PD is characterized by progressive death of midbrain dopaminergic neurons of substantia nigra pars compacta (SNc) (Barzilai and Melamed 2003) and the presence of intracellular inclusions called Lewy bodies consisting mainly of aggregated α-synuclein (α-Syn) (Braak et al. 1999; Trojanowski and Lee 1998). The gene discussed is SNCA; the disease is Parkinson disease.