Diamond Blackfan Anemia (DBA) is a rare congenital ribosomopathy that leads to failed erythropoiesis (red blood cell production), congenital abnormalities and a predisposition to cancer. Also known as one of the rare groups of inherited bone marrow failure syndromes, DBA was first described by Josephs in 1936 and then as a distinct entity in 1938 by Diamond and Blackfan {25}.

Numerous theories regarding the exact cause of DBA have been proposed. The most widely accepted theory, is that of DBA being a ribosomopathy, caused by genetic mutations affecting ribosome synthesis. In more than 50% of cases, DBA appears to be as a result from haploinsufficiency of either a small or large subunit-associated ribosomal protein {21}. Approximately 45% of cases are familial, displaying an autosomal dominant inheritance, with variable penetrance {17}.

Children usually appear to be affected with anemia by 2 months of age with a range from birth to 6 years. 93% of the patients present with anemia during the first year of life.  The diagnosis of DBA is generally made at 3 months of age with a range from birth to adulthood.

 

Incidence of DBA

The incidence and prevalence of DBA in South Africa and Africa is not known. International data on DBA have the incidence estimated at 5-10 cases for every million children born. The DBAR estimates about 20-40 new cases per year in the United States and Canada.  There are an equal number of males and females affected by the disease.

We have no way to compare or describe the prevalence, gender predominance or age of presentation of DBA in Africa with international data without the establishment of a DBA Africa registry. With 1 084 511 live births recorded in South Africa in 2015, we could expect from International data between 5-10 children are born with DBA every year. Africa has an estimated population of 1.2 billion, and with 4.46 million children dying before their fifth birthday, the importance of identifying and providing help becomes apparent.

 

Congenital Abnormalities

About 50% of the patients in the DBAR have physical abnormalities (not including short stature).

Of these,

  • 50% of the abnormalities are of the face and head (including cleft lip and palate)

  • about 40% are of the upper arm and hand

  • about 40% are of the kidney

  • 30% are of the heart

Approximately 20% of patients have more than one physical abnormality.

Mutations in the genes RPL5, RPL11 and RPS26 have been associated with orofacial clefts and thumb anomalies, respectively.

This information is taken from the Diamond Blackfan Anemia Registry with special permission from Dr A Vlachos. Please visit this website for up-to-date information on DBA and further topics. https://www.dbar.org/congenital-anomalies

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