Objective: Since 2012, over 60 mutations of SCN8A have been identified in early infantile epileptic encephalopathy (EIEE) 13. In order to refine this syndrome phenotype, we performed a review of patients reported to date, adding a new personal case.
Methods: Whole exom sequencing was performed on our proband patient. We performed a review of the clinical picture of other patients reported to date.
Results: A de novo mutation in the SCN8A gene (c.2641G>T(p.V881L) was detected in our 4 year old male patient presented by 8 month with global developmental delay and infantile spasms. He was treated with ACTH with partial impact. He was then treated with numerous anti epileptic agents and ketogenic diet with no influence on his intractable seizures. Following syndrome diagnosis, he was treated with carbamezapine reported as efficient. The seizure number decreased but he suffered from irritability. He is now treated with cannabis. Mutations in SCN8A account for about 1% of EIEE. Most patients have generalized tonic-clonic seizures, followed by intellectual disability. Febrile seizures are rare in distinction from Dravet. Hypsarrthmia is also rare. Some patients have movement disorder and SUDEP was also reported. Seizures are typically refractory. Carbamazepine and Oxcarbazepine were useful in the largest number of patients also in distinction from Dravet.
Conclusions: Patient exomes revealed the role of SCN8A in EIEE. Differences among treatment options of EIEE emphasize the importance of early genetic diagnosis for the new era precision medicine: targeted treatment based on genetic profile.
