Association of Methylenetetrahydrofolate Reductase C677T Gene Polymorphisms with Mild Cognitive Impairment Susceptibility: A Systematic Review and Meta-Analysis.

Jiahui Sun,Nanyang Liu,Lina Ma,Xuefan Jiang,Ming Zhao,Hui Pei,Hao Li

doi:10.1155/2021/2962792

Abstract

Background Methylenetetrahydrofolate reductase (MTHFR) C677T (rs1801133) gene polymorphisms are related to a growing risk of Alzheimer's disease; however, whether this association applies to mild cognitive impairment (MCI) remains unclear. Objective We conducted this meta-analysis to evaluate the contribution of MTHFR C677T (rs1801133) gene variants to the risk of MCI. Methods PubMed, Embase, Web of Science, and China National Knowledge Infrastructure databases were searched from their inception to March 21, 2021, with language restricted to English or Chinese. We used fixed or random effects to examine the association between MTHFR C677T (rs1801133) gene variants and MCI susceptibility. Forest plots of pooled odds ratios (ORs) and 95% confidence intervals (CIs) were generated. Results Eight articles with 2,175 participants were included in the present meta-analysis. There was no significant association between MTHFR C677T (rs1801133) gene variants and MCI susceptibility under the allelic (OR, 1.318; 95% CI, 0.964–1.801; p = 0.084), dominant (OR, 1.296; 95% CI, 0.925–1.817; p = 0.132), recessive (OR, 1.397; 95% CI, 0.845–2.312; p = 0.193), heterozygous (OR, 1.031; 95% CI, 0.855–1.243; p = 0.749), or homozygous (OR, 1.506; 95% CI, 0.850–2.667; p = 0.160) models. Conclusion The results suggest that MTHFR C677T (rs1801133) gene polymorphisms are not associated with MCI susceptibility. However, large-scale studies covering various factors are required.

Highlights

Mild cognitive impairment (MCI) is defined as a transitional stage between normal aging and dementia [1], that is, the symptomatic predementia stage, which does not fulfill the criterion for dementia diagnosis [2]
This study represents the first meta-analysis of Methylenetetrahydrofolate reductase (MTHFR) C677T gene polymorphisms and mild cognitive impairment (MCI) susceptibility based on a broad range of studies involving 2,175 participants
We did not find any statistically significant evidence that MTHFR C677T gene variants can contribute to MCI susceptibility

Summary

Introduction

Mild cognitive impairment (MCI) is defined as a transitional stage between normal aging and dementia [1], that is, the symptomatic predementia stage, which does not fulfill the criterion for dementia diagnosis [2]. Methylenetetrahydrofolate reductase (MTHFR) C677T (rs1801133) gene polymorphisms are related to a growing risk of Alzheimer’s disease; whether this association applies to mild cognitive impairment (MCI) remains unclear. We conducted this meta-analysis to evaluate the contribution of MTHFR C677T (rs1801133) gene variants to the risk of MCI. We used fixed or random effects to examine the association between MTHFR C677T (rs1801133) gene variants and MCI susceptibility. There was no significant association between MTHFR C677T (rs1801133) gene variants and MCI susceptibility under the allelic (OR, 1.318; 95% CI, 0.964–1.801; p = 0:084), dominant (OR, 1.296; 95% CI, 0.925–1.817; p = 0:132), recessive (OR, 1.397; 95% CI, 0.845–2.312; p = 0:193), heterozygous (OR, 1.031; 95% CI, 0.855–1.243; p = 0:749), or homozygous (OR, 1.506; 95% CI, 0.850–2.667; p = 0:160) models. The results suggest that MTHFR C677T (rs1801133) gene polymorphisms are not associated with MCI susceptibility.

Methods

Results

Conclusion