Phenotypic spectrum of all known STXBP1 patients. (a) Patients were categorized by their final clinical diagnosis (green = non-epileptic syndromes; blue = epileptic syndromes). (b–g) Phenotypic spectra subcategorized by mutations. Final patient diagnoses were separated by type of mutation into (b) missense mutations, (c) nonsense mutations, (d) frameshift mutations, (e) splice site mutations, (f) intragenic deletions/duplications, and (g) whole-gene deletions (ASD, autism spectrum disorder; ATR, ataxia-tremor-retardation syndrome; ID, intellectual disability; EE, epileptic encephalopathies; EOEE, early onset epileptic encephalopathy)