An international team of researchers has linked three genes to the debilitating mental disorder schizophrenia.  The investigators say the findings are the beginning of a search for clues into the mysterious and disabling mental illness.  VOA's Jessica Berman reports.

Schizophrenia is a severe mental disorder characterized by hallucinations, delusions and a lack of awareness of one's surroundings.

The illness strikes approximately one in 100 individuals and runs in families between 70 and 90 percent of the time.

Devoted to finding a cure, the International Schizophrenia Consortium of 11 research institutes worldwide conducted a study in which they compared the entire DNA sequence of 3,300 people with schizophrenia to that of 3,200 healthy individuals. 

In three papers published in the journal Nature, investigators report the discovery of deletions and additions of large chunks of two chromosomes in the genetic material of people with schizophrenia.

The scientists also confirm the involvement of a third genetic abnormality in schizophrenia that had previously been identified.

Pamela Sklar is a psychiatrist and geneticist at Massachusetts General Hospital and co-author of the consortium paper. 

Sklar says the findings give hope to people with the severe mental disorder and their caregivers.

"We have only explained a tiny fraction of why people might develop schizophrenia," said Pamela Sklar. "And of course much more work needs to be done to connect the specific changes to the full spectrum of genetic factors that might influence schizophrenia."

Investigators found the rare genetic abnormalities in 13 percent of the schizophrenics they studied.  But they also found the DNA glitches in 10 percent of the healthy volunteers.

Investigators say the finding suggests more genetic abnormalities are involved in the development of schizophrenia.  The discovery may also mean that the mental illness is several disorders rolled into one.

Michael O'Donovan is a psychiatrist at Cardiff University in Wales and lead author of one of the studies. 

"Some of the findings operate beyond schizophrenia," said Michael O'Donovan. "So, the findings that we reported have been previously been implicated in diseases like autism and mental retardation.  So, really what we are trying to get a handle on is disturbance of mechanisms.  But a disturbance of one mechanism may well lead to different outcomes."

Researchers say they have some potential molecular targets for the development of drugs to treat schizophrenia. 

But diagnostic tests are a bit more elusive, since so many people who are not schizophrenic have the genetic abnormalities.