Methylenetetrahydrofolate reductase C677T and A1298C polymorphisms and gastric cancer susceptibility

Table 1 Characteristics of eligible studies included in the meta-analysis

Ref.	Country	Ethnicity	Sample size		C677T											A1298C
					Genotypes distribution						Alleles frequency				P	Genotypes distribution						Alleles frequency				P
			Case	Control	Case			Control			Case		Control		HWE	Case			Control			Case		Control		HWE
					CC	CT	TT	CC	CT	TT	C	T	C	T		AA	AC	CC	AA	AC	CC	A	C	A	C
Gao et al[12]	China	Eastern	264	535	115	105	44	277	207	51	335	193	761	309	0.19
Guo et al[13]	China	Eastern	97	114	22	48	27	32	57	25	92	102	121	107	0.97
Saberi et al[14]	Iran	Eastern	405	780	198	172	35	422	308	50	578	242	1152	408	0.54
Yang et al[15]	China	Eastern	139	165	44	80	15	62	75	28	168	110	197	131	0.5
Cui et al[16]	South Korea	Eastern	2213	1700	778	1052	382	540	863	297	2608	1816	1943	1457	0.13
De Re et al[17]	Italy	Western	48	96	12	23	13	37	46	13	47	49	120	72	0.73	24	19	5	33	54	9	67	29	120	72	0.08
Galvan-Portillo et al[18]	Mexico	Western	248	478	37	132	79	89	217	172	216	290	395	561	0.17
Gotze et al[19]	Germany	Western	106	106	46	45	12	41	49	16	137	69	131	81	0.74
Zeybek et al[20]	Turkey	Eastern	35	144	18	12	5	64	65	15	48	22	193	95	0.76
Vollset et al[21]	Europea1	Western	247	631	109	104	32	248	277	94	322	168	773	465	0.27	103	116	25	315	246	53	322	166	876	352	0.61
Mu et al[22]	China	Eastern	196	397	50	106	38	135	199	57	206	182	469	313	0.23	147	49	0	275	112	7	343	49	662	126	0.25
Zhang et al[23]	Poland	Western	305	427	146	116	33	185	178	36	408	182	548	250	0.48	135	125	31	180	179	41	395	187	539	261	0.72
Boccia et al[24]	Italy	Western	102	254	29	51	22	98	115	41	109	95	311	197	0.43	50	43	9	125	107	22	143	61	357	151	0.89
Fu et al[25]	China	Eastern	169	169												96	73	0	125	44	0	265	73	294	44	0.12
Graziano et al[26]	Italy	Western	162	164	34	86	42	67	68	29	154	126	202	126	0.10
Li et al[27]	China	Eastern	170	140	61	78	31	67	56	17	200	140	190	90	0.32	126	42	2	97	41	2	294	46	235	45	0.32
Weng et al[28]	China	Eastern	38	34	14	19	5	15	11	8	47	29	41	27	0.06	26	12	0	22	11	1	64	12	55	13	0.79
Kim et al[29]	South Korea	Eastern	133	445	42	64	27	143	239	63	148	118	525	365	0.022	98	34	1	308	129	8	230	36	745	145	0.19
Si et al[30]	China	Eastern	122	101	58	48	16	49	43	9	164	80	141	61	0.92	73	44	5	58	38	5	190	54	154	48	0.70
Sarbia et al[31]	Germany	Western	332	255	138	153	41	107	115	33	429	235	329	181	0.81
Bi et al[32]	China	Eastern	309	188	139	150	20	97	76	15	428	190	270	106	0.99
Wang et al[33]	China	Eastern	129	315	25	45	59	74	143	98	95	163	291	339	0.12
Stolzenberg-Solomon et al[34]	China	Eastern	90	398	17	36	37	65	209	124	70	110	339	457	0.14	69	21	0	294	104	0	159	21	692	104	0.0032
Miao et al[35]	China	Eastern	217	468	47	107	63	151	217	100	201	233	519	417	0.18	150	64	3	324	139	5	364	70	787	149	0.022
Gao et al[36]	China	Eastern	107	200	22	61	24	63	99	38	105	109	225	175	0.93
Shen et al[37]	China	Eastern	187	166	55	90	42	60	80	26	200	174	200	132	0.96	130	55	2	111	50	5	315	59	272	60	0.83

¹Study involving Denmark, France, Greece, Germany, Italy, the Netherlands, Norway, Spain, Sweden, and United Kingdom;

²Studies with the controls not in Hardy-Weinberg equilibrium (HWE).