TET2, ASXL1 and EZH2 mutations in Chinese with myelodysplastic syndromes

Somatic mutations of epigenetic gene regulators are common in patients with myelodysplastic syndromes (MDS) and correlate with some clinical and laboratory features. We studied mutations in TET2, ASXL1 and EZH2 in 153 Chinese patients with MDS. TET2 mutations were detected in 35 patients (23%), ASXL1 in 33 patients (22%) and EZH2 in 8 (5%). ASXL1 mutations were associated with increased colony formation of BFU-E, CFU-E and CFU-GM (P-values, 0.049, 0.011 and 0.006). EZH2 mutations were common in patients with poor IPSS cytogenetics (P = 0.001) and in patients in the IPSS intermediate-2/high-risk cohorts (P = 0.06). In uni- but not multi-variate analyses, mutated TET2 was associated with longer survival (P = 0.044) whereas EZH2 mutations were associated with an increased risk of transformation to acute myeloid leukemia (AML; P = 0.039). These data suggest ASXL1 mutations might results in dominance of the mutant clone in Chinese with MDS whereas EZH2 mutations might predict an increased risk of transformation to AML.