title: Methylenetetrahydrofolate reductase gene polymorphisms and their association with trisomy 21.
abstract: OBJECTIVE
  To verify whether the frequencies of 5,10-methylenotetrahydrofolate reductase (MTHFR) polymorphisms at positions 677 and 1298 are higher in women with children affected by trisomy 21 than in those with chromosomally normal offspring.
  
  
  METHODS
  A case-control study was carried out with 70 women whose children had trisomy 21 and 88 controls whose children were chromosomally normal. The frequencies of polymorphisms of points C677T and A1298C of MTHFR gene coding were studied in these two groups. Odds ratios (OR) for having a child affected by trisomy 21 were estimated for homozygosis, heterozygosis or the absence of the above-mentioned MTHFR polymorphisms. Logistic regression models were used to control for the effect of confounding variables on these odds ratios.
  
  
  RESULTS
  The frequency of joint heterozygotic polymorphism (677 and 1298) was significantly higher in women with children affected by trisomy 21 than in those with chromosomally normal offspring (OR: 5.7).
  
  
  CONCLUSIONS
  The presence of joint heterozygotic polymorphism in the codifying gene for MTHFR was a risk factor for having a child with trisomy 21.
authors.affiliation: Department of Obstetrics and Gynecology, School of Medical Sciences, State University of Campinas, Brazil. glacacio@uol.com.br
authors.forename: Gregório Lorenzo
authors.initials: GL
authors.lastname: Acácio
authors.forename: Ricardo
authors.initials: R
authors.lastname: Barini
authors.forename: Carmem Sílvia
authors.initials: CS
authors.lastname: Bertuzzo
authors.forename: Egle Cristina
authors.initials: EC
authors.lastname: Couto
authors.forename: Joyce Maria
authors.initials: JM
authors.lastname: Annichino-Bizzacchi
authors.forename: Walter Pinto
authors.initials: WP
authors.lastname: Júnior
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000097:blood; D016022:Case-Control Studies; D004314:Down Syndrome / Q000175:diagnosis / Q000235:genetics*; D005260:Female; D005492:Folic Acid / Q000097:blood; D006579:Heterozygote; D006801:Humans; D016015:Logistic Models; D042965:Methylenetetrahydrofolate Reductase (NADPH2) / Q000235:genetics*; D011110:Polymorphism, Genetic; D011247:Pregnancy
chemical_list: D015415:Biomarkers; D005492:Folic Acid; D042965:Methylenetetrahydrofolate Reductase (NADPH2)