Recent works demonstrated that, α-Synuclein can be detected in the ENS years before clinical onset of PD, similar to tau and β-amyloid (Hawkes et al., 2010; Shannon et al., 2012; Devos et al., 2013; Driver-Dunkley et al., 2014; Hilton et al., 2014; Iranzo et al., 2014; Stokholm et al., 2016). This evidence concerns the gene MAPT and Parkinson disease.