Cyclin-dependent kinase-like 5 (CDKL5) deficiency disorder (CDD) is a rare neurodevelopmental disease caused by mutations in the X-linked CDKL5 gene, a major role of which is to encode a serine-threonine kinase that is highly expressed in the brain [1,2,3]. This evidence concerns the gene CDKL5 and craniodiaphyseal dysplasia.