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Half of all cases of age-related macular degeneration (AMD) could be caused by a variation in a particular gene, according to UT Southwestern Medical Center researchers involved in a multicenter study.
"This adds a major piece to the jigsaw puzzle in understanding age-related macular degeneration," said Stephen Daiger, an FFB-funded researcher from the Human Genetics Center at the University of Texas Health Sciences Center in Houston.
The study – which appeared in the April 15 issue of the journal Science – links a mutation in the gene Complement Factor H to an increased risk of AMD. The study was funded by the National Eye Institute, The Foundation Fighting Blindness, and other organizations.
Macular degeneration is a complex disease that is the leading cause of blindness in people over the age of 50. By age 75, an estimated 30 percent of Americans have some manifestation of AMD.
The macula is an area in the center of the retina where light is focused and changed into nerve signals to compose an image in the brain. This central or "macular" vision enables us to read, drive and do things requiring fine, sharp, straight-ahead vision.
"We've identified a gene that is implicated in the pathogenesis of AMD," said Robert Ritter, a UT Southwestern research scientist involved in the Science study. "It provides a starting point for future investigations that will help us understand what takes place during the breakdown of the visual process."
"We know that one of the most significant factors in determining who gets macular degeneration is family history," said Dr. Albert Edwards, the study's lead author and an assistant professor of ophthalmology at UT Southwestern when he conducted his research. "A positive family history can increase a person's chances of developing macular degeneration several fold compared to people in the general population."
In the study, researchers analyzed genetic data from more than 200 patients who were at high risk for developing AMD or who already had AMD in one or both eyes, and from more than 130 healthy participants without a known family history of the disease. The genetic mutation of Complement Factor H was present in half of those with AMD or at high risk for the disease.
Researchers from the UT Southwestern Eugene McDermott Center for Human Growth and Development provided genotyping, technical advice and assistance.
"This is an important study that gives us new insight into a disease that impacts a growing population of aging Americans," said Dr. Helen Hobbs, director of the center and chief of Clinical Genetics at UT Southwestern. "Genetic studies such as this provide the basis for clinicians to identify those at risk and may lead to better treatment options."
These findings may help researchers develop new preventive and therapeutic strategies for managing AMD.
"By finding genes, we can understand where the biological pathways are and the processes involved in the disease," said Dr. Edwards, who is now the president of the Institute for Retina Research at Presbyterian Hospital of Dallas. "Once we determine which genes are responsible for macular degeneration, we can screen the population and manipulate biological pathways to develop treatments."
Also involved in the study were researchers from Boston University School of Medicine and Sequenom, Inc.
DISCLAIMER: Physicians differ in their approach to incorporating research results into their clinical practice. You should always consult with and be guided by your Physician’s advice when considering treatment based on research results.
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