SNCA and Parkinson disease: Parkinson’s Disease (PD) is a neurodegenerative disease identified by the loss of dopaminergic neurons in the substantia nigra (midbrain dopaminergic nucleus modulating motor movement and reward functions as part of the basal ganglia circuitry) and the a-synuclein (neuronal protein regulating synaptic vesicle trafficking and neurotransmitter release) aggregation into Lewy bodies.