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.

Anemia, Diamond-Blackfan ; genetics ; Computational Biology ; Humans ; Infant ; Male ; Mutation ; Ribosomal Proteins ; genetics

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

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

OBJECTIVES: To investigate the distribution of body mass index (BMI) and risk factors for obesity in children with Diamond-Blackfan Anemia (DBA). METHODS: The children with DBA who attended National Clinical Research Center for Blood Diseases, Institute of Hematology & Blood Diseases Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, from January 2003 to December 2020 were enrolled as subjects. The related clinical data and treatment regimens were recorded. The height and weight data measured within 1 week before or after follow-up time points were collected to calculate BMI. The risk factors for obesity were determined by multivariate regression analysis in children with DBA. RESULTS: A total of 129 children with DBA were enrolled, among whom there were 80 boys (62.0%) and 49 girls (38.0%), with a median age of 49 months (range 3-189 months). The prevalence rate of obesity was 14.7% (19/129). The multivariate logistic regression analysis showed that the absence of ribosomal protein gene mutation was closely associated with obesity in children with DBA (adjusted OR=3.63, 95%CI: 1.16-11.38, adjusted P=0.027). In children with glucocorticoid-dependent DBA, obesity was not associated with age of initiation of glucocorticoid therapy, duration of glucocorticoid therapy, and maintenance dose of glucocorticoids (P>0.05). CONCLUSIONS There is a high prevalence rate of obesity in children with DBA, and the absence of ribosomal protein gene mutation is closely associated with obesity in children with DBA.
Child ; Male ; Female ; Humans ; Anemia, Diamond-Blackfan/genetics* ; Pediatric Obesity/complications* ; Glucocorticoids/therapeutic use* ; Prevalence ; Risk Factors ; Ribosomal Proteins/genetics* ; Mutation

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

Diamond-Blackfan anemia (DBA) is a rare congenital erythroid hypoplastic anemia that usually presents early in infancy and is inherited in up to 45% of cases. It is characterized by red cell aplasia, congenital anomalies, and a predisposition to cancer. Corticosteroids and red blood cell transfusions are the mainstays of therapy. We describe a case of 3-month-old infant who presented with severe anemia, elevated levels of HbF and adenosine deaminase and bilateral hydronephrosis, who was later confirmed as DBA by mutation analysis using the direct sequencing method. Direct sequencing analysis of RPS19 gene was performed with both cDNA and genomic DNA extracted from peripheral blood and a c.3G>A point mutation of exon 2 resulting in p.Met1Ile was identified in this patient. The patient showed an inadequate response to steroid therapy and a partial response to RBC transfusion with a follow-up Hb level of 8.3 g/dL on her last visit to the outpatient clinic. DBA is a genetically and phenotypically heterogeneous disease, and we have reviewed the clinical characteristics of 25 Korean patients thus far reported in the literature. To our knowledge, this is the first case of DBA confirmed by mutation analysis in Korea, and mutation identification using molecular method is recommended for confirmation of this genetically and phenotypically heterogeneous disease.
Anemia, Diamond-Blackfan/*diagnosis/genetics/therapy ; Asian Continental Ancestry Group/*genetics ; Bone Marrow/pathology ; Erythrocyte Transfusion ; Exons ; Humans ; Infant ; Point Mutation ; Republic of Korea ; Ribosomal Proteins/*genetics ; Sequence Analysis, DNA

OBJECTIVETo enrich our national database with data of rare diseases by analyzing molecular diagnosis and hematopoietic stem cell transplantation (HSCT) in children with inherited bone marrow failure syndromes (IBMFS).

METHODNext-generation sequencing (NGS)-based genetic diagnosis panel was applied for the clinical diagnosis and management of IBMFS. Retrospective analysis was performed on clinical and genetic data of 17 consecutive children who received HSCT over a long time interval (November. 2005-June 2015).

RESULTThree patients were diagnosed only by clinical manifestation before 2012. After that NGS-based genetic diagnosis panel was used to identify IBMFS-related genes in 12/14.IBMFS patients (except two Diamond-Blackfan anemia (DBA) patients). Two Fanconi anemia (FA) patients were confirmed to be new variations through family-genotype-analysis and 3 families accepted prenatal diagnosis to avoid birth of affected fetuses. Seventeen IBMFS patients (10 FA,5 DBA and 2 dyskeratosis congenital (DKC)) were treated with HSCT from matched sibling donors (n=2), matched unrelated donors (n=8) or mismatched unrelated donors (n=7). The source of stem cells for transplantation included peripheral blood (n=12) and cord blood (n=5). With regard to the conditioning regimens, FA and DKC patients received fludarabine-based reduced intensity conditioning, while DBA patients received classical busulfan-based myeloablative conditioning. Median age at the time of HSCT was 36 months (7-156 months). The number of infused mononuclear cells and CD34⁺ cells was (10.6 ± 6.7) × 10⁸ and (5.9 ± 7.0) × 10⁶ per kilogram of recipient body weight, respectively. The median number of days to neutrophil recovery was 13 days after HSCT (range: 10-19 days). Platelet recovery was faster in the PBSCT group than in the CBT group ((16.3 ± 6.0) days vs. (30.0 ± 17.1) days,t=-2.487,P=0.026). During a median follow-up of 17 months (range: 2-114 months), except one FA patient who was transplanted with HLA-matched unrelated cord blood (CB) died from pneumonia and heart failure because of engraftment failure, other 16 children are alive after the successful HSCT. The failure-free survival rate of the patients three years after HSCT was 94%.

CONCLUSIONNGS-based molecular diagnosis technology and effective HSCT have significantly facilitated the treatment of children with IBMFS in our country, and our national database about this rare disease is to be further exploited.

Anemia, Aplastic ; Anemia, Diamond-Blackfan ; therapy ; Bone Marrow Diseases ; Child ; Dyskeratosis Congenita ; therapy ; Fanconi Anemia ; therapy ; Fetal Blood ; Hematopoietic Stem Cell Transplantation ; Hemoglobinuria, Paroxysmal ; diagnosis ; genetics ; therapy ; Humans ; Retrospective Studies ; Siblings ; Survival Rate ; Transplantation Conditioning ; Unrelated Donors ; Vidarabine ; analogs & derivatives ; therapeutic use