CLINICAL-FEATURES AND STUDIES OF ERYTHROPOIESIS IN ISRAELI BEDOUINS WITH CONGENITAL DYSERYTHROPOIETIC ANEMIA TYPE-I

Congenital dyserythropoietic anemia (CDA) type I is a rare macrocytic anemia of unknown etiology. In the present study, we redefined the cli nical and laboratory picture of CDA type I, some of its pathogenic asp ects, and the association with thalassemia-like features in 20 patient s, all of whom belong to one Bedouin tribal group and are probably des cended from a common ancestor. In each case ultrastructural studies of bone marrow (BM) erythroblasts showed the classic morphological findi ngs of CDA type I. Serological tests for CDA type II were negative. Th e clinical picture was variable, but mostly benign. Some patients disp layed elevated hemoglobin A2 levels or a high ratio of alpha-to non-al pha globin. However, neither family studies nor complete sequence anal ysis of the beta-globin was compatible with beta-thalassemia. Increase d erythropoiesis was manifested by a high number of BM erythroid burst -forming units. Serum erythropoietin was also elevated. BM Row cytomet ry studies demonstrated arrest of erythroid precursors in the S phase of the cell cycle. The ultrastructural morphological features of the e rythroid precursors, showing peripheral chromatin condensation, sugges t apoptosis. Additional studies are indicated to define the molecular basis of this disease. (C) 1996 by The American Society of Hematology.