Further family studies on the genetic control of β₂-glycoprotein I concentration in human serum

Summary

88 families with a total of 213 children were examined for β₂-glycoprotein I serum concentrations. In 74 families parents and children had normal concentrations. In 9 families one of the parents and approximately half of the children had intermediate concentrations. These individuals are presumably heterozygous for a deficiency gene Bg^D. In these families β₂-glycoprotein I concentration appears to be controlled by a pair of alleles which are transmitted as autosomal co-dominants. The results in 5 families did not conform to this genetic hypothesis, since children with an intermediate concentration of β₂-glycoprotein I were found whose both parents had a normal concentration of this protein. Non-genetic factors may be responsible for phenotypic variations in the different genetic types.