Therefore, the smoking group with the T allele has the highest risk of VD, and synergy appears to exist between the MTHFR gene polymorphisms and smoking in susceptibility to VD.
In this case-control study, we examined C677T and A1298C (rs1801133 and rs1801131) polymorphism in the methylenetetrahydrofolate reductase (MTHFR) genes and their correlation with plasma levels of homocysteine (Hcy) in AD and VaD cases and evaluated the gene-gene interaction (epistasis) with IL-6-174 G/C (rs1800795).
MTHFR genotype was not found to influence homocysteine levels, although the T allele was found to increase risk for VaD and perhaps dementia after stroke.
Paraoxonase, ACE, and MTHFR polymorphisms were not associated with VD or LOAD; these common polymorphisms might have a marginal role in the pathogenesis of dementia in older subjects.
Taken together, these findings indicate a possible role of MTHFR TT genotype combined with hyperhomocyst(e)inemia in the pathogenesis of vascular dementia.
We examined apolipoprotein E (Apo E) polymorphism and methylenetetrahydrofolate reductase (MTHFR) 677 C to T mutation by using the polymerase chain reaction (PCR) method in 100 elderly Japanese aged 60 or more, and assessed whether these genetic factors are associated with an increased risk for the clinical phenotypes of senile dementia, Alzheimer's disease (AD) and vascular dementia (VD) by cross-sectional survey.