ASXL1 is a molecular predictor in idiopathic cytopenia of undetermined significance.

We analyzed the mutational profile of idiopathic cytopenia of undetermined significance (ICUS) compared with that of myelodysplastic syndrome (MDS). Targeted sequencing of 88 genes associated with myeloid malignancies was performed using samples of bone marrow mononuclear cells from ICUS and MDS patients. Forty patients with ICUS and 128 patients with MDS were included in this study. The median mutational burden was 0.7 mutation/person in the ICUS group and 2.2 mutation/person in the MDS group. ASXL1 (seven patients) was the most frequently mutated gene. ASXL1 was an independent significant prognostic factor for event-free survival (EFS) and overall survival (OS) (hazard ratio (HR) = 10.07 and 30.63, p = .004 and .003, respectively). The ASXL1 mutation which is frequently detected in elderly patients is a molecular predictor for pancytopenia and survival in patients with ICUS. A larger prospective study is needed to validate the role of this genetic mutation in an ICUS prognosis.