Epigenetic and Genetic Aberrations of the Brain Dopaminergic System in Schizophrenia and Bipolar Disorder: Achievements and Prospective

The molecular mechanisms of the fact that more than 50% of the individuals with the same genetic make up (e.g. identical twins in schizophrenia) do not show the same psychiatric phenotype remained undefined in psychiatry. This along with the failure to find responsible genes with major effects in psychiatric disorders and lack of consistency of genetic association studies led to the current unanimous conclusion that, in addition to the genetic factors, environmental and epigenetic factors influence the functions of brain and the presentation of the symptoms in mental diseases. Here we reviewed the potential epigenetic dysregulations of genes related to dopaminergic (DAergic) system. A comprehensive genetic and epigenetic analysis of the DAergic and the interacting pathways such as serotoninergic and glutaminergic systems could help to understand the molecular bases of the differences in disease severity in individuals with similar or identical genetic make-up that can assist for the identification of novel targets with therapeutic and preventive applications.