SNCA and Parkinson disease: Thus, the identification of these PD-related genes has led to the proposition that the progressive deterioration of dopaminergic neurons may arise from cellular disturbances produced by misfolding and aggregation of alpha-synuclein, mitochondrial dysfunction, disruption of the autophagy-lysosome system, endoplasmic reticulum stress, dysregulation of calcium homeostasis as well as chronic neuroinflammation [22, 23].