Molecular Vision: Zanon-Moreno, Mol Vis 2013; 19:231-242. Table 3

Table 3. Plasma vitamin C, vitamin E and glutathione peroxidase concentrations (mean ± SD) depending on the corresponding SLC23A2, TTPA, TAP or GPX4 genotypes in primary open glaucoma cases and controls

Vitamin	Gene	SNP	Alleles*	Plasma concentration of antioxidants
			Alleles*	Cases (n=250)					Controls (n=250)
			(1/2)	1/1	1/2	2/2	p1	p2	1/1	1/2	2/2	p1	p2
Vitamin C (µg/ml)	SLC23A2	rs1279683	A/G	10.5±1.7	10.6±1.4	9.1±1.5^a,b	<0.001	<0.001	12.5±1.7	12.5±1.4	10.6±1.4^a,b	<0.001	<0.001
Vitamin E (µg/ml)	TTPA	rs6994076	T/A	11.1±1.5	11.0±1.6	10.1±1.8^c	<0.001	<0.001	12.0±1.5	11.5±1.7	10.6±2.0^d	<0.001	<0.001
Vitamin E (µg/ml)	TAP	rs737723	G/C	10.6±1.6	11.0±1.7	10.5±1.7	0.103	0.095	11.3±1.7	11.4±1.9	11.4±1.7	0.984	0.997
GPx (U/ml)	GPX4	rs757228	G/A	25.9±8.7	26.8±8.0	26.0±9.5	0.727	0.752	18.8±7.0	17.8±6.1	16.5±5.2	0.146	0.094

GPx: glutathione peroxidase; SD: Standard deviation; SE: Standard error. *Allele 1 is the ancestral allele. Allele 2 is the variant allele. p1: p value obtained in the ANOVA test including the three genotypes. p2: p value obtained in the Student t test comparing the homozygous subjects for the variant allele [2] with carriers of the ancestral allele (1/1+1/2) for each polymorphism. Post-hoc comparisons: a: p values for comparison of means of vitamin C concentrations in GG subjects versus AA (p<0.001 in POAG cases and p=0.001 in controls); b: p values for comparison of means between vitamin C concentrations in GG subjects versus AG (p<0.001 in POAG cases and p=0.001 in controls). c: Regression coefficient (B) ±SEM and p value for additive effects (coded a 0, 1 or 2 variant alleles, A) in POAG cases (B=-0.54±0.14 µg/ml; p<0.001). d: Regression coefficient (B) ±SEM and p value for additive effects (coded a 0, 1 or 2 variant alleles, A) in controls (B=-0.70±0.16 µg/ml; p<0.001). A p value <0.0125 indicate that the results is statistically significant after correction for multiple testing.