Correlation of polymorphism of MTHFRs and RFC-1 genes with neural tube defects in China.
BACKGROUND
Maternal periconceptional supplementation of folate reduces the incidence of neonatal Neural Tube Defects, indicating that changes in folate metabolism play a role in formation of NTDs. The mutations on two genes involved in folate metabolism, the C677 of the MTHFR gene and the RFC-1(A80G) gene are potential risk factors of NTDs.


METHODS
In this study, we analyzed the genotypic distributions and allele frequencies of MTHFR C677T and RFC-1 A80G polymorphisms in DNA samples from mothers with at least one previous child with NTDs (the NTD group) and controls.


RESULTS
Our results indicated that there was a significant difference in the genotype and allele frequencies of RFC-1 80A-->G between the NTD group and controls (p = .008 and p = .017, respectively). There was, however, no significant difference in the genotype and allele frequencies of the MTHFR 677C-->T polymorphism between the NTD group and controls. The NTD group was further separated into the upper and lower types by location of abnormalities. The frequency of RFC-1 80A/G and 80G/G was significantly higher in the upper group than the control (p = .009 and p = .005, respectively). The frequency of G-alleles was also significantly higher in the upper group than the control (OR 2.42; p = .006; 95% CI: 1.28-4.58). For the MTHFR C677 gene, the frequency of T-alleles was significantly lower in the lower defect type than the control group (OR 0.32; p = .027; 95% CI: 0.11-0.9).


CONCLUSIONS
These results suggest that in the Shanxi population RFC-1 polymorphisms may play a role in NTD risk, whereas the impact of MTHFR C677T polymorphisms requires further clarification. Birth Defects Research (Part A) 2008.
Shang
Yali
Y
Department of Biochemistry and Molecular Biology, Shanxi Medical University, Taiyuan.
Zhao
Hong
H
Niu
Bo
B
Li
Wan-I
WI
Zhou
Ran
R
Zhang
Ting
T
Xie
Jun
J
D002681:China; D006801:Humans; D042965:Methylenetetrahydrofolate Reductase (NADPH2) / Q000235:genetics*; D009436:Neural Tube Defects / Q000235:genetics*; D016133:Polymerase Chain Reaction; D011110:Polymorphism, Genetic; D012150:Polymorphism, Restriction Fragment Length; D058978:Reduced Folate Carrier Protein / Q000235:genetics*
D058978:Reduced Folate Carrier Protein; C548699:SLC19A1 protein, human; D042965:Methylenetetrahydrofolate Reductase (NADPH2)