New findings may transform hunt for schizophrenia genes

Two independent studies published in the journal Science this week suggest that many rare gene mutations may be responsible for causing schizophrenia, challenging the widely held theory that combinations of several relatively common mutations are to blame. The researchers found that very rare genetic disruptions, often unique to the family or even the individual, were up to four times more common in people with schizophrenia.

Dr Matthew Slate, director of the neurogenetics programme at Yale University, who was not involved in the research, agrees that the findings could transform the way in which scientists view brain development and disorders. 'This paper represents a paradigm shift in the way we think about identifying genes in schizophrenia', he told The New York Times.

Schizophrenia is a disease which affects 1 in 100 people and onset, typically characterised by hallucinations and delusions, is usually in late adolescence.

The researchers compared the genetic makeup of 150 people with schizophrenia to that of 268 unaffected people in the search for genes disrupted by large deletions or duplications. They found that 15 per cent of schizophrenia patients carried such mutations, compared to five per cent of healthy controls, rising to 20 per cent among those who developed schizophrenia during childhood.

Many of the genes identified play a role in brain development, Jack McClellan, a psychiatrist at the University of Washington in Seattle who led the study, told New Scientist. 'A lot of them help regulate how neurones get from point A to point B over time,' he said.

The findings could potentially lead to new drug targets for schizophrenia and may help with a variety of brain disorders including bipolar disorder, autism and depression, claim the researchers.