By analyzing the PD-causing genes with more than five AAO items, we found that five genes (DNAJC6, ATP13A2, FBXO7, SYNJ1, PARK7) were associated with a juvenile-onset, four genes (PARKN, PINK1, SNCA, DCTN1) were associated with an early onset, while VPS35 and LRRK2 were associated with a late-onset (Figure 4A). This evidence concerns the gene SNCA and Parkinson disease.