Alpha-1-antitrypsin-deficient phenotype is not maintained by segregation distortion.

Recent reports have suggested that the alpha-1-antitrypsin allele PiZ, which in homozygotes results in severe deficiency of this important protease inhibitor, is maintained at a relatively high gene frequency through the mechanism of segregation distortion. We report here on 121 nuclear families selected because only one parent was segregating the Z allele. After correcting for ascertainment, no evidence of preferential transmission was observed in 278 informative offspring.