The heterogeneity test (Cochran's Q statistic) was formally statistically significant for the FTO variant (p = 0.014) and the rs9300039 marker (p = 0.018). As Q is grossly underpowered with only 3 studies, lack of nominal statistical significance for heterogeneity in the other polymorphisms does not prove homogeneity of effects. Of interest, the two loci with highest-between study heterogeneity were not unanimously proposed as “conformed” susceptibility loci by all 3 GWA investigations.
