Following a GWA meta-analysis, researchers should prioritize interesting signals (whether they reach genome-wide significance or not) for follow-up and further replication. Follow-up sample sets should be adequately powered to detect the diminishingly low effect sizes observed at newly identified variants. Issues of set-up, information aggregation, estimation of heterogeneity and summary effects in such extended replication efforts are similar to those described above for GWA meta-analysis.
