The molecular genetics of schizophrenia: an update

Objective: This paper aims to summarise the latest molecular genetic findings in schizophrenia, while providing background information on a number of relevant methodological issues. Method: Accumulative genetic data indicate that schizophrenia is a genetically complex disease with an unclear mode of transmission. The development and rapid progression of molecular genetics have provided a wide variety of methods to search for genes predisposing to human disease. The genetic basis for a number of the simpler diseases has been identified and characterised using these methods. More recently, progress has been made in identifying genes predisposing to the genetically more complex diseases such as diabetes mellitus, multiple sclerosis, bipolar disorder and schizophrenia. Results: The latest findings on chromosomes 3, 6, 8, 13, 18 and 22 and on the X chromosome are reviewed. Conclusions: There is now suggestive support for three susceptibility loci (6P24-22, 8p22-21 and 22q12-q13.1) for schizophrenia, and it is likely that other regions will emerge from studies now in progress. Finding and then characterising genes within these loci will require long-term commitment and systematic efforts in clinical, laboratory and analytical fields.