Table 1. CAYP1A1 3801T >C genotype distribution and allele frequencies in cases and controls.

Study	Year	Country	Ethnicity	Control source	Genotyping method	Cases/controls	Genotype data (cases)					Genotype data (controls)					MAF	HWE (P)a	Quality score
							T	C	TT	TC	CC	T	C	TT	TC	CC
Lu et al [27]	2008	China	Asian	HB	PCR-RFLP	192/226	234	150	69	96	27	294	158	95	104	27	0.35	0.86	6
Vani et al [28]	2009	India	Caucasian	HB	PCR-RFLP	206/230	296	116	108	80	18	372	88	146	80	4	0.19	0.06	8
Chen et al [29]	2010	China	Asian	HB	PCR-RFLP	105/140	117	93	35	47	23	221	59	88	45	7	0.21	0.69	5
Peng et al [30]	2012	China	Asian	HB	PCR-RFLP	204/202	237	171	72	93	39	250	154	78	94	30	0.38	0.85	5
Salehi et al [31]	2012	Iran	Caucasian	HB	PCR-RFLP	150/200	188	112	58	72	20	261	139	85	91	24	0.35	0.96	6
Yarosh et al [32]	2013	Russia	Caucasian	HB	PCR-RFLP	203/227	365	41	165	35	3	400	54	176	48	3	0.12	0.89	8

HB hospital based, PCR-RFLP polymerase chain reaction-restriction fragment length polymorphism, MAF minor allele frequency, HWE Hardy–Weinberg equilibrium,

^aP value for HWE in control group.