Table 2. Overall and subgroup results of the association between MTHFR C677T polymorphism and NSCL/P.

Study(n)	T vs. C		TT vs. CC		CT vs. CC		CT/TT vs. CC		TT vs. CC/CT
	OR(95%CI)	P	OR(95%CI)	P	OR(95%CI)	P	OR(95%CI)	P	OR(95%CI)	P
Overall
Children(n = 8)	1.41(1.23–1.61)	<0.001	1.85(1.30–2.63)	0.001	1.61(1.21–2.14)	0.001	1.61(1.22–2.11)	0.001	1.36(1.00–1.86)	0.052
Mothers(n = 6)	1.70(1.19–2.42)	0.003	2.58(1.09–6.09)	0.031	1.66(1.08–2.55)	0.021	1.83(1.17–2.88)	0.008	1.95(1.32–2.86)	0.001
Eastern Asia
Children(n = 4)	1.31(0.95–1.80)	0.099	1.79(1.16–2.76)	0.009	1.68(0.88–3.22)	0.117	1.66(0.89–3.10)	0.111	1.26(0.87–1.83)	0.217
Mothers(n = 3)	1.39(0.75–2.54)	0.293	2.19(0.46–10.44)	0.326	1.09(0.72–1.65)	0.688	1.28(0.64–2.59)	0.487	2.06(0.64–6.61)	0.224
Western/Central Asia
Children(n = 4)	1.50(1.25–1.81)	<0.001	1.96(1.08–3.55)	0.026	1.56(1.25–1.95)	<0.001	1.61(1.30–1.99)	<0.001	1.44(0.53–3.95)	0.477
Mothers(n = 3)	2.11(1.58–2.81)	<0.001	3.66(1.78–7.52)	<0.001	2.40(1.64–3.50)	<0.001	2.53(1.75–3.64)	<0.001	2.38(1.22–4.66)	<0.001