ABSTRACT
Myelodysplastic syndrome (MDS) and juvenile myelomonocytic leukemia (JMML) in children have attained increasing attention in recent years. With this attention, it has become evident that there are significant differences between MDS in children and adults (Table 1). MDS and JMML are very rare in children, with a combined annual incidence of 3.6/million (1,2), the incidence being highest in infants. In contrast with that of children, the incidence in adults is greater and increases with age, with the incidence estimated between 35 and 120 per million per year (3). Refractory anemia with ringed sideroblasts, which constitutes 25% of the adult cases of MDS (4), is also extremely rare in children (5,6). Monosomy 7 is by far the most common cytogenetic abnormality in children whereas 5q-, observed frequently in adults, is very rare in children (7). Associated abnormalities occur much more often in children (in up to one-third) than in adults. Finally, the therapeutic possibilities are limited in adults and the therapy often has a palliative perspective whereas the aim in all children with MDS is cure.
