The group specific component/vitamin D binding protein (GC/DBP) system in the analysis of disputed paternities

The group-specific component (GC) was discovered in 1959, and in the same year a vitamin D binding protein (DBP) in human plasma was found; however, their identity was established as late as 1975. In the GC/DBP system three common alleles, GC*1F, GC*1S, and GC*2, determine six GC phenotypes: 1F, 1S, 2, 1F-1S, 2-1F and 2-1S, these common alleles having been found in all human populations studied. In addition, more than 120 GC variants have been discovered, with varying frequencies in different populations. The distribution of the common GC phenotypes and the presence of rare GC variant phenotypes render the GC/DBP system useful for the analysis of disputed paternities.