A case of familial deficiency in alpha-1-antitrypsin connected with Pi-0Z gene led to the finding of a new Gcler variant partly deficient, the electrofocusing pattern of which, located between that of G and I variants, was modified after neuraminidase digestion. A study of three generations shows that Gcler variant is transmitter according to an autosomally codominant mode. Moreover serum trypsin inhibitory capacity and concentration of ten proteins have been measured in this family. Except the known relation between serum alpha-1-antitrypsin level and trypsin inhibitory, capacity, only serum IgA showed a significant correlation with serum alpha-1-antitrypsin in the deficient group with Pi-Z allele.