PRRT2 and Familial paroxysmal ataxia: Mutations in proline-rich transmembrane protein 2 (PRRT2) result in conditions of involuntary movement, such as paroxysmal kinesigenic dyskinesia, benign familial infantile seizures, and episodic ataxia (Gardiner et al., 2015; Valtorta et al., 2016).