Thiopurine-methyltransferase variants in inflammatory bowel disease: Prevalence and toxicity in Brazilian patients

Table 3 Allelic frequencies of C238G, G460, and A719G in patients with inflammatory bowel disease

Polymorphism	CHz	HTz	RHz	n	Allelic frequency		χ2	P-value
CD
C238G	C:C	C:G	G:G		C	G
Observed	141	5	0	146	0.98	0.02	0.04	0.83
Expected	141	5	0
G460A/A719G	G:G/A:A	G:A/A:G	A/A:G/G		G/A	A/G
Observed	137	9	0	146	0.97	0.03	0.14	0.70
Expected	137	9	0
A719G	A:A	A:G	G:G		A	G
Observed	128	18	0	146	0.94	0.06	0.63	0.42
Expected	128	16	1
UC
C238G	C:C	C:G	G:G		C	G
Observed	71	2	0	73	0.99	0.01	0.01	0.90
Expected	71	2	0
G460A/A719G	G:G/A:A	G:A/A:G	A/A:G/G		G/A	A/G
Observed	70	3	0	73	0.98	0.02	0.03	0.85
Expected	70	3	0
A719G	A:A	A:G	G:G		A	G
Observed	66	7	0	73	0.95	0.05	0.18	0.66
Expected	66	7	0

CD: Crohn’s disease; UC: Ulcerative colitis; CHz: Common homozygous; HTz: Heterozygous; RHz: Rare homozygous. Data were analyzed using Fisher’s exact test. If P < 0.05-not consistent with HWE. Not accurate if < 5 individuals in any genotype group.