According to a team of researchers from the Edinburgh University, the risk of development of psychotic symptoms is higher in people with a variant of a gene called neuregulin.
This study was published in the journal Nature Neuroscience.
200 youths at high risk of developing schizophrenia were monitored for 10 years in this study. As schizophrenia is a hereditary disorder, all the volunteers had 2 or more relatives affected by this condition. All of them were of the age group 16-25 years at the beginning of the study, the vulnerable age at which the symptoms were expected to develop.
The researchers conducted interviews, brain scans, psychological tests and genetic analysis in their study. Their findings revealed that volunteers with a variant of the gene neuregulin were more likely to develop psychotic symptoms like paranoia or hearing voices linked with schizophrenia, than those with out the variant.
This was confirmed by brain scans that showed that abnormal brain activity in the frontal and temporal regions were more likely to occur in people with the gene variant. These changes are usually linked to schizophrenia.
Previous studies have revealed that a gene linked to brain development is controlled by this gene variant.
These findings could help in the development of treatment.
Dr Jeremy Hall, lead researcher on the paper, based at the division of psychiatry, Edinburgh University, said: "These major mental illnesses have really been for a very long time a big black box in terms of what is causing them - it is not that long ago that people thought you got schizophrenia because you had a bad mother. And treatments have not advanced a lot over the last 50 years.
"You have to understand more about what causes diseases before you can start designing treatments for it.
"These results help us to understand how a gene might alter brain function and then cause symptoms, and could represent a target for treatments in the future."
Dr James MacCabe of the Institute of Psychiatry, Kings College London, said: "It is a very interesting study, and, potentially, quite an exciting one.
"We have known for years that schizophrenia had a genetic contribution, but until quite recently no genes had been found.
"Over the past five years there have been about 10 possible genes identified, and neuregulin is a very promising gene."
He said: "It is a relatively small study and will have to be repeated on a much larger scale, but if the results hold true the findings would be significant.
"The next stage would be to understand how a defect in this gene causes schizophrenia so as to understand the neurobiology of the disorder and design treatments that could reduce the symptoms."
Marjorie Wallace, chief executive of the mental health charity Sane, said: "There have been so many hopes of finding a gene for schizophrenia which have ended in a cul-de-sac.
"If this latest research were to prove a breakthrough and lead to understanding what causes schizophrenia, we could at last find more effective treatments and potential cures, transforming the future for the one in 100 who suffer from this devastating condition."