Figure 1.
Flow chart for ataxin-2 and ALS related article search, screen, evaluation, and data analysis.
Figure 2.
Identification of the differences of the presence of intermediate CAG repeats and potential ethnic variances in the ATXN2 gene among ALS and control subjects.
The data about the number of CAG repeats in ALS and control subjects from 9 included studies in Caucacians and from 2 included studies from Chinese were summarized and plotted separately (left panel; right panel).
Figure 3.
The presence of intermediate CAG 30–33 repeats in the ATXN2 gene is associated with ALS.
The data of intermediate CAG 30–33 repeats in ATXN2 were extracted from 13 included studies and the OR of intermediate CAG repeat among ALS and control subjects was synthesized with meta-analysis using random effects model. Similar results were also obtained when use fixed effects model (data not shown).
Figure 4.
The heterogeneity among included studies was reduced dramatically after excluding two studies from China.
This meta-analysis was conducted using same protocol as in Figure 3 except excluding two studies with patients with Chinese background. Please refer to Figure 3.
Figure 5.
The synthesized OR of the presence of intermediate CAG repeats with meta-analysis is not different from FALS and SALS cases in the ATXN2 gene.
The relative risks (OR) among fALS cases (top panel) or sALS cases (lower Panel) compared to controls were synthesized with meta-analysis using extracted data from 4 included case-control studies. The results from random effects model were presented. Similar results were also obtained when use fixed effects model (data not shown).