A meta-analysis of the MTHFR C677T polymorphism and schizophrenia risk

Lewis et al., 2005 | Am J Med Genet B Neuropsychiatr Genet | Meta Analysis

Citation

Lewis Sarah J, Zammit Stanley, ... Smith George Davey. A meta-analysis of the MTHFR C677T polymorphism and schizophrenia risk. Am J Med Genet B Neuropsychiatr Genet. 2005-May-05;135B(1):2-4

Abstract

Epigenetic mechanisms such as methylation of DNA, could lead to abnormal neurodevelopment and may be important in the etiology of schizophrenia. Maternal dietary folate intake may play a role in determining methylation levels. The MTHFR gene C677T polymorphism influences folate metabolism and intracellular availability of folate metabolites for methylation. We carried out a meta-analysis of MTHFR C677T genotype and schizophrenia risk, and found that TT homozygotes had a significantly increased risk, OR 1.48 (1.18-1.86). This supports the hypothesis that folate status is a determinant of schizophrenia risk. Larger studies of this issue are required, together with studies of maternal genotype which could identify whether maternal folate status during pregnancy is important.

Key Findings

Larger studies of this issue are required, together with studies of maternal genotype which could identify whether maternal folate status during pregnancy is important.

Outcomes Measured

Requires manual extraction

Population

Field	Value
Population	See abstract
Sample Size	See abstract
Age Range	See abstract
Condition	See abstract

MeSH Terms

Alleles
Female
Gene Frequency
Genotype
Humans
Male
Methylenetetrahydrofolate Reductase (NADPH2)
Polymorphism, Genetic
Risk Factors
Schizophrenia

Evidence Classification

Level: Meta Analysis
Publication Types: Journal Article, Meta-Analysis
Vertical: folate

Provenance

PMID: 15729744
DOI: (not available)
PMCID: Not in PMC
Verified: 2026-04-09 via PubMed E-utilities API

Source extracted via PubMed E-utilities API on 2026-04-09