In the light of recent findings, the genetic approach can finally be considered to have started to deliver what it has promised for a number of years. The identification of genes associated with schizophrenia is already beginning to substantially increase our knowledge of its underlying pathophysiology. Is there still room for the dopamine hypothesis of schizophrenia when recent genetic findings are taken into consideration? The performance of GWA studies has led to the identification of previously unknown and largely unexpected genes. It is possible that genetic variants in risk genes identified in GWA studies lead to downstream impairments in dopaminergic function. It is also important to remember that only a very small fraction of all truly associated variants have been detected and that many more associated variants will be identified in the future. These will include already known variants which do not currently surpass the level of genome-wide significance in GWA studies; the identification of other variants will require additional experimental approaches (see above). It is possible that these as yet undetected genes encode proteins that participate directly in dopaminergic neurotransmission such as dopamine transporters, dopamine receptors, and synthetic and catabolic enzymes.
