SNCA and multiple system atrophy: Abdominal skin from autopsy-confirmed patients with PD, MSA, Lewy body dementia, and non-synucleinopathies showed positive α-synuclein seeding activity in 44 of 47 PD (94% sensitivity), 2 of 3 MSA (67% sensitivity), all 7 Lewy body dementia (100% sensitivity), and 6 of 73 control group (92% specificity) [252].