ALPHA1-ANTITRYPSIN - FURTHER GENETIC-HETEROGENEITY REVEALED BY ISOELECTRIC-FOCUSING

  • 1 January 1978
    • journal article
    • research article
    • Vol. 30  (4) , 359-365
Abstract
.alpha.1-Antitrypsin is a major human serum protein that shows an extensive polymorphism. Genetic heterogeneity has previously been demonstrated by starch gel electrophoresis. By applying analytical isoelectric focusing (pH 3.5-5.0) to this system, a common variant, Pi[protease inhibitor]M3 was found, with an isoelectric point between those of PiM1 and PiM2. The gene frequency of this variant was 0.11 in U.S. whites and 0.054 in blacks. When PiM3 and PiM1 are included in the Pi system, the heterozygosity at the Pi locus is 5 times greater in whites and 10 times greater in blacks than that detected by earlier electrophoretic techniques.