Transcription factors play a central role in the pathogenesis of acute leukaemia. Genes encoding transcription factors are frequently perturbed by chromosome rearrangements. More recently acquired point mutations have been described in a number of important genes for normal haematopoiesis. The stem cell leukaemia (SCL) gene encodes a basic helix-loop-helix transcription factor and is upregulated by chromosome rearrangements in T-acute lymphoblastic leukaemia. SCL function is essential for the development of both primitive and definitive haematopoiesis. We searched for SCL mutations in myeloid leukaemias and chronic myeloproliferative disorders. Our data demonstrated that SCL point mutations were rare in acute myeloid leukaemia and myeloproliferative disorders.