Figure 1.
Simplified overview of folate metabolism pathway, highlighting enzymes with polymorphisms investigated in this study.
MTHFR, methylene tetrahydrofolate reductase; MTR, methionine synthase; SAH, S-adenosylhomocysteine; SAM, S-adenosylmethionine; MTRR, methionine synthase reductase; THF, tetrahydrofolate. RFC, the reduced folate carrier.
Figure 2.
Flow chart of the literature search.
Figure 3.
Pooled frequencies of the MTHFR C677T alleles and MTHFR A1298C alleles in controls stratified by ethnicity.
Native A, Native America.
Figure 4.
The overall forest plot of OR with 95%CI for MTR A2756G, MTRR A66G and RFC-1 A80G polymorphism and Neural tube defects risk in dominant model.
Table 1.
Summarized odds ratios with 95% confidence intervals for the association between genetic polymorphisms in the folate pathway and Neural Tube Defects risk.
Table 2.
Stratified analysis of the association between MTHFR C677T polymorphism and Neural Tube Defects in dominant model.
Table 3.
Summarized odds ratios with confidence intervals of stratified studies for MTHFR A1298C polymorphism.
Table 4.
Sensitive analysis of pooled OR for Genetic polymorphisms in MTHFR in the folate pathway.
Figure 5.
The cumulative forest plot of OR with 95%CI for MTHFR C677T polymorphism, MTHFR A1298C and Neural tube defects risk in dominant model.
Figure 6.
The funnel plot of natural logarithm of OR against inverse standard error in each study.