Summary
Adenosine deaminase (ADA) deficiency is characterized by severe combined immune deficiency (SCID) resulting in severe and multiple infections (bacterial, viral and mycotic) generally occurring within the first months of life. The disease is autosomal recessive and accounts for about 50% of non-X-linked SCIDs. When children have not been transfused, diagnosis is made by measuring ADA activity in erythrocytes. Biologically, extreme lymphopenia is noted, and the thymus is lacking on X-rays. Possible treatments include bone marrow transplantation and replacement therapy using ADA coupled to polyethylene glycol. Several attempts at gene therapy have been conducted over the past 15 years, but long-term correction of the deficit has only recently been obtained, in four patients, by stem cell gene therapy combined with low-intensity myeloablation.* Author: Dr J.L. Pérignon (February 2005)*.
