including mutations in the leucine-rich repeat kinse 2 (LRRK2) and glucosylceramidase (GBA1) genes, have been linked to both familial and sporadic PD, underscoring the complexity of the underlying disease mechanisms (Di Maio et al., 2018, Eblan et al., 2005, Sidransky et al., 2009).