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MTRR 66A>G polymorphism as maternal risk factor for Down syndrome: a meta-analysis
Márcia R Amorim1, Marcelo A Costa Lima
1Departamento de Biologia Geral, Instituto de Biologia, Universidade Federal Fluminense, Niterói, Rio de Janeiro, Brazil.
Genetic Testing and Molecular Biomarkers
|October 26, 2012
Summary
Maternal MTRR 66A>G polymorphism, a common genetic variation in the folic acid pathway, is linked to an increased risk of having a child with Down syndrome (DS). This finding emerges from a comprehensive meta-analysis of available studies.
Area of Science:
- Genetics
- Maternal Health
- Developmental Disorders
Background:
- Down syndrome (DS) is the leading cause of intellectual disability.
- Genetic factors influencing maternal risk for DS are under investigation.
- The Methionine synthase reductase (MTRR) gene plays a role in the folic acid pathway, with a common c.66A>G polymorphism previously studied for its association with DS.
Purpose of the Study:
- To conduct a meta-analysis summarizing existing data on the association between the MTRR 66A>G polymorphism and Down syndrome risk.
- To clarify controversial findings regarding the MTRR 66A>G polymorphism's role in maternal DS risk.
Main Methods:
- A systematic search of online databases was performed to identify relevant case-control studies.
- Data from 11 articles encompassing six populations (1226 DS mothers, 1533 controls) were analyzed.
- Fixed and random effects models were used to calculate pooled odds ratios (OR) and 95% confidence intervals (CI) for maternal risk.
Main Results:
- Significant heterogeneity was observed among the included studies (I²=66.3%).
- The pooled OR in a random effects model indicated an increased risk of having a DS child associated with the G allele (OR 1.23, 95% CI 1.02-1.49).
- The fixed effect model also suggested an increased risk (OR 1.19, 95% CI 1.08-1.31).
Conclusions:
- Maternal MTRR 66A>G polymorphism is associated with an elevated risk of having a child with Down syndrome.
- This meta-analysis provides a consolidated view of the genetic link between MTRR polymorphism and DS.
- Further research may explore the functional implications of this polymorphism in the folic acid pathway concerning DS etiology.
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