-
Blood Sep 2020Diamond-Blackfan anemia (DBA) was the first ribosomopathy described and is a constitutional inherited bone marrow failure syndrome. Erythroblastopenia is the major... (Review)
Review
Diamond-Blackfan anemia (DBA) was the first ribosomopathy described and is a constitutional inherited bone marrow failure syndrome. Erythroblastopenia is the major characteristic of the disease, which is a model for ribosomal diseases, related to a heterozygous allelic variation in 1 of the 20 ribosomal protein genes of either the small or large ribosomal subunit. The salient feature of classical DBA is a defect in ribosomal RNA maturation that generates nucleolar stress, leading to stabilization of p53 and activation of its targets, resulting in cell-cycle arrest and apoptosis. Although activation of p53 may not explain all aspects of DBA erythroid tropism, involvement of GATA1/HSP70 and globin/heme imbalance, with an excess of the toxic free heme leading to reactive oxygen species production, account for defective erythropoiesis in DBA. Despite significant progress in defining the molecular basis of DBA and increased understanding of the mechanistic basis for DBA pathophysiology, progress in developing new therapeutic options has been limited. However, recent advances in gene therapy, better outcomes with stem cell transplantation, and discoveries of putative new drugs through systematic drug screening using large chemical libraries provide hope for improvement.
Topics: Abnormalities, Multiple; Adenosine Deaminase; Anemia, Diamond-Blackfan; Child, Preschool; Congenital Abnormalities; Diagnosis, Differential; Disease Management; Drug Resistance; Erythrocytes; Fetal Growth Retardation; GATA1 Transcription Factor; Genetic Heterogeneity; Genetic Therapy; Glucocorticoids; HSP70 Heat-Shock Proteins; Hematopoietic Stem Cell Transplantation; Humans; Infant; Infant, Newborn; Intercellular Signaling Peptides and Proteins; Models, Biological; Mutation; Neoplastic Syndromes, Hereditary; Ribosomal Proteins; Tumor Suppressor Protein p53
PubMed: 32702755
DOI: 10.1182/blood.2019000947 -
Blood Nov 2016Pure red cell aplasia (PRCA) is a syndrome defined by a normocytic normochromic anemia with severe reticulocytopenia and marked reduction or absence of erythroid... (Review)
Review
Pure red cell aplasia (PRCA) is a syndrome defined by a normocytic normochromic anemia with severe reticulocytopenia and marked reduction or absence of erythroid precursors from the bone marrow. Diamond-Blackfan anemia is a congenital form of PRCA. Acquired PRCA may be either a primary disorder or secondary to some other disorder or agent. Primary acquired PRCA is an autoimmune disorder that is frequently antibody-mediated. Myelodysplastic syndromes may also present with the morphologic appearance of PRCA. Secondary acquired PRCA may be associated with collagen vascular/autoimmune disorders such as systemic lupus erythematosus; lymphoproliferative disorders such as chronic lymphocytic leukemia or large granular lymphocyte leukemia; infections, particularly B19 parvovirus; thymoma and other solid tumors; or a variety of other disorders, drugs, or toxic agents. The therapeutic approach to PRCA typically involves immunosuppression, but specific pathogenic subtypes are associated with specific therapeutic approaches. Cyclosporine A, with or without concurrent corticosteroids, appears to be the single most effective immunosuppressive agent.
Topics: Anemia, Diamond-Blackfan; Autoimmune Diseases; Erythema Infectiosum; Humans; Leukemia, Large Granular Lymphocytic; Leukemia, Lymphocytic, Chronic, B-Cell; Lupus Erythematosus, Systemic; Myelodysplastic Syndromes; Parvovirus B19, Human
PubMed: 27881371
DOI: 10.1182/blood-2016-05-717140 -
Hematology. American Society of... Dec 2021Diamond-Blackfan anemia (DBA) is an inherited bone marrow failure syndrome, characterized as a rare congenital bone marrow erythroid hypoplasia (OMIM#105650). Erythroid...
