The genes for schizophrenia: finally a breakthrough?

A number of susceptibility genes for schizophrenia have recently been identified. They have engendered excitement because replicate studies have attained greater consistency than in the past. In this review, we outline gene mapping methods, and briefly review their strengths and challenges. We also evaluate peer-reviewed genetic association studies that have implicated six selected genes: catechol-O-methyl transferase (COMT), neuregulin 1 (NRG1), dysbindin (DTNBP1), regulator of G-protein signaling 4 (RGS4), and G72 and D-amino-acid oxidase (DAAO). The available supporting evidence is variable. Though credible evidence is available for all of these genes, it is strongest for NRG1 and DTNBP1. Further studies, particularly exhaustive analyses of all polymorphisms at each locus, meta-analyses, and investigations of the likely function of risk alleles (variants) are desirable.