Parkinson’s disease (PD) is characterized by the progressive loss of A9 midbrain dopaminergic (mDA) neurons, and the accumulation of intracellular aggregates of α-synuclein in Lewy bodies and Lewy neurites (Spillantini et al., 1997; Lees et al., 2009). The gene discussed is SNCA; the disease is Parkinson disease.