Table 1. Genotypic frequencies of the nNOS exon 1c promoter -84 G/A SNP in IHPS and controls.

Genotype	Controls (n = 81)	IHPS (n = 16)	Odds ratio (95% confidence interval)	P value
G/G	67 (82.72%)	6 (37.5%)	—	—
G/A	13 (16.05%)	8 (50%)	6.9 (G/A vs. G/G) (2.0-23.1)	0.002
A/A	1 (1.23%)	2 (12.5%)	22.3 (A/A vs. G/G) (1.8-283.6)	0.0271
A carriers	14 (17.28%)	10 (62.5%)	8.0 (A carriers vs. G/G) (2.5-25.6)	0.0004

The statistical significance of differences between control subjects and patients was tested by Fisher's exact test.