Clinical characteristics: Diamond-Blackfan anemia (DBA) in its classic form is characterized by a profound normochromic and usually macrocytic anemia with normal leukocytes and platelets, congenital malformations in up to 50% of affected individuals, and growth retardation in 30% of affected individuals. The hematologic complications occur in 90% of affected individuals during the first year of life. The phenotypic spectrum ranges from a mild form (e.g., mild anemia, no anemia with only subtle erythroid abnormalities, physical malformations without anemia) to a severe form of fetal anemia resulting in nonimmune hydrops fetalis. DBA is associated with an increased risk for acute myelogenous leukemia (AML), myelodysplastic syndrome (MDS), and solid tumors including osteogenic sarcoma.
Diagnosis/testing: The diagnosis is established in a proband when all four of the following diagnostic criteria are present: Other causes of bone marrow failure (e.g., Fanconi anemia, Pearson syndrome, dyskeratosis congenita, human immunodeficiency virus infection) need to be considered and ruled out as appropriate. DBA has been associated with pathogenic variants in 19 genes that encode ribosomal proteins and in GATA1 and TSR2. A pathogenic variant in one of these 21 genes is identified in approximately 65% of individuals with DBA.
Management: Treatment of manifestations: Corticosteroid treatment, recommended in children older than age 12 months, initially improves the red blood cell count in approximately 80% of affected individuals. Chronic transfusion with packed red blood cells is initially necessary while the diagnosis is made and in those not responsive to corticosteroids. Hematopoietic stem cell transplantation (HSCT), the only curative therapy for the hematologic manifestations of DBA, is often recommended for those who are transfusion dependent or develop other cytopenias. Treatment of malignancies should be coordinated by an oncologist. Chemotherapy must be given cautiously as it may lead to prolonged cytopenia and subsequent toxicities. Prevention of secondary complications: Transfusion-related iron overload is the most common complication in transfusion-dependent individuals. Iron chelation therapy with deferasirox orally or desferrioxamine subcutaneously is recommended after ten to 12 transfusions. Corticosteroid-related side effects must also be closely monitored, especially as related to risk for infection, growth retardation, and loss of bone density in growing children. Often individuals will be placed on transfusion therapy if these side effects are intolerable. Surveillance: Complete blood counts several times a year; bone marrow aspirate/biopsy periodically to evaluate morphology and cellularity in the event of another cytopenia or a change in response to treatment. In steroid-dependent individuals: monitor blood pressure and (in children) growth. Agents/circumstances to avoid: Deferiprone for the treatment of iron overload, which has led to severe neutropenia in a few individuals with DBA; infection (especially those on corticosteroids). Evaluation of relatives at risk: Molecular genetic testing of at-risk relatives of a proband with a known pathogenic variant allows for early diagnosis and appropriate monitoring for bone marrow failure, physical abnormalities, and related cancers.
Genetic counseling: DBA is most often inherited in an autosomal dominant manner; GATA1-related and TSR2-related DBA are inherited in an X-linked manner. Approximately 40% to 45% of individuals with autosomal dominant DBA have inherited the pathogenic variant from a parent; approximately 55% to 60% have a de novo pathogenic variant. Each child of an individual with autosomal dominant DBA has a 50% chance of inheriting the pathogenic variant. Males with GATA1- or TSR2-related DBA pass the pathogenic variant to all of their daughters and none of their sons. Women heterozygous for a GATA1 or TSR2 pathogenic variant have a 50% chance of transmitting the pathogenic variant in each pregnancy: males who inherit the pathogenic variant will be affected; females who inherit the pathogenic variant will be carriers and will usually not be affected. Carrier testing of at-risk female relatives is possible if the GATA1 or TSR2 pathogenic variant has been identified in the family. Prenatal testing for pregnancies at increased risk is possible if the familial pathogenic variant has been identified.
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Fanconi Anemia.2002 Feb 14 [updated 2018 Mar 8]. In: Adam MP, Ardinger HH, Pagon RA, Wallace SE, Bean LJH, Stephens K, Amemiya A, editors. GeneReviews® [Internet]. Seattle (WA): University of Washington, Seattle; 1993–2020. GeneReviews®. 1993–2020. PMID: 20301575 Free Books & Documents. Review.
GATA1-Related X-Linked Cytopenia.2006 Nov 22 [updated 2017 May 11]. In: Adam MP, Ardinger HH, Pagon RA, Wallace SE, Bean LJH, Stephens K, Amemiya A, editors. GeneReviews® [Internet]. Seattle (WA): University of Washington, Seattle; 1993–2020. GeneReviews®. 1993–2020. PMID: 20301538 Free Books & Documents. Review.
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Shwachman-Diamond Syndrome.2008 Jul 17 [updated 2018 Oct 18]. In: Adam MP, Ardinger HH, Pagon RA, Wallace SE, Bean LJH, Stephens K, Amemiya A, editors. GeneReviews® [Internet]. Seattle (WA): University of Washington, Seattle; 1993–2020. GeneReviews®. 1993–2020. PMID: 20301722 Free Books & Documents. Review.
Congenital Erythropoietic Porphyria.2013 Sep 12 [updated 2016 Apr 7]. In: Adam MP, Ardinger HH, Pagon RA, Wallace SE, Bean LJH, Stephens K, Amemiya A, editors. GeneReviews® [Internet]. Seattle (WA): University of Washington, Seattle; 1993–2020. GeneReviews®. 1993–2020. PMID: 24027798 Free Books & Documents. Review.