The underlying mechanism of the involvement of G72 and DAAO in schizophrenia is probably based on decreased levels of D-serine and decreased NMDA receptor functioning in patients.
These data suggest a potential role for DAO in susceptibility to depressive symptoms in schizophrenia, but a more general role for DAO in affective disorders cannot be excluded.
We identified evidence for epistatic interaction between the associated SNPs at DAOA and DAO genes in contributing to schizophrenia risk (OR = 9.3 (1.4, 60.5).
In the haplotype analysis based on the information of linkage-disequilibrium block across this gene locus, we demonstrated a highly significant association between schizophrenia and a DAAO haplotype (P = 2.0173 x 10(-21)), which therefore provides an independent statistical support for association of the DAAO gene with schizophrenia and indicates that the DAAO gene may play a significant role in the etiology of schizophrenia in the Han Chinese.
The association of both DAAO and a new gene G72 from 13q34 with schizophrenia together with activation of DAAO activity by a G72 protein product points to the involvement of this N-methyl-d-aspartate receptor regulation pathway in schizophrenia.