The deposition of misfolded β-sheet enriched amyloid protein is a shared feature 
of many neurodegenerative diseases. Recent studies demonstrated the existence of 
conformationally diverse strains as a common property for multiple amyloidogenic 
proteins including α-Synuclein (α-Syn). α-Syn is misfolded and aggregated in a 
group of neurodegenerative diseases collectively known as α-Synucleinopathies, 
which include Parkinson's disease (PD), dementia with Lewy body, multiple system 
atrophy and also a subset of Alzheimer's disease patients with concomitant 
PD-like Lewy bodies and neurites. While sharing the same pathological protein, 
different α-Synucleinopathies demonstrate distinct clinical and pathological 
phenotypes, which could result from the existence of diverse pathological α-Syn 
strains in patients. In this review, we summarized the characteristics of 
different α-Synucleinopathies and α-Syn strains generated with recombinant α-Syn 
monomers. We also make predictions of α-Syn strains that could potentially exist 
in patients based on the knowledge from other amyloid proteins and the clinical 
and pathological features of different α-Synucleinopathies.