Paroxysmal Kinesigenic Dyskinesia Secondary to Novel Variant in PRRT2: A Case Report

Paroxysmal kinesigenic dyskinesia (PKD) is a movement disorder characterized by frequent, brief episodes of choreiform or dystonic movements, often triggered by voluntary movement or a startle sensation. Here, we report a case of PKD associated with a novel variant in PRRT2 gene. A 19-year-old male with no medical history presented with hyperkinetic movement disorder symptoms consistent with PKD. Clinical evaluation, laboratory studies, and genetic testing were performed to confirm the diagnosis. Treatment with carbamazepine was initiated, and the patient's response was monitored over a 9-month period. The patient exhibited classic clinical criteria for PKD, including brief episode duration, an identified kinesigenic trigger, and responsiveness to pharmacological treatment. Genetic testing revealed a pathogenic variant in PRRT2 gene not previously reported in association with PKD. Treatment with carbamazepine led to complete resolution of symptoms, with sustained improvement observed during follow-up. This case highlights the importance of considering PKD in the differential diagnosis of hyperkinetic movement disorders and emphasizes the role of genetic testing in confirming the diagnosis. Furthermore, it underscores the efficacy of carbamazepine in managing PKD symptoms associated with PRRT2 gene. Further research is warranted to elucidate the underlying pathophysiological mechanisms and optimize treatment strategies for PKD.