Genetics and Epigenetics of Myelodysplastic Syndromes and Response to Drug Therapy: New Insights.

Myelodysplastic syndromes (MDS) are a heterogeneous group of hematologic neoplasms ocurring mostly in the elderly. The clinical outcome of MDS patients is still poor despite progress in treatment approaches. About 90% of patients harbor at least one somatic mutation. This review aimed to assess the potential of molecular abnormalities in understanding pathogenesis, prognosis, diagnosis and in guiding choice of proper therapy in MDS patients. Papers related to this topic from 2000 to 2016 in PubMed and Scopus databases were searched and studied. The most common molecular abnormalities were TET2, ASXL1 as well as molecules involved in spliceosome machinery (U2AF1, SRSF2 and SF3B1). Patients with defects in TET2 molecule show better response to treatment with azacitidine. IDH and DNMT3A mutations are associated with a good response to decitabine therapy. In addition, patients with del5q subtype harboring TP53 mutation do not show a good response to lenalidomide therapy. In general, the results of this study show that molecular abnormalities can be associated with the occurrence of a specific morphological phenotype in patients. Therefore, considering the morphology of patients, different gene profiling methods can be selected to choice the most appropriate therapeutic measure in these patients in addition to faster and more cost-effective diagnosis of molecular abnormalities.