SNCA and Parkinson disease: The development and progression of PD manifestations have been mainly related to the significant decrease of the population of dopaminergic neurons (DA neurons) in the substantia nigra pars compacta (SNPc), in conjunction with the presence of Lewy bodies (LBs), which are intracytoplasmic inclusions, including insoluble and misfolded α-synuclein (α-syn) aggregates, considering LBs and the presence of α-syn as a pathognomonic molecular characteristic of PD [3,4].