Nonetheless, despite similar UPDRS III scores among GBA carriers and non-carriers [189,191,292,293], the H&Y stage and Levodopa-non responsive symptoms are significantly higher in GBA carriers compared to PD noncarriers [189,191], postural instability/gait phenotype (PIGD) is more frequent in GBA-PD [189,191], and the carriers of severe GBA mutations display more severe motor symptoms and H&Y stage OFF-medication [191]. Here, GBA1 is linked to Postural instability.