Table 2.

Allele and genotype frequencies of SNPs in COMT, DRD1, DRD2, DRD3 and DRD4 genes and their association status with diabetic CRI.

SNPs	Allele frequency		Genotype frequency		Association
	DM (n = 225)	CRI (n = 196)	DM (n = 225)	CRI (n = 196)	Allele (df = 1)	Genotype (df = 2)
COMT -287 G>A	G = 0.63	G = 0.65	GG = 0.38	GG = 0.43	χ2 = 0.45;	χ2 = 0.93;
	A = 0.37	A = 0.35	GA = 0.49	GA = 0.44	P = 0.50	P = 0.63
			AA = 0.13	AA = 0.13
COMT 408 C>G	C = 0.71	C = 0.69	CC = 0.51	CC = 0.47	χ2 = 0.61;	χ2 = 0.98;
	G = 0.29	G = 0.31	CG = 0.39	CG = 0.44	P = 0.43	P = 0.61
			GG = 0.10	GG = 0.09
COMT 472 G > A (Val158 Met)	G = 0.53	G = 0.59	GG = 0.28	GG = 0.38	χ2 = 2.71;	χ2 = 4.10;
	A = 0.47	A = 0.41	GA = 0.51	GA = 0.42	P = 0.10	P = 0.13
			AA = 0.21	AA = 0.20
COMT 900 Ins/Del C	Ins = 0.71	Ins = 0.69	Ins/Ins = 0.54	Ins/Ins = 0.46	χ2 = 0.59;	χ2 = 5.83;
	Del = 0.29	Del = 0.31	Ins/Del = 0.34	Ins/Del = 0.46	P = 0.44	P = 0.054
			Del/Del = 0.12	Del/Del = 0.08
DRD1 -48A>G	A = 0.55	A = 0.82	AA = 0.33	AA = 0.34	χ2 = 0.33;	χ2 = 1.83;
	G = 0.45	G = 0.18	AG = 0.44	AG = 0.46	P = 0.57	P = 0.401
			GG = 0.23	GG = 0.20
DRD2 -141 ins/del C	Ins = 0.74	Ins = 0.85	Ins/Ins = 0.57	Ins/Ins = 0.74	χ2 = 12.11;	χ2 = 11.3;
	Del = 0.26	Del = 0.15	Ins/Del = 0.35	Ins/Del = 0.23	P < 0.001a	P = 0.004a
			Del/Del = 0.08	Del/Del = 0.03
DRD2 G>A	G = 0.77	G = 0.66	GG = 0.61	GG = 0.45	χ2 = 7.94;	χ2 = 7.83;
	A = 0.23	A = 0.34	GA = 0.31	GA = 0.42	P = 0.005	P = 0.02
			AA = 0.08	AA = 0.13
DRD2 T>C	T = 0.74	T = 0.69	TT = 0.55	TT = 0.48	χ2 = 2.30;	χ2 = 2.18;
	C = 0.26	C = 0.31	TC = 0.37	TC = 0.41	P = 0.13	P = 0.335
			CC = 0.08	CC = 0.11
DRD3 Ser9Gly	C = 0.64	C = 0.59	CC = 0.43	CC = 0.35	χ2 = 2.03;	χ2 = 2.8
	G = 0.36	G = 0.41	CG = 0.42	CG = 0.48	P = 0.15	P = 0.25
			GG = 0.15	GG = 0.17
DRD4 -120 bp Deletion	Ins = 0.68	Ins = 0.73	Ins/Ins = 0.48	Ins/Ins = 0.53	χ2 = 1.77;	χ2 = 1.72;
	Del = 0.32	Del = 0.27	Ins/Del = 0.42	Ins/Del = 0.39	P = 0.18	P = 0.42
			Del/Del = 0.105	Del/Del = 0.08
DRD4 -521 C>T	C = 0.40	C = 0.45	CC = 0.18	CC = 0.22	χ2 = 1.25;	χ2 = 1.15;
	T = 0.60	T = 0.55	CT = 0.44	CT = 0.45	P = 0.26	P = 0.56
			TT = 0.38	TT = 0.33
DRD4 48 bp VNTR	371 = 0.06	371 = 0.08	371/371 = 0.005	371/371 = 0.02	χ2 = 7.25;	χ2 = 10.6;
	419 = 0.02	419 = 0.02	467/371 = 0.10	467/371 = 0.10	P = 0.30 (df = 6)	P = 0.156 (df = 7)
	467 = 0.86	467 = 0.80	467/419 = 0.02	467/419 = 0.04
	563 = 0.03	563 = 0.04	467/467 = 0.78	467/467 = 0.68
	611 = 0.01	611 = 0.01	467/563 = 0.02	467/563 = 0.03
	647 = 0.02	647 = 0.04	467/611 = 0.02	467/611 = 0.03
			467/647 = 0.02	467/647 = 0.067
			563/563 = 0.014	419/647 = 0.007

^aSignificant after Bonferroni's correction α = 0.0042