PRDM9 and leukemia: Tumor predisposition has been associated with other chromatin gene disorders associated with congenital overgrowth such as Sotos syndrome (e.g. overall risk ~ 3% including teratoma, neuroblastoma, ganglioma, leukemia, lung cancer and glioma) and Weaver syndrome (e.g. overall risk ~ 2% including leukemia, neuroblastoma and lymphoma) that are caused by mutations in the histone methyltransferases NSD1 and EZH2, respectively (21,40).