Electrophoretic variation in human serum ceruloplasmin: a new genetic polymorphism.

Abstract

Through the application of a specific oxidase stain to results of starch gel electrophoresis of human serum, three different electrophoretic forms of ceruloplasmin—denoted CpA (fast), CpB (intermediate), and CpC (slow)—have been defined. The electrophoretic differences are small and were first recognized through a rare variant individual who had only the fast and slow forms. Five phenotypes displaying different combinations of the three electrophoretic forms have been defined in American Negroes; these are called CpA, CpAB, CpB, CpAC, and CpBC. Twin, family, and population studies have yielded evidence indicating that the A and B electrophoretic forms are controlled by a pair of autosomal codominant alleles, designated Cp Aand Cp B, and suggesting that the C form may be determined by a third allele, Cp C, at the same locus. The variants constitute a genetic polymorphism in American Negroes, but occur only rarely in Caucasians.