Plasma renin concentration above the normal upper limit (46.1 μUI/mL) was associated with HT in univariate analysis (OR = 3.35, 95% CI = 2.09–5.39, p = 0.04) and, after model adjustment, was an independent factor associated with HT (OR = 2.49, 95% CI = 2.001–5.03, p = 0.001). The gene discussed is REN; the disease is hematocrit.