Table 1.

Main characteristics and genotype information of included studies

First author	Year	Cases	Controls	Cases					Controls
				AA	AB	BB	A	B	AA	AB	BB	A	B
rs1447295 (C/A)				AA	AC	CC	A	C	AA	AC	CC	A	C
Wang L	2007	491	545	9	99	383	117	865	5	101	439	111	979
Chen M	2009	340	337	6	119	215	131	549	9	75	253	93	581
Xie HJ	2010	120	120	5	41	74	51	189	4	26	90	34	206
Zheng SL	2010	288	155	15	96	173	126	442	6	35	110	47	255
Liu Y	2011	40	40	22	7	11	51	29	20	15	5	55	25
Chan J	2013	289	144	17	92	180	126	452	5	44	94	54	232
Zhao CX	2013	289	288	8	108	161	124	430	4	86	197	94	480
Zhang Z	2014	123	137	4	45	74	53	193	2	44	91	48	226
rs6983267 (T/G)				GG	GT	TT	G	T	GG	GT	TT	G	T
Zheng SL	2010	288	155	62	134	86	258	306	29	72	51	130	174
Liu Y	2011	40	40	5	23	12	33	47	16	17	7	49	31
Chan J	2013	289	144	63	136	89	262	314	23	74	47	120	168
Zhao CX	2013	289	288	56	149	77	261	303	51	137	94	239	325
Zhang Z	2014	124	138	28	54	42	110	138	26	67	45	119	157
rs6983561 (A/C)				CC	AC	AA	C	A	CC	AC	AA	C	A
Chen M	2010	324	336	37	152	135	226	422	25	136	175	186	486
Xie HJ	2010	120	120	11	53	56	75	165	8	50	62	66	174
Zheng SL	2010	288	155	34	141	109	209	359	8	53	80	69	213
Zhang YR	2012	212	231	22	80	110	124	300	14	87	130	115	347
rs7837688 (G/T)				TT	GT	GG	T	G	TT	GT	GG	T	G
Zhao CX	2013	289	288	5	103	171	113	445	4	84	194	92	472
Zhang Z	2014	122	135	1	46	75	48	196	2	48	85	52	218
rs10090154 (C/T)				TT	CT	CC	T	C	TT	CT	CC	T	C
Zheng SL	2010	288	155	14	98	170	126	438	6	30	112	42	254
Pu LM	2011	124	111	1	48	74	50	196	1	32	63	34	158
Zhao CX	2013	289	288	5	106	168	116	442	4	73	203	81	479
Zhang Z	2014	123	131	1	48	74	50	196	2	39	90	43	219
rs16901979 (C/A)				AA	AC	CC	A	C	AA	AC	CC	A	C
Chen M	2010	331	335	35	148	148	218	444	24	138	173	186	484
Xie HJ	2010	120	120	10	56	54	76	164	8	54	58	70	170
Zheng SL	2010	288	155	34	139	110	207	359	8	52	85	68	222
Chan J	2013	289	144	31	119	139	181	397	12	68	64	92	196

A = risk allele; B = non-risk allele; AA = homozygous risk alleles; AB = heterozygous; BB = homozygous non-risk alleles.