Monosomy-7 in childhood hemopoietic disorders.

Acquired pure monosomy-7 is associated with various myeloproliferative disorders (MPD), myelodysplasias (MDS), and acute myeloblastic leukemias (AML) in children and a poor prognosis. A series of 14 malignant blood disorders with pure monosomy-7 in children (eight MPD, two refractory anemia with excess of blasts, (RAEB), and four AML) is reported and compared with cases in the literature. The median age is significantly different in the patients with MPD and those with MDS or AML: 23, 80.5, and 112 months, respectively. The outcomes of MPD and RAEB are characterized by a high risk of rapid blastic transformation and resistance to polychemotherapy. Bone marrow transplantation (BMT) seems to be the best treatment, and one survival of two years in complete remission after autologous BMT in a child with AML is reported. Several myeloid cell lineages are involved in the proliferation, which partly explains the difficulties of cytologic classification and suggests that a pluripotent stem-cell is at the origin of the disease.