Infantile Epileptic Encephalopathy Associated With SCN2A Mutation Responsive to Oral Mexiletine

Genetic alterations are significant causes of epilepsy syndromes; especially early-onset epileptic encephalopathies and voltage-gated sodium channelopathies are among the best described. Mutations in the SCN2A subunit of voltage-gated sodium channels have been associated with benign familial neonatal-infantile seizures, generalized epilepsy febrile seizures plus, and an early-onset infantile epileptic encephalopathy.

We describe two infants with medically refractory seizures due to a de novo SCN2A mutation.

The first child responded to intravenous lidocaine with significant reduction in seizure frequency and was successfully transitioned to enteral mexiletine. Mexiletine was subsequently used in a second infant with reduction in seizure frequency.

Class 1b antiarrhythmic agents, lidocaine and mexiletine, may be useful in infants with medically refractory early infantile epileptic encephalopathy secondary to mutations in SCN2A.