Congenital dyserythropoietic anemias

[Hereditary spherocytosis: guidelines for the diagnosis and management in children]

Hereditary spherocytosis (HS) is the commonest inherited disorder of the erythrocyte membrane in Northern Europe and North America. It is marked by a regenerative anemia which varies widely from asymptomatic patients to severe hemolysis. In 75% of HS patients, inheritance is autosomal dominant. The diagnosis of HS is easily made when there are a family history, hemolytic anemia, reticulocytosis, spherocytes and increased hyperdense cells. Specialized testing to clarify the nature of membrane disorder is required when the film appearance is atypical without a positive family history, in the absence of a family history, in the newborn and before the splenectomy, to rule out the stomatocytosis which is contraindicated. The indication for splenectomy is dependent on the degree of anemia and its clinical manifestation.

Advances in the understanding of the congenital dyserythropoietic anaemias

The congenital dyserythropoietic anaemias (CDAs) are a heterogeneous group of diseases in which the anaemia is predominantly caused by dyserythropoiesis and marked ineffective erythropoiesis; three major (types I, II and III) and several minor subgroups have been identified. Additional information on the natural history of these conditions, the beneficial role of splenectomy in CDA type II and efficacy of interferon-alpha in type I have recently been reported. A disease gene has been localised to a chromosomal segment in the three major types and in CDA type I, a disease gene has been identified (CDANI). Mutations have been detected in both familial and sporadic cases but the predicted protein structure gives few clues as to its function. In both type I and II, there are cases unlinked to the identified localisations, suggesting genetic heterogeneity.