Genetic polymorphism of inter-alpha-trypsin-inhibitor (ITI): formal genetic and linkage analyses.

The polymorphism of inter-alpha-trypsin-inhibitor, ITI, was demonstrated by isoelectric focusing in agarose gels (pH 5-8) followed by protein blotting and immunoassay. Segregation in 239 families with 677 children is consistent with the formal hypothesis that there are two common codominant alleles, ITI1, ITI2, and one rare codominant allele, ITI3, at an autosomal locus ITI. Allele frequencies were calculated as ITI1 = 0.600, ITI2 = 0.393, ITI3 = 0.007. Linkage analysis with 36 markers is presented. Slightly positive lod scores were obtained for PGM3 (zeta = 1.35, theta = 0.10) and AK1 (zeta = 1.34, theta = 0.10).