Cyclin-dependent kinase-like 5 (CDKL5) deficiency disorder (CDD) is a severe neurological condition that primarily affects brain development, leading to significant challenges such as early-onset, treatment-resistant seizures, profound developmental delay, intellectual and motor impairments, sleep issues, and cortical visual dysfunction (1). The gene discussed is CDKL5; the disease is craniodiaphyseal dysplasia.