The relationship between homocysteine (Hcy), MTHFR C677T polymorphism and cerebral (brain) blood clot risk was studied by Bharatkumar et al (2014). Homocysteine was higher in patients with cerebral blood clotting, representing a 4.54 fold increased risk of brain blood clotting. When examining the link with MTHFR C677T, the authors concluded that the 677TT genotype was not linked with blood clot risk, but is a determinate of homocysteine levels.