Diamond Blackfan anemia (DBA) is a rare inherited bone marrow failure disorder where the body cannot produce enough red blood cells. It typically appears in the first year of life, with most children diagnosed before their first birthday. About 75% of people with DBA are alive at age 50, but the condition requires lifelong management and carries an elevated risk of serious complications starting around age 25.
What Goes Wrong in the Bone Marrow
Red blood cells are built using tiny cellular machines called ribosomes, which assemble proteins inside every cell. In DBA, genetic mutations cause defects in the ribosomal proteins that cells need to function properly. The most commonly affected gene is RPS19, which accounts for roughly 25% of cases. Mutations in five other ribosomal protein genes have been identified, and together these six genes explain more than half of all DBA diagnoses. In the remaining cases, the specific genetic cause hasn’t been pinpointed yet.
These ribosomal defects hit red blood cell production especially hard. The bone marrow of someone with DBA looks mostly normal under a microscope, with one glaring exception: the early-stage red blood cells (called erythroid progenitors) are nearly absent. The rest of the blood cell types, white cells and platelets, are generally produced normally. This selective failure of red blood cell production is what makes DBA distinct from other bone marrow failure syndromes.
Signs and Symptoms
The hallmark of DBA is severe anemia in infancy. Babies may appear pale, tire easily during feeding, and have a rapid heartbeat as the body tries to compensate for too few red blood cells. Most cases are diagnosed within the first few months of life, though a small number of patients present later in childhood.
About half of people with DBA also have physical abnormalities present at birth. These can affect many parts of the body. Craniofacial differences are common: a small head, wide-set eyes, droopy eyelids, a broad flat nasal bridge, small low-set ears, and a small lower jaw. Some children are born with a cleft palate, with or without a cleft lip. Hand abnormalities are particularly characteristic, especially malformed or absent thumbs. Other possible features include a short, webbed neck, abnormally positioned shoulder blades, kidney malformations, heart defects, and genital abnormalities in boys. The severity varies widely. Some people with DBA have no physical differences at all, while others have several.
How DBA Is Diagnosed
Diagnosis starts with blood work showing a specific pattern: anemia with abnormally large red blood cells and a very low reticulocyte count (reticulocytes are young red blood cells freshly released from the bone marrow, so a low count signals that the marrow isn’t keeping up). A bone marrow biopsy confirms the picture by revealing a marrow that looks normal in overall cellularity but is almost completely missing early red blood cell precursors.
A blood test measuring the activity of an enzyme called adenosine deaminase (ADA) inside red blood cells helps distinguish DBA from other causes of red cell aplasia. In the presence of red cell aplasia, an elevated ADA level in a specific range is considered diagnostic for DBA. Genetic testing for known ribosomal protein mutations can confirm the diagnosis in the majority of cases, though a negative genetic test doesn’t rule it out.
Treatment: Steroids and Transfusions
Corticosteroids are the first treatment tried for nearly all DBA patients. They stimulate the bone marrow to produce red blood cells in many people with this condition. The typical starting dose for children is 2 milligrams of prednisone per kilogram of body weight per day. Blood counts are checked 10 to 14 days after starting, and responders usually show improvement within two to four weeks.
For those who respond, doctors gradually taper the dose to the lowest amount that keeps the anemia under control. Not everyone responds to steroids, though, and some people who initially respond lose that benefit over time. Long-term steroid use also carries significant side effects, particularly in growing children, including slowed growth, weakened bones, and immune suppression. This means many patients eventually need to weigh whether the benefits still outweigh the downsides.
Patients who don’t respond to steroids, or who can’t tolerate them, rely on regular blood transfusions to maintain adequate red blood cell levels. Transfusions are effective at managing the anemia, but they introduce a major long-term problem: iron overload. Each unit of transfused blood delivers a large dose of iron, and the body has no efficient way to get rid of excess iron. It accumulates in the liver, heart, and other organs, eventually causing serious damage.
Iron chelation therapy, which uses medications to remove excess iron from the body, typically begins after about a year of regular transfusions, when blood ferritin levels (a marker of stored iron) reach approximately 1,000 ng/mL. Chelation is a lifelong commitment for transfusion-dependent patients and requires regular monitoring of iron levels in the blood and liver.
Stem Cell Transplant as a Cure
A stem cell transplant (also called a bone marrow transplant) is currently the only cure for DBA. It replaces the defective bone marrow with healthy donor marrow capable of producing red blood cells normally. The decision to pursue a transplant is complex, because the procedure itself carries real risks, including graft failure and graft-versus-host disease.
Outcomes have improved dramatically over the past two decades. Early data showed that transplants from matched sibling donors had survival rates around 75 to 88%, while transplants from unrelated donors had much grimmer outcomes, sometimes as low as 14 to 23%. More recent data from French and German registries tell a different story: survival rates for matched sibling and matched unrelated donor transplants have converged, reaching roughly 91% and 92% respectively. Advances in donor matching, conditioning regimens, and supportive care have largely closed the gap.
Age matters. Children who undergo transplant before age 9 tend to have better outcomes than older patients. Because of this, transplant is often considered earlier in the disease course for patients who have a well-matched donor available, particularly if they are transfusion-dependent and accumulating iron.
Spontaneous Remission
One of the more surprising aspects of DBA is that some patients go into spontaneous remission, meaning their bone marrow begins producing red blood cells on its own without any ongoing treatment. This can happen at any point, though it’s most commonly reported in adolescence or early adulthood. Remission may be permanent or temporary, and patients in remission still need regular monitoring because the underlying genetic defect remains and the associated cancer risks persist.
Cancer Risk Over a Lifetime
People with DBA face an elevated risk of certain cancers compared to the general population. The risk of myelodysplastic syndrome (a precancerous bone marrow condition) is approximately 42 times higher than expected, with a cumulative incidence of about 5% by age 50. Osteosarcoma, a type of bone cancer, and cancers of the lung, colon, and cervix have also been reported at higher-than-expected rates in DBA registries.
This cancer risk is one of the reasons that lifelong follow-up is important for all DBA patients, including those in remission and those who have been cured by transplant of their anemia but may still carry the underlying genetic predisposition in non-blood tissues.