not detected, the MDD replication data reported here raise some questions whether MDD also has an association in this region. We obtained MDD replication data for two SNPs on 3p21.1 (Supplementary Table S18), and observed no additional support for association for rs2535629 (discovery P = 0.0001, replication P = 0.56, combined P = 0.002) or rs3773729 (discovery P = 0.00022, replication P = 0.022 with different direction of association, combined P = 0.0095). Similarly, replication samples for the PGC BIP study36 provided little additional evidence for two SNPs in this region (rs736408 and rs3774609). In contrast, stronger evidence for association was observed in the PGC SCZ study after adding data from replication samples (rs2239547, chr3:52 830 269; discovery P = 2.2×10−6, replication P = 0.003, combined P=6×10−8).37 The PGC analyses reported here include most samples used in previous reports of genome-wide significant association in this region for BIP,66 BIP-SCZ36 and MDD-BIP,67 underscoring the need for analysis of independent samples.
