Polymorphisms of DNA repair genes XRCC1 and XRCC3, interaction with environmental exposure and risk of chronic gastritis and gastric cancer

Table 1 XRCC1 and XRCC3 allele frequencies in patients with chronic gastritis (CG) and gastric cancer (GC) and in the respective control groups C1 and C2

	Genotypes	CG (n = 202)	C1 (n = 202)	P	GC (n = 160)	C2 (n = 150)	P
		n (%)	n (%)		n (%)	n (%)
XRCC1	Arg/Arg	176 (87.1)	183 (90.6)		140 (87.5)	130 (86.7)
Codon 194	Arg/Trp	24 (11.9)	19 (9.4)		20 (12.5)	19 (12.7)
	Trp/Trp	2 (1.0)	0 (0.0)		0 (0.0)	1 (0.6)
	Arg/Trp+Trp/Trp	26 (12.9)	19 (9.4)	0.2683	20 (12.5)	20 (13.3)	0.8269
	Allele frequency	0.07	0.05		0.06	0.07
XRCC1	Arg/Arg	98 (48.5)	95 (47)		73 (45.6)	70 (46.7)
Codon 399	Arg/Gln	91 (45.0)	82 (40.6)		67 (41.9)	57 (38.0)
	Gln/Gln	13 (6.5)	25 (12.4)	0.7651	20 (12.5)	23 (15.3)	0.5035
	Arg/Gln+Gln/Gln	104 (51.5)	107 (53.0)		87 (54.4)	80 (53.3)
	Allele frequency	0.29	0.33		0.33	0.34
XRCC3	Thr/Thr	92 (45.5)	84 (41.6)		84 (52.5)	67 (44.7)
Codon 241	Thr/Met	81 (40.1)	89 (44.1)		53 (33.1)	60 (40.0)
	Met/Met	29 (14.4)	29 (14.3)	0.4221	23 (14.4)	23 (15.3)	0.1679
	Thr/Met+Met/Met	110 (54.5)	118 (58.4)		76 (47.5)	83 (55.3)
	Allele frequency	0.34	0.36		0.31	0.35