Congenital pure red cell aplasia, also known as Diamond-Blackfan anemia (DBA), is a hereditary disease characterized by pure red cell aplasia and congenital malformation. Its main clinical features are anemia, dysplasia, and tumor susceptibility. Ribosomal protein (RP) gene mutation is the main pathogenesis of DBA. The most common type of gene mutation is RPS19 gene mutation. Heterozygous mutations in as many as 19 RP genes and other non-RP genes mutations have been identified in DBA. This review summarized briedfly the latest research advances in the pathogenesis of DBA.
Anemia, Diamond-Blackfan ; Humans ; Mutation ; Ribosomes

OBJECTIVETo investigate the clinical features of Diamond-Blackfan anemia (DBA) and related pathogenic genes.

METHODSA retrospective analysis was performed for the clinical data of two children with DBA, and related literature was reviewed.

RESULTSThe two children with DBA (2-3 months old) manifested with severe normochromic normocytic anemia, decreased reticulocyte count, and increased serum iron and serum ferritin. Normal white blood cell and platelet counts were noted in the two patients. Bone marrow examination showed a decreased percentage of erythrocytes and rare normoblasts in the two patients. Gene screening showed a reported pathogenic heterozygous mutation in RPS19 gene, c.212G>A (p. Gly71Glu), in one patient, and there were no mutations in his parents. In the other patient, gene screening showed a heterozygous mutation in RPL5 gene, c.740T>C (p. I247L), which had not been reported in literature, and there were no mutations in her parents. A bioinformatic analysis showed that this might be a pathogenic mutation.

CONCLUSIONSThe onset age of DBA is early infancy in most children, with a manifestation of erythroid deficiency. RPS19 and RPL5 gene mutations are common causes of this disease. Molecular detection helps with the early diagnosis of DBA.

Iron overload from repeated blood transfusions in patients with hematologic problems is a problem of clinical significance, because eventually it can lead to secondary hemochromatosis with diabetes. So it is important to diagnose iron overload early and to restrict blood transfusions in these patients. Recently, we experienced one case of secondary hemochromatosis with diabetes in patient wi th congenital pure red cell anemia, diagnosed by serum ferritin level, TIBC, transferrin saturation, random blood sugar, C-peptide and insulin level. This patient had received 30,000ml of RBCs for 9 years. Treatments with insulin mixed spitting therapy because of insulin dependent diabetes clinically, restriction of blood transfusion and steroid therapy for maintenance of Hemoglobin level were done just after discharge. We report this one case with a brief review of the literature.
Anemia, Diamond-Blackfan ; Blood Glucose ; Blood Transfusion ; C-Peptide ; Diabetes Mellitus* ; Ferritins ; Hemochromatosis* ; Humans ; Insulin ; Iron Overload ; Transferrin

This study was aimed to explore the mutations of ribosomal protein (RP) genes in patients with Diamond Blackfan anemia (DBA). Twenty-one cases of DBA admitted in our hospital from Dec 2008 to Aug 2012 were screened by PCR for mutations in the nine known genes associated with DBA: RPS19, RPS24, RPS17, RPL5, RPL11, RPS7, RPL35a, RPS10 and RPS26. The results found that 8 patients (38.1%) with DBA had mutations in the genes coding for ribosomal protein, in which RPS19 mutation was identified in 3 patients, RPS24, RPS7, RPL5, RPL11 and RPL35A mutations were identified respectively in 1 of the patient. No mutations were detected in RPS17, RPS10 or RPS26 genes. Thumb anomalies were found in 2 patients with RPL11 or RPL5 mutation, and hypospadias was found in 1 patient with RPS19 mutation. It is concluded that the mutation frequency of the genes coding for ribosomal protein in the patients with DBA here is lower than that in western countries. The hypospadias can be observed in some patients with RPS19 mutation and some dactyl anomalies are associated with RPL11 and RPL5 mutations.
Anemia, Diamond-Blackfan ; genetics ; DNA Mutational Analysis ; Female ; Humans ; Infant ; Infant, Newborn ; Male ; Mutation ; Ribosomal Proteins ; genetics

