Researchers at the University of Washington and Cold Spring Harbor Laboratories have found a link between genetic errors and schizophrenia.
Schizophrenia is a debilitating psychiatric disorder in which people suffer from hallucinations, delusions, and disorganized thinking, and are at risk for unusual or bizarre behaviours.
Researchers found that deletions and duplications of DNA are more common in Schizophrenics, and that many of those errors occur in genes related to brain development and neurological function.
As a part of the study, boffins led by Tom Walsh, Jon McClellan, and Mary-Claire King at the UW, and Shane McCarthy and Jonathan Sebat at Cold Spring Harbor, compared DNA from 150 people with schizophrenia and 268 healthy individuals.
They found rare deletions and duplications of genes present in 15 percent of those with schizophrenia, versus only 5 percent in the healthy controls.
The rate was even higher in patients whose schizophrenia first presented at a younger age, with 20 percent of those patients having a rare mutation.
Based on this, the researchers theorized that rare mutations found only in schizophrenic patients would be more likely to disrupt genes related to brain functioning and thus may cause schizophrenia.
The findings of a second research team led by Anjene Addington and Judith Rapoport at the National Institutes of Mental Health, further supported this theory by discovering a higher rate of rare duplications or deletions in patients whose schizophrenia began before age 12 years, a very rare and severe form of the disorder.
In individuals with schizophrenia, mutations were more likely to disrupt signalling genes that help organize brain development. Each mutation was different, and impacted different genes. However, several of the disrupted genes function in related neurobiological pathways.
The findings suggest that schizophrenia is caused by many different mutations in many different genes, with each mutation leading to a disruption in key pathways important to a developing brain.
Thus, for most cases of schizophrenia, the genetic causes may be different.
This observation, the researchers state, has important implications for schizophrenia research.
The findings appear in the March 27 online edition of the journal Science.