Cytogenetic abnormalities in myelodisplastic syndrome patients OBJECTIVES: The aim of this research is to examine the prevalence of cytogenetic abnormalities in myelodisplastic syndrome patients. STUDY DESIGN: Cross-sectional study on historical data PARTICIPANTS (MATERIAL) AND METHODS: The cross-sectional study included 32 patients which were diagnosed with myelodislastic syndrome in the Clinical Hospital Centre Osijek in the period from January 1, 2017 to December 31, 2021. The values of laboratory and cytogenetics features in determining the diagnosis of myelodisplastic syndrome were processed. RESULTS: There were 18 (56 %) female patients. 14 (44 %) patients are in the range of 70 to 79 years, while only one patient was of a worrying age of 18 years. Patients have a reduced concentration of hemoglobin and platelets and an increased percentage of blasts in the bone marrow, which amounts to a median of 7 %. 22 (69 %) patients have proven cytogenetic abnormalities with GTG striping and/or FISH method. Patients with cytogenetic abnormalities have a less favorable clinical picture, especially patients with -7/del(7q) abnormalities. GTG striping most often diagnosed del(5q) in 9 (41 %) patients, while FISH method -7 in 7 (32 %) patients. 11 (50 %) patients have one abnormality each. Complex karyotypes with four or more abnormalities appeared in three (14 %) patients. Numerical abnormalities are most common in 25 % of all patients. 13 (40 %) patients are classified in the high and very high risk group according to the revised International Prognostic Scoring System. CONCLUSION: Laboratory and demographic characteristics are in accordance with the guidelines for the diagnosis of myelodisplastic syndrome. Cytogenetic abnormalities occur more often than in other studies, but the frequency of certain abnormalities is in line with other European studies.