Forty-four cases of childhood myelodysplasia with cytogenetics, documented by the groupe français de cytogénétique hématologique

Forty-four cases of myelodysplasia in children were studied. A third of the cases were unclassifiable according to the FAB system. Twenty-five cases were 'idiopathic' myelodysplastic syndromes (MDS), four were secondary to chemo- and/or radiotherapy, and 15 (1/3) were found associated with a congenital genetic disease (such as familial myelodysplasia, chromosome syndrome, or various dysmorphic features). Polyclonality was retained in some cases, even in the 'idiopathic MDS' group, demonstrating that non-malignant myelodysplasia does exist. Sex ratio was well balanced in this study; mean age at diagnosis was 4 years; median survival was 3 years; prognosis was better in girls and in young children; normal karyotypes were associated with a better outcome, monosomy 7 with intermediate survival, and other chromosomal findings, including trisomy 8 and 19, with a worse prognosis; refractory anaemia with excess of blasts in transformation, and cases of secondary MDS were associated with a bad prognosis. Childhood MDS are extremely heterogeneous conditions deserving more studies.