CDKL5 and craniodiaphyseal dysplasia: CDKL5 deficiency disorder (CDD) (OMIM #300672) is a rare neurodevelopmental condition affecting primarily females, with a ~4:1 female‐to‐male ratio1 characterized by a variety of behavioral and physiological symptoms that include the onset of seizures within the first weeks/months of life, severe global developmental delay resulting in intellectual disability, poor motor control and the presence of peculiar hand stereotypies.2, 3