Influence of endothelial nitric oxide synthase T-786C single nucleotide polymorphism on aneurysm size

Object. Among patients with aneurysms, those with heterozygous (T/C) endothelial nitric oxide synthase (eNOS) T-786C single nucleotide polymorphism (SNP), a mutation reducing endothelial nitric oxide synthesis, are reported to have larger ruptured intracranial aneurysms (IAs) than those with homozygous (C/C or T/T) genotype. The authors tested patients harboring aneurysms for eNOS T-786C SNP in two populations-Japanese and Korean. Methods. The eNOS T-786C SNP was genotyped through direct sequencing in genomic DNA obtained from 336 Japanese and 191 Korean patients with IAs and 214 Japanese and 191 Korean control volunteers. Differences in genotype frequencies among the various aneurysm sizes were evaluated using the Fisher exact test. There was no significant difference in heterozygous (T/C) eNOS T-786C SNP between aneurysms 5 mm or smaller and those from 6 to 9 mm, and between lesions 5 mm or smaller and those 10 mm or larger in 336 Japanese patients harboring aneurysms-220 with ruptured and 116 with unruptured lesions-and in 191 Korean patients with ruptured aneurysms. Conclusion. The eNOS T-786C SNP genotype does not influence the size of aneurysms.