Congenital dyserythropoietic anemia type II. Radioautographic, ultrastructural and cytogenetical study in two familial cases.

The case of two sisters is reported in whom morphological (multinucleated erythroblasts in the bone marrow) and serological (positive Ham test, negative sucrose and water-sugar tests) characteristics of a congenital dyserythropoietic anemia type II were found. Radioautographic, cytogenetic and electron microscope studies confirmed the presence of an inefficient erythropoiesis and of a membrane defect, common in this disease. The finding of a nil LAP score has never been reported so far.