Sustained cyclosporine-induced erythropoietic response in identical male twins with diamond-blackfan anemia

Pathogenic germline IKZF1 variant alters hematopoietic gene expression profiles

IKZF1 encodes Ikaros, a zinc finger–containing transcription factor crucial to the development of the hematopoietic system. Germline pathogenic variants in IKZF1 have been reported in patients with acute lymphocytic leukemia and immunodeficiency syndromes. Diamond–Blackfan anemia (DBA) is a rare inherited bone marrow failure syndrome characterized by erythroid hypoplasia, associated with a spectrum of congenital anomalies and an elevated risk of certain cancers. DBA is usually caused by heterozygous pathogenic variants in genes that function in ribosomal biogenesis; however, in many cases the genetic etiology is unknown. We identified a germline IKZF1 variant, rs757907717 C > T, in identical twins with DBA-like features and autoimmune gastrointestinal disease. rs757907717 C > T results in a p.R381C amino acid change in the IKZF1 Ik-x isoform (p.R423C on isoform Ik-1), which we show is associated with altered global gene expression and perturbation of transcriptional networks involved in hematopoietic system development. These data suggest that this missense substitution caused a DBA-like syndrome in this family because of alterations in hematopoiesis, including dysregulation of networks essential for normal erythropoiesis and the immune system.

Diamond-Blackfan anemia with mutation in RPS19: A case report and an overview of published pieces of literature

Introduction

Diamond-Blackfan anemia (DBA), one of a rare group of inherited bone marrow failure syndromes, is characterized by red cell failure, the presence of congenital anomalies, and cancer predisposition. It can be caused by mutations in the RPS19 gene (25% of the cases).

Methods

This case report describes a 10-month-old boy who presented with 2 months' history of gradually increasing weakness and pallor.

Results

The patient was diagnosed as a case of DBA based on peripheral blood finding, bone marrow aspiration with trephine biopsy reports, and genetic mutation analysis of the RPS19 gene. His father refused hematopoietic stem cell transplantation for financial constraints. Patient received prednisolone therapy with oral folic acid and iron supplements.

Conclusion

Hemoglobin raised from 6.7 to 9.8g/dL after 1 month of therapeutic intervention.

Clinical features, mutations and treatment of 104 patients of Diamond-Blackfan anemia in China: a single-center retrospective study

Diamond-Blackfan anemia (DBA) is an inherited bone marrow failure syndrome characterized by a paucity of erythroid progenitors. We summarized the clinical and genetic features of 104 DBA patients in a single-center retrospective study in China. Data of DBA patients who received consultations at our center from 2003 to 2015 were analyzed retrospectively. Genes encoding 10 ribosomal proteins (RPs) and GATA1 were sequenced for mutation detection. Our cohort was composed of 65 males and 39 females. Congenital malformations were observed in 19 patients. Mutations of the RP genes were detected in 58.3 % patients. Twenty different mutations were first reported. Thirty-four patients received prednisone combined with CsA therapy, and improvement was observed in 20 cases. During follow-up for a median 39 months, 33.7 % of the patients achieved remission, 41.3 % of the patients were persistently transfusion independent, 21.7 % of the patients were transfusion dependent, and three patients died. The patient group with detected mutations had a younger age of disease onset, a higher malformation rate, and tended to have a lower remission rate and a higher transfusion-dependence rate. Prednisone in combination with cyclosporine A can be a second-line choice for DBA patients. Differences were detected between DBA patients with and without detectable mutations in the genes studied.

