We present a patient diagnosed with OS associated with a novel SCN2A mutation (c.408G > A, p.Met136lle; OMIM®: 182390) who had a complete resolution of seizures and EEG abnormalities with KD commenced at 39 days of age.
In conclusion, we have identified a de novo SCN2A mutation as the etiology for Ohtahara syndrome in monozygotic twins associated with a unique dentate-olivary dysplasia in the deceased twin.
SCN2A mutations have been identified in various encephalopathy phenotypes, ranging from benign familial neonatal-infantile seizure (BFNIS) to more severe forms of epileptic encephalopathy such as Ohtahara syndrome or epilepsy of infancy with migrating focal seizure (EIMFS).
In conclusion, we have identified a de novo SCN2A mutation as the etiology for Ohtahara syndrome in monozygotic twins associated with a unique dentate-olivary dysplasia in the deceased twin.
We found 14 novel SCN2A missense mutations in 15 patients: 9 of 67 OS cases (13.4%), 1 of 150 West syndrome cases (0.67%), and 5 of 111 with unclassified EOEEs (4.5%).