[Positive acid serum test and elevated agglutinability by Anti-i in patients with congenital dyserythropoietic anemia]

Congenital dyserythropoietic anemia type II (CDAII/HEMPAS): where are we now?

Congenital diserythropoietic anemias (CDA) were classified according to bone marrow changes and biochemical features 40 years ago. A consistent finding in CDA type II, the most frequent subgroup of CDAs is a relevant hypoglycosylation of erythrocyte membrane proteins. It is a matter of debate if the hypoglycosylation is the primary cause of the disorder or a phenomenon secondary to other pathomechanisms. The molecular cause of the disorder is still unknown although some enzyme deficiencies have been proposed to cause CDA II in the last 2 decades and a linkage analysis locating the CDA II gene in a 5 cM region on chromosome 20 was done in 1997. In this review biochemical and genetic data are discussed and diagnostic methods based on biochemical observations of the recent years are reviewed.

Congenital dyserythropoietic anemia type II: epidemiology, clinical appearance, and prognosis based on long-term observation

Congenital dyserythropoietic anemia type II (CDA II) is the most frequent type of congenital dyserythropoietic anemia. More than 200 cases have been described, but with the exception of a report by the International CDA II Registry, these reports include only small numbers of cases and no data on the lifetime evolution of the disease. Since 1967, we were able to follow 48 cases of CDA II from 43 families for up to 35 years. All patients exhibit chronic anemia of variable severity requiring regular red cell transfusions only in a minority of children; 60% developed gallstones before the age of 30 years, and 16 patients had cholecystectomy between 8 and 34 years of age. Iron overload was a frequent complication. In 16 cases, iron depletion started between 7 and 36 years. Three patients died from secondary hemochromatosis. Splenectomy, performed in 22 cases, led to moderate increases in hemoglobin values and eliminated the need for transfusions but did not prevent further iron loading. The current recommendation is to consider splenectomy if the anemia compromises patients' performance, and to manage iron overload according to the guidelines derived from patients with thalassemia.

Congenital dyserythropoietic anaemia, types I and II: aberrant pattern of erythrocyte membrane proteins in CDA II, as revealed by two-dimensional polyacrylamide gel electrophoresis

The protein composition of the erythrocyte membrane of two patients with CDA I and four patients with CDA II has been investigated by two-dimensional polyacrylamide gel electrophoresis. The two-dimensional patterns of erythrocyte membrane proteins of the patients with CDA were compared with the well-established pattern of normal individuals. No alterations could be detected in the patients with CDA I, but a striking deviation from normal was observed in all patients with CDA II. The major aberrations of the erythrocyte membrane proteins in CDA II are the lack of protein B1.1, the drastically increased concentration of protein B1.4 and the presence of a new component, C2'. These results are discussed in relation to the known morphological and immunological abnormalities of the erythrocyte membrane in CDA II.