title: Endometriosis in monozygotic twins.
abstract: OBJECTIVE
  To describe the occurrence of endometriosis in monozygotic twins.
  
  
  METHODS
  Postal questionnaire plus confirmation of disease status.
  
  
  METHODS
  Twins were recruited via the American Endometriosis Association and the National Endometriosis Society of Great Britain and via British gynecologists.
  
  
  RESULTS
  Fourteen twin pairs were concordant for endometriosis, and two were discordant. Nine pairs of twins had moderate-severe endometriosis.
  
  
  CONCLUSIONS
  These findings contribute to the growing body of literature that suggests endometriosis has a genetic basis.
authors.affiliation: Nuffield Department of Obstetrics and Gynaecology, University of Oxford, John Radcliffe Hospital, United Kingdom.
authors.forename: R M
authors.initials: RM
authors.lastname: Hadfield
authors.forename: H J
authors.initials: HJ
authors.lastname: Mardon
authors.forename: D H
authors.initials: DH
authors.lastname: Barlow
authors.forename: S H
authors.initials: SH
authors.lastname: Kennedy
mesh_terms: D004200:Diseases in Twins; D004715:Endometriosis / Q000453:epidemiology* / Q000235:genetics / Q000473:pathology; D005260:Female; D006801:Humans; D014430:Twins, Monozygotic