EZH1 and overgrowth syndrome: For example, mice carrying DNMT3A mutations show postnatal growth retardation, which is different from the phenotype of DNMT3A overgrowth syndrome patients.30,31 In addition, deletion of EZH1 and EZH2 in chondrocytes causes severe skeletal growth impairment in mice, which is due to reduced growth plate chondrogenesis rather than longitudinal bone overgrowth.12,32