Diamond-Blackfan anemia (DBA) is an inherited bone marrow failure syndrome, characterized as a rare congenital bone marrow erythroid hypoplasia (OMIM#105650). Erythroid defect in DBA results in erythroblastopenia in bone marrow as a consequence of maturation blockade between the burst forming unit-erythroid and colony forming unit-erythroid developmental stages, leading to moderate to severe usually macrocytic aregenerative (<20 × 109/L of reticulocytes) anemia. Congenital malformations localized mostly in the cephalic area and in the extremities (thumbs), as well as short stature and cardiac and urogenital tract abnormalities, are a feature of 50% of the DBA-affected patients. A significant increased risk for malignancy has been reported. DBA is due to a defect in the ribosomal RNA (rRNA) maturation as a consequence of a heterozygous mutation in 1 of the 20 ribosomal protein genes. Besides classical DBA, some DBA-like diseases have been identified. The relation between the defect in rRNA maturation and the erythroid defect in DBA has yet to be fully defined. However, recent studies have identified a role for GATA1 either due to a specific defect in its translation or due to its defective regulation by its chaperone HSP70. In addition, excess free heme-induced reactive oxygen species and apoptosis have been implicated in the DBA erythroid phenotype. Current treatment options are either regular transfusions with appropriate iron chelation or treatment with corticosteroids starting at 1 year of age. The only curative treatment for the anemia of DBA to date is bone marrow transplantation. Use of gene therapy as a therapeutic strategy is currently being explored.
Topics: Adult; Anemia, Diamond-Blackfan; Bone Marrow; Bone Marrow Transplantation; Child, Preschool; Disease Management; Female; Humans; Infant; Male; Mutation; Ribosomal Proteins
PubMed: 34889440
DOI: 10.1182/hematology.2021000314 -
Hematology. American Society of... Dec 2022In this review, we present a clinical case report and discussion to outline the importance of long-term specific Fanconi anemia (FA) monitoring, and we discuss the main... (Review)
Review
In this review, we present a clinical case report and discussion to outline the importance of long-term specific Fanconi anemia (FA) monitoring, and we discuss the main aspects of the general management of patients with FA and clinical complications. While several nontransplant treatments are currently under evaluation, hematopoietic stem cell transplantation (HSCT) remains the only therapeutic option for bone marrow failure (BMF). Although HSCT outcomes in patients with FA have remarkably improved over the past 20 years, in addition to the mortality intrinsic to the procedure, HSCT increases the risk and accelerates the appearance of late malignancies. HSCT offers the best outcome when performed in optimal conditions (moderate cytopenia shifting to severe, prior to transfusion dependence and before clonal evolution or myelodysplasia/acute myeloid leukemia); hence, an accurate surveillance program is vital. Haploidentical HSCT offers very good outcomes, although long-term effects on malignancies have not been fully explored. A monitoring plan is also important to identify cancers, particularly head and neck carcinomas, in very early phases. Gene therapy is still experimental and offers the most encouraging results when performed in early phases of BMF by infusing high numbers of corrected cells without genotoxic effects. Patients with FA need comprehensive monitoring and care plans, coordinated by centers with expertise in FA management, that start at diagnosis and continue throughout life. Such long-term follow-up is essential to detect complications related to the disease or treatment in this setting.
Topics: Humans; Fanconi Anemia; Hematopoietic Stem Cell Transplantation; Myelodysplastic Syndromes; Leukemia, Myeloid, Acute
PubMed: 36485157
DOI: 10.1182/hematology.2022000393 -
American Journal of Human Genetics Dec 2018Diamond-Blackfan anemia (DBA) is a rare bone marrow failure disorder that affects 7 out of 1,000,000 live births and has been associated with mutations in components of...
Diamond-Blackfan anemia (DBA) is a rare bone marrow failure disorder that affects 7 out of 1,000,000 live births and has been associated with mutations in components of the ribosome. In order to characterize the genetic landscape of this heterogeneous disorder, we recruited a cohort of 472 individuals with a clinical diagnosis of DBA and performed whole-exome sequencing (WES). We identified relevant rare and predicted damaging mutations for 78% of individuals. The majority of mutations were singletons, absent from population databases, predicted to cause loss of function, and located in 1 of 19 previously reported ribosomal protein (RP)-encoding genes. Using exon coverage estimates, we identified and validated 31 deletions in RP genes. We also observed an enrichment for extended splice site mutations and validated their diverse effects using RNA sequencing in cell lines obtained from individuals with DBA. Leveraging the size of our cohort, we observed robust genotype-phenotype associations with congenital abnormalities and treatment outcomes. We further identified rare mutations in seven previously unreported RP genes that may cause DBA, as well as several distinct disorders that appear to phenocopy DBA, including nine individuals with biallelic CECR1 mutations that result in deficiency of ADA2. However, no new genes were identified at exome-wide significance, suggesting that there are no unidentified genes containing mutations readily identified by WES that explain >5% of DBA-affected case subjects. Overall, this report should inform not only clinical practice for DBA-affected individuals, but also the design and analysis of rare variant studies for heterogeneous Mendelian disorders.
