It is noted that 7 genes, DAO [28], PRDX6 [29], KCNN3 [30], TCF7L2 [31], RFX4 [32], FYN [33], and B3GAT2 [34] (yellow-colored nodes), relevant to psychiatric disorders are involved and interestingly these genes except B3GAT2 constitute a connected subgraph. This evidence concerns the gene DAO and psychiatric disorder.