The MTHFR C677T polymorphism contributes to increased risk of Alzheimer's disease: evidence based on 40 case-control studies.
Level 4 - case-series / case-control
Systematic review and meta-analysis of 40 case-control studies
PubMed 25486592 · doi:10.1016/j.neulet.2014.11.049
What was done
A systematic literature search of PubMed, Alzgene, Embase, and the Chinese Biomedical Literature database (up to June 2014) was conducted to evaluate the association between the methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism and Alzheimer's disease (AD) risk. The meta-analysis included 40 case-control studies comprising 4,503 AD cases and 5,767 controls, with subgroup analyses stratified by ethnicity, age of onset, and APOE ϵ4 carrier status.
What was found
Pooled analysis of all 40 studies demonstrated a statistically significant increased risk of AD. Subgroup analyses identified significant increased risk in Asians, individuals with late-onset AD, and APOE ϵ4 carriers, but not in Caucasians, individuals with early-onset AD, or non-APOE ϵ4 carriers. Specific numerical effect sizes (such as odds ratios, confidence intervals, and p-values) were not reported in the abstract.
Why it matters
The study aggregates conflicting observational data to indicate that the MTHFR C677T polymorphism may be a susceptibility marker for Alzheimer's disease, particularly in Asian populations and among APOE ϵ4 carriers.
Limits
The abstract does not provide numerical effect estimates, confidence intervals, or heterogeneity statistics. All included evidence originates from case-control designs subject to selection bias and confounding, and gene-gene or gene-environment interactions were not assessed.
Cited by
- context MTHFR gene polymorphism is a significant risk factor for Alzheimer's disease.