Topics: Adolescent; Anemia, Diamond-Blackfan; Child; Child, Preschool; Cohort Studies; Exome; Exons; Female; Gene Deletion; Genetic Association Studies; Humans; Intercellular Signaling Peptides and Proteins; Male; Mutation; Phenotype; Ribosomal Proteins; Ribosomes; Sequence Analysis, RNA; Exome Sequencing
PubMed: 30503522
DOI: 10.1016/j.ajhg.2018.10.027 -
Blood Aug 2023Systematic studies of germ line genetic predisposition to myeloid neoplasms in adult patients are still limited. In this work, we performed germ line and somatic...
Systematic studies of germ line genetic predisposition to myeloid neoplasms in adult patients are still limited. In this work, we performed germ line and somatic targeted sequencing in a cohort of adult patients with hypoplastic bone marrow (BM) to study germ line predisposition variants and their clinical correlates. The study population included 402 consecutive adult patients investigated for unexplained cytopenia and reduced age-adjusted BM cellularity. Germ line mutation analysis was performed using a panel of 60 genes, and variants were interpreted per the American College of Medical Genetics and Genomics/Association for Molecular Pathology guidelines; somatic mutation analysis was performed using a panel of 54 genes. Of the 402 patients, 27 (6.7%) carried germ line variants that caused a predisposition syndrome/disorder. The most frequent disorders were DDX41-associated predisposition, Fanconi anemia, GATA2-deficiency syndrome, severe congenital neutropenia, RASopathy, and Diamond-Blackfan anemia. Eighteen of 27 patients (67%) with causative germ line genotype were diagnosed with myeloid neoplasm, and the remaining with cytopenia of undetermined significance. Patients with a predisposition syndrome/disorder were younger than the remaining patients and had a higher risk of severe or multiple cytopenias and advanced myeloid malignancy. In patients with myeloid neoplasm, causative germ line mutations were associated with increased risk of progression into acute myeloid leukemia. Family or personal history of cancer did not show significant association with a predisposition syndrome/disorder. The findings of this study unveil the spectrum, clinical expressivity, and prevalence of germ line predisposition mutations in an unselected cohort of adult patients with cytopenia and hypoplastic BM.
Topics: Humans; Leukemia, Myeloid; Genetic Predisposition to Disease; Clonal Hematopoiesis; Male; Female; Middle Aged; Anemia, Aplastic; Penetrance; Germ Cells; DNA Mutational Analysis
PubMed: 37216690
DOI: 10.1182/blood.2022019304 -
Developmental Cell Mar 2015CRISPR/Cas9 technology of genome editing has greatly facilitated the targeted inactivation of genes in vitro and in vivo in a wide range of organisms. In zebrafish, it...
CRISPR/Cas9 technology of genome editing has greatly facilitated the targeted inactivation of genes in vitro and in vivo in a wide range of organisms. In zebrafish, it allows the rapid generation of knockout lines by simply injecting a guide RNA (gRNA) and Cas9 mRNA into one-cell stage embryos. Here, we report a simple and scalable CRISPR-based vector system for tissue-specific gene inactivation in zebrafish. As proof of principle, we used our vector with the gata1 promoter driving Cas9 expression to silence the urod gene, implicated in heme biosynthesis, specifically in the erythrocytic lineage. Urod targeting yielded red fluorescent erythrocytes in zebrafish embryos, recapitulating the phenotype observed in the yquem mutant. While F0 embryos displayed mosaic gene disruption, the phenotype appeared very penetrant in stable F1 fish. This vector system constitutes a unique tool to spatially control gene knockout and greatly broadens the scope of loss-of-function studies in zebrafish.
