Increased adenosine deaminase activity in a patient with cartilage-hair hypoplasia.

A boy aged 9 years presenting short stature and recurrent respiratory-tract infections was studied. The clinical and roentgenological pictures allowed the diagnosis of cartilage-hair hypoplasia (metaphyseal chondrodysplasia, McKusick type). Biochemical studies disclosed a four-fold increase in adenosine deaminase activity, but without evidence of anemia. Immunological evaluation showed abnormal cellular but normal humoral immunity.