Abstract Abstract 2187 Poster Board II-164 Chronic myeloid leukemia (CML) progression is characterized by occurrence of new cytogenetic and molecular abnormalities. In the previous study, we have shown the important role of GATA-2 L359V mutation in CML progression. To further ascertain the truth of transcription factor GATA-2 in hematological malignancies, we expanded our study to GATA-2 full length by directly sequencing and applied MassARRAY assay into GATA-2 L359V mutation analysis. Finally, no GATA-2 L359V mutation was found in 270 acute myeloid leukemia, 30 myelodysplastic syndrome, 50 acute lymphoblastic leukemia, 12 chronic lymphocytic leukemia, 40 CML chronic phase and 286 BCR/ABL negative myeloproliferative disorders except CML blast crisis. A new variation of GATA-2 resulted in P250A change was identified, which was not found to have statistical difference between patients with hematological malignancies and healthy control. Hence, we concluded GATA-2 L359V is exclusively associated with CML progression but not other hematological malignancies and P250A is a new single nucleotide polymorphism. Disclosures: No relevant conflicts of interest to declare.