Newly developed alpha-synuclein seeding assays [36, 43, 47, 48, 55] (αSyn-SAA) can identify misfolded alpha-synuclein in cerebrospinal fluid (CSF) and can be used as a proxy for the presence of Lewy body pathology in the brain to assist diagnosis of PD and other synucleopathies. Here, SNCA is linked to Parkinson disease.