Table 1. Characteristics of the included case-control studies on the MTHFR C677T polymorphism in cervical lesions.

Firstauthor[reference]	Year	Sourceofcontrol	SourceofDNA	Country	Ethnicity	HWE	Histology	Samplesize		Case						Control
								case	control	C	T	CC	CT	TT	CT+TT	C	T	CC	CT	TT	CT+TT
Prasad [20]	2011	Mixed	Blood	India	Asian	NS	ICC	62	125	119	5	57	5	0	5	240	10	116	8	1	9
Mostowska [21]	2011	Healthy persons	Blood	Poland	Caucasian	NS	ICC	124	168	194	77	56	59	9	68	219	117	69	81	18	99
Tong [26]	2011	Healthy persons	Blood	Korea	Asian	NS	LSIL	159	427	186	132	52	82	25	107	502	352	152	198	77	275
							HSIL	160	427	182	138	54	74	32	106	502	352	152	198	77	275
							ICC	146	427	171	121	53	65	28	93	502	352	152	198	77	275
Kohaar [22]	2010	Healthy persons	Tissue or cell	India	Asian	NS	HSIL	39	231	67	11	28	11	0	11	387	75	161	65	5	70
							ICC	164	231	273	55	113	47	4	51	387	75	161	65	5	70
Shekari [32]	2008	Healthy persons	Blood	India	Asian	NS	ICC	200	200	368	32	170	28	2	30	318	82	125	68	7	75
Nandan [27]	2008	Healthy persons	Blood	India	Asian	NA	SIL	80	77	NA	NA	34	NA	NA	46	NA	NA	53	NA	NA	24
							ICC	62	77	NA	NA	36	NA	NA	26	NA	NA	53	NA	NA	24
Piyathilake [33]	2007	Mixed	Blood	USA	Mixed	NS	HSIL	80	355	134	26	59	16	5	21	562	148	223	116	16	132
Zoodsma [34]	2005	Mixed	Blood	Netherlands	Caucasian	NS	HSIL	264	592	362	166	121	120	23	143	808	376	273	262	57	319
							ICC	636	592	944	328	357	230	49	279	808	376	273	262	57	319
Kang [23]	2005	Healthy persons	Blood	Korean	Asian	NS	ICC	79	74	86	72	27	32	20	52	92	56	30	32	12	44
Sull [28]	2004	Healthy persons	Blood	Korean	Asian	NS	LSIL	40	454	42	38	10	22	8	30	527	381	153	221	80	301
							HSIL	176	454	190	162	50	90	36	126	527	381	153	221	80	301
							ICC	246	454	261	231	73	115	58	173	527	381	153	221	80	301
Lambropoulos [24]	2003	Healthy persons	Tissue or cell	Greece	Caucasian	NS	LSIL	53	91	68	38	20	28	5	33	121	61	42	37	12	49
							HSIL	64	91	83	45	27	29	8	37	121	61	42	37	12	49
							ICC	21	91	30	12	11	8	2	10	121	61	42	37	12	49
Goodman [29]	2001	Hospital patients	Blood	USA	Mixed	NS	SIL	150	179	213	87	73	67	10	77	261	97	93	75	11	86
Piyathilake [30]	2000	Healthy persons	Tissue or cell	USA	Mixed	NS	LSIL	25	31	25	25	6	13	6	19	44	18	16	12	3	15
							HSIL	39	31	45	33	11	23	5	28	44	18	16	12	3	15
Agodi [35]	2010	Healthy persons	Cell	Italy	Caucasian	NA	SIL	123	66	NA	NA	118	NA	NA	5	NA	NA	55	NA	NA	11
Yang [25]	2011	Mixed	Blood	China	Asian	NS	SIL	38	382	60	16	23	14	1	15	530	234	182	166	34	200
							ICC	157	382	229	85	77	75	5	80	530	234	182	166	34	200
Ma [31]	2006	Hospital patients	Blood	China	Asian	NS	ICC	111	111	93	129	20	53	38	91	126	96	33	60	18	78

Abbreviations: HWE, Hardy-Weinberg Equilibrium; NA, not available; NS, not significant; LSIL, low-grade squamous intraepithelial lesion; HSIL, high-grade squamous intraepithelial lesion; ICC, invasive cervical cancer; SIL, squamous intra-epithelial lesion.