Splice site mutations of GATA1 have beenfound in a family with macrocytic anaemia and in patients with Diamond-Blackfan anaemia(an anaemia characterised by a selective hypoplasia of erythroid cells), resulting inimpaired production of the full-length form of the GATA1 protein (Refs 19, 20). The gene discussed is GATA1; the disease is Diamond-Blackfan anemia.