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, ITI*1, ITI*2, and one rare codominant allele, ITI*3, at an autosomal locus ITI. Allele frequencies were calculated as ITI*1 = 0.600, ITI*2 = 0.393, ITI*3 = 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).