GBA1 and Parkinson disease: Our data are in line with and extend on previous estimations targeting only patients with a GBA mutation (such as L444P) for a hypothetical trial with MMSE as the primary outcome.11 Notably, this hypothetical trial was found to reduce trial size by as much as 25-fold compared to a trial of patients with PD without a GBA mutation.11 However, neuropathic GBA mutations are rare in the general PD population (1.4% in our study), whereas we considered all types of GBA variant and thus substantially increased the number of eligible trial participants.