CONGENITAL DYSERYTHROPOIESIS CHARACTERIZED BY MARKED MACROCYTOSIS, VITAMIN B-12-INDEPENDENT AND FOLATE-INDEPENDENT MEGALOBLASTIC CHANGE ANDABSENCE OF THE DEFINING FEATURES OF CONGENITAL DYSERYTHROPOIETIC ANEMIA TYPE-I OR TYPE-III

Four patients with congenital dyserythropoiesis characterized by marke d macrocytosis, little or no anaemia, and vitamin B-12- and folate-ind ependent megaloblastic erythropoiesis are reported. Their erythroblast s also showed various dysplastic changes but not those diagnostic for congenital dyserythropoietic anaemia (CDA) types I or III. The haemato logical features of the four patients, who included two siblings, rese mble those of a previously reported patient and together these patient s form a recognizable subgroup within those cases of CDA not belonging to CDA types I-III. In two of the cases studied, and possibly a third , the inheritance was as an autosomal recessive character.