title: Familial risk among Japanese patients with endometriosis.
abstract: OBJECTIVE
  This study was designed to examine the prevalence of endometriosis among female siblings of patients with endometriosis in Japan.
  
  
  METHODS
  A total of 339 patients with endometriosis were questioned about endometriosis in their sisters. The control group consisted of 284 Japanese healthy fertile women with no history of endometriosis. Similarly, the controls were interviewed about their sisters.
  
  
  RESULTS
  We detected sisters with endometriosis in 8.8% of cases and 1.5% of the control population. The relative risk of endometriosis in female siblings was 5.7. However, a significant difference was not seen in age at diagnosis and clinical stage between patients with or without a family history of endometriosis.
  
  
  CONCLUSIONS
  These data demonstrate a familial tendency for endometriosis and suggest that endometriosis has a genetic factor in the pathogenesis.
authors.affiliation: Department of Obstetrics and Gynecology, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan. kashimak@med.niigata-u.ac.jp
authors.forename: K
authors.initials: K
authors.lastname: Kashima
authors.forename: T
authors.initials: T
authors.lastname: Ishimaru
authors.forename: H
authors.initials: H
authors.lastname: Okamura
authors.forename: H
authors.initials: H
authors.lastname: Suginami
authors.forename: K
authors.initials: K
authors.lastname: Ikuma
authors.forename: T
authors.initials: T
authors.lastname: Murakami
authors.forename: M
authors.initials: M
authors.lastname: Iwashita
authors.forename: K
authors.initials: K
authors.lastname: Tanaka
mesh_terms: D000293:Adolescent; D000328:Adult; D016022:Case-Control Studies; D004715:Endometriosis / Q000453:epidemiology / Q000235:genetics*; D005260:Female; D020022:Genetic Predisposition to Disease / Q000453:epidemiology*; D006801:Humans; D007564:Japan / Q000453:epidemiology; D008875:Middle Aged; D015995:Prevalence; D012307:Risk Factors; D035781:Siblings; D011795:Surveys and Questionnaires