Table 3. Summary of datasets included for meta-analysis.

ID	Author	Year	Ethnicity	Genotyping method	Study design	SNP loc	Case/Control	GD genotype			Control genotype			pHWE
								AA	AG	GG	AA	AG	GG
1	Heward et al.	1999	European	PCR-RFLP	CC	rs231775	379/363	122	192	65	164	171	28	0.07
2	Park et al.	2000	Asian	PCR-RFLP	CC	rs231775	97/199	5	35	57	26	75	98	0.06
3	Kouki et al.	2000	European	PCR-RFLP	CC	rs231775	45/43	8	29	8	15	23	5	0.39
4	Hadj et al.	2001	European	PCR-RFLP	CC	rs231775	144/205	31	63	50	26	94	85	0.99
5	Kouki et al.	2002	Asian	PCR-RFLP	CC	rs231775	120/80	22	67	31	30	36	14	0.58
6	Yung et al.	2002	Asian	SSCP	CC	rs231775	123/158	3	54	66	23	36	14	0.99
7	Vaidya et al.	2003	European	PCR-RFLP	CC	rs231775	301/349	88	139	74	146	158	45	0.83
8	Kalantari et al.	2003	Asian	PCR-RFLP	CC	rs231775	90/90	21	49	20	30	53	7	0.013
9	Petrone et al.	2005	European	Taqman	CC	rs3087243	150/301	26	79	45	83	149	69	0.89
						rs231775		59	68	23	139	138	24	0.201
10	Weng et al.	2005	Asian	PCR-RFLP	CC	rs3087243	107/101	2	27	78	2	45	54	0.033
						rs231775	104/101	5	53	46	15	58	28	0.091
11	Ban et al.	2005	Asian	PCR-RFLP	CC	rs3087243	131/179	2	38	91	14	70	95	0.83
12	Cho et al.	2006	Asian	Sequencing	CC	rs3087243	283/472	7	78	198	13	125	334	0.75
						rs231775	288/471	16	112	160	30	197	244	0.24
13	Han et al.	2006	Asian	DCFH	CC	rs3087243	261/196	8	71	182	13	60	123	0.14
						rs231775	261/196	32	94	135	32	89	75	0.52
14	Wang et al.	2007	Asian	PCR-RFLP	CC	rs3087243	189/192	5	46	138	9	58	125	0.50
						rs231775	208/192	15	69	124	18	77	97	0.63
15	Chong et al.	2008	Asian	Taqman	CC	rs3087243	177/151	4	48	125	12	51	88	0.24
						rs231775		7	73	97	24	56	71	0.03
16	Tsai et al.	2008	Asian	PCR-RFLP	CC	rs3087243	189/192	5	48	136	9	58	125	0.50
17	Namo et al.	2008	European	PCR-RFLP	CC	rs231775	217/149	116	43	58	78	39	32	0.000
18	Sahin et al.	2009	Asian	PCR-RFLP	CC	rs231775	77/98	29	33	15	43	48	7	0.19
19	Esteghamati et al.	2009	Asian	PCR-RFLP	CC	rs231775	205/103	114	71	20	75	25	3	0.61
20	Kimura et al.	2009	Asian	PCR-RFLP	CC	rs231775	415/795	62	143	210	142	358	295	0.07
21	Bicek et al.	2009	European	Taqman	CC	rs3087243	123/117	16	57	50	26	61	30	0.63
						rs231775		33	73	17	47	64	6	0.01
22	Kimkong et al.	2011	Asian	PCR-RFLP	CC	rs3087243	132/153	8	46	78	12	59	82	0.76
23	Yang et al.	2012	Asian	PCR-RFLP	CC	rs231775	303/215	12	139	152	29	97	89	0.75
24	Jurecka-Lubieniecka	2013	European	PCR-RFLP	CC	rs231775	620/340	159	302	159	126	156	58	0.42
25	Chen et al.	2015	Asian	PCR-HRM	CC	rs3087243	260/248	20	100	140	40	101	107	0.056
26	Pawlak-Adamska et al.	2016	European	PCR-RFLP	CC	rs3087243	172/388	18	80	74	68	187	133	0.87
27	Ting et al.	2016	Asian	PCR-RFLP	CC	rs3087243	554/1058	10	149	395	46	382	630	0.21
						rs231775		34	209	311	112	469	477	0.84
Our study	Tu et al.	2017	Asian	Sequencing	CC	rs3087243	271/298	12	65	194	18	103	177	0.56
						rs231775	271/298	16	75	180	50	141	107	0.76

CC: case/control

HWE: Hardy-Weinberg equilibrium

DCFH: Dual-color fluorescence hybridization technique

PCR-HRM: Polymerase chain reaction-high resolution melting