The postsynaptic density protein 95 (PSD-95) - the prototype of this family - is a modular protein that enables anchoring of NMDA receptors, modulates NMDA receptor sensitivity to glutamate and coordinates NMDA receptor-related intracellular processes. Since hypofunction of NMDA receptors has been implicated in the pathophysiology of schizophrenia, we explored the hypothesis that genetic variants of the PSD-95 gene were associated with a diagnosis of schizophrenia. Three PSD-95 polymorphisms were studied in a sample population of 248 people with schizophrenia and 208 normal controls. One polymorphism (rs373339) was not informative in our Chinese population while the other two polymorphisms (rs2521985 and rs17203281) were analysed with chi-square tests and haplotype analysis. Results demonstrated that the two informative polymorphisms are in strong linkage disequilibrium with each other. Neither single marker nor haplotype analysis revealed an association between variants at the PSD-95 locus and schizophrenia, suggesting that it is unlikely that the PSD-95 polymorphisms investigated play a substantial role in conferring susceptibility to schizophrenia in the Chinese population. Further genetic studies in schizophrenia with other PSD-95-like molecules that interact with the glutamate system are suggested.
