Diamond-Blackfan Anemia (DBA)

DBA patients have primarily low red cell counts (anemia). The rest of their blood cells (the platelets and the white cells) are usually normal. ~25% of DBA patients have physical abnormalities, often involving malformations of the thumbs. Most patients are diagnosed within the first year of life. Detecting a mutation in a known DBA gene confirms the diagnosis. However, failure to find a mutation in a DBA gene does not eliminate the diagnosis of DBA. This is because the genes which have been identified so far explain less than half of the disease occurrences. Currently, DBA is diagnosed by clinical findings after exclusion of other known causes of pure red cell anemia. Males and females are affected equally.

1. What are the major findings on physical examination?
1. Short stature
2. Abnormal thumbs
   
   
2. What is the age at diagnosis?
1. Anytime from birth to 60 years of age.
2. 90% are less than 1 year old when the diagnosis is made.
   
   
3. What is the pattern of bone marrow failure?
1. Pure anemia (low red blood cell count, often with large red cells)
2. Normal platelet count usually (Platelets are the cells in the blood which help the blood to clot)
3. Normal white cells usually (White cells help the body fight off infection)
   
   
4. What specific kinds of cancer develop?
1. Leukemia (cancer of the blood and bone marrow)
2. Sarcomas (cancer arising in bone, fat, cartilage, tendons or connective tissue)
   
   
5. How is DBA specifically diagnosed?
1. Patients with DBA usually have an increase in a specific red cell enzyme called adenosine deaminase (ADA).
2. Mutation analysis (genetic testing)
   1. Laboratories can now identify the genetic "error" (or mutation) in some patients.
   2. There are now 9 different genes responsible for DBA: RPS19, RPS26, RPS10, RPS24, RPS17, RPS7, RPL5, RPL11, RPL35a; about 50% of patients do not have mutations in the known genes, and more genes await discovery.
   3. The disease is inherited in an autosomal dominant fashion. This means that illness may occur if a person has only one copy of the abnormal (mutant) gene.