Acquired mutations in GATA1 in neonates with Downʹs syndrome with transient myeloid disorder

Transient myeloid disorder is a unique self-regressing neoplasia specific to Downʹs syndrome. The transcription factor GATA1 is needed for normal growth and maturation of erythroid cells and megakaryocytes. Mutations in GATA1 have been reported in acute megakaryoblastic leukaemia in Downʹs syndrome. We aimed to investigate changes in GATA1 in patients with Downʹs syndrome and either transient myeloid disorder (n=10) or acute megakaryoblastic leukaemia (n=6). We recorded mutations eliminating exon 2 from GATA1 in all patients with transient myeloid disorder (age 0–24 days) and in all with acute megakaryoblastic leukaemia (age 14–38 months). The range of mutations did not differ between patients with each disorder. Patients with transient myeloid disorder with mutations in GATA1 can regress spontaneously to complete remission, and mutations do not necessarily predict later acute megakaryoblastic leukaemia.