Evidence map›Paper›PMID 42566580›Full record

SynthesisMedicine2026

Association of methylenetetrahydrofolate reductase C677T polymorphism with lacunar infarction: A systematic review and meta-analysis.

Qing Gao, Fanxin Kong, Songjun Lin, Min Pi, Xiude Qin, Haotao Zheng

Abstract readMeta-AnalysisSystematic Review
In one paragraph

Synthesis in Medicine, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

0numbers the graph read from it
0cells of the map it votes in
0citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

0 citing papers in PubMed.

No citing paper in PubMed yet.

4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

6 authors.

Qing GaoDepartment of Clinical Psychology, Shenzhen Clinical College of Integrated Chinese and Western Medicine, Guangzhou University of Chinese Medicine, Shenzhen, China.
Fanxin KongThe Fourth Clinical Medical College of Guangzhou University of Chinese Medicine, Shenzhen, China.
Songjun LinThe Fourth Clinical Medical College of Guangzhou University of Chinese Medicine, Shenzhen, China.
Min PiOffice of Academic Affairs, Shenzhen Traditional Chinese Medicine Hospital, Shenzhen, China.
Xiude QinThe Fourth Clinical Medical College of Guangzhou University of Chinese Medicine, Shenzhen, China.
Haotao ZhengThe Fourth Clinical Medical College of Guangzhou University of Chinese Medicine, Shenzhen, China.ORCID 0000-0002-8992-8299

Funding

2025 Annual Scientific Research Project Approved by Shenzhen Association of Chinese Medicine 2025053Guangdong Provincial Administration of Traditional Chinese Medi-cine Project 20261329Shenzhen High-level Hospital Construction Fund G3030202101
6 · The paper itself

Abstract

backgroundThe association between the methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism and lacunar infarction (LI) remains inconclusive.

methodsThe literature retrieval encompassed PubMed, EMBASE, Cochrane Library, China National Knowledge Infrastructure, and Wanfang (inception - March 2026). Case-control studies that reported genotype frequencies of MTHFR C677T (CC, CT, and TT) in LI patients and controls were included. Pooled odds ratios (ORs) with 95% confidence intervals (CIs) for 5 genetic models were calculated using random/fixed-effects models in Stata 13.0. Prespecified exploratory subgroup analyses were conducted by ethnicity and symptom status. Four methodological sensitivity analyses assessed the robustness of findings by restricting analyses to studies with magnetic resonance imaging (MRI) only versus CT/MRI, Trial of Org 10172 in Acute Stroke Treatment classification versus radiological criteria, Hardy-Weinberg equilibrium-compliant controls, and Newcastle-Ottawa Scale score ≥ 7. Meta‑regression, heterogeneity (I2), and publication bias (Begg/Egger tests with trim‑and‑fill) were also performed.

resultsTwelve studies comprising 5097 participants (1598 cases/3499 controls) were included. Significant associations were observed in 4 genetic models: recessive (TT vs CT + CC): OR = 1.36, 95% CI = 1.05 to 1.77; dominant (TT + CT vs CC): OR = 1.22, 95% CI = 1.05 to 1.41; allelic model (T vs C): OR = 1.19, 95% CI = 1.07 to 1.33; and homozygous contrast (TT vs CC): OR = 1.45, 95% CI = 1.11 to 1.89. Exploratory subgroup analyses, limited by small numbers of studies in several strata, suggested stronger associations in Asian populations and symptomatic lacunar stroke; these findings are underpowered and should be interpreted with caution. Sensitivity analyses restricting to MRI‑only studies, Trial of Org 10172 in Acute Stroke Treatment‑defined cases, Hardy-Weinberg equilibrium‑compliant controls, or higher‑quality studies (Newcastle-Ottawa Scale ≥ 7) produced results broadly consistent with the primary findings. However, significant publication bias was detected, and all pooled ORs decreased and lost statistical significance after trim‑and‑fill adjustment.

conclusionThe initially observed association between MTHFR C677T and LI was no longer significant after trim‑and‑fill adjustment for publication bias. All analyses used unadjusted crude genotype data, so residual confounding by vascular and nutritional factors cannot be excluded, and the pooled estimate combined distinct lacunar phenotypes. A formal assessment using the Grading of Recommendations Assessment, Development and Evaluation framework showed very low certainty of evidence. Routine MTHFR genotyping for LI risk assessment is therefore not currently supported, and further rigorous studies are warranted.

Indexed as

Genetic Predisposition to DiseaseMethylenetetrahydrofolate Reductase (NADPH2)Polymorphism, Single NucleotideStroke, LacunarAsian PeopleCase-Control StudiesGenotypeHumansOdds RatioMethylenetetrahydrofolate Reductase (NADPH2)MTHFR protein, humangenetic polymorphismlacunar infarctionmeta-analysismethylenetetrahydrofolate reductaseMTHFR C677T polymorphism

Identifiers

PMID42566580
PMCPMC13456852

What Socratic holds

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Registered trials

None linked

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the Socratic graph.