Chronic obstructive pulmonary disease and alpha-1-antitrypsin (Pi) variation: a family study.

A kindred of a white male proband with alpha1-antitrypsin deficiency, ZZ phenotype, and a severe obstructive ventilatory defect secondary to pulmonary emphysema was studied with regard to alpha1-antitrypsin phenotype, serum trypsin inhibitory capacity (T.I.C.), and pulmonary function. T.I.C.'s and alpha1-antitrypsin phenotypes were consistent with autosomal codominant inheritance. While MZ relatives as well as the proband had pulmonary function abnormalities, the pattern varied within the kindred and abnormalities were observed in some MM relatives also.