Study Shows Genetic Causes of Schizophrenia

A study reported in the magazine Science showed that multiple errors or deletions in a person's genetic code, or DNA, can lead to schizophrenia. Schizophrenia is a mental illness characterized by delusions, hallucinations, and disordered thinking. Today, it affects about one of every 100 people.

Scientists have long suspected that schizophrenia runs in families. What is surprising to the team who conducted the study is that they found strong evidence that it's usually not the same set of genes going bad in people who develop schizophrenia.

The scientists from the University of Washington and Cold Spring Harbor Laboratory examined the DNA of 150 people with schizophrenia and compared what they found with the genetics of 268 people without the illness. Findings shows that people with schizophrenia had flaws in brain-related genes 15 percent of the time compared with 5 percent in healthy people. But it was never the same set of genes going bad.

"They were all different", said Mary-Claire King, a world renowned geneticist and co-authors on the report. "The standard dogma is that any complex trait (such as mental illness) is going to be caused by the cumulative effect of multiple common defects. But that's not what we found," said King. "The only way we could have found this was to look at the overall (genetic) profile," she added.