title: The genetics of haemostasis: a twin study.
abstract: BACKGROUND
  The concentrations of fibrinogen, factor VII and VIII, von Willebrand factor, plasminogen activator inhibitor-1 (PAI-1), and tissue plasminogen activator have been associated with coronary-heart disease. In addition, polymorphisms in the genes coding for fibrinogen, factor VII, PAI-1, and factor XIII have been reported to affect both protein concentrations and cardiovascular disease risk.
  
  
  METHODS
  We did a classic twin study to assess heritabilities of these haemostatic factors. We enrolled 1002 female twins; 149 pairs of monozygotic and 352 pairs of dizygotic twins. 89 monozygotic and 196 dizygotic twin pairs were analysed for factor VII.
  
  
  RESULTS
  Quantitative genetic model fitting showed that genetic factors contributed to about 41-75% of the variation in concentrations of fibrinogen, factor VII, factor VIII, PAI-1, tissue plasminogen activator, factor XIII A-subunit and B-subunit, and von Willebrand factor. Factor XIII activity showed higher (82%) and factor XIIa lower (38%) heritability.
  
  
  CONCLUSIONS
  We have shown that genetic factors have a major effect on plasma concentrations of haemostatic proteins. Our results stress the importance of research into the genetic regulation of proteins involved in haemostasis and atherothrombotic disorders, including myocardial infarction and stroke.
authors.affiliation: Twin Research and Genetic Epidemiology Unit, St Thomas' Hospital, London, UK.
authors.forename: M
authors.initials: M
authors.lastname: de Lange
authors.forename: H
authors.initials: H
authors.lastname: Snieder
authors.forename: R A
authors.initials: RA
authors.lastname: Ariëns
authors.forename: T D
authors.initials: TD
authors.lastname: Spector
authors.forename: P J
authors.initials: PJ
authors.lastname: Grant
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001779:Blood Coagulation Factors / Q000032:analysis*; D005260:Female; D006487:Hemostasis / Q000235:genetics*; D006801:Humans; D008875:Middle Aged
chemical_list: D001779:Blood Coagulation Factors