IntroductionThe congenital dyserythropoietic anemias (CDAs) comprise a group of rare hereditary disorders of erythropoiesis, characterized by ineffective erythropoiesis as the predominant mechanism of anemia and by distinct morphologic abnormalities of the majority of erythroblasts in the bone marrow. The term was first used by Crookston et al 1 (for cases later classified as CDA II) and by Wendt and Heimpel 2 (for cases later classified as CDA I), but a few reports of similar cases had been published previously. 3 In 1968, we proposed classifying these disorders into 3 types. 3 Although initially proposed as a working classification, it was widely accepted and is still used today in clinical practice. 4,5 CDA II, also known as hereditary erythroblastic multinuclearity with a positive acidified-serum test (HEMPAS), 6 is the most frequently encountered disorder of the CDA group. 4,5,7,8 The leading morphologic abnormality is binuclearity or multinuclearity occurring in 10% to 50% of mature erythroblasts, with equal DNA content in both nuclei. 9 Electron microscopy (EM) shows a double membrane close to the cell membrane of mature erythroid cells, 10 which is due to residual endoplasmic reticulum. 11 Band 3 appears thinner and shows faster migration on sodium dodecyl sulfatepolyacrylamide gel electrophoresis (SDS-PAGE). 12 Red cells of patients with CDA II retain throughout life a very high agglutinability by anti-i sera. 6 The abnormalities of the CDA II red blood cell membrane are due to abnormal processing of N-glycans. 13 Band 3 and band 4.5 glycoproteins carry truncated polylactosamine structures, while glycolipids are sometimes overglycosylated. 14 An association to a gene locus on chromosome 20 (q11.2) was described in families from Southern Italy. 7,15 After our description of the first families in 1968, 3,16 we observed many more cases, mostly in residents of Germany, but also from Austria, Switzerland, and the Czech Republic, and we were able to follow some patients up to 35 years. Data from these patients as well as from case reports in the literature were collected in the German CDA registry, set up in 1993. Here we report epidemiologic data, clinical manifestations, and diagnostic features of 48 patients with CDA II. Particular emphasis is given to the course of the disease as a basis for management of these patients. Patients, materials, and methodsDiagnosis of CDA II was based on the criteria shown in Table 1. Data were extracted from files of the institutions and physicians responsible for patients' management from 1950 to 2002, in addition to the personal observations of one of the authors (H.H.) from the university hospitals of Freiburg and Ulm, Germany. Informed consent was obtained for additional blood samples taken for research objectives. A code identifying the family, the cases, and their relatives was assigned to each individual. Family trees were constructed by Cyrillic 2.1.2 (Cherwell Scientific Publishing, Oxford, United Kingdom). Data from 14 patients from 11 families had been published ...

Congenital dyserythropoietic anemia type I (CDA I) is a rare autosomal recessive disorder with ineffective erythropoiesis and iron overloading. More than 100 cases have been described, but with the exception of a report on a large Bedouin tribe, these reports include only small numbers of cases, and no data on the lifetime evolution of the disease are available.

The results do not provide evidence for using one intervention rather than the other. Clinical decisions should take into account patients' preferences. Randomized controlled trials of coercive interventions are feasible. Such studies contribute to the development of ethical and evidence-based guidelines.

Rapid identification of a matched unrelated donor is essential for patients in need of hematopoietic SCT. We carried out a retrospective evaluation of 549 unrelated donor searches (UDSs), which were completed in 2005 for 23 German transplant centers. On the basis of the patient's HLA-DRB1 allele and DRB1-DQB1 haplotype frequencies, UDSs were divided into four groups with different search success probability predictions. For 90.5% of the patients, an acceptable HLA-matched, and for 61.6% an HLA-A-B-Cw-DRB1-DQB1-identical (10/10 matched) unrelated donor was found. The median search duration was 22 days. In the groups with high (n ¼ 318), medium (n ¼ 157), low (n ¼ 56) and very low (n ¼ 18) UDS success probability, an acceptable donor was found for 99.1, 86.6, 75.0 and 22.2% of the patients, and a 10/10-matched donor was found for 78.3, 49.7, 17.9 and 4.5% of the patients, respectively. The median search duration was 20, 27, 45 and 477 days in the groups with high, medium, low and very low probability, respectively. The search success rate and duration can be predicted on the basis of the patient's HLA-DRB1 allele and HLA-DRB1-DQB1 haplotype frequencies. An unrelated donor can be found for most of the patients, even if the indication for transplantation is urgent.