[Dyserythropoietic anemia, type I: ineffective erythropoiesis due to disorders in the DNA-nucleoprotein complex]

The relative DNA, RNA histone and hemoglobin contents and 3H-thymidine incorporation in vitro were determined sequentially in individual erythroblasts of type I dyserythropoietic anemia. The histone/DNA ratio was increased due to a rise in histone extinction, indicating a pathological DNA-nucleoprotein complex. In addition, the erythroblasts displayed an increase in DNA content exceeding tetraploid values, a loss of DNA-synthesis activity at immature stages with low hemoglobin content, and a reduction of RNA. These variations were assumed to be caused by the preceding and primary impairment of the DNA-nucleoprotein complex.