The Association Between Fever and CDKL5 Deficiency Disorder: a Nationwide Survey

Inclusion Criteria: * A diagnosis of CDKL5 deficiency, including molecular confirmation of a pathogenic or likely pathogenic CDKL5 variant and refractory seizures. * Parents or guardians are willing to complete and provide information about the child's medical history and fever history after receiving the survey questionnaire online. Exclusion Criteria: * Any history of previous brain disease (trauma, etc.) that likely to precipitate seizures. * Presence of any clinical condition that in the opinion of the principal investigator makes the patient not suitable to participate in the trial.