Topics: Anemia, Diamond-Blackfan; Animals; Clustered Regularly Interspaced Short Palindromic Repeats; Disease Models, Animal; Erythrocytes; Gene Knockout Techniques; Genetic Engineering; Genetic Vectors; Luminescent Proteins; Promoter Regions, Genetic; Tumor Suppressor Protein p53; Zebrafish; Zebrafish Proteins; Red Fluorescent Protein
PubMed: 25752963
DOI: 10.1016/j.devcel.2015.01.032 -
International Journal of Molecular... Aug 2017Investigators have dedicated considerable effort to understanding the molecular basis underlying Fanconi Anemia (FA), a rare human genetic disease featuring an extremely... (Review)
Review
Investigators have dedicated considerable effort to understanding the molecular basis underlying Fanconi Anemia (FA), a rare human genetic disease featuring an extremely high incidence of cancer and many congenital defects. Among those studies, FA group D2 protein (FANCD2) has emerged as the focal point of FA signaling and plays crucial roles in multiple aspects of cellular life, especially in the cellular responses to DNA damage. Here, we discuss the recent and relevant studies to provide an updated review on the roles of FANCD2 in the DNA damage response.
Topics: DNA Damage; DNA Repair; Fanconi Anemia; Fanconi Anemia Complementation Group D2 Protein; Humans; Signal Transduction
PubMed: 28825622
DOI: 10.3390/ijms18081804 -
Trends in Genetics : TIG Mar 2018In 1927 Guido Fanconi described a hereditary condition presenting panmyelopathy accompanied by short stature and hyperpigmentation, now better known as Fanconi anemia... (Review)
Review
In 1927 Guido Fanconi described a hereditary condition presenting panmyelopathy accompanied by short stature and hyperpigmentation, now better known as Fanconi anemia (FA). With this discovery the genetic and molecular basis underlying FA has emerged as a field of great interest. FA signaling is crucial in the DNA damage response (DDR) to mediate the repair of damaged DNA. This has attracted a diverse range of investigators, especially those interested in aging and cancer. However, recent evidence suggests FA signaling also regulates functions outside the DDR, with implications for many other frontiers of research. We discuss here the characteristics of FA functions and expand upon current perspectives regarding the genetics of FA, indicating that FA plays a role in a myriad of molecular and cellular processes.
Topics: DNA Damage; DNA Repair; Fanconi Anemia; Fanconi Anemia Complementation Group Proteins; Humans; Models, Genetic; Mutation; Signal Transduction
PubMed: 29254745
DOI: 10.1016/j.tig.2017.11.006 -
Tidsskrift For Den Norske Laegeforening... Mar 2024Anemia in children is common and finding the underlying cause is often uncomplicated. However, in some cases, the underlying diagnosis is rare and difficult to diagnose.
BACKGROUND
Anemia in children is common and finding the underlying cause is often uncomplicated. However, in some cases, the underlying diagnosis is rare and difficult to diagnose.
CASE PRESENTATION
A toddler presented with severe anemia with normal red cell indices and a low reticulocyte count. The remaining hematological parameters were normal, bar a slight thrombocytosis. At this point a diagnosis of transient erythroblastopenia of childhood (TEC) was made. The child continued to have slight anemia with intermittent macrocytosis and reticulocytopenia throughout childhood. Growth and development was normal, and there were no signs of congenital abnormalities in the heart or kidneys nor any craniofacial or phalangeal defects. Repeated bone marrow examinations showed no significant abnormal findings. As a teenager the patient was diagnosed with Diamond-Blackfan anemia through an exome-based gene panel which revealed a mutation in the RPL11 gene.
INTERPRETATION
Congenital bone marrow failure syndromes do not always present in the classical way, leading to a delayed diagnosis. The increasing availability of different gene panels for patients with persistent abnormal hematological laboratory parameters offers the possibility of a more accurate diagnostic pathway, which is important for adequate follow-up and genetic counselling.
Topics: Adolescent; Humans; Anemia; Anemia, Diamond-Blackfan; Anemia, Hemolytic, Congenital; Mutation
PubMed: 38506013
DOI: 10.4045/tidsskr.23.0415