Characterized by motor symptoms such as bradykinesia, rigidity, tremor, and postural instability, PD is pathologically defined by α-synuclein-positive inclusions (Lewy bodies and Lewy neurites) and the degeneration of dopaminergic neurons in the substantia nigra pars compacta and striatal projections (Sorrentino and Giasson, 2020; Tan et al., 2020). The gene discussed is SNCA; the disease is Parkinson disease.