Table 1. Study characteristics.

First author	year	Loc.	case	control	controlsource	308-Afrequency	p HWE	238-Afrequency	p HWE
Madani	2008	W	51	46	PB	–	–	1.09%	0.94
Park	1998	E	139	324	PB	7.07%	0.79	–	–
Jang	2001	E	27	92	HB	3.80%	0.85	7.07%	0.39
Landi	2003	W	363	320	HB	15.00%	0.70	–	–
Macarthur	2005	W	246	389	PB	23.78%	0.63	–	–
Fei	2005	E	92	132	PB	7.95%	0.78	–	–
Theodoropoulos	2006	W	222	200	PB	16.00%	0.69	–	–
Gunter	2006	W	217	202	PB	17.08%	0.68	–	–
Toth	2007	W	183	141	PB	10.64%	0.74	–	–
Wu	2008	W	156	116	PB	14.66%	0.70	3.73%	0.32
Wang	2008	E	344	669	PB	8.89%	0.77	–	–
Garrity-Park	2008	W	114	114	HB	10.53%	0.75	3.51%	0.02
Tsilidis	2009	W	204	372	PB	13.98%	0.71	–	–
Suchy	2008	W	350	350	PB	15.57%	0.69	–	–
Li	2011	E	180	180	HB	5.83%	0.60	–	–

Year: Publication year; Loc.: Location of the population; E: Eastern country; W: Western country; p _HWE: p value of Hardy–Weinberg equilibrium, chi-square test; 308-A%: Percentage of 308-A allele frequency among controls; 238-A%: Percentage of 238-A allele frequency among controls.