Lymphocyte dysfunction caused by deficiencies in purine metabolism.

Two inborn errors of purine metabolism have been associated with autosomally inherited human immunodeficiency diseases. A lack of adenosine deaminase (ADA) produces severe lymphopenia and a combined immunodeficiency syndrome. A deficiency of purine nucleoside phosphorylase (PNP) is associated with a selective cellular immune depth. This article discusses the probable biochemical basis for lymphocyte-specific toxicity in these disorders.