NDN and atypical Rett syndrome: HPO terms are shared with SLC6A8 (cerebral creatine deficiency syndrome 1), CREBBP (Rubenstein-Taybi syndrome), MECP2 (Rett syndrome, mental retardation, X-linked syndromic, Lubs type), KANSL1 (Koolen-de Vries syndrome), RAI1 (Smith-Magenis syndrome), PTEN, SNRPN, MAP 2K2, FGFR3, KMT2A, MED12, NDN, and NAA10. Notably, AKS has been suggested to be similar to Kabuki syndrome, although they do not share the most HPO terms.