Hereditary recombined three-allele variant of the Gc system.

A three-allele variant with Gc 2, Gc 1F and Gc 1A2 alleles was detected in both a baby and his mother during paternity testing by isoelectric focusing. His father had a normal Gc phenotype, Gc 2-1F. Further examination of his mother's relatives revealed that his grandfather also had the same three-allele variant, while his grandmother and his aunt had normal Gc 2-1F and Gc 2-2. From these results, it was considered that the Gc 1F and Gc 1A2 alleles were on the same single chromosome. It was suggested that recombination had occurred between two chromosomes that had the Gc 1F and Gc 1A2 allele, respectively, forming the variant allele Gc 1F1A2 on a single chromosome.