The genetic polymorphism of alpha 2-HS glycoprotein: study by ultrathin-layer isoelectric focusing and immunoblot.

The genetic polymorphism of human alpha 2-HS glycoprotein was studied by ultrathin-layer isoelectric focusing in a pH range 4.2-4.9 followed by immunoblotting using antisera specific for the protein. Three common phenotypes, HSGA1-1, HSGA2-2, and HSGA1-2, were easily recognized using this technique. Each homozygous phenotype was constituted by five major bands with different pI's, and the heterozygous phenotype represented an exact combination of each of them. After removal of sialic acid, each homozygous pattern was resumed in a single band, which differed in charge between HSGA1 and HSGA2. Asialo-heterozygous HSG1-2 combined the two bands characteristic of each allele product. Family studies are in agreement with an autosomal codominant transmission of the two alleles. Population studies indicate that the frequency of the HSGA1 and 2 alleles are .65 and .35, respectively.