Table 2. Characteristics of include studies about MTHFR A1298C polymorphism.

Author, year	Country	Race	Case group				Control group				pHWE	NOS
			AA	AC	CC	Total	AA	AC	CC	Total
Hanson, 2001	America	Caucasian	60	62	15	137	164	139	26	329	0.90	8
Karmadonova, 2014	Russia	Caucasian	67	96	11	174	204	196	49	449	0.98	7
Martine, 1999	France	Caucasian	65	86	17	168	195	215	46	456	0.49	7
Li, 2015	China	Asian	163	65	18	246	180	97	15	292	0.92	7
Ray, 2001	Canada	Caucasian	68	49	12	129	69	49	11	129	0.86	8
Spiroski, 2008	Macedonia	Caucasian	32	29	2	63	38	39	3	80	0.18	8

pHWE, P values for Hardy–Weinberg equilibrium test.