Background: Schizophrenia is a severe mental disorder with a lifetime risk in the population of 1%. Despite extensive research, the underlying neurobiological mechanisms remain largely unknown.
Material and methods: Based on relevant research literature, an overview of the molecular genetics of schizophrenia is given.
Results and interpretation: Family, twin and adoption studies have shown that schizophrenia has a high heritability, indicating a significant genetic component to its aetiology. There is positive linkage to chromosomal regions which probably contain susceptibility genes of moderate effect. Genetic variants in different candidate genes and different chromosome abnormalities are apparently associated with increased susceptibility to schizophrenia. However, the genetic mechanisms of schizophrenia are still largely unknown. As a result of recent advancements in molecular genetic knowledge and methods, high-throughput techniques are now available in functional genomic research that will enable genome-wide search for susceptibility genes. This has to be combined with a new clinical approach where schizophrenia is characterized based on symptoms and traits that might more directly reflect fundamental processes of relevance to the disorder.