Genetic landscape of recurrent ASXL1, U2AF1, SF3B1, SRSF2, and EZH2 mutations in 304 Chinese patients with myelodysplastic syndromes

Abstract

We determined the biological and prognostic significance of five recurrent genetic aberrations in Chinese patients with myelodysplastic syndromes (MDS). A total of 304 Chinese MDS patients were screened for known mutations in five genes (ASXL1, U2AF1, SF3B1, SRSF2, and EZH2) using next-generation sequencing. Of these, 97 patients (31.9 %) harbored at least one mutation in the five genes, and patients harboring these mutations had distinct clinical features. Incidence ratios for mutations in ASXL1, U2AF1, SF3B1, SRSF2, and EZH2 were 11.8, 8.6, 8.2, 4.3, and 3.6 %, respectively. Patients with U2AF1, SRSF2, and EZH2 mutations more commonly had high-risk than low-risk subtypes, while SF3B1 mutations were frequently confirmed in MDS subtypes with increased ring sideroblasts. Cases with ASXL1 mutations had a higher percentage of complex karyotypes, while U2AF1 mutations were more common in patients with trisomy 8 or 20q deletions. Notably, among 124 patients with a normal karyotype, 48 (38.7 %) had at least one mutation. Patients with U2AF1 or SRSF2 mutations had significantly shorter overall survival (OS) times compared with patients without these mutations (U2AF1 mutations: median OS, 18 vs 54 months, p = 0.032; SRSF2 mutations: median OS 11 vs 54 months, p = 0.005, respectively). Multivariate analysis showed that the presence of SRSF2 mutations was an independent unfavorable prognostic factor for OS (hazard ratio 2.039; 95 % confidence interval 1.040-4.000; p = 0.038). These data suggest that mutations in epigenetic modification and splicesome genes are common in Chinese patients with MDS, while mutations in U2AF1 and SRSF2 appear to predict an unfavorable prognosis.

Keywords: Molecular markers; Myelodysplastic syndromes; Next-generation sequencing; Prognosis.