[Alpha-1-antitrypsin deficiency. Phenotype study of 60 members of the same family].

In two brothers treated for severe pulmonary emphysema, was demonstrated an alpha-1-antitrypsin deficiency associated with a ZZ phenotype (Pi system). The authors carried out a genetic study of the family including 60 members spread over 4 generations. In all, were demonstrated 4 subjects of phenotype ZZ, 29 of phenotype MZ, 3 of phenotype MS ; one subject had a phenotype SZ and 23 members of this family had normal levels of alpha-1-antitrypsin and were of phenotype MM. The disease was transmitted in all cases as an autosomic codominant. The interest of a study of the phenotype in alpha-1-antitrypsin deficiency is emphasized together with the practical steps to be taken on discovery of a subject with the allele responsible for a reduction in serum levels of alpha-1-antitrypsin.