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Diamond-Blackfan anemia (DBA) is a rare blood disorder that affects the bone marrow.
Diamond-Blackfan anemia (DBA) is a rare blood disorder that affects the bone marrow. In this condition, the bone marrow fails to make red blood cells, which are essential for carrying oxygen from the lungs to all the other parts of the body. Blood cells are made in the bone marrow. In patients with DBA, many of the cells that would have become red blood cells die before they develop. DBA is characterized by a shortage of red blood cells, which usually becomes evident during the first year of life when the patient develops anemia. About half of the affected patients have abnormal physical abnormalities associated with DBA.
Causes:
- DBA may be passed down through families. About 50% of children with this disorder have a gene defect. In the other 50% of children with DBA, no gene defects are found, and the cause is not known.
- It is a genetic disease that affects the body’s ribosomes, which are small cellular structures that play an important role in building proteins in the body. More than half of patients with DBA have mutations in a ribosomal protein gene, and mutations in at least 11 such genes have been linked to DBA.
- In rare cases, DBA in boys can be due to a mutation in a gene called GATA-1, which controls the earliest steps of red blood cell production.
- DBA affects approximately five to seven people per million live births per year. There is an equal number of men and women with the disease.
Signs and symptoms: DBA causes lowered blood cell counts and hemoglobin (anemia) without substantially affecting the other blood components (the platelets and white blood cells). A common trait found in children is an unusual facial appearance, such as a snub nose, widely spaced eyes, and a thick upper lip.
- Paleness
- Tiredness
- Weakness
- Irritability
- Poor appetite (failing to feed properly)
- Poor growth
- Cleft palate
- Headaches
- Heart abnormalities
- Kidney defects
- Short neck or short stature
- Dyspnea (shortness of breath or difficulty breathing)
- Thumb defects
Diagnosis: The average age of presenting with anemia is two months, and the average age of diagnosis with DBA is three to four months. Some tests that aid in diagnosing DBA are as follows:
- Complete blood count (CBC): It shows the values for the number of red blood cells, white blood cells, and platelets in a blood sample.
- Reticulocyte count (retic): The number of immature or young red blood cells is given as a percentage.
- Mean corpuscular volume (MCV): It is a measure of the size of the red blood cells and is found as part of the CBC. MCV is increased with age in patients with DBA.
- Erythrocyte adenosine deaminase (eADA) activity level: Elevated eADA levels are present in approximately 80-85% of patients with DBA.
- Genetic testing: Genetic testing can identify a mutation in approximately 80-85% of patients with DBA.
What are the treatment options for Diamond-Blackfan anemia?
The following are the treatment options for Diamond-Blackfan anemia (DBA):
- Steroid therapy: To increase hemoglobin by stimulating the bone marrow to produce more red blood cells. Most children respond well to steroid therapy, and the dose can often be weaned to a lower dose that causes fewer side effects.
- Blood transfusion: It is used when anemia is unusually severe or when steroid therapy is not effective.
- Chelation therapy: A potential drawback of regular blood transfusions is the accumulation of too much iron. Normally, the body uses iron when making new red blood cells, but because someone with DBA isn't making many cells, the iron builds up. Excessive iron in the blood can cause heart and liver problems, congestive heart failure, diabetes, and hypothyroidism, as well as other serious problems. To remove the excess iron from the body, chelation therapy is necessary with one of the two drugs approved for this purpose: Exjade (deferasirox) and Desferal (deferoxamine).
- Stem cell transplant: At present, this is the only cure for DBA. Stem cell transplantation involves replacing the diseased blood-forming stem cells with another person’s healthy stem cells. Unfortunately, it may not be an option for everyone. The success of a transplant depends on many factors, such as how close the match is between child and donor and the patient's age. Matched siblings are best; if your child has a sibling, the chance of a complete tissue match is 1 in 4. The degree to which your child's bone marrow has failed also factors into the discussion of whether to pursue a transplant. The decision to proceed with a bone marrow transplant should be discussed with your child’s hematologist and a stem cell transplant team.
Patients with DBA require lifelong follow-up care to manage symptoms, receiving therapies such as steroids and blood transfusions, or monitor a child’s health following a stem cell transplant. Severe cases of DBA require lifelong treatment for potentially life-threatening anemia and other complications. New methods are continually being discovered to improve treatment and decrease the side effects of therapies.