SNCA and Parkinson disease: Polymeropoulos et al. described a causative mutation (A53T) in SNCA, the α-synuclein gene, in the Contursi kindred and three smaller Greek families with PD, whereas Spillantini et al. reported the presence of α-synuclein in Lewy bodies and Lewy neurites of idiopathic PD and dementia with Lewy bodies (DLB).