Two distinct splice site mutations in CACNA2D2, for example, lead to the truncation of the protein, causing epilepsy, dyskinesia, and cerebellar atrophy in one patient (Pippucci et al., 2013), whereas the other mutation is associated with congenital ataxia (Valence et al., 2018). The gene discussed is CACNA2D2; the disease is drug-induced dyskinesia.