Table 1. Association between individual study characteristics and MTHFR C677T polymorphism.

Study	Country	Ethnicity	Genetic type	Mean age, yearcases/controls	CIN I			CIN II/III			Invasive cancer			Control			Scores
					CC	CT	TT	CC	CT	TT	CC	CT	TT	CC	CT	TT
Mostowska et al.	Poland	Caucasian	C677T	54.6/53.3							56	59	9	69	81	18	9
Prasad et al.	India	Mixed	C677T	NA/NA							57	5	0	116	8	1	6
Tong et al.	Kerea	Asian	C677T	50.8/45.7	52	82	25	54	74	32	53	65	28	152	198	77	8
Kohaar et al.	India	Caucasian	C677T	49.4/48.2				28	11	0	113	47	4	161	65	5	7
Nandan et al.	India	Mixed	C677T	NA/NA							36	0	26	53	0	24	8
Shekari et al.	India	Caucasian	C677T	48.6/48.8							125	68	7	170	28	2	7
Ma et al.	China	Asian	C677T	52.5/50.6							20	53	38	33	60	18	7
Kang et al.	Kerea	Asian	C677T	NA/NA							27	32	20	30	32	12	7
Zoodsma et al.	Netherlands	Caucasian	C677T	NA/NA	27	21	6	121	120	23	357	230	49	273	262	57	8
Sull et al.	Kerea	Asian	C677T	50.3/46.2	10	22	8	50	90	36	73	115	58	153	221	80	7
Lambropoulos et al.	Greece	Caucasian	C677T	33.2/33.2	20	28	5	27	29	8	11	8	2	42	37	12	6
Piyathilake et al.	USA	Mixed	C677T	30.4/23.9	6	13	6	11	23	5				16	12	3	7

Abbreviations and definitions: CIN, cervical intraepithelial neoplasia; MTHFR, methylenetetrahydrofolate reductase; NA, not available.