MELVILLE, N.Y. — Previously unsuspected flaws in genes involving brain development and neurological function may underlie schizophrenia, researchers have found in an investigation shedding new light on a perplexing psychiatric disorder.
Scientists at Cold Spring Harbor Laboratory, working with a team at the University of Washington in Seattle, have uncovered an array of DNA duplications and deletions that increase the risk of schizophrenia, some so unique that they exist only in the individual — a personal signature for the disorder.
Jonathan Sebat and colleagues discovered dozens of deleted or duplicated pieces of DNA, occurring over an array of chromosomes. He theorizes that some mutations probably overlap with other brain disorders, such as autism and bipolarism.
"We're seeing a statistically significant increase in the number of mutations in these patients, which suggests a role for rare variants — rare mutations — is the causation of schizophrenia," said Sebat, an assistant professor of genetics at Cold Spring Harbor Laboratory and the senior study author.
The analysis involved studying DNA from 150 people with schizophrenia and 268 healthy individuals. Investigators found rare deletions and duplications of genes in 15 percent of those with schizophrenia, compared with 5 percent in the healthy group. Genetic flaws were found in higher percentages among patients whose schizophrenia occurred at a very young age, with 20 percent of patients having a rare mutation.
Schizophrenia is a heart-wrenching psychiatric disorder that often emerges in young adulthood. It is characterized by hallucinations and delusions, such as hearing voices.
The work adds yet another dimension to studies of the brain by Sebat and collaborators at Cold Spring Harbor Laboratory, who last year announced groundbreaking research in the area of autism.
Sebat's research is the second major schizophrenia study by a New York area research team in recent months. In December, scientists at Zucker Hillside Hospital in Queens found a series of nine relatively rare genetic mutations that also increase the risk for schizophrenia.
Dr. Anil Malhotra, co-author of that research, said the Cold Spring Harbor team is breaking new ground in the genetics of schizophrenia.
Many of the DNA variants uncovered in the schizophrenia research — and the autism study — occur spontaneously. However, some DNA flaws relative to schizophrenia are, in fact, rooted in family trees.
The new study was reported Thursday in the online version of the journal Science.