Adenosine deaminase deficiency in a child with severe combined immunodeficiency

Abstract

A case is reported of an apparent total erythrocyte adenosine deaminase (ADA) deficiency in a girl suffering from severe combined immunodeficiency (c.i.d.). Four other erythrocyte enzymes investigated showed apparent normal activity. The ADA activity in erythrocytes from her parents was about half normal, suggesting that the girl had inherited a chromosome pair without information for normal red cell ADA‐isoenzymes. The suspected chromosome deficit may have affected the ADA locus only, or it may involve a more extensive part of a chromosome including the ADA locus. In another child, a boy exhibiting clinically the same immunodeficiency syndrome, the ADA type and ADA activity were found to be normal. Recently, two other cases of lack of red cell ADA activity, both affecting girls with similar manifestations of immunological deficiency, have been reported from the U.S.A. (Giblett et al. 1972). These findings indicate that coexistence of a total lack of red cell ADA activity and some immunodeficiency syndromes may be a common condition.