GBA1 and Parkinson disease: We noted that the removal of the mutation cases resulted in a significant age difference between the control and PD groups (64 ± 1 and 69 ± 1 years respectively, p < 0.05), as the GBA1 mutation carriers with PD had an earlier age-at-diagnosis than those without (58 ± 3 and 65 ± 1 years respectively, p < 0.05).