MTRR 66A > G Polymorphism as Maternal Risk Factor for Down Syndrome: A Meta-Analysis

作者：Amorim Marcia R; Costa Lima Marcelo A

来源：Genetic Testing and Molecular Biomarkers, 2013, 17(1): 69-73.

DOI：10.1089/gtmb.2012.0200

Down syndrome (DS) is the most common cause of mental retardation. Recent reports have investigated possible genetic factors that may increase maternal risk for DS. Methionine synthase reductase (5-methyltetra-hydrofolate- homocysteine methyltransferase reductase MTRR) plays an important role in folic acid pathway and a common polymorphism (c.66A > G) has been associated with DS but results were controversial. This meta-analysis summarizes the available data concerning this association. Online major databases were searched to identify case-control studies regarding MTRR 66A > G polymorphism and DS. Crude odds ratios (OR) and 95% confidence intervals (CI) were calculated for maternal risk to have a DS child both using fixed and random effects (RE) models. Eleven articles from six populations were identified, including 1226 DS mothers and 1533 control mothers. Heterogeneity among studies was significant (Q=29.7, DF = 10, p = 0.001; I-2 = 66.3%). The pooled OR in a RE model showed an increase in the risk of having a DS child associated with the G allele (OR 1.23, 95% CI 1.02-1.49). The fixed effect pooled OR was 1.19 (95% CI 1.08-1.31). This meta-analysis indicates that maternal MTRR 66A > G polymorphism is associated with an increased risk of having a DS child.