Deficiency of adenosine deaminase (ADA), an enzyme of purine nucleoside metabolism, is found in about 15% of all patients with severe combined immunodeficiency disease (SCID), or in 30% to 40% of those with autosomal recessive inheritance.<sup>12 Buckley R.H., Schiff R.I., Schiff S.E. , et al. Human severe combined immunodeficiency: Genetic, phenotypic, and functional diversity in one hundred eight infants J Pediatr 1997 ;  130 : 378-387  [cross-ref]

Cliquez ici pour aller à la section Références, 41 Hershfield M.S., Mitchell B.S. Immunodeficiency diseases caused by adenosine deaminase deficiency and purine nucleoside phosphorylase deficiency The Metabolic and Molecular Bases of Inherited Disease New York: McGraw-Hill (1995).  1725-1768

Cliquez ici pour aller à la section Références, 75 Stephan J.L., Vlekova V., Le Deist F. , et al. Severe combined immunodeficiency: A retrospective single center study of clinical presentation and outcome in 117 patients J Pediatr 1993 ;  123 : 564-572  [cross-ref]

Cliquez ici pour aller à la section Références</sup> ADA deficiency is also associated with milder degrees of immune deficiency that are compatible with survival beyond early childhood. The enzyme deficiency should be considered in the differential diagnosis of children and adults with a history of serious and recurrent infections who have persistent lymphopenia and findings indicating both cellular and humoral immune dysfunction.

Determining whether a patient with SCID is ADA-deficient is important for genetic counseling, but also for reasons related to the systemic metabolic disorder. Even though devastating consequences of immunodeficiency dominate the clinical presentation, ADA deficiency may cause nonlymphoid pathology over time. There are presently more treatment options available for ADA deficiency than for SCID caused by other genetic defects. These options include bone marrow transplantation (BMT), enzyme replacement, and gene therapy. This article summarizes the clinical presentation and diagnosis of ADA deficiency, metabolic and genetic factors that underlie immunodeficiency and influence disease severity, and provides an overview of the status of current therapies. A more comprehensive review can be found in Hershfield and Mitchell (an updated version is in press).<sup>41 Hershfield M.S., Mitchell B.S. Immunodeficiency diseases caused by adenosine deaminase deficiency and purine nucleoside phosphorylase deficiency The Metabolic and Molecular Bases of Inherited Disease New York: McGraw-Hill (1995).  1725-1768

Cliquez ici pour aller à la section Références</sup>