A Case Series and Review of CDKL5 Deficiency Disorder: More than Rett

CDKL5 Deficiency Disorder (CDD) or CDKL5-associated epileptic encephalopathy (CAEE) is a distinct X-linked dominant epileptic encephalopathy that shares many features with Rett syndrome. In the past decade, mutations in CDKL5 gene were identified as part of the molecular heterogeneity of MECP2- negative Rett syndrome. CDD has increasingly gained recognition as a distinct molecular and clinical phenotype. Here we present four new patients with CDD: one with a clinical presentation of reflex seizures previously reported as a case report by the same group, and three cases with novel disease-causing mutations. The emerging distinct phenotype of CDD should allow the clinician to suspect the diagnosis early and avoid a lengthy diagnostic odyssey.