title: Polymorphic variants of the third component of complement in Graves' disease.
abstract: We have examined electrophoretic variants of the third complement component (C3) in 294 controls and in 44 patients suffering from Graves' disease, drawn from the Avalon Peninsula of Newfoundland. Two common C3 variants, S and F, account for 99% of the gene frequencies. The S homozygote phenotype was observed in 170 controls and in 27 patients; 18 controls were found to be homozygous for the F allele (3 patients), and the FS phenotype was observed in 103 controls and 14 patients. The phenotypic frequencies did not differ significantly between controls and patients. It is concluded that C3 variants do not distinguish individuals who have Graves' disease.
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000483:Alleles; D003176:Complement C3 / Q000235:genetics*; D005260:Female; D005787:Gene Frequency; D014644:Genetic Variation; D006111:Graves Disease / Q000235:genetics* / Q000276:immunology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009523:Newfoundland and Labrador; D011110:Polymorphism, Genetic
chemical_list: D003176:Complement C3