The toxicity from dopamine and its metabolites appears to plausibly contribute to several pathologic mechanisms of Parkinson’s, including increased oxidative stress [26, 43–45], mitochondrial dysfunction [49–54], alpha-synuclein oligomerization [47, 56–59], vesicle dysfunction[46, 64], and neuronal death [34, 39–42]. This evidence concerns the gene SNCA and Parkinson disease.