MTHFR and heart disorder: Meta-analyses of ischaemic heart disease using (i) 75 studies in which the prevalence of a mutation (CT) in the MTHFR gene (which increases homocysteine) was determined in cases (22,068) and controls (23,618), and (ii) 14 randomised trials (39,597 participants) of homocysteine lowering and ischaemic heart disease events.