MYELODYSPLASTIC SYNDROMES IN CHILDHOOD - REPORT OF 49 PATIENTS FROM AFRENCH MULTICENTER STUDY

We describe the clinical, cytological and cytogenetic features of 49 c ases of myelodysplastic syndromes (MDS) in childhood. Three children h ad received prior cytotoxic treatment (group 1); all of these had cyto genetic abnormalities and died shortly after diagnosis. 22 children ha d constitutional anomalies (group 2). The remaining 24 MDS were consid ered as 'primary' (group 3). Hypoplastic marrow was found in nine case s, and only 53% of the MDS fitted the adult FAB classification. Transf ormation to AML occurred in 11 cases. development of aplastic anaemia in three cases, and spontaneous remission in one case each of RA and R AEB. Differences were observed between groups 2 and 3 in terms of mean age at diagnosis (11.1 months v 5 years), rate of cytogenetic anomali es (15% v 38%) and rate of progression towards acute leukaemia (13% v 29%). In group 2, all the four girls studied exhibited a polyclonal pa ttern of X-inactivation, which suggests that MDS may be only the haema tological expression of an embryological defect with different target tissues. This study suggests that some MDS in childhood can exhibit pa rticular features such as congenital anomalies associated with MDS, bo ne marrow hypoplasia, polyclonality, and spontaneous remission. It emp hasizes that the FAB classification is not adequate for children and a ddresses the question of whether these MDS are always malignant diseas es.