SNCA and Parkinson disease: Further, in the differential diagnosis of PD from other movement disorders like MSA, progressive supranuclear palsy, corticobasal degeneration, and vascular parkinsonism, the utility of α-synuclein in CSF as a single biomarker is not established (Aerts et al., 2012; Gao et al., 2015; Zhou et al., 2015).