GBA1 and Parkinson disease: Furthermore, it is also worth noting that after a follow-up of 2 years, both GD patients as well as heterozygous carriers of GBA1 mutations showed prodromal signs of parkinsonism, such as olfactory deficits, higher UPDRS motor scores, lower cognitive assessment scores, REM sleep disturbances and higher depression scores (McNeil et al. 2012; Beavan et al. 2015).