Case ReportA case of autosomal dominant nocturnal frontal lobe epilepsy (ADNFLE) coexisting with pervasive developmental disorder harboring SCN1A mutation in addition to CHRNB2 mutation

We report a case of autosomal dominant nocturnal frontal lobe epilepsy (ADNFLE) with several characteristics distinct from previously reported cases, in which genetic studies identified mutations in two different genes. This case differed from typical ADNFLE with respect to the following: (1) slightly younger onset and refractory to antiepileptic drugs and (2) borderline intellectual functioning and coexistence of pervasive developmental disorder from infancy. Genetic testing revealed a novel mutation and a silent substitution in SCN1A (c.4285G > T, A1429S and c.4371G > C, silent) in addition to a known mutation in CHRNB2 (c.1200C > G, I312M). SCN1A is a gene that codes for the voltage-dependent sodium channel α1 subunit and has been implicated in generalized epilepsy with febrile seizures plus and severe myoclonic epilepsy in infancy. However, the relation between SCN1A and ADNFLE is unknown. We report the clinical course and symptomatic characteristics of this case although the relationship between ADNFLE mutation and SCN1A mutation remains to be elucidated.