Tehran University of Medical Sciences International Journal of Hematology-Oncology and Stem Cell Research 2008-2207 11 3 2016 12 29 232 240 EN Mohammad Zahid Medical Graduate, Aga Khan University, Karachi, Pakistan Umair Malik Medical Graduate, Aga Khan University, Karachi, Pakistan Momena Sohail Medical Graduate, Aga Khan University, Karachi, Pakistan Irfan Hassan Medical Graduate, Aga Khan University, Karachi, Pakistan Sara Ali Medical Graduate, Aga Khan University, Karachi, Pakistan Muhammad Hamza Saad Shaukat Medical Graduate, Aga Khan University, Karachi, Pakistan 2016 03 16 2016 04 30 Karyotype is one of the main constituents of the International Prognostic Scoring System (IPSS) and revised-IPSS that are the cornerstones for the prognostication of patients with myelodysplastic syndromes (MDS). Del(5q), –7/del(7q), +8 and –Y are among the most extensively studied cytogenetic abnormalities in MDS. The same applies for normal karyotype. There are hundreds of other rare cytogenetic abnormalities that have been reported in MDS, included but not limited to –X, 3q abnormalities, +13/del(13q), i(17q), +21/–21. However, due to a very low number of patients, their impact on the prognosis of MDS is limited. Knowledge of the molecular consequences of different cytogenetic abnormalities allows us to modify treatment regimens based on drugs most active against the specific karyotype present, allowing for the opportunity to individualize MDS treatment and improve patient care and prognosis. https://ijhoscr.tums.ac.ir/index.php/ijhoscr/article/view/582 https://ijhoscr.tums.ac.ir/index.php/ijhoscr/article/download/582/563