The known genetic mutations associated with PD can be grouped in three categories: alpha-synuclein mutations (E46K, A30P and A53T) and over-expression (mutations in PARK-1), defects in protein degradation (mutations in PARK-2 and PARK-5) and increases in oxidative stress (mutations in PARK-6 and PARK-7). This evidence concerns the gene SNCA and Parkinson disease.