Abstract: Objective To investigate the relationship between 2 polymorphic loci (G-894T and T-786C) of endothelial nitric oxide
synthase (eNOS) gene and sporadic intracranial aneurysms. Methods Two eNOS gene polymorphisms at G-894T and T-786C
were genotyped using polymerase chain reaction-restriction fragment length polymorphism analysis. The genotype and allele
frequencies were calculated for the patients and the control group and the association between the gene polymorphisms and
the size of aneurysms was analyzed. Results Significant differences were found in the genotype distribution for eNOS G-894T
polymorphism between the patient and control groups. The GG genotype was associated with a higher risk of intracranial
aneurysm than GT + TT genotype (OR:1.897, 95% CI: 1.023-3.519, P=0.04). The patients with intracranial aneurysms had a
significantly higher eNOS T-786C C allele frequency than the control group. The C allele was associated with a higher risk of
intracranial aneurysm than T allele (OR: 2.116, 95%CI: 1.073-4.151, P=0.030). No significant association was found between the
eNOS polymorphisms and the size of aneurysms. Conclusion eNOS gene may be involved in the occurrence and development
of intracranial aneurysms.