GBA1 mutations represent the strongest genetic risk factor for PD (OR 5-20x), and GCase dysfunction creates a druggable lysosomal impairment that promotes alpha-synuclein aggregation. Multiple chemical scaffolds (ambroxol derivatives, AT337) demonstrate target engagement, and Phase 2 trials show trends toward benefit. The primary translational barrier remains BBB penetration; existing chaperones achieve marginal CNS levels. Enrichment strategies using GBA-PD carriers (15% of PD population) can accelerate trial timelines.