GBA1 and Parkinson disease: In the subgroup analysis, the PD patients with N370S [19, 21] and L444P variants [19, 22] of GBA were at a higher risk of developing RBD than patients without these variants (N370S: OR, 1.64; 95% CI, 1.03–2.61; I2 = 0.0; L444P: OR, 2.02; 95% CI, 1.08–3.75; I2 = 37.9%) (Fig. 3a).