SNCA and multiple system atrophy: In particular, the SNCA gene (which encodes for α-Syn), is located at the q21.3–q22 region of chromosome 4 [9,10,11]: mutations of this gene, also called PARK1, are associated with dominantly-inherited PD [12,13,14], while specific point mutations and polymorphisms of its sequence are associated with the pathogenesis of other neurodegenerative diseases such as amyotrophic lateral sclerosis (ALS) and multiple system atrophy (MSA) [15,16,17].