[Folate gene polymorphism and the risk of Down syndrome pregnancies in young Chinese women].
To explore the relationship between genetic polymorphisms in methylenetetrahydrofolate reductase (MTHFR), methionine synthase reductase (MTRR), reduced folate carrier1 (RFC-1), methionine synthase (MTR) involved in folate metabolism and the risk of offsprings of young Chinese women with Down syndrome (DS) through a case-control study, the polymorphisms of MTHFR 677C>T, MTRR 66A>G, RFC-1 80G>A, and MTR 2756A>G in 60 mothers of children with DS and 68 control mothers were investigated by PCR-RFLP. Significant differences in alle-lic frequencies were present between the cases and controls for MTHFR (Plt;0.05), but not in allelic frequencies for MTRR, RFC-1, and MTR. Homozygous MTHFR 677C>T polymorphism was more prevalent among the mothers of children with DS than among the control mothers, with an odds ratio of 3.51 (OR=3.51, 95% CI=1.30~9.46, Plt;0.05). No significant association was observed in the combined heterozygotes. In addition, the homozygous MTRR 66A>G polymorphism was independently associated with a 3.16-fold increase in estimated risk (OR=3.16, 95% CI=1.20~8.35, Plt;0.05). The increased risk of DS for homozygous RFC-1 80G>A was not associated with MTR 2756A>G. Positive interactions were found for the following genotype-pairs: MTHFR(CT+TT)/MTRR GG, MTHFR (CT+TT)/RFC-1 AA, MTHFR CC/MTR(AG+GG), MTHFR (CT+TT)/MTR AA, MTRR GG/MTR AA, and RFC-1 AA/MTRAA. In conclusion, MTHFR 677C>T and MTRR 66A>G polymorphisms are two independent risk factors for DS pregnancies in young women, but RFC-1 80G>A and MTR 2756A>G polymorphism are not independent risk factor. A role for combined genotypes in the risk of DS pregnancies cannot be excluded.
Liao
Ya-Ping
YP
Department of Cell Biology, Bengbu Medical College, Bengbu 233030, China. liaoyaping2003@sina.com
Bao
Ming-Sheng
MS
Liu
Chang-Qing
CQ
Liu
Hui
H
Zhang
Ding
D
D013766:5-Methyltetrahydrofolate-Homocysteine S-Methyltransferase / Q000235:genetics*; D000328:Adult; D000483:Alleles; D016022:Case-Control Studies; D004314:Down Syndrome / Q000235:genetics*; D005260:Female; D005287:Ferredoxin-NADP Reductase / Q000235:genetics*; D005787:Gene Frequency; D020022:Genetic Predisposition to Disease / Q000235:genetics; D005838:Genotype; D006801:Humans; D016015:Logistic Models; D026901:Membrane Transport Proteins / Q000235:genetics*; D042965:Methylenetetrahydrofolate Reductase (NADPH2) / Q000235:genetics*; D016017:Odds Ratio; D016133:Polymerase Chain Reaction; D012150:Polymorphism, Restriction Fragment Length; D020641:Polymorphism, Single Nucleotide; D011247:Pregnancy; D018570:Risk Assessment; D012307:Risk Factors; D055815:Young Adult
D026901:Membrane Transport Proteins; C120043:SLC19A2 protein, human; C111241:methionine synthase reductase; D005287:Ferredoxin-NADP Reductase; D042965:Methylenetetrahydrofolate Reductase (NADPH2); D013766:5-Methyltetrahydrofolate-Homocysteine S-Methyltransferase