Distribution of alpha 1-antitrypsin (PI) subtypes from newborns

PI phenotypes were determined from 420 cord bloods from Adelaide. Allele frequencies for the subvariants PI*MI, PI*M2 and PI*M3 were 0.73, 0.14 and 0.09, respectively. The combined frequency of other alleles was 0.04. This relatively high level of variation makes PI useful for gene mapping, paternity testing and zygosity testing. For this locus the average probability of detecting non-paternity in this population is 28%.