Ketogenic Diet for Prevention of Epileptic Spasms in Infantile Onset Genetic Epilepsies

Inclusion Criteria: * Plan for initiation of ketogenic diet by clinical team for treatment of epilepsy * The clinical team initiating the ketogenic diet agrees that the use of the KetoVie formula is appropriate for the subject, as all study subjects need to receive the same formula * Male or female, age 0 to less than 9 months (including neonates per investigator's judgment) * Epilepsy onset at less than 6 months of age * Abnormal development (any sub score of the Bayley-4 less than 1 standard deviation below the mean) and/or neurologic exam (microcephaly, macrocephaly, strabismus, abnormal vision/CVI, hypotonia, spasticity, dystonia, movement disorder), per investigators judgment * Genetic epilepsy diagnosis, pathogenic or likely pathogenic variant(s) with consistent phenotype and inheritance pattern * Weight adequate to complete required study laboratory testing without exceeding maximum allowable blood draws per draw or in a 30 day period per BCH policy Exclusion Criteria: * Epileptic spams prior to enrollment * Tuberous sclerosis complex, trisomy 21 (based on differential response to ES treatment) * Metabolic diagnosis with targeted treatment (including specific indication for ketogenic diet such as glucose transporter disorder, vitamin dependent epilepsies, and others) or exclusion for the ketogenic diet * Ongoing treatment with vigabatrin, ACTH, corticosteroids, topiramate or zonisamide. Other anti-seizure medications are permitted.