In unadjusted analysis each 1 g/dL increase in Hb was associated with a 17% lower odds of balance impairment (OR 0.83, 95% CI 0.78–0.87; p < 0.001); this association remained essentially unchanged after sequential adjustment for demographic factors, stroke characteristics, comorbidities and motor impairment (fully adjusted OR 0.89, 95% CI 0.83–0.96; p = 0.002), corresponding to a 11% risk reduction per 1 g/dL. The gene discussed is GSTM1; the disease is stroke disorder.