Although considerable clinical variation is seen [33], GBA-associated PD is typically associated with an earlier age of onset, a faster deterioration of motor functions, and a higher frequency and faster progression of cognitive decline compared to non GBA-associated PD, thus highlighting the importance of detection of the GBA1 variant in patients with PD (as well as with other synucleinopathies; see Reference [32]). The gene discussed is GBA1; the disease is Parkinson disease.