title: Methylenetetrahydrofolate reductase enzyme polymorphisms as maternal risk for Down syndrome among Turkish women.
abstract: Advanced maternal age is the only fully accepted risk factor for trisomy 21, while most children with Down syndrome (DS) are born to younger mothers (<35 years). The relationship between chromosomal nondisjunction leading to aneuploidy and folate metabolism has drawn attention in the recent years. In this study, we examined the two polymorphisms in genes encoding the folate metabolizing enzyme methylenetetrahydrofolate reductase (MTHFR), namely, 677C > T and 1298A > C. The prevalence of these variant genotypes in mothers of DS children (case mothers) (n = 152) was compared with controls (n = 91). Frequencies of MTHFR 677C > T genotypes (CC, CT, and TT) and also combination of heterozygous and homozygous variant genotypes (CT or TT) (P = 0.28) demonstrated no difference between the case and control groups. Genotype frequencies of MTHFR 1298A > C (AA, AC, and CC) were similar among the case and control mothers. Variant genotypes of MTHFR 1298A > C (AC or CC) were also insignificant when compared between the two groups. This is yet the largest case-control study conducted for MTHFR 677C > T and also the first to investigate a possible relation with MTHFR 1298A > C. The data presented in this study fail to support the relationship between MTHFR 677C > T and 1298A > C polymorphisms and risk of having a child with DS.
authors.affiliation: Hacettepe University, İhsan Doğramacı Children's Hospital, Department of Pediatrics, Genetics Unit, Ankara, Turkey.
authors.forename: Koray
authors.initials: K
authors.lastname: Boduroğlu
authors.affiliation: Hacettepe University, İhsan Doğramacı Children's Hospital, Department of Pediatrics, Genetics Unit, Ankara, Turkey.
authors.forename: Yasemin
authors.initials: Y
authors.lastname: Alanay
authors.affiliation: Hacettepe University, İhsan Doğramacı Children's Hospital, Department of Pediatrics, Genetics Unit, Molecular Genetics Laboratory, Ankara, Turkey.
authors.forename: Berrin
authors.initials: B
authors.lastname: Koldan
authors.affiliation: Hacettepe University, İhsan Doğramacı Children's Hospital, Department of Pediatrics, Genetics Unit, Ankara, Turkey.
authors.forename: Ergül
authors.initials: E
authors.lastname: Tunçbilek
mesh_terms: D000328:Adult; D000483:Alleles; D016022:Case-Control Studies; D002891:Chromosomes, Human, Pair 21; D004314:Down Syndrome / Q000235:genetics*; D005260:Female; D005492:Folic Acid / Q000235:genetics / Q000378:metabolism; D005787:Gene Frequency / Q000235:genetics; D005838:Genotype; D006801:Humans; D008423:Maternal Age; D042965:Methylenetetrahydrofolate Reductase (NADPH2) / Q000235:genetics*; D011110:Polymorphism, Genetic; D011247:Pregnancy; D018566:Pregnancy, High-Risk; D012307:Risk Factors; D014314:Trisomy; D014421:Turkey
chemical_list: D005492:Folic Acid; D042965:Methylenetetrahydrofolate Reductase (NADPH2)