Diamond-Blackfan anemia
Diamond-Blackfan anemia | |
ICD-10 | D61.0 |
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ICD-9 | 284.01 |
OMIM | 105650 |
DiseasesDB | 29062 |
MeSH | D029503 |
Diamond-Blackfan anemia Microchapters |
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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]
Overview
Clinical Features
Diamond-Blackfan anemia is characterized by anemia (low red blood cell counts) with decreased erythroid progenitors in the bone marrow. This usually develops during the neonatal period. About 47% of affected individuals also have a variety of congenital abnormalities, including craniofacial malformations, thumb or upper limb abnormalities, cardiac defects, urogenital malformations, and cleft palate. Low birth weight and generalized growth retardation are sometimes observed. DBA patients have a modest risk of developing leukemia and other malignancies.
Diagnosis
A diagnosis of DBA is made on the basis of anemia, low reticulocyte (immature red blood cells) counts, and diminished erythroid precursors in bone marrow. Features that support a diagnosis of DBA include the presence of congenital abnormalities, macrocytosis, elevated fetal hemoglobin, and elevated adenosine deaminase levels in red blood cells. Most patients are diagnosed in the first two years of life. However, some mildly affected individuals only receive attention after a more severely affected family member is identified. About 20-25% of DBA patients may be identified with a genetic test for mutations in the RPS19 gene.
History
Genetics
Molecular Basis of Disease
The phenotype of DBA patients suggests a hematological stem cell defect specifically affecting the erythroid progenitor population. This is difficult to reconcile with the known function of the single known DBA gene. The RPS19 protein is involved in the production of ribosomes. As such, loss of RPS19 function would be predicted to affect translation and protein biosynthesis and have a much broader impact. Disease features may be related to the nature of RPS19 mutations. The disease is characterized by dominant inheritance, and therefore arises due to a partial loss of RPS19 protein function. It is possible that erythroid progenitors are acutely sensitized to this decreased function, while most other tissues are unaffected.
Clinical Management and Treatments
Corticosteroids can be used to treat anemia in DBA. In a large study of 225 patients, 82% initially responded to this therapy, although many side effects were noted.[1] Some patients remained responsive to steroids, while efficacy waned in others. Blood transfusions can also be used to treat severe anemia in DBA. Periods of remission may occur, during which transfusions and steroid treatments are not required. Bone marrow transplantation (BMT) can cure hematological aspects of DBA. This option may be considered when patients become transfusion-dependent because frequent transfusions can lead to iron overloading and organ damage. However, data from a large DBA patient registry indicated that adverse events in transfusion-dependent patients were more frequently caused by BMTs than iron overloading.
References
- ↑ Vlachos A, Klein GW, Lipton JM (2001). "The Diamond Blackfan Anemia Registry: tool for investigating the epidemiology and biology of Diamond-Blackfan anemia". J. Pediatr. Hematol. Oncol. 23 (6): 377–82. PMID 11563775.