[Cytogenetics of myelodysplastic syndromes and its impact as prognostic factor].

Myelodysplastic syndromes (MDS) are a group of disorders of the hematopoietic stem cell. They are characterized by cytopenia(s), dysplasia of one or more cell lines, ineffective hematopoiesis, and an increased risk for developing acute myelogenous leukemia. The classification of MDS has been complicated due to the great heterogeneity in clinical phenotype as well as in the morphological and cytogenetic characteristics. The prognostic value of cytogenetic abnormalities in MDS has been analyzed in multicenter studies. This approach raised the development of the revised International Prognostic Scoring System (IPSS-R), which analyzes five prognostic variables, among which the cytogenetic study stands out. According to the cytogenetic findings, a classification of MDS in five subgroups was developed. Knowledge of the cytogenetic abnormalities has led to the study of genes involved in various chromosomal rearrangements. Moreover, DNA sequencing has helped to identify mutations in approximately 50 genes related to signal transduction, DNA methylation, transcriptional regulation, and RNA splicing. Therefore, the cytogenetic study should be used to improve the classification and therapeutic management of MDS. This approach will be an essential tool for the development of targeted therapy protocols.