title: A twin study of polycystic ovary syndrome.
abstract: OBJECTIVE
  To examine the role of genetic and environmental factors in polycystic ovary syndrome (PCOS) by using the classic twin model.
  
  
  METHODS
  Outpatient clinic of the Royal Hospital for Women, Paddington, Sydney, New South Wales, Australia.
  
  
  METHODS
  A group of 19 monozygotic (MZ) and 15 dizygotic (DZ) twin pairs identified from the national twin register.
  
  
  METHODS
  Ultrasound, clinical, and biochemical parameters were used to define PCOS.
  
  
  RESULTS
  Eleven pairs of twins (5 MZ, 6 DZ pairs) were scan-discordant (i.e., one twin had scan-PCOS and the co-twin did not). Model-fitting analysis suggested that fasting insulin level, androstanediol glucuronide, and body mass index (BMI) were significantly influenced by genetic factors.
  
  
  CONCLUSIONS
  This study suggests that PCOS is not the result of a single autosomal genetic defect, but rather environmental factors, perhaps both intrauterine and extrauterine, are involved in the pathogenesis of this disorder or that PCOS may be an X-linked disorder or the result of polygenic factors. However, fasting insulin level, androstanediol glucuronide, and BMI did appear to be under significant genetic influence.
authors.affiliation: Royal Hospital for Women, Paddington, New South Wales, Australia.
authors.forename: S
authors.initials: S
authors.lastname: Jahanfar
authors.forename: J A
authors.initials: JA
authors.lastname: Eden
authors.forename: P
authors.initials: P
authors.lastname: Warren
authors.forename: M
authors.initials: M
authors.lastname: Seppälä
authors.forename: T V
authors.initials: TV
authors.lastname: Nguyen
mesh_terms: D000293:Adolescent; D000328:Adult; D000728:Androgens / Q000097:blood; D001786:Blood Glucose / Q000032:analysis; D015992:Body Mass Index; D002352:Carrier Proteins / Q000097:blood; D004200:Diseases in Twins; D005260:Female; D005640:Follicle Stimulating Hormone / Q000097:blood; D006628:Hirsutism; D006801:Humans; D007328:Insulin / Q000097:blood; D018970:Insulin-Like Growth Factor Binding Protein 1; D018971:Insulin-Like Growth Factor Binding Protein 2; D007334:Insulin-Like Growth Factor I / Q000032:analysis; D007986:Luteinizing Hormone / Q000097:blood; D008875:Middle Aged; D015233:Models, Statistical; D011085:Polycystic Ovary Syndrome / Q000000981:diagnostic imaging / Q000453:epidemiology* / Q000235:genetics; D011388:Prolactin / Q000097:blood; D012016:Reference Values; D012738:Sex Hormone-Binding Globulin / Q000032:analysis; D014429:Twins, Dizygotic; D014430:Twins, Monozygotic; D014463:Ultrasonography
chemical_list: D000728:Androgens; D001786:Blood Glucose; D002352:Carrier Proteins; D007328:Insulin; D018970:Insulin-Like Growth Factor Binding Protein 1; D018971:Insulin-Like Growth Factor Binding Protein 2; D012738:Sex Hormone-Binding Globulin; D007334:Insulin-Like Growth Factor I; D011388:Prolactin; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone