 |
|
|
|
|
Gene Mutation May Cause Some Cases of Seasonal Affective Disorder
|
| | | | Related Healthscout Videos | |
|
Page: << Prev | 1 | 2 The gene is called the melanopsin gene, and it produces a light-sensitive protein found in photoreceptors in the eye's retina. The protein is not involved with vision, but it is linked to non-visual responses, such as circadian rhythms, hormones, alertness and sleep, Provencio said.
A mutation of the melanopsin gene may cause a change in responses to light, which can lead to symptoms of depression. Among SAD patients, about 29 percent have a family history of the condition, suggesting there may be a genetic component, according to background information in the study.
"Not all people with SAD have this mutation," Provencio said. "But, at least in our study, all the people who had two mutated copies of this gene were in the SAD group. We think we may have found a cause of SAD among a subset of patients."
Text Continues Below
Dr. Daniel F. Kripke, a professor of psychiatry emeritus at the University of California, San Diego, called the finding interesting, but said it only accounts for a small number of SAD cases.
"This is a responsible piece of work," Kripke said. "The finding is promising, but it needs to be repeated and may not be correct. If it is correct, it appears to explain only about 5 percent of the cause of SAD."
More information
To learn more about SAD, visit the U.S. National Library of Medicine.
Page: << Prev | 1 | 2
|
Copyright © 2008 ScoutNews, LLC. All rights reserved.
Last updated 11/7/2008
|
|
SOURCES: Ignacio Provencio, Ph.D., associate professor, biology, University of Virginia, Charlottesville; Daniel F. Kripke, M.D., professor emeritus, psychiatry, University of California, San Diego; November 2008 Journal of Affective Disorders, online
|
.gif)
