SNCA and Parkinson disease: Parkinson’s disease (PD) is a progressive neurodegenerative disorder characterized by motor dysfunction, including bradykinesia, tremor, rigidity, and postural instability2 The main cause of PD is the progressive loss of dopaminergic neurons in the substantia nigra (SN) pars compacta (SNpc) and the accumulation of Lewy bodies, which are primarily composed of alpha-synuclein (α-syn) proteins.