The Czech Working Group for Paediatric Haematology participated in the international prospective study for the diagnosis and therapy of myelodysplastic syndrome (MDS) in childhood organized by the European Working Group for Myelodysplastic Syndrome (EWOG-MDS) in 1998–2002. The aim of the study was to improve the accuracy of diagnosis in children and adolescents withMDS by a standardized review of morphology and standardized cytogenetic and molecular analyses. The secondary objective of the study was to improve survival of children with primary MDS over that reported in the literature. During the study period (1998–2002), twenty-one children were diagnosed with MDS in the Czech Republic – 16 with primary MDS and juvenile myelomonocytic leukaemia (JMML); 3 with myeloid leukaemia and Down’s syndrome; and 2 with secondary MDS. MDS accounted for 5.5–8 % of the haematologicmalignancies.Of the 16 childrenwith primaryMDS 5 suffered from refractory cytopenia, 7 from RAEB/RAEBt, and 4 from JMML. The most common cytogenetic abnormality was monosomy 7 in 33 % of the patients. Two boys with primary MDS had a predisposing condition – neurofibromatosis type 1. Thirteen children underwent stem cell transplantation, 4 were treated by intensive AML-type chemotherapy, and 4 patients were followed up without treatment. Eleven children (52 %) are alive and well.

        Key words: MDS, children, epidemiology, morphology, cytogenetics, stem cell transplantation