Three case reports have described patients with a saccular anterior communicating artery aneurysm[17-19], and another described a patient with a saccular aneurysm at a fenestrated basilar artery[20]; this is the only case report of SAH in a patient with OI in whom the SNP28 of the COL1A2 gene was detected. Here, COL1A2 is linked to osteogenesis imperfecta.