| Abstract: | The polymorphism of the fourth component of complement (C4) as demonstrated by antigen—antibody crossed electrophoresis was used to study paired samples of maternal and cord plasma. Curve analysis was employed to analyse the qualitative and quantitative composition of the C4 patterns. Among the fifty-two paired samples studied, the findings in nine could not be explained by placental passage of C4 from mother to foetus, and evidence for foetal synthesis of C4 was found in five cases. Family studies supported the genetic basis for the electrophoretic polymorphism of C4. |
