Anemia (Diamond-Blackfan)

Definition

Definition of Anemia (Diamond-Blackfan)
Diamond-Blackfan anemia (DBA), also known as Blackfan-Diamond anemia and Inherited erythroblastopenia, is a congenital erythroid aplasia that usually presents in infancy. DBA patients have low red blood cell counts (anemia). The rest of their blood cells (the platelets and the white blood cells) are normal. This is in contrast to Shwachman Bodian Diamond syndrome, in which the bone marrow defect results primarily in neutropenia, and Fanconi anemia, where all cell lines are affected resulting in pancytopenia.

Symptoms

Symptoms of Anemia (Diamond-Blackfan)
People with DBA have symptoms common to all other types of anemia, including pale skin, sleepiness, rapid heartbeat, and heart murmurs. In some cases there are no obvious physical signs of DBA. About one-quarter of people with DBA have abnormal features involving the face, head, and hands, especially the thumbs. They may also have heart and kidney defects. Many children are short for their age and may start puberty later than normal.

Causes

Causes of Anemia (Diamond-Blackfan)
Diamond-Blackfan anemia can be caused by mutations in the RPL5, RPL11, RPL35A, RPS7, RPS10, RPS17, RPS19, RPS24, and RPS26 genes. These genes provide instructions for making several of the approximately 80 different ribosomal proteins, which are components of cellular structures called ribosomes. Ribosomes process the cell's genetic instructions to create proteins.

Each ribosome is made up of two parts (subunits) called the large and small subunits. The RPL5, RPL11, and RPL35A genes provide instructions for making ribosomal proteins that are among those found in the large subunit. The ribosomal proteins produced from the RPS7, RPS10, RPS17, RPS19, RPS24, and RPS26 genes are among those found in the small subunit.

Diagnosis

Diagnosis of Anemia (Diamond-Blackfan)
Typically, a diagnosis of DBA is made through a blood count and a bone marrow biopsy.

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.

Treatment

Treatment of Anemia (Diamond-Blackfan)
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. 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.

The only cure available for Blackfan Diamond anemia is bone marrow transplantation, which replaces the person's defective bone marrow with healthy marrow. However, transplantation is a difficult procedure to go through and it doesn't always work. It is usually reserved for people whom steroid medications and blood transfusions don't help.

Prognosis

Prognosis of Anemia (Diamond-Blackfan)
Consult with your doctor.

Prevention

Prevention of Anemia (Diamond-Blackfan)
Sometimes patients can develop transfusion reactions with fever and rash. Medication may be given before the next transfusion to help prevent these symptoms. Red cell transfusions can also cause a build-up of extra iron in the body which can harm the heart and/or liver, cause diabetes, or slow down normal growth. The amount of iron must be regularly checked. If iron levels are too high, your doctor may recommend drugs to remove excess iron in body tissues. This process is called chelation therapy. People getting transfusions should avoid iron supplements.