PRRT2 and episodic kinesigenic dyskinesia 1: A unique and poorly understood feature of PRRT2-related diseases is the age dependence of the various phenotypes: seizures tend to occur in the infantile period [14] and abate within the first 2 years, whereas paroxysmal kinesigenic dyskinesia typically appears among school-age children, and may continue through mid-adulthood, after which time it often improves.