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THURSDAY, March 27 (HealthDay News) -- Scientists have found that deletions and duplications in DNA are more common in people with schizophrenia, and these errors are in genes related to brain development and neurological function.
Because these deletions and duplications differ from person to person, the study findings could eventually lead to new individualized treatments for those suffering from the disabling mental disorder, the researchers said.
"We found areas in people's DNA that are either deleted or duplicated -- we all have some of these, and some are rare," said lead researcher Dr. Jon M. McClellan, an associate professor of psychiatry at the University of Washington, in Seattle. "The assumption is that common ones are probably less likely to cause illnesses, but the rare ones might."
The researchers looked to see if people with schizophrenia had more rare mutations than healthy individuals did. "We found they had a lot more," McClellan said. "So there was about a threefold increased risk of having a rare deletion or duplication in someone with schizophrenia versus healthy people."
For those who developed schizophrenia early in life, there was a fourfold increased risk of rare deletions and duplications, McClellan added.
The findings were published in the March 27 edition of the journal Science.
For the study, McClellan's team analyzed DNA from 150 people with schizophrenia and 268 people without the disease. The researchers found deletions and duplications of genes in 15 percent of those with schizophrenia, compared to only 5 percent among people without the disorder.
Genetic deletions and duplications were even greater among people whose schizophrenia started when they were young -- before 12 years of age. Among these people, 20 percent had the rare gene mutations.
The results were confirmed by a second team of researchers led by Anjene Addington and Judith Rapoport at the U.S. National Institutes of Mental Health. In their study, Addington and Rapoport found that the rate of rare duplications and deletions of genes was even higher among people who developed schizophrenia before they were 12 years old.
