CDKL5 and craniodiaphyseal dysplasia: Interestingly, we observed no significant difference in the number of motor neurons along the spinal cord but recorded a marked decrease in the density of motor neuron processes emerging from the spinal cord in cdkl5 mutants at 6 dpf, consistent with phenotypes observed in CDD patients and Cdkl5 KO mice (Fuchs et al., 2018; Pizzo et al., 2016).