STXBP1 and Epileptic encephalopathy: We have previously shown that within a group of 663 individuals with various developmental and epileptic encephalopathies assessed across almost 3500 cumulative patient-years, STXBP1-related disorders represent the only genetic aetiology significantly associated with infantile spasms.34 The overall high frequency of infantile spasms may open up a window for rapid identification of individuals with STXBP1-related disorders for precision medicine trials.