HIGH-VOLTAGE STARCH-GEL ELECTROPHORESIS IN STUDY OF POST-ALBUMIN PROTEINS AND C3 (BETA1C-GLOBULIN) POLYMORPHISM

Improved methods for high-voltage starch-gel electrophoresis were developed, resulting in improved resolutions of post-albumin proteins and observation of an additional component in Gc (group specific component) proteins of phenotypes 1-1 and 2-1. Common inherited differences in the C'3 proteins (ß1c-globulin) of the complement system were discovered with the new systems. Autosomal codominant inheritance of two common alleles (C31and C32) and three relatively uncommon alleles (C33, C34, and C35) at a single locus was supported by studies of randomly selected sera from 123 Caucasians and 113 Negroes. Frequencies of C'3 genes were: for Caucasions, C31=0.21, C32=0.77, C33≈0.01, C34≈0.004, C35≈0.004; for Negroes, C31=0.04, C32=0.96. Studies of 34 families and 99 children supported the proposed autosomal codominant inheritance of C31, C32, C33, and C34. The C'3 phenotype was fully expressed in the newborn and sometimes differed from that of the mother, suggesting synthesis of C'3 by the newborn without placental transmission. © 1969 Plenum Publishing Corporation.