Several genes and polymorphisms were selected for a significant association with ischaemic stroke: in particular polymorphisms in the genes encoding MTHFR (enzyme in homocysteine metabolism), ACE (enzyme in renin-angiotensin-aldosterone system), Factor V Leiden, prothrombin and PAI 1 (Haemostatic system) [78]. The gene discussed is MTHFR; the disease is ischemic stroke.