It is well known that the formation of super-aggregates of misfolded and toxic accumulation of α-synuclein is pathognomonic for PD: a point mutation of the SNCA gene, coding for α-synuclein, is related to oxidative stress and to impaired activity of serotonergic neurotransmitters, a dysfunction that occurs before the clinical diagnosis of Parkinson's disease. Here, SNCA is linked to Parkinson disease.