Nearly 80% schizophrenia risk is genetic: Study

London: Nearly 80 percent of schizophrenia risk can be traced to genes inherited from parents, scientists have found.

Schizophrenia is a disorder that affects a person's ability to think, feel and behave clearly.

According to previous estimates, genes were found to be responsible only between 50 per cent and 80 per cent. 

However, the new estimates show that genetics plays as much as 79 per cent risk for the disorder.

"Our results show a substantial genetic component in liability to schizophrenia, with a heritability estimate of 79 per cent, and that the genetic effects seem to play a similar role in schizophrenia spectrum disorders," said Rikke Hilker from the University of Copenhagen.

Many factors such as DNA sequence, epigenetic DNA modifications, differences in gene expression, environmental factors and the complex interaction between these are thought to act in concert to influence the outcome of schizophrenia, the researchers said. 

For the study, published in the journal Biological Psychiatry, the team assessed genetic liability in over 30,000 pairs of twins in Denmark born since 1870.

Researchers found that consistency of schizophrenia is 33 per cent in monozygotic or identical twins and seven per cent in dizygotic or fraternal twins. 

The heritability was also estimated using a broader illness category, including related disorders on the schizophrenia spectrum. 

The results showed a similar estimate of 73 per cent, indicating the importance of genetic factors across the full illness spectrum, the researchers said.