Methylenetetrahydrofolate reductase gene polymorphisms and their association with trisomy 21.
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.
Acácio
Gregório Lorenzo
GL
Department of Obstetrics and Gynecology, School of Medical Sciences, State University of Campinas, Brazil. glacacio@uol.com.br
Barini
Ricardo
R
Bertuzzo
Carmem Sílvia
CS
Couto
Egle Cristina
EC
Annichino-Bizzacchi
Joyce Maria
JM
Júnior
Walter Pinto
WP
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
D015415:Biomarkers; D005492:Folic Acid; D042965:Methylenetetrahydrofolate Reductase (NADPH2)