In the control source stratification, three control genetic models from hospitals found an obvious correlation among the MTHFR A1298C polymorphism and increased stroke risk (C vs A: OR = 1.24, 95%CI = 1.08–1.42, p = 0.002; CC + CA vs AA: OR = 1.23, 95%CI = 1.06–1.44, p = 0.008; CC vs CA + AA: OR = 1.54, 95%CI = 1.28–1.86, p = 0.007). The gene discussed is MTHFR; the disease is Stroke.