Subjects with alpha 1-antitrypsin deficiency, Pizz, are often subject to hepatopathies in infancy and pneumopathies in adulthood. The authors make a number of genetic and clinical observations together with a laboratory diagnosis of alpha 1-antitrypsin and describe an asymptomatic clinical case in which the diagnosis of alpha 1-antitrypsin in a PiZZ phenotype was made following the initial and occasional finding of altered transaminase and alpha 1-globulin values.