Patients carrying any GBA mutation were at 1.8 times higher risk of dementia (P = 0.001), and this remained significant after we excluded the 6 patients with GBA variants of unknown severity (HR 1.68; 95% CI, 1.19 to 2.37; P = 0.003) or the 278 patients screened for selected GBA variants using TaqMan and RFLP assays (HR 1.78; 95% CI, 1.10 to 2.86, P = 0.019). Here, GBA1 is linked to dementia.