Diamond-Blackfan anemia (DBA)
Diamond-Blackfan anemia (DBA) is a condition in which the child has a low red cell count (anemia) due to a genetic problem that affects the ability of the body to make red blood cells
What causes DBA?
DBA is an inherited disease affecting the ability of special cells in the bone marrow to make healthy red blood cells (bone marrow failure syndrome). The most common gene defect involves RPS19, which affects the protein-manufacturing ability of those cells, but other gene defects have been found, and in a minority of patients no gene defect is identified.
How is DBA diagnosed?
DBA presents most commonly in the first year of life with increasing pallor (pale skin) due to anemia. Over one-third of patients also have congenital abnormalities, affecting the face, forearm, thumbs, kidneys, heart, and eyes.
The complete blood count (CBC) is a simple blood test that can be done in almost any medical lab. In DBA this shows severe anemia, with larger red cells, and fewer young red cells (reticulocytopenia), while the rest of the blood cells such as white cells and platelet cells are usually normal. Along with the physical appearance, this may be diagnostic, but a bone marrow aspiration is often done to confirm a lack of red cells.
Other special blood tests for confirmation include:
- red cell enzyme (adenosine deaminase)
- fetal hemoglobin
- gene testing
How is DBA treated?
- Corticosteroids (e.g. prednisone) is usually effective and the goal is to give a trial of an adequate dose for a month then gradually reduce to a low dose to avoid side effects which include fractures, cataracts, growth retardation, high BP and diabetes. Due to these side effects, steroids are not given to young children (less than 6-12 months of age) for whom blood transfusions are initially given. Once steroids are started, around 40% of patients will continue at a low dose, 40% will not respond or need too high a dose and be switched back to blood transfusions, and 20% will go into remission and be able to stop all treatments
- Blood transfusions are given to patients below 12 months of age, and those who do not respond or are needing too high a dose of steroid, to avoid the side effects of steroid. Chelation with deferasirox is essential with chronic transfusions to avoid organ (liver, heart) overload with iron.
- Bone marrow transplantation should be considered for patients who have an HLAmatched related donor, especially if are transfusion-dependent and under 5-10 years of age.