Table 2.

Frequency distribution of the 1858 C/T polymorphism of PTPN22 in patients with early rheumatoid arthritis and matched controls

Genotype	Patients (n = 504)		Controls (n = 970)		χ2	P value	Pc value	Odds ratio	95% confidence interval
	n	%	n	%
CC	338	67.1	761	78.5	22.68	0.000002	0.00001	0.56	0.44–0.72
CT	151	30.0	196	20.2	17.53	0.000028	0.00014	1.69	1.31–2.18
TT	15	3.0	13	1.3	4.76	0.02907	0.14535	2.26	1.01–5.08
CT + TT	166	33.0	209	21.5	22.68	0.000002	0.00001	1.79	1.40–2.29
T allele	181	18.0	222	11.4	23.84	0.000001	0.000005	1.69	1.36–2.11

P_c, corrected P value.