Serum Levels of Alpha-1-Antitrypsin in Individuals with Different Pi M Subtypes

Abstract

Individuals with heterozygous Pi M subtypes were found to have higher serum levels of α₁-antitrypsin (α₁-AT) than homozygotes. The α₁-AT levels in heterozygotes showed a unimodal distribution. Among homozygotes, a tendency towards a bimodal distribution was found. The mechanism behind this difference is not known. The result can apparently not be explained as the result of a hitherto undiscovered deficiency gene.