The bias toward megakaryocyte and away from erythroid progenitor formation that was specifically attributable to trisomy of Erg in Ts(1716)65Dn mice resembles progenitor abnormalities observed in pre-leukemic human DS foetal livers prior to acquisition of GATA1 mutations, although human DS foetal livers exhibit reduced numbers of GMP, in contrast to the mouse model [15]. The gene discussed is ERG; the disease is Dravet syndrome.