Gain-of-function polymorphisms of cystathionine β-synthase and delayed cerebral ischemia following aneurysmal subarachnoid hemorrhage: Clinical article

Object Cystathionine β-synthase (CBS) is an enzyme that metabolizes homocysteine to form H2S in the brain. Hydrogen sulfide functions as a vasodilator as well as a regulator of neuronal ion channels and multiple intracellular signaling pathways. Given the myriad effects of H2S, the authors hypothesized that patients possessing gain-of-function polymorphisms of the CBS gene will experience a decreased incidence of delayed cerebral ischemia (DCI) following aneurysmal subarachnoid hemorrhage (aSAH). Methods Patients were enrolled in a prospective observational database of aSAH outcomes. DNA was extracted from buccal swabs and sequenced for 3 functional polymorphisms of the CBS gene (699C→T, 844ins68, and 1080C→T) by polymerase chain reaction. Serum homocysteine levels (μmol/L) were assayed. Multivariate analysis was used to determine the relationship between CBS genotype and occurrence of both angiographic vasospasm and DCI. Results There were 87 patients included in the study. None of the polymorphisms inve...