Genetic polymorphism of serum alpha-1-protease inhibitor (alpha-1-antitrypsin): Pi i, a deficient allele of the Pi system.
The microheterogeneity of the I allele of the Pi system of APi (alpha-1-antitrypsin) was studied in 43 individuals with the new PAGIF technique. The unique aspect of the I allele product (unequal distribution of bands 4 and 6), previously demonstrated with acid-starch gel, was confirmed. In addition, two subtypes of the  Pi I allele--I1 and I2--were clearly distinguished. Serum concentrations of APi associated with the expression of the I allele were significantly decreased (68% of normal values) and thus very similar to those associated with the expression of the S allele. This indicates that the I allele can be considered as a "deficient" allele of the Pi system.
D000483:Alleles; D006801:Humans; D007525:Isoelectric Focusing; D010375:Pedigree; D010641:Phenotype; D011110:Polymorphism, Genetic; D000515:alpha 1-Antitrypsin / Q000032:analysis / Q000235:genetics*
D000515:alpha 1-Antitrypsin