De novo polymorphism discovery based upon mutation scanning of all ZNF804A coding exons did not reveal evidence for the existence of a common non-synonymous variant (MAF≥0.01) that explains the original signal in our sample (table 1), in the fatSNP2 meta-analysis (table 2) or in the larger meta-analyses of those samples for which data were available for these SNPs (supplemental table 7). The second approach we applied was to test SNPs that, in the GeneVar database, were associated with ZNF804A expression. In fatSNP phase 1, two of these markers were more significantly associated with schizophrenia than rs1344706 (table 1). Since those two markers were in perfect LD, we followed up only one, rs1583048. As was the case for the non-synonymous variants, the evidence for association in fatSNP2 (table 2) and in the larger meta-analyses of those samples for which data were available for these SNPs (supplemental table 7) was much weaker than for rs1344706. Therefore it is likely that the signal observed at rs1583048 derives from LD (D’=1) with rs1344706. That the signals are not independent was also supported by the fact that rs1583048 was not required in the regression model.
