The main characteristics of the included studies regarding association between the GNB3 C825T polymorphism and stroke.

HT, hypertension; SOC, source of control; PB, population-based, controls were blood donors, healthy controls matched for age, gender and domicile and participants in an health service programme from the same geographical region without clinically detectable hypertension; HB, hospital-based, controls were patients admitted to hospital without hypertension matched for age, gender and domicile; HWE, Hardy–Weinberg equilibrium; and MAF, minor allele frequency. Five studies [11], [12], [34]–[36] regarding the association of the GNB3 C825T polymorphism and ischemic stroke were identified while one [37] was regarding cerebral hemorrhage and the other two [38], [39] included ischemic stroke or cerebral hemorrhage cases.