Dallas, TX – (October 