GBA1 and Parkinson disease: The clinical manifestation of Parkinson-GBA1 is very similar to that for idiopathic Parkinson’s disease, but with a slightly younger age of onset, a higher incidence of neuropsychiatric features (including depression, anxiety, sleep disturbance and hallucinations) and a tendency to earlier and more prevalent cognitive impairment (Tan et al., 2007; Neumann et al., 2009; Sidransky et al., 2009; Brockmann et al., 2011; McNeill et al., 2012b; Winder-Rhodes et al., 2013).