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Disease Markers
Volume 29 (2010), Issue 2, Pages 95-101

Maternal Gene Polymorphisms Involved in Folate Metabolism as Risk Factors for Down Syndrome Offspring in Southern Brazil

Ana Paula Carneiro Brandalize,1,2,3 Eliane Bandinelli,1 Pollyanna Almeida Dos Santos,1,2 and Lavínia Schüler-Faccini1,2,3

1Departamento de Genética, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
2Programa de Pós-Graduação em Genética e Biologia Molecular, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
3Serviço de Genética Médica, Hospital de Clínicas de Porto Alegre, Porto Alegre, Brazil

Received 21 October 2010; Accepted 21 October 2010

Copyright © 2010 Hindawi Publishing Corporation. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


This study aimed to investigate the role of maternal polymorphisms, as well as their risk genotypes combinations of MTR A2756G, MTRR A66G, CBS 844ins68, and RFC A80G, involved in folate/homocysteine metabolism, as possible risk factors for Down syndrome (DS) in Southern Brazil. A case-control study was conducted with 239~mothers of DS children and 197 control mothers. The investigation of polymorphisms was performed by PCR and PCR-RFLP. The distribution of genotypic variants was similar in both groups when they were analyzed separately. An investigation of combined risk genotypes showed that the risk of having a DS child for one, two or three risk genotypes was 6.23, 6.96 and 5.84 (95%CI 1.48–26.26; 1.69–28.66; 1.37–24.86), respectively. The combined MTRR 66G and MTHFR 677T alleles were significantly more common among mothers of children with DS than among control mothers (OR 1.55; IC 95% 1.03–2.35). The results show that individual polymorphisms studied in this work are not associated with DS; however, the effects of the combined risk genotypes among MTR, MTRR, CBS and RFC genes are considered maternal risk factors for DS offspring in our population.