A specific region in the human genome may harbor genes that play a major role in the onset of depression, according to scientists at the Texas Biomedical Research Institute and Yale University.
The researchers were able to pinpoint this area by developing and implementing the new Texas Biomed’s AT&T Genomics Computing Center (GCC), a method that analyzes thousands of potential risk factors for depression.
This led to a biomarker that may help identify individuals at risk for major depression.
“We were searching for things in psychiatric disease that are the equivalent of what cholesterol is to heart disease,” said John Blangero, Ph.D., director of the GCC and lead author of the new study.
“We wanted to find things that can be measured in everybody and that can tell you something about risk for major depression.”
Studies have shown that that up to 17 percent of Americans will suffer depression at some point in their lives. Although there is strong evidence that people can inherit a susceptibility to major depression, scientists have been unable to locate any of the key genes that underlie the disorder.
For the study, researchers analyzed blood samples from 1,122 individuals enrolled in the Genetics of Brain Structure and Function Study, a large family study that includes people from 40 extended Mexican-American families in the San Antonio area.
Blangero and his team looked at more than 11,000 endophenotypes, or heritable factors, and searched for any links to major depression. It was discovered that disease risk correlated most strongly with expression levels of a gene called RNF123, which helps regulate neuron growth.
Once this risk factor was found, further analysis pointed scientists to an area on chromosome 4 containing genes that appear to regulate RNF123.
Because the RNF123 expression levels can be measured relatively easily in the blood, this finding could lead to a way of identifying people at risk for major depressive disorder, Blangero said.
“We might be able to know in advance that a person will be less able to respond to the normal challenges that come about in life,” he said. “Then doctors may be able to intervene earlier after a traumatic life event to remove some of the debilitation of depression.”
The study also shows promise for using this method as a way to analyze a variety of heritable traits to hone in on gene variants that underlie other diseases.
The research was published online in October in the journal Biological Psychiatry and supported by the National Institutes of Health.