title: An unusual case of leukemia with high fetal hemoglobin: demonstration of abnormal hemoglobin synthesis localized in a red cell clone.
abstract: A high level of fetal hemoglobin was found in an 8-yr-old boy without any hematologic disorders except for a moderate anemia. The absence of hemoglobin abnormalities in the parents led us to suspect a latent malignant disease that, on follow-up, was confirmed to be myelomonocytic leukemia. Hemoglobin biosynthetic studies provided evidence of unbalanced synthesis of globin subunits by reticulocytes, while the production of non-alpha chains was equal to that of alpha chains in bone marrow cells. The expression of red cell antigen i was increased, while those of I, A, and A1 antigens were found to decrease progressively. Two populations of erythrocytes, A-positive and A-negative, were distinguished and could be separated by differential agglutination. Unbalanced globin chain synthesis, increased fetal hemoglobin, and antigenic changes of the membrane were shown to be restricted to the A-negative population. The biologic data were not entirely consistent with a genuine reversion to fetal erythropoiesis. The question remains of a polychromosomal lesion of either quiescent F cells or adult stem cells.
mesh_terms: D000017:ABO Blood-Group System; D001853:Bone Marrow / Q000378:metabolism; D001854:Bone Marrow Cells; D002478:Cells, Cultured; D002648:Child; D004912:Erythrocytes / Q000276:immunology; D005319:Fetal Hemoglobin / Q000032:analysis*; D005914:Globins / Q000096:biosynthesis; D006801:Humans; D007048:I Blood-Group System; D007137:Immunoglobulin alpha-Chains / Q000096:biosynthesis; D037102:Lectins; D007948:Leukemia, Monocytic, Acute / Q000097:blood*; D015470:Leukemia, Myeloid, Acute / Q000097:blood*; D008297:Male; D009030:Mosaicism
chemical_list: D000017:ABO Blood-Group System; D007048:I Blood-Group System; D007137:Immunoglobulin alpha-Chains; D037102:Lectins; D005914:Globins; D005319:Fetal Hemoglobin