STXBP1 and epilepsy syndrome: The main epilepsy syndromes were Ohtahara syndrome and West syndrome, accounting for 52.6% of cases, which is consistent with the ILAE definition of STXBP1-encephalopathy.[7] During follow-up, we observed the progression of seizure phenotypes (Ohtahara syndrome to West syndrome), which is similar to the reported natural course of early-onset epileptic encephalopathy.[14] However, no patient progressed to Lennox–Gastaut syndrome, which may be related to the short follow-up duration (median 24 months) and small sample size.