[A patient with an early diagnosis of PCDH19-related epilepsy].

An abnormality in PCDH19 causes intractable early-onset epilepsy limited to females, and its significance in pediatric epilepsy is currently increasing. We report the case of a girl with an early diagnosis of PCDH19-related epilepsy. Focal seizures, consisting of eye deviation and asymmetrical tonic posturing, first appeared in clusters at the age of 5 months. Although each seizure was brief (less than a few minutes), seizures occurred in clusters. Cluster was observed at ages of 7, 10, 11, 14, and 19 months, respectively, and all were intractable to multiple treatments. Each cluster continued for 3 days to 2 weeks. However, no seizures occurred outsides the clusters. The pattern of seizure occurrences was characteristic of PCDH19-related epilepsy, which we first suspected when the patient was 11 months old. Genetic analysis of PCDH19 revealed two novel missense substitutions: c.1294G≥C (p.D417H) and c.1786G≥T (p.D596Y). Her psychomotor development was normal at the last follow-up at age of 1 year and 9 months. Currently, the pathogenesis and best treatments of PCDH19-related epilepsy remain unclear. However, to provide correct diagnosis and genetic counseling, and to avoid overtreatments, the possibility of this disease should be considered early in girls with intractable seizure clusters which starting during infancy to early childhood.