Adenosine deaminase deficiency

Adenosine deaminase deficiency, or ADA deficiency, is an inherited immunodeficiency syndrome accounting for about 25% of all cases of severe combined immunodeficiency (SCID).

This disease is due to a lack of the enzyme adenosine deaminase coded for by a gene on chromosome 20. There is an accumulation of dATP, which causes an increase in S-adenosylhomocysteine; both substances are toxic to immature lymphoid cells, so fail to reach maturity. As a result, the immune system of the afflicted person is severely compromised or completely lacking.

The enzyme adenosine deaminase is important for purine metabolism.

Treatment

 * bone marrow transplant
 * gene therapy (efforts halted due to increased incidence of leukemia)
 * ADA enzyme in PEG vehicle
 * Stem Cell Therapy(still in the experimental stage)

The first gene therapy to combat this disease was performed by Dr. W. French Anderson on a 4yr old girl, Ashanti DeSilva, in 14 September 1990 at the National Institute of Health, Bethesda, Maryland, U.S.A.

The therapy performed was the first successful case of gene therapy.