CDKL5 and craniodiaphyseal dysplasia: This response may be in reference to reported findings of somatic mosaicism in patients with CDD (79, 80) or germline mosaicism with CDKL5 which was described in one family with two daughters with CDD found to have the same CDKL5 variant (c.283-3_290del) with parents that tested negative for CDKL5 variants in all tissues (81).