title: The ADA*2 allele of the adenosine deaminase gene (20q13.11) and recurrent spontaneous abortions: an age-dependent association.
abstract: OBJECTIVE
  Adenosine deaminase acts on adenosine and deoxyadenosine metabolism and modulates the immune response. The adenosine deaminase G22A polymorphism (20q.11.33) influences the level of adenosine deaminase enzyme expression, which seems to play a key role in maintaining pregnancy. The adenosine deaminase 2 phenotype has been associated with a protective effect against recurrent spontaneous abortions in European Caucasian women. The aim of this study was to investigate whether the G22A polymorphism of the adenosine deaminase gene is associated with recurrent spontaneous abortions in Brazilian women.
  
  
  METHODS
  A total of 311 women were recruited to form two groups: G1, with a history of recurrent spontaneous abortions (N = 129), and G2, without a history of abortions (N = 182). Genomic DNA was extracted from peripheral blood with a commercial kit and PCR-RFLP analysis was used to identify the G22A genetic polymorphism. Fisher's exact test and odds ratio values were used to compare the proportions of adenosine deaminase genotypes and alleles between women with and without a history of recurrent spontaneous abortion (p<0.05). The differences between mean values for categorical data were calculated using unpaired t tests. The Hardy-Weinberg equilibrium was assessed with a chi-square test.
  
  
  RESULTS
  Statistically significant differences were identified for the frequencies of adenosine deaminase genotypes and alleles between the G1 and G2 groups when adjusted for maternal age.
  
  
  CONCLUSIONS
  The results suggest that the adenosine deaminase *2 allele is associated with a low risk for recurrent spontaneous abortions, but this association is dependent on older age.
authors.affiliation: Immunogenetics Laboratory, Molecular Biology Department, Faculdade de Medicina de São José do Rio Preto (FAMERP), São José do Rio Preto, SP, Brazil.
authors.forename: Daniela Prudente Teixeira
authors.initials: DP
authors.lastname: Nunes
authors.forename: Lígia Cosentino Junqueira Franco
authors.initials: LC
authors.lastname: Spegiorin
authors.forename: Cinara Cássia Brandão de
authors.initials: CC
authors.lastname: Mattos
authors.forename: Antonio Helio
authors.initials: AH
authors.lastname: Oliani
authors.forename: Denise Cristina Mós
authors.initials: DC
authors.lastname: Vaz-Oliani
authors.forename: Luiz Carlos de
authors.initials: LC
authors.lastname: Mattos
mesh_terms: D000026:Abortion, Habitual / Q000453:epidemiology / Q000235:genetics*; D000022:Abortion, Spontaneous / Q000453:epidemiology / Q000235:genetics; D000243:Adenosine Deaminase / Q000235:genetics*; D000328:Adult; D000367:Age Factors; D000483:Alleles; D001938:Brazil / Q000453:epidemiology; D016022:Case-Control Studies; D016009:Chi-Square Distribution; D005260:Female; D005838:Genotype; D006801:Humans; D011110:Polymorphism, Genetic / Q000235:genetics*; D011247:Pregnancy
chemical_list: D000243:Adenosine Deaminase
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