Table 2. The positive tag SNPs genotypes and allele frequencies in NTDs and controls.

SNP	Genotype/Allele	Cases (%)	Controls (%)	P a	OR	OR(95%CI)
rs4586354	TT	81 (47.4)	164 (54.1)		1
	CT	70 (40.9)	123 (40.6)	0.48	1.15	[0.77,1.71]
	CC	20 (11.7)	16 (5.3)	0.009	2.53	[1.25,5.10]
	CT+CC	90 (52.6)	139 (45.9)	0.15	1.31	[0.90,1.91]
	T	232 (67.8)	451 (74.4)		1
	C	110 (32.2)	155 (25.6)	0.03	1.38	[1.03,1.85]
rs3783903	AA	74 (40.9)	165 (52.2)		1
	AG	87 (48.1)	136 (43)	0.07	1.43	[0.97,2.09]
	GG	20 (11)	15 (4.7)	0.002	2.97	[1.44,6.13]
	AG+GG	107 (57.5)	151 (47.8)	0.015	1.58	[1.09,2.28]
	A	235 (64.9)	466 (73.7)		1
	G	127 (35.1)	166 (26.3)	0.003	1.52	[1.10,2.00]
rs2236131	GG	78 (44.3)	181 (58)		1
	AG	79 (44.9)	115 (36.9)	0.019	1.59	[1.08,2.35]
	AA	19 (10.8)	16 (5.1)	0.004	2.76	[1.35,5.64]
	AG+AA	98 (55.7)	138 (42.3)	0.008	1.65	[1.13,2.4]
	G	235 (66.8)	477 (76.4)		1
	A	117 (33.2)	147 (23.6)	0.001	1.62	[1.20,2.15]
rs1740689	AA	55 (31.6)	139 (44.3)		1
	AG	88 (50.6)	143 (45.5)	0.043	1.55	[1.03,2.30]
	GG	31 (17.8)	32 (10.2)	0.002	2.45	[1.36,4.40]
	AG+GG	119 (68.4)	175 (55.8)	0.006	1.7	[1.16,2.54]
	A	198 (56.9)	421 (67)		1
	G	150 (43.1)	207 (33)	0.002	1.54	[1.17, 2.02]

Abbreviations: NTD, neural tube defect; SNP, single-nucleotide polymorphism; OR, odds ratio; CI, confidence interval.

^a The P value remained significant after Bonferroni correction at 0.05 levels.