Monkeys overexpressing simian or human SNCA coding for a protein with the A53T change via adeno-associated virus (AAV) vectors exhibit motor impairment and neuropathological features of PD including but not limited to: head position bias, loss of TH- and VMAT2-positive innervation throughout caudate nucleus and putamen, dystrophic neurites and swollen axons, SNCA-positive inclusions (Kirik et al., 2003). This evidence concerns the gene SNCA and Parkinson disease.