5q− in a Child with Refractory Anemia with Excess Blasts: Similarities to 5q− Syndrome in Adults

A 19-month-old boy was referred to our institution because of chronic macrocytic anemia and severe thrombocytopenia. At age 17 months, he had developed petechiae. He had a leukocyte count of 4.4 × 109/L, hemoglobin concentration of 7.9 g/dL, packed cell volume of 21%, mean corpuscular volume of 101 fL, and platelet count of 19 × 109/L. At the time of referral, a bone marrow aspirate and biopsy revealed myelodysplastic changes that included megakaryocytic hyperplasia with hypolobated megakaryocytes, megaloblastoid erythropoiesis, 12% blast cells, and bone marrow fibrosis; the diagnosis was refractory anemia with excess blasts (RAEB). Cytogenetic analysis showed the following abnormalities: 47,XY,inv(3)(p21q25),del(5)(q22q31),+21/46,XY. By dinucleotide polymorphism analysis, the 5q22–q31 loci were normal in peripheral blood granulocytes. Because of severe thrombocytopenia that became refractory to platelet transfusions and because of possible progression to leukemia, the patient received an unrelated-donor bone marrow transplant. Recovery was complicated by a visceral fungal infection, but the patient now has normal, fully reconstituted bone marrow function. This patient is the youngest to be reported with RAEB and a 5q− anomaly accompanied by thrombocytopenia, megakaryocytic hyperplasia with hypolobated megakaryocytes, and macrocytic anemia with megaloblastoid erythropoiesis, similar to “5q− syndrome” in adults.