Functional polymorphisms of the MAO gene with Parkinson disease susceptibility: a meta-analysis

We carried out a meta-analysis focusing on the relationships between rs1137070 C>T and rs1799836 A>G polymorphisms in the MAO gene as a modifier of Parkinson disease (PD) susceptibility.

A literature search of the Cochrane Library Database, Web of Science, PubMed, CINAHL, EMBASE, and the Chinese Biomedical Database (CBM) was performed without any language restrictions on articles published before April 10st, 2014. We choose the STATA 12.0 statistical software to deal with statistical data. Crude odds ratios (ORs) estimates with 95% confidence interval (95% CI) were also provided.

Fourteen independent case-control studies met our predetermined inclusion criteria and were included in the meta-analysis. Two major polymorphisms rs1137070 C>T and rs1799836 A>G in the MAO gene were performed in this meta-analysis. When all the eligible studies were pooled into the meta-analysis, our results indicated that rs1137070 C>T polymorphism and rs1799836 A>G polymorphism have statistically significant correlation with the increased risk of PD in the majority groups. Ethnicity-stratified analysis revealed a relation between the rs1137070 C>T polymorphism and PD risk among Asians and Caucasians in the majority groups. Additionally, there was an apparent association between the rs1799836 A>G variant and PD risk among the Asian populations under 4 genetic models (G allele vs. A allele: OR=0.84, 95% CI=0.72-0.97, P=0.021; GG vs. AA+AG: OR=1.73, 95% CI=1.25-2.39, P=0.001; GG vs. AA: OR=1.56, 95% CI=1.18-2.04, P=0.002; GG vs. AG: OR=3.42, 95% CI=1.86-6.30, P<0.001; respectively).

The relationships in the polymorphisms of rs1137070 C>T and rs1799836 A>G in the MAO gene with PD susceptibility observed in our meta-analyses support the view that the MAO gene may play an important role in the development of PD.