SLC1A2 rs3794087 variant and risk for essential tremor: a systematic review and meta-analysis

BACKGROUND/OBJECTIVERecently, a genome-wide association study showed a statistically significant association between the rs3794087 single nucleotide polymorphism (SNP) in the solute carrier family 1 – glial affinity glutamate transporter, member 2 (SLC1A2) and the risk for essential tremor (ET). However, four further association studies showed controversial results.We carried out a systematic review and a meta-analysis including all the studies published on the risk of ET related to this SNP. MATERIALS AND METHODSThe systematic review was performed using several databases, the meta-analysis was carried out using the software Meta-DiSc 1.1.1, and heterogeneity between studies was tested using the Q statistic. RESULTSThe meta-analysis included five association studies for the SLC1A2 rs3794087 SNP (1925 ET patients, 4914 controls) and the risk for ET. The global diagnostic odds ratio (95% confidence intervals) was 1.08 (0.79–1.48) for the total group. After excluding data from the discovery series (which was responsible for a high degree of heterogeneity), the global diagnostic odds ratio (95% confidence intervals) was 0.96 (0.74–1.23). The separate analysis in White and Asiatic individuals on the frequency of the minor allele of rs3794087 did not show significant differences between ET patients and controls in both subgroups after excluding the discovery series. CONCLUSIONThe results of the meta-analysis suggest that rs3794087 is not associated with the risk for ET.