GATA1 and acute megakaryoblastic leukemia: Patients with Down syndrome have a high risk of developing a transient myeloproliferative disorder, which frequently develops into acute megakaryocytic leukemia.[48] In this context, mutations in the transcription factor GATA1 result in the expression of an N-terminally truncated protein that was termed GATA1s.[49] Like p30, GATA1s retains the ability to bind DNA and can act as a transcriptional activator.