Researchers find 3 new genes for schizophrenia

By Michael Kahn

LONDON (Reuters) - International researchers have identified three new DNA variations that increase the risk of schizophrenia and said on Wednesday they were some of the strongest genetic links yet found to the disease.

The results published in two independent studies in the journal Nature also confirmed a previously known genetic variation and could lead to new treatments for the condition that affects around 1 in 100 people, the researchers said.

"This is, if you like, the beginning of a new era in the field, said David St. Clair, a psychiatrist at the University of Aberdeen in Scotland who worked on both studies.

"Once we understand what the mutations are doing, new drugs and new approaches like preventative measures can be developed. It opens up the way to new methods for classifying and diagnosing people with the illness."

Schizophrenia, characterised by hallucinations, delusions and disordered thinking, is far more common in men than in women and is usually diagnosed in late adolescence or early adulthood.

While anti-psychotic drugs such as AstraZeneca's Seroquel and Eli Lilly and Co's Zyprexa can help, such drugs do not cure the mental illness and can cause unpleasant side-effects, including sometimes dangerous weight gain.

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. These changes can increase the risk of developing schizophrenia by up to 15 times, the researchers said.