A 21-year-old woman presented with a chief complaint of generalized tonic-clonic seizures occurring once a month at night since the age of 14. The patient was treated with clonazepam plus levetiracetam, but seizure frequency was not reduced. After the detailed re-examination of her history of illness, it was revealed that she has been suffering from transient and recurrent choreoathetoid attacks triggered by sudden voluntary movements since she was a junior high school student, and it recently increased in frequency. Neither she nor her family recognize that it was significant to describe to the doctors. She was diagnosed as a complex of paroxysmal kinesigenic choreoathetosis (PKC) and its related conditions. Direct sequencing of proline-rich transmembrane protein 2 (PRRT2) revealed the most frequently described gene mutation, (NM_145239.2:c.649dupC), among PRRT2-related paroxysmal disorders. PKC and seizures were readily controlled with small dose of carbamazepine. Given the broad spectrum of PRRT2-related paroxysmal disorders, assessment of potential clinical complication of paroxysmal disorders including PKC might therefore be critical.