Table 1.

NAT1 and NAT2 allele and genotype frequencies and odds ratios for colon cancer in African Americans and whites (North Carolina Colon Cancer Study)

	African Americans			Whites
	Cases	Controls	OR (95% CI)a	Cases	Controls	OR (95% CI)a
NAT1
n	208	299		282	528
Allele frequency (n)b
NAT1*3	0.07 (28)	0.07 (39)		0.05 (26)	0.04 (43)
NAT1*4	0.48 (201)	0.45 (271)		0.73 (414)	0.76 (801)
NAT1*10	0.45 (186)	0.48 (286)		0.20 (114)	0.18 (187)
NAT1*11	0.00 (1)	0.00 (2)		0.02 (10)	0.02 (25)
Chi-square P-value		0.793c			0.496
Genotype frequency (n)d
NAT1-non*10	0.31 (65)	0.28 (83)	1.0 (ref)	0.66 (186)	0.68 (360)	1.0 (ref)
NAT1*10	0.69 (143)	0.72 (216)	0.8 (0.6, 1.2)	0.34 (96)	0.32 (168)	1.1 (0.8, 1.5)
Chi-square P-value		0.395			0.520
NAT2
n	215	307		285	523
Allele frequency (n)b
NAT2*4	0.38 (164)	0.38 (236)		0.29 (168)	0.24 (254)
NAT2*5	0.29 (125)	0.27 (167)		0.43 (245)	0.47 (491)
NAT2*6	0.24 (104)	0.26 (160)		0.25 (141)	0.27 (279)
NAT2*7	0.03 (11)	0.03 (18)		0.03 (15)	0.02 (21)
NAT2*14	0.06 (26)	0.05 (33)		0.00 (1)	0.00 (1)
Chi-square P-value		0.909			0.127c
Genotype frequency (n)d
NAT2-slow	0.39 (83)	0.39 (120)	1.0 (ref)	0.51 (144)	0.58 (305)	1.0 (ref)
NAT2-intermediate	0.47 (100)	0.45 (138)	0.9 (0.5, 1.5)	0.40 (114)	0.35 (182)	1.6 (0.9, 2.7)
NAT2-rapid	0.15 (32)	0.16 (49)	1.1 (0.7, 1.6)	0.09 (27)	0.07 (36)	1.3 (1.0, 1.8)
NAT2-rapid/intermediate	0.61 (132)	0.61 (187)	1.0 (0.7, 1.5)	0.49 (141)	0.42 (218)	1.4 (1.0, 1.8)
Chi-square P-valuee		0.911			0.033

^aAdjusted for age, sex, and offsets.

^bAllele frequency = number of alleles/number of chromosomes. N=number of chromosomes.

^cFisher's exact test was used because cell size was less than five counts.

^dGenotype frequency = Number of participants with genotype/total number of participants. N=number of participants.

^eChi-square statistic compares case and control frequencies by slow and combined rapid/intermediate groups.