title: A deficiency mutant of the Gc system.
abstract: In the course of a paternity investigation an apparent mother-child incompatibility was observed in the Gc system. An extensive family study was undertaken to test the hypothesis of a silent gene or null allele responsible for the contrary phenotypes: the mother had the type Gc 2, the son was GC 1. The apparent incompatibility was due to a "pseudo" silent allele, called Gc * 1, which controlled a group-specific component with extremely reduced serum concentrations. This double-band mutant could be differentiated from the Gc 1S bands by two-dimensional electrophoresis: isoelectric focusing (IEF)/6 M urea IEF. The allele Gc * 1 was found in 12 persons from this family, it was not associated with any apparent disease state. Also present in this family was the variant Gc 1C1. Pedigree analysis revealed a possible (not significant) distorted segregation ratio for the allele Gc * 1C1, which was found in 22 of 33 offspring from marriages with one parent heterozygous for Gc * 1C1.
mesh_terms: D000328:Adult; D002352:Carrier Proteins / Q000235:genetics*; D002648:Child; D005260:Female; D006579:Heterozygote; D006801:Humans; D007123:Immunoelectrophoresis, Two-Dimensional; D007525:Isoelectric Focusing; D008297:Male; D009154:Mutation; D010375:Pedigree; D010641:Phenotype; D014809:Vitamin D-Binding Protein
chemical_list: D002352:Carrier Proteins; D014809:Vitamin D-Binding Protein