New phenotypes of serum ? 1-antitrypsin in Japanese detected by gel slab isoelectric focusing

Abstract

The phenotype distribution and gene frequencies of serum α ₁-antitrypsin in 856 healthy blood donors in Tokyo were examined by gel slab isoelectric focusing (pH 4–6). The allele of the common subtype variant Pi M₂ was present with a frequency of 0.1099 in Japanese. A study of 23 twin pairs and their parents was in agreement with the hypothesis of autosomal codominant inheritance of Pi M subtypes. Other rare variant alleles, Pi M^F, Pi M^S, Pi M^N, Pi M^V, Pi M^X, Pi M^Z were found in very low frequencies. The total concentration of serum α ₁-antitrypsin was compared among three different phenotypic groups (M₁, M₁M₂, M₂). Statistically significant quantitative differences were found among these three groups (P<0.01).