Congenital dyserythropoiesis characterized by marked macrocytosis, vitamin B₁₂‐ and folate‐independent megaloblastic change and absence of the defining features of congenital dyserythropoietic anaemia types I or III

Abstract

Four patients with congenital dyserythropoiesis characterized by marked macrocytosis, little or no anaemia, and vitamin B12- and folate-independent megaloblastic erythropoiesis are reported. Their erythroblasts also showed various dysplastic changes but not those diagnostic for congenital dyserythropoietic anaemia (CDA) types I or III. The haematological features of the four patients, who included two siblings, resemble those of a previously reported patient and together these patients 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.

Evaluation of Macrocytic Anemias

“…44 In patients with the rare congenital dyserythropoietic anemia (CDA) Type I, macrocytosis is present, together with dysplastic changes in the erythroid precursors. 46 Patients with Diamond-Blackfan anemia may be macrocytic, and it is important to consider this diagnosis in anemic children with MCV above normal for age. 47 A more recently recognized cause of macrocytic anemia is copper deficiency.…”

Advances in the understanding of the congenital dyserythropoietic anaemias

“…This group is characterised by marked congenital macrocytosis (MCV 119–125 fl) with little or no anaemia, vitamin B 12 ‐ and folate‐independent grossly megaloblastic erythropoiesis and non‐specific dyserythropoietic changes (Wickramasinghe et al , 1996b). There may be mild jaundice and an increased plasma bilirubin.…”

Dyserythropoiesis and Congenital Dyserythropoietic Anaemias

“…Patients had little or no anaemia, marked macrocytosis (MCV 119-125 fl), florid megaloblastic erythropoiesis and non-specific dysplastic changes in erythroblasts. Serum B 12 and red cell folate levels are normal and the bone marrow cells give a normal deoxyuridine-suppressed value (Wickramasinghe et al, 1996a). Before diagnosing this type of CDA, other congenital disorders known to cause vitamin B 12 -and folate-independent macrocytosis such as orotic aciduria and thiamineresponsive anaemia must be excluded.…”