SNCA and Parkinson disease: Mutations in the distal enhancer of SNCA, the gene encoding α-synuclein, lead to aberrant ex pression and oligomerization of α-synuclein, which then induces the formation of α-synuclein aggregates in dopaminergic neurons, ultimately leading to the death of dopaminergic neurons and the development of PD (Soldner et al., 2016).