Study Finds Genetic Risk Factors Shared by 5 Psychiatric Disorders
Two of the aberrations discovered in the new study were in genes used in a major signaling system in the brain, giving clues to processes that might go awry and suggestions of how to treat the diseases.
“What we identified here is probably just the tip of an iceberg,” said Dr. Jordan Smoller, lead author of the paper and a professor of psychiatry at Harvard Medical School and Massachusetts General Hospital. “As these studies grow we expect to find additional genes that might overlap.”
The new study does not mean that the genetics of psychiatric disorders are simple. Researchers say there seem to be hundreds of genes involved and the gene variations discovered in the new study confer only a small risk of psychiatric disease.
Steven McCarroll, director of genetics for the Stanley Center for Psychiatric Research at the Broad Institute of Harvard and M.I.T., said it was significant that the researchers had found common genetic factors that pointed to a specific signaling system.
“It is very important that these were not just random hits on the dartboard of the genome,” said Dr. McCarroll, who was not involved in the new study.
The work began in 2007 when a large group of researchers began investigating genetic data generated by studies in 19 countries and including 33,332 people with psychiatric illnesses and 27,888 people free of the illnesses for comparison. The researchers studied scans of people’s DNA, looking for variations in any of several million places along the long stretch of genetic material containing three billion DNA letters. The question: Did people with psychiatric illnesses tend to have a distinctive DNA pattern in any of those locations?
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