In the Advanced Online Publication of
They assembled data from published reports of 36 different disease associations, ranging from schizophrenia to hypertension. They used meta-analysis to explore the diversity and discrepancies between different studies. In 39% of cases they found statistically relevant heterogeneity between studies. The first published reports (often appearing in high impact-factor journals) tended to give more impressive disease association, which became less prominent in subsequent reports. In some cases the accumulation of additional data led to increased statistical significance of the genetic association.