Among the disorders caused by mutations in the STXBP1 gene is developmental and epileptic encephalopathy 4 (OMIM: 612164), which is an autosomal dominant neurological condition characterized by the onset of tonic seizures in early infancy (usually in the first months of life) (Di Meglio et al., 2015). The gene discussed is STXBP1; the disease is developmental and epileptic encephalopathy, 4.