Genetics of schizophrenia

Genetic epidemiological studies suggest that individual variation in susceptibility to schizophrenia is largely genetic, reflecting alleles of small to moderate effect in multiple genes. Molecular genetic studies have identified a number of potential regions of linkage and two associated chromosomal abnormalities, and evidence is accumulating in favour of several positional candidate genes. The positional candidate genes for which the evidence is strongest are those encoding Dysbindin (DTNBP1) and Neuregulin1 (NRG1). For others, Disrupted in Schizophrenia 1 (DISC1), D-amino-acid oxidase (DAO), D-amono-acid oxidase activator (DAOA, formerly known as G72) and Regulator of G-protein Signalling 4 (RGS4), the data are promising but not yet compelling. The identification of these, and other susceptibility genes, will open up new avenues for research aimed at understanding the pathogenesis of schizophrenia, and will catalyse a re-appraisal of the classification of psychiatric disorders.