title: Association of maternal IL-1 receptor antagonist intron 2 gene polymorphism and preterm birth.
abstract: OBJECTIVE
  This study was undertaken to determine whether the interleukin-1 receptor antagonist (IL-1RN) variable number tandem repeat polymorphism is associated with preterm birth.
  
  
  METHODS
  A case-control study was performed. Cases (n = 95) delivered before 37 weeks after preterm labor (PTL) or preterm premature rupture of membranes (PPROM) and controls (n = 105) delivered after 37 weeks. Maternal DNA was genotyped by polymerase chain reaction for a length polymorphism in intron 2 of the IL-1RN gene.
  
  
  RESULTS
  There was no significant difference in maternal age, ethnicity, insurance status, or parity between groups. Allele and genotype frequencies did not differ significantly from that expected under Hardy-Weinberg equilibrium (P = .59) in the total group as well as study groups. Of the 95 cases, 26.8% had at least 1 copy of allele 2 present compared with 12.4% in the control group (P < .0004).
  
  
  CONCLUSIONS
  Maternal carriage of at least 1 copy of the IL-1RN allele 2 appears to be associated with increased risk of preterm birth.
authors.affiliation: Department of Obstetrics and Gynecology, Division of Maternal Fetal Medicine, Duke University Medical Center, Durham, NC, USA.
authors.forename: Amy P
authors.initials: AP
authors.lastname: Murtha
authors.forename: Angel
authors.initials: A
authors.lastname: Nieves
authors.forename: Elizabeth R
authors.initials: ER
authors.lastname: Hauser
authors.forename: Geeta K
authors.initials: GK
authors.lastname: Swamy
authors.forename: Bryan A
authors.initials: BA
authors.lastname: Yonish
authors.forename: Tammy R
authors.initials: TR
authors.lastname: Sinclair
authors.forename: R Phillips
authors.initials: RP
authors.lastname: Heine
mesh_terms: D000328:Adult; D000483:Alleles; D016022:Case-Control Studies; D005260:Female; D018628:Gene Dosage; D005787:Gene Frequency; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006801:Humans; D053590:Interleukin 1 Receptor Antagonist Protein / Q000235:genetics*; D007438:Introns / Q000235:genetics*; D011110:Polymorphism, Genetic; D011247:Pregnancy / Q000235:genetics*; D047928:Premature Birth / Q000235:genetics*; D020080:Tandem Repeat Sequences
chemical_list: C507763:IL1RN protein, human; D053590:Interleukin 1 Receptor Antagonist Protein