While mutations in other well-recognized epilepsy-causing genes such as SCN2A, SCN8A, or STXBP1 result in a wide range of disorders, including mild and severe epilepsies and even isolated autism spectrum disorders,20,25,26 the majority of patients with DNM1 encephalopathy have a relatively homogeneous developmental and epileptic encephalopathy. This evidence concerns the gene STXBP1 and autism spectrum disorder.