[Bone marrow monosomy 7 in children]

Three new cases of monosomy 7 are described. Two children, before onset of overt leukemia, had a preleukemic state: one with thrombopathy and myelodysplastic syndrome, the other with a moderate splenomegaly and an absolute monocytosis. In these two cases the leukemia was chemoresistant. The last child had a subacute myelomonocytic syndrome (juvenile type of chronic myelogenous leukemia) without high fetal hemoglobin value. She died from cachexia. The poor prognosis of monosomy 7 is underlined and such a chromosome deletion should be searched in myeloproliferative syndrome with monocytosis.