Adenosine deaminase deficiency
Adenosine deaminase deficiency (ADA deficiency) is a rare disease with an incidence of <1 case per 100,000 live births worldwide, which was discovered in 1972 by Eloise Giblett. It results from an inherited ADA gene autosomal recessive manner mutation that leads to a metabolic disorder and immunodeficiency.
Despite being an inherited disorder, ADA deficiency can present in infancy, childhood, adolescence, or adulthood. The main implication of ADA deficiency is the build-up of a toxic substance called deoxyadenosine. This substance prevents cells from dividing effectively and impacts the white blood cells that are essential for a healthy immune system leading to Adenosine deaminase deficient severe combined immunodeficiency (SCID). Actually, most individuals with ADA deficiency are diagnosed with SCID in the first 6 months of life.
Pneumonia, chronic diarrhea, and widespread skin rashes are among the main symptoms of ADA deficiency. Additionally, it was found that children with ADA deficiency grow much slower than healthy children and some may suffer from developmental delay. Moreover, association with polyarteritis nodosa (PAN) has been reported too, which is a condition that causes swollen arteries.
Diagnosis is straightforward and based on clinical features, with a concomitant decreased blood adenosine deaminase level that supports the diagnosis.
In addition to bone marrow transplantation the FDA approved two medications for the treatment of ADA deficiency:
- Pegademase bovine (Adagen)
- Elapegademase-lvlr (Revcovi)
