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Sorting wheat from chaff in genomewide association studies may well entail more time and effort than the original study. It is therefore important to critically evaluate results from truly independent data sets and, as this study attempts, to take the analysis beyond just statistical association toward some sort of functional analysis. That said, this would appear to be a fairly dramatic example of winner's curse, for the strength of association reported in the Irish sample would not have warranted even the briefest mention in the original Cardiff study (O'Donovan et al., 2008).

References:

O'Donovan MC, Craddock N, Norton N, Williams H, Peirce T, Moskvina V, Nikolov I, Hamshere M, Carroll L, Georgieva L, Dwyer S, Holmans P, Marchini JL, Spencer CC, Howie B, Leung HT, Hartmann AM, Möller HJ, Morris DW, Shi Y, Feng G, Hoffmann P, Propping P, Vasilescu C, Maier W, Rietschel M, Zammit S, Schumacher J, Quinn EM, Schulze TG, Williams NM, Giegling I, Iwata N, Ikeda M, Darvasi A, Shifman S, He L, Duan J, Sanders AR, Levinson DF, Gejman PV, Cichon S, Nöthen MM, Gill M, Corvin A, Rujescu D, Kirov G, Owen MJ, Buccola NG, Mowry BJ, Freedman R, Amin F, Black DW, Silverman JM, Byerley WF, Cloninger CR; Molecular Genetics of Schizophrenia Collaboration. Identification of loci associated with schizophrenia by genome-wide association and follow-up. Nat Genet. 2008 Sep;40(9):1053-5. Abstract

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