Which is the most common cytogenetic abnormality in myelodysplastic syndrome (MDS)?

Monosomy 7 is most common cytogenetic abnormality in children whereas 5q - is seen frequently in adults and is very rare in children. Although 5q may be commoner than monosomy 7 in some settings, overall monosomy 7 appears more common. Myelodysplastic syndromes are a group of stem cell disorders with altered hematopoesis causing anemia. It is the most common hematologic cancer in the older adult. Course may be indolent or rapidly progress to an AML. They are characterized by the constellation of cytopenias, usually hypercellular marrow, and a number of morphologic and cytogenetic abnormalities. Ref: The Myelodysplastic Syndromes: Pathobiology and Clinical Management By John M. Bennett, Page 264 ; Wintrobe's Clinical Hematology, 10th Edition ; Neoplastic Diseases of the Blood, Issue 439, Edited By Peter H. Wiernik, 4th Edition, Page 114 ; Neoplastic Hematopathology By Daniel M. Knowles, 2nd Edition, Page 397