SNCA and Parkinson disease: The main pathological features of PD are the loss of dopaminergic neurons in the Substantia Nigra compacta (SNpc) and the appearance of Lewy bodies and Lewy neurites composed of abnormally aggregated α-synuclein (Kalia and Lang, 2015), which leads to dyskinesia with typical motor symptoms (Radhakrishnan and Goyal, 2018).