title: Complement polymorphism in herpes gestationis: association with C4 null allele.
abstract: BACKGROUND
  Herpes gestationis (HG) is a rare, pregnancy-related skin disease characterized by the production of an autoantibody to a component of the hemidesmosome. It is associated with the class II antigens HLA-DR3 and HLA-DR4, but its potential association with the "class III antigens" C2, C4, and factor B has not previously been studied.
  
  
  OBJECTIVE
  Our purpose was to study complement polymorphism in HG.
  
  
  METHODS
  Using electrophoresis and immunofixation techniques, we determined the allele frequencies of C4A, C4B, C3, and factor B in 42 patients with a history of HG.
  
  
  RESULTS
  Ninety percent of patients carried a C4 null allele (C4*QO). No statistically significant association with C3 or factor B alleles was seen.
  
  
  CONCLUSIONS
  HG is associated with the presence of a C4*QO. Whether the C4*QO is the primary genetic association, or whether the C4*QO is related to its linkage disequilibrium with DR3 and DR4 has yet to be determined.
authors.affiliation: St. John's Institute of Dermatology, St. Thomas' Hospital, London, UK.
authors.forename: J K
authors.initials: JK
authors.lastname: Shornick
authors.forename: C M
authors.initials: CM
authors.lastname: Artlett
authors.forename: R E
authors.initials: RE
authors.lastname: Jenkins
authors.forename: D C
authors.initials: DC
authors.lastname: Briggs
authors.forename: K I
authors.initials: KI
authors.lastname: Welsh
authors.forename: M P
authors.initials: MP
authors.lastname: Garvey
authors.forename: S E
authors.initials: SE
authors.lastname: Kelly
authors.forename: M M
authors.initials: MM
authors.lastname: Black
mesh_terms: D000328:Adult; D000483:Alleles; D002874:Chromosome Mapping; D003176:Complement C3 / Q000235:genetics*; D015934:Complement C4a / Q000235:genetics*; D015935:Complement C4b / Q000235:genetics*; D011415:Complement Factor B / Q000235:genetics*; D005260:Female; D005787:Gene Frequency; D005838:Genotype; D006801:Humans; D006559:Pemphigoid Gestationis / Q000235:genetics*; D010641:Phenotype; D011110:Polymorphism, Genetic; D011247:Pregnancy
chemical_list: D003176:Complement C3; D015934:Complement C4a; D015935:Complement C4b; D011415:Complement Factor B