Low folate intake and genetic variants in folate metabolism, such as the methylenetetrahydrofolate reductase (MTHFR) 677 C>T polymorphism, have been suggested to impact brain function and increase the risk for cognitive decline and late-onset Alzheimer's disease.
These data suggest that both MTHFR C677T and eNOS G894T variants should be regarded as genetic risk factors for hyperhomocysteinemia in patients with cognitive decline.
The T allele in a C677T variant in methylenetetrahydrofolate reductase (MTHFR) gene is associated with elevated plasma homocysteine, which is detrimental to vascular integrity and has been linked to cognitive decline.
Methylenetetrahydrofolate reductase 677C>T and methionine synthase 2756A>G mutations: no impact on survival, cognitive functioning, or cognitive decline in nonagenarians.