Two remarkably similar human overgrowth conditions, known as Sotos syndrome and Tatton-Brown–Rahman syndrome, are caused by heterozygous mutations in the genes encoding two other chromatin regulators, namely nuclear receptor-binding SET domain 1 (NSD1) and DNA (cytosine-5)-methyltransferase 3A (DNMT3A), respectively (Table 2), suggesting some level of functional interplay between PRC2, NSD1 and DNMT3A. Here, DNMT3A is linked to Tatton-Brown-Rahman overgrowth syndrome.