In order to explore the diagnosis and therapy of Diamond Blackfan anemia (DBA), the clinical data of 45 cases of DBA admitted in our hospital from February 1994 to July 2011 were analyzed retrospectively. The clinical characteristics, results of laboratory examination, treatment reaction and outcome of disease were investigated. The results indicated that out of 45 children diagnosed as DBA, 14 cases (31.1%) had short stature and physical malformation. All patients had anemia with reticulocytopenia. Thirty-four patients (75.6%) had mean corpuscular volume. Eleven patients (24.4%) had macrocytic anemia. Bone marrow examination showed a marked erythroid hypoplasia in all patients. Out of 29 cases tested for fetal hemoglobin (HbF), 13 cases (44.8%) had high level of HbF. Erythroid colony-forming unit of bone marrow was tested in 25 patients, among them 12 patients (48%) showed normal plasia, 13 (52%) showed hypoplasia. The erythropoietin (EPO) levels of 17 patients were elevated. Karyotypes were examined in 28 patients, and showed all normal. The treatment was based on corticosteroids and Cyclosporine A. Thirty patients had good response to corticosteroid therapy, and 10 of them obtained a sustained corticosteroid-induced remission. Twenty cases discontinued corticosteroid therapy after remission, as a result, 15 cases (75%) relapsed, moreover all the relapsed cases still had good response to corticosteroid. Two relapsed patients suffered from aplastic anemia, one of them died of therapy failure. Six patients were unresponsive to corticosteroid, 1 of which achieved remission with cyclosporine A and the others continued to receive regular transfusions. 3 patients received iron chelation therapy. It is concluded that the clinical characteristics, complete blood count, bone marrow smear, HbF level and EPO level are useful to make a diagnosis of DBA. Most patients have a good response to corticosteroid therapy, but relapse rate is high when drug was discontinued. Patients unresponsive to corticosteroid should receive regular transfusions and chelation therapy.
Anemia, Diamond-Blackfan ; diagnosis ; therapy ; Bone Marrow Examination ; Child ; Child, Preschool ; Erythroid Precursor Cells ; Female ; Humans ; Infant ; Male ; Retrospective Studies

PURPOSE: Paroxysmal nocturnal hemoglobinuria (PNH) has been known to be a late clonal complication of aplastic anemia (AA). Flow cytometric analysis using CD55 and CD59 antibodies became the gold standard of diagnosing PNH, replacing a traditional, less sensitive Ham's test, as the pathophysiologic mechanism was identified as the deficiency of glycophosphatidyl-inositol anchored protein. Although the incidence of AA seems to be higher in Korea than that of other Western countries, the study of PNH in Korean pediatric AA has never been accomplished. We studied the frequency of PNH in AA, and tried to compare the characteristics of them with those from other countries. METHODS: Twenty-two pediatric AA patients were enrolled for the study. As a control, 5 patients with inherited bone marrow failure syndromes (Fanconi anemia, 1; Diamond-Blackfan anemia, 3; dyskeratosis congenita, 1) and 11 normal children were pooled. For the flow cytometry, 10muL each of CD55-PE and CD59-FITC was mixed with 50muL of whole blood and incubated for 15 min. Red cells were lysed with Q-prep apparatus (Coulter, Fullerton, USA). Beckman Coulter XL flow cytometer was used for the analyses. RESULTS: The median age for the patients was 14 years (range, 2~21). CD55- and CD59-negative cells from controls were 0.13+/-0.18%. Cut-off value for the diagnosis for PNH was designated as > 0.49%, which was mean +2 S.D. of controls. All the patients showed CD55- and CD59-negative PNH cell proportions within the normal ranges, except for a 19-year-old boy who was still cyclosporine-dependent after initial response to immunosuppressive therapy 4 years before. He had 4.79% of CD55- and CD59-negative PNH population. CONCLUSION: The frequency of PNH clones in Korean children with AA was low (1/22=4.5%). This might reflect the relatively low association of PNH in childhood AA, the limitation caused by small numbers of the study population, or true ethnic differences. A further study incorporating more patients seems to be warranted.
Anemia ; Anemia, Aplastic* ; Anemia, Diamond-Blackfan ; Antibodies ; Bone Marrow ; Child ; Clone Cells ; Diagnosis ; Dyskeratosis Congenita ; Flow Cytometry* ; Hemoglobinuria, Paroxysmal* ; Humans ; Incidence ; Korea ; Male ; Reference Values ; Young Adult

PURPOSE: The primary purpose of this study was to evaluate the growth and neuropsychologic function following treatments for pediatric hematologic and oncologic diseases. Healthy monozygotic twins served as ideal controls for comparison to exclude possible confounding factors. METHODS: Seven children treated with various hematologic and oncologic diseases were included in the study: acute lymphoblastic leukemia (ALL; n=2), Diamond-Blackfan anemia twins (n=2), and aplastic anemia (n=3). The median age at the diagnosis was 5.2 (0.3-15) years. The median duration of follow-up was 7.2 (4.9-10) years. Controls were healthy monozygotic twins. Growth was measured and the percentile channels were evaluated sequentially for patients. The K-WISC III was applied and compared in 5 pairs of patients and controls. RESULTS: Similar growth profiles were noted for the twins. The percentiles at diagnosis was 3-10 in 3, 25-50 in 2, and 50-75 in 2 cases. All patients stayed in their growth percentiles through follow-up, except for 1 patient who became obese. For IQ tests, the mean behavioral, verbal and full scale IQ scores of patients were 88.0, 93.8, and 89.8, respectively, and those from their corresponding controls were 92.2, 97.0, and 91.7 (P>0.05). However, 2 children who were treated for ALL had lower IQ scores. CONCLUSION: Similar growth profiles were observed in the monozygotic twins in terms of height and weight. The IQ scores of patients were similar to those of monozygotic twins. However, prophylactic CNS-directed therapy for leukemia might adversely affect the IQ scores. A further prospective study on larger number of twins is warranted.
Anemia, Aplastic ; Anemia, Diamond-Blackfan ; Child ; Diagnosis ; Follow-Up Studies ; Humans ; Leukemia ; Precursor Cell Lymphoblastic Leukemia-Lymphoma ; Stem Cell Transplantation ; Twins, Monozygotic*

BACKGROUND: Diamond Blackfan anemia (DBA), characterized by impaired red cell production, is a rare condition that is usually symptomatic in early infancy. The purpose of this study was to assess nationwide experiences of DBA encountered over a period of 20 years. METHODS: The medical records of 56 patients diagnosed with DBA were retrospectively reviewed from November 1984 to July 2010. Fifteen institutions, including 13 university hospitals, participated in this study. RESULTS: The male-to-female ratio of patients with DBA was 1.67:1. The median age of diagnosis was 4 months, and 74.1% were diagnosed before 1 year of age. From 2000 to 2009, annual incidence was 6.6 cases per million. Excluding growth retardation, 38.2% showed congenital defects: thumb deformities, ptosis, coarctation of aorta, ventricular septal defect, strabismus, etc. The mean hemoglobin concentration was 5.1+/-1.9 g/dL, mean corpuscular volume was 93.4+/-11.6 fL, and mean number of reticulocytes was 19,700/mm3. The mean cellularity of bone marrow was 75%, with myeloid:erythroid ratio of 20.4:1. After remission, 48.9% of patients did not need further steroids. Five patients with DBA who received hematopoietic transplantation have survived. Cancer developed in 2 cases (3.6%). CONCLUSION: The incidence of DBA is similar to data already published, but our study had a male predilection. Although all patients responded to initial treatment with steroids, about half needed further steroids after remission. It is necessary to collect further data, including information regarding management pathways, from nationwide DBA registries, along with data on molecular analyses.
Anemia ; Anemia, Diamond-Blackfan ; Aortic Coarctation ; Bone Marrow ; Congenital Abnormalities ; Diamond ; Erythrocyte Indices ; Heart Septal Defects, Ventricular ; Hemoglobins ; Hospitals, University ; Humans ; Incidence ; Korea ; Male ; Medical Records ; Registries ; Reticulocytes ; Retrospective Studies ; Steroids ; Strabismus ; Thumb ; Transplants

Diamond-Blackfan anemia (DBA) is a congenital bone marrow failure syndrome characterized by hypoproliferative anemia, associated physical malformations and a predisposition to cancer. DBA has been associated with mutations and deletions in the large and small ribosomal protein genes, and genetic aberrations have been detected in approximately50-60% of patients. In this study, nine Korean DBA patients were screened for mutations in eight known DBA genes (RPS19, RPS24, RPS17, RPS10, RPS26, RPL35A, RPL5 and RPL11) using the direct sequencing method. Mutations in RPS19, RPS26 and RPS17 were detected in four, two and one patient, respectively. Among the mutations detected in RPS19, two mutations were novel (c.26T>A, c.357-2A>G). For the mutation-negative cases, array-CGH analysis was performed to identify copy-number variations, and no deletions involving the known DBA gene regions were identified. The relative mRNA expression of RPS19 estimated using real-time quantitative PCR analysis revealed two- to fourfold reductions in RPS19 mRNA expression in three patients with RPS19 mutations, and p53 protein expression analysis by immunohistochemistry showed variable but significant nuclear staining in the DBA patients. In conclusion, heterozygous mutations in the known DBA genes RPS19, RPS26 and RPS17 were detected in seven out of nine Korean DBA patients. Among these patients, RPS19 was the most frequently mutated gene. In addition, decreased RPS19 mRNA expression and p53 overexpression were observed in the Korean DBA patients, which supports the hypothesis that haploinsufficiency and p53 hyperactivation represent a central pathway underlying the pathogenesis of DBA.
Anemia, Diamond-Blackfan/*genetics ; Female ; Gene Frequency ; Humans ; Infant, Newborn ; Male ; *Mutation ; RNA, Messenger/genetics/metabolism ; Republic of Korea ; Ribosomal Proteins/*genetics/metabolism ; Tumor Suppressor Protein p53/genetics/metabolism

We describe a girl with Diamond-Blackfan anemia with accompanying red cell enolase deficiency. At the age of 9 yr old, the patient received allogeneic bone marrow transplantation from her HLA-identical sister who had normal red cell enolase activity. While the post transplant DNA analysis with short tandem repeat has continuously demonstrated a stable mixed chimerism on follow-up, the patient remains transfusion independent and continues to show a steady increase in red cell enolase activity for over two and a half years following bone marrow transplantation.
*Anemia, Diamond-Blackfan/blood/enzymology/surgery ; Bone Marrow Cells/cytology/metabolism ; *Bone Marrow Transplantation ; Child ; Child, Preschool ; Erythrocytes/*enzymology ; Female ; Humans ; Infant ; Phosphopyruvate Hydratase/genetics/*metabolism ; *Transplantation, Homologous