SNCG and synucleinopathy: Despite the extensive studies into α-syn proteoforms in CSF, plasma/serum, brain tissue, appendix and saliva (Guerreiro et al., 2012; Kellie et al., 2014; Oeckl et al., 2016; Killinger et al., 2018; Bhattacharjee et al., 2019; Mollenhauer et al., 2019) it appears that total synuclein concentrations are global markers of synaptic degeneration rather than specific clinical diagnostics for synucleinopathies.