This finding, published in three independent studies, identified new genetic variants that increase the risk of schizophrenia and may open ways to new methods for classifying and diagnosing people with the mental illness.
In the studies, the researchers analysed the genes of 6,000 to 10,000 people from around the world, half of whom had schizophrenia. They found one mutation on chromosome 1, two on chromosome 15 and confirmed a variant associated with the condition on chromosome 22.
Scientists now say that people with schizophrenia are more than 10 times as likely to have these rare chromosomal alterations as people who don't have the illness. The genes are also found in some people with autism and other psychological disorders, suggesting the conditions may be related, the researchers said.
Since the disease may be caused by a complex set of genetic flaws, it could complicate the search for effective treatments, researchers added.
Schizophrenia, characterised by hallucinations, delusions and disordered thinking, is believed by scientists to result from a combination of both genetic and environmental causes. It is far more common in men than in women and is usually diagnosed in late adolescence or early adulthood.
