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 11 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. (C) 2009 Elsevier B.V. All rights reserved.