Preferential Transmission of the Z Deficient Allele of α 1 -Antitrypsin

Abstract
The transmission of the Z deficient allele of α 1 -antitrypsin was studied in 23 families, each with a single parent heterozygous for this allele. When the mother carried the Z allele, the distribution of phenotypes in the children did not differ significantly from the expected frequency. In contrast, when the father was the carrier, a significant increase of heterozygous phenotypes was observed in the children. This observation suggests that a selective advantage is associated with the expression of the Z allele in male gametes.