Untangling the phenotypic heterogeneity of Diamond Blackfan anemia

Diamond Blackfan anemia (DBA) is a lineage-selective inherited bone marrow failure syndrome characterized primarily by anemia and physical malformations. Recent advances in identifying the genetic abnormalities underlying DBA have demonstrated involvement of genes encoding both large (RPL) and small (RPS) ribosomal subunit proteins, including mutations of RPL5, RPL11, RPL35A, RPS7, RPS10, RPS17, RPS19, RPS24, and RPS26 in 50% to 60% of affected patients. Despite significant progress, identification of gene abnormalities in the remaining patients remains an important question since present data suggest that mutations in other members of the ribosomal protein gene complement do not explain those cases without an identified genetic lesion in these genes. Genetic studies have also raised new questions with the recognition of substantial variability in the manifestations of DBA, ranging from ribosomal protein mutations in otherwise asymptomatic individuals to those with classic severe red blood cell aplasia with characteristic malformations, at times within the same kindred. In this review, we summarize the genetic basis of DBA and discuss mechanisms by which the phenotype of DBA might be modified.

Diamond Blackfan anemia treatment: past, present, and future

Despite significant improvements in our understanding of the pathophysiology of Diamond Blackfan anemia (DBA), there have been few advances in therapy. The cornerstones of treatment remain corticosteroids, chronic red blood cell transfusions, and hematopoietic stem cell transplantation, each of which is fraught with complications. In this article, we will review the history of therapies that have been offered to patients with DBA, summarize the current standard of care, including management of side effects, and discuss novel therapeutics that are being developed in the context of the research into the roles of ribosomal haplo-insufficiency and p53 activation in Diamond Blackfan anemia.

How I treat Diamond-Blackfan anemia

Diamond-Blackfan anemia (DBA) is characterized by red cell failure, the presence of congenital anomalies, and cancer predisposition. In addition to being an inherited bone marrow failure syndrome, DBA is also categorized as a ribosomopathy as, in more than 50% of cases, the syndrome appears to result from haploinsufficiency of either a small or large subunit-associated ribosomal protein. Nonetheless, the exact mechanism by which haploinsufficiency results in erythroid failure, as well as the other clinical manifestations, remains uncertain. New knowledge regarding genetic and molecular mechanisms combined with robust clinical data from several international patient registries has provided important insights into the diagnosis of DBA and may, in the future, provide new treatments as well. Diagnostic criteria have been expanded to include patients with little or no clinical findings. Patient management is therefore centered on accurate diagnosis, appropriate use of transfusions and iron chelation, corticosteroids, hematopoietic stem cell transplantation, and a coordinated multidisciplinary approach to these complex patients.

Diagnosing and treating Diamond Blackfan anaemia: results of an international clinical consensus conference

Diamond Blackfan anaemia (DBA) is a rare, genetically and clinically heterogeneous, inherited red cell aplasia. Classical DBA affects about seven per million live births and presents during the first year of life. However, as mutated genes have been discovered in DBA, non-classical cases with less distinct phenotypes are being described in adults as well as children. In caring for these patients it is often difficult to have a clear understanding of the treatment options and their outcomes because of the lack of complete information on the natural history of the disease. The purpose of this document is to review the criteria for diagnosis, evaluate the available treatment options, including corticosteroid and transfusion therapies and stem cell transplantation, and propose a plan for optimizing patient care. Congenital anomalies, mode of inheritance, cancer predisposition, and pregnancy in DBA are also reviewed. Evidence-based conclusions will be made when possible; however, as in many rare diseases, the data are often anecdotal and the recommendations are based upon the best judgment of experienced clinicians. The recommendations regarding the diagnosis and management described in this report are the result of deliberations and discussions at an international consensus conference.

Use of rituximab to treat refractory Diamond-Blackfan anemia

We report here the first case with Diamond-Blackfan anemia (DBA) who responded to rituximab. The patient is an 8-yr-old Japanese girl with refractory DBA accompanied by complex congenital heart disease. She received two doses of rituximab, 375 mg/m(2)/wk. She became transfusion independent 6 months after the treatment without any serious side effect. However, after 8 months of transfusion-free period, her condition returned to the pretreatment level with recovery of peripheral B cells. Rituximab may be a successful therapy for refractory DBA where B cells play a crucial role in the pathogenesis of the severe anemia.