From a total of 381 SNPs assayed for the 3 NOS-1,-2 and-3 genes, 15 SNPs in the NOS1 gene and 1 SNP for NOS3 gene exhibited statistically significant differences in their frequencies among children with OSA and their matched controls, even after correction for multiple comparisons (Table 2). Here, NOS1 is linked to obstructive sleep apnea syndrome.