title: Genetic polymorphisms of the renin-angiotensin system in preterm delivery and premature rupture of membranes.
abstract: BACKGROUND
  Premature rupture of membranes (PRM) is a late pregnancy complication commonly associated with preterm delivery (PD). Although several markers related to the renin-angiotensin system (RAS) have been evaluated in certain pregnancy complications, only the angiotensin-converting enzyme (ACE) I/D variant has been studied in PD-PRM. The aim of this survey was to investigate the association of the polymorphisms (angiotensin II type 1 [AT1] receptor T174M and M235T, renin G2805A, ACE I/D and AT1-receptor A1166C) of the genes of RAS in women with PD-PRM.
  
  
  METHODS
  Deoxyribonucleic acid samples from 89 Mexican Mestizo women with PD and PRM and 224-288 controls were studied. Polymorphisms were analysed by polymerase chain reaction-restricted fragment length polymorphism or sequence specific primer assays.
  
  
  RESULTS
  For all loci, genotype distribution was in agreement with Hardy-Weinberg expectations in the control group. Significant intergroup difference (case vs. control) was seen for angiotensinogen (AGT) M235T polymorphism, with an increased allele M235 in affected cases (50% vs. 40% in controls). Analysis of two-locus haplotype agrees with an independent segregation of physically unlinked genes. Haplotype AGT 174T-235M was also increased (50% vs. 40% in controls).
  
  
  CONCLUSIONS
  Physically unlinked genes involved in RAS segregate independently. The AGT 174-235 region is associated with PD-PRM in this population.
authors.affiliation: Universidad de Colima Facultad de Ciencias Químicas. Kilometro 9 carretera Colima-Coquimatlán, Colima, México. lauravaldez@ucol.mx
authors.forename: Laura L
authors.initials: LL
authors.lastname: Valdez-Velazquez
authors.forename: Antonio
authors.initials: A
authors.lastname: Quintero-Ramos
authors.forename: Sandra A
authors.initials: SA
authors.lastname: Perez
authors.forename: Francisco
authors.initials: F
authors.lastname: Mendoza-Carrera
authors.forename: Hector
authors.initials: H
authors.lastname: Montoya-Fuentes
authors.forename: Fernando
authors.initials: F
authors.lastname: Rivas
authors.forename: Norma
authors.initials: N
authors.lastname: Olivares
authors.forename: Alfredo
authors.initials: A
authors.lastname: Celis
authors.forename: Oscar F
authors.initials: OF
authors.lastname: Vazquez
authors.forename: Fernando
authors.initials: F
authors.lastname: Rivas
mesh_terms: D000293:Adolescent; D000328:Adult; D000808:Angiotensinogen / Q000235:genetics; D016022:Case-Control Studies; D005260:Female; D005322:Premature Rupture of Fetal Membranes / Q000235:genetics*; D005787:Gene Frequency; D006239:Haplotypes; D006801:Humans; D015810:Linkage Disequilibrium; D011110:Polymorphism, Genetic; D011247:Pregnancy; D047928:Premature Birth / Q000235:genetics*; D012084:Renin-Angiotensin System / Q000235:genetics*
chemical_list: D000808:Angiotensinogen