Polymorphism of the endoglin gene in patients with intracranial saccular aneurysms

Object. Endoglin, a transforming growth factor β—binding protein, is a glycoprotein expressed on the surface of human vascular endothelial cells. Mutations of this gene are responsible for hereditary hemorrhagic telangiectasis and are associated with sporadic intracerebral hemorrhage as a risk factor. The purpose of this study was to examine the polymorphism of this gene in patients with intracranial aneurysms. Methods. The authors identified the mutations and insertion polymorphism around exon 7 of the endoglin gene in 82 patients with intracranial saccular aneurysms (aneurysm group) and 114 control volunteers (control group). A 6-base insertion (GGGGGA) was found in intron 7 at 26 bases beyond the 3′ end of exon 7. The homozygous insertion of intron 7 of the gene was present in 20.7% of the aneurysm group compared with 6.1% of the control group (χ 2 = 9.837, p = 0.0073). The insertion allele frequency was significantly higher in the aneurysm group (67 [40.8%] of 164) than that in the control group (63 [27.6%] of 228) (χ 2 = 7.48, p = 0.0062). The most notable clinical characteristic of the 17 patients with homozygous insertion in the aneurysm group was the relatively high percentage of patients with hypertension and of those with multiple aneurysms. Conclusions. The data provide evidence of an association between aneurysm development and a polymorphism at a genetic variant of endoglin in patients with these lesions.