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 ha d developed petechiae. He had a leukocyte count of 4.4 x 10(9)/L, hemo globin concentration of 7.9 g/dL, packed cell volume of 21 %, mean cor puscular volume of 101 fL, and platelet count of 19 x 10(9)/L. At the time of referral, a bone marrow aspirate and biopsy revealed myelodysp lastic changes that included megakaryocytic hyperplasia with hypolobat ed megakaryocytes, megaloblastoid erythropoiesis, 12% blast cells, and bone marrow fibrosis; the diagnosis was refractory anemia with excess blasts (RAEB). Cytogenetic analysis showed the following abnormalitie s: 47,XY,inv(3)(p21q25),del(5)(q22q31), +21/46,XY. By dinucleotide pol ymorphism analysis, the 5q22-q31 loci were normal in peripheral blood granulocytes. Because of severe thrombocytopenia that became refractor y to platelet transfusions and because of possible progression to leuk emia, the patient received an unrelated-donor bone marrow transplant. Recovery was complicated by a visceral fungal infection, but the patie nt now has normal, fully reconstituted bone marrow function. This pati ent is the youngest to be reported with RAEB and a 5q- anomaly accompa nied by thrombocytopenia, megakaryocytic hyperplasia with hypolobated megakaryocytes, and macrocytic anemia with megaloblastoid erythropoies is, similar to ''5q- syndrome'' in adults. (C) Elsevier Science Inc., 1998