In this study, we investigated whether a single nucleotide polymorphism (rs42524 G > C) in the type Ⅰ alpha 2 collagen gene was associated with sporadic ruptured intracranial aneurysm or its clinical characteristics in patients from Northeast China. Genotyping of the rs42524 G > C polymorphism was carried out using a polymerase chain reaction-restriction fragment length polymorphism assay. The data showed that the frequency of the rs42524 GC + CC genotype was significantly higher than the GG genotype among intracranial aneurysm patients whose Hunt and Hess grading scale was > 3. In addition, the rs42524 G > C genotype was found to have a statistically significant association with intracranial aneurysm risk. These findings indicate that the type Ⅰ alpha 2 collagen gene gene may be involved in a predisposition to intracranial aneurysm in the Northeast Chinese population. Crucially, the rs42524 C allele may be an important risk factor for increased severity of the condition in patients with ruptured intracranial aneurysms. In this study, we investigated whether a single nucleotide polymorphism (rs42524 G> C) in the type I alpha 2 collagen gene was associated with sporadic ruptured intracranial aneurysm or its clinical characteristics in patients from Northeast China. Genotyping of the rs42524 G> C polymorphism was carried out using a polymerase chain reaction-restriction fragment length polymorphism assay. The data showed that the frequency of the rs42524 GC + CC genotype was significantly higher than the GG genotype among intracranial aneurysm patients whose Hunt and Hess grading scale was> 3. In addition, the rs42524 G> C genotype was found to have a significant association with intracranial aneurysm risk. These findings indicate that the type I alpha 2 collagen gene gene be involved in a predisposition to intracranial aneurysm in the Northeast Chinese population. Crucially, the rs42524 C allele may be an important risk factor for increased severity of the condition in patient s with ruptured intracranial aneurysms.