title: Genetic analysis of C4 deficiency.
abstract: The inherited structural polymorphism in the fourth component of complement was studied in the family of a child with homozygous deficiency of this protein. It was shown that a number of family members, including the child's parents, carried a C4 haplotype, C4A*QO C4B*QO, that produced no detectable protein at either the Chido (C4B) or Rodgers (C4A) locus. The family contained individuals with one, two, three, or four expressed C4 genes, and the mean serum C4 levels in such individuals roughly reflected the number of structural genes.
mesh_terms: D002874:Chromosome Mapping; D003181:Complement C4 / Q000172:deficiency* / Q000235:genetics; D005260:Female; D005796:Genes; D005838:Genotype; D006801:Humans; D007153:Immunologic Deficiency Syndromes / Q000235:genetics*; D008297:Male; D010375:Pedigree
chemical_list: D003181:Complement C4