Mother's and child's methylenetetrahydrofolate reductase C677T polymorphism is associated with preterm delivery and low birth weight.
OBJECTIVE
To investigate the association of the C677T polymorphism of the 5,10-methyleneterahydrofolate reductase(MTHFR) gene with preterm delivery(PTD) and low birth weight (LBW).


METHODS
A total of 250 normal gestational age families and 250 PTD families were enrolled in the study. Polymerase Chain Reaction (PCR) followed by restriction enzyme digestion were used for genotyping the polymorphism of MTHFR C677T. A Maximum Likelihood Ratio Test approach based on the log-linear model was used to analyze the relationship of MTHFR gene polymorphism and risk of PTD and LBW.


RESULTS
Firstly, we checked the Mendelian transmissions of the variant alleles of MTHFR 677T in PTD and LBW control-parent-triads using TDT test, respectively. These analyses of controls support Mendelian transmission. When children's genotypes were considered, the MTHFR CT and TT genotypes could significantly increase the risk of PTD and LBW, compared to the genotype of MTHFR CC, the odds ratio and 95% confidence interval (CI) for MTHFR CT and TT genotypes were 2.01,1.21-3.32  1.82, 1.02-3.26 in PTD group, and were 1.87, 1.08-3.24;1.90, 1.02-3.54 in LBW group respectively. When mother's genotypes were considered, the MTHFR gene polymorphism was not associated with PTD and LBW. Meanwhile, we also examined the association of mothers' and children's combined genotypes of MTHFR C677T with the risk of PTD and LBW, and did not find any significant interaction between mothers' and children's genotypes.


CONCLUSIONS
The infant MTHFR CT and TT genotypes are responsible for mothers' PTD and LBW in our study population. It supports that the non-Mendelian transmission among preterm children is due to a causal association between the MTHFR 677T variant alleles and preterm delivery  and MTHFR gene likely affects LBW via shortened gestation (PTD).
Chen
Da-fang
DF
Department of Cell Biology and Genetics,Peking University School of basic medical Science, Beijing 100083,China. dafengchen@bjmu.edu.cn
Hu
Yong-hua
YH
Yang
Fan
F
Wu
Bai-yan
BY
Chen
Li
L
Fang
Zhi-an
ZA
Wang
Li-hua
LH
D001724:Birth Weight; D005260:Female; D005838:Genotype; D006801:Humans; D007230:Infant, Low Birth Weight; D007231:Infant, Newborn; D042965:Methylenetetrahydrofolate Reductase (NADPH2) / Q000235:genetics*; D007752:Obstetric Labor, Premature / Q000209:etiology*; D011110:Polymorphism, Genetic; D011247:Pregnancy
D042965:Methylenetetrahydrofolate Reductase (NADPH2)