Cytogenetic abnormalities in myelodysplastic syndrome: an overview

The myelodysplastic syndromes (MDS) are clonal disorders of haematopoietic stem cells characterized by ineffective haematopoiesis leading to blood cytopenias and by high incidence of progression to acute myeloid leukaemia (AML). These disorders generally arise de novo, but may also occur years after exposure to mutagenic chemotherapy. Clonal cytogenetic abnormalities are detected in about 30-50% de novo cases, whereas more than 80% of therapy-related forms harbour such markers. Although in the Western countries, MDS cases are mainly reported in the elderly population and rarely in the paediatric age group; this disease is increasingly seen in young adults in India. Cytogenetic study plays an important role in the diagnosis and is useful for prediction of individual prognosis using the international prognostic scoring system. Specific chromosomal abnormalities, such as -5/5q-, -7/7q-, and complex abnormalities, play an important role in the development of new therapeutic options and clinical management of MDS. In this review, we summarize the cytogenetic abnormalities in MDS from various parts of the world.