Epilepsy as the Symptom of a Spinocerebellar Ataxia 13 in a Patient Presenting with a Mutation in the KCNC3 Gene

Background: The spinocerebellar ataxias (SCAs) are a clinically and genetically heterogeneous Group of neurodegenerative diseases, among which SCAl3 is a rare subtype, and its pathogenic gene is the KCNC3 gene. At present, the incidence of SCA13 is still unclear, and only two cases have been reported in the Chinese population. We report a case of SCA13 with ataxia and epilepsy as the clinical manifestations. The diagnosis was confirmed by full-exome testing. Case presentation: A 17-year-old young patient was unable to carry out many sports activities since childhood, and had repeated episodes of unconsciousness in the past 2 years. Neurologic examination revealed poor coordination of the lower extremities. Magnetic resonance imaging (MRI) of the brain performed cerebellar atrophy. Gene detection indicated that the patient had a heterozygous mutation of c.1268G>A in the KCNC3 gene (chr19:50826942). Urgent treatment with antiepileptic therapy was initiated; her seizures resolved shortly thereafter, and she remains seizure-free.The patient's condition had no obvious progress and aggravation with 1 year follow-up. Couclusion: This case report suggests that ataxia patients with unknown causes, especially children and young onset patients, it is necessary to actively improve cranial MRI and genetic detection to make a clear diagnosis.Young patients with ataxia initially characterized by epilepsy and extrapyramidal system should first consider the possibility of SCA13.