Clonal monosomy 7 and 5q--in a child with myelodysplastic syndrome

The authors report the case of a 5-year-old boy referred for thrombocytopenia and neutropenia. Bone marrow examination showed a myelodysplasia with clonal monosomy 7. The acceleration of the disease was marked by the appearance of an additional cytogenetic abnormality, i.e., the deletion of the long arm of chromosome 5 in the clonal cells. RAS gene mutation was not detected. Chemotherapy was started to achieve complete remission before a bone marrow transplantation. This treatment was complicated by a prolonged aplasia and the patient died of systemic mycotic infection.