For example, Weaver syndrome and Sotos syndrome are caused by pathogenic variants in histone methyltransferases EZH2 (5) and NSD1 (6), respectively, while Tatton-Brown-Rahman syndrome is caused by pathogenic variants in a DNA methyltransferase, DNMT3A (7). The gene discussed is EZH2; the disease is Tatton-Brown-Rahman overgrowth syndrome.