EHMT1 and Kleefstra syndrome 1: On the other hand, cancer development is also uncommon in individuals with neurodevelopmental disorders carrying pathogenic germline variants in the methyl-/demethyltransferases such as EHMT1 (Kleefstra Syndrome 1, MIM:610253), KMT2A (Wiedemann–Steiner syndrome, MIM:605130), and KDM4B30 that regulate methylation of those lysine residues in H3 protein.