SNCG and Parkinson disease: Although originally considered a potential cause of PD (where aggregated α-synuclein is present in the form of intracellular inclusions, Lewy bodies [LBs] and Lewy neurites [LNs]5,6), this protein is known to be involved in the pathogenesis of a diverse group of neurodegenerative diseases collectively known as synucleinopathies.