OBJECTIVE: The present study aimed to investigate the initial clinical features of infantile-onset genetic epilepsy and compare initial seizure variables and responses to sodium channel blockers between SCN1A and non-SCN1A group. METHODS: We selected 122 patients, comprising 58 patients with SCN1A mutations and 64 patients with mutations in other than SCN1A, from our institutional database. RESULTS: Patients identified in the SCN1A group tended to present with fever, prolonged seizure duration, and hemiclonic seizure semiology. Clustering of seizures was found more frequently in patients from the non-SCN1A group. However, an overlap of seizure variables and seizure type in both groups was also noted. While sodium channel blockers aggravated seizures in more than half of the patients (21/29, 72.4 %) in the SCN1A group, the opposite tendency toward a favorable response to sodium channel blockers (19/30, 63.3 %) was found in those in the non-SCN1A group. Notably, no patient showed seizure aggravation after the use of sodium channel blockers in the non-SCN1A group. CONCLUSION: This study highlights the need for comprehensive comparative research to guide the management of infantile onset genetic epilepsy patients.