Congenital dyserythropoietic anaemia with peculiar nuclear abnormality.

A patient with clinical and haematological findings compatible with congenital dyserythropoietic anaemia (CDA) most porbably type II is described. In contradistinction to previous observations, electron microscope examination of the erythroid cells in the bone marrow showed the concomitant appearance of nuclei at different maturation stages in a single cell. In addition, a marked tendency toward multinuclearity of the megakaryocytes was found. The mature erythroblasts showed an increased uptake of 3H-thymidine less than is normally found in these cells. Thes findings suggest an impairment in RNA and DNA synthesis.