Definition of Alpha-synuclein

Alpha-synuclein: One in a family of structurally related proteins that are prominently expressed in the central nervous system. Aggregated alpha-synuclein proteins form brain lesions that are hallmarks of some neurodegenerative diseases (synucleinopathies). The gene for alpha-synuclein, which is called SNCA, is on chromosome 4q21. Defects in this protein are believed to be related to the development of Parkinson disease.See also: Parkinson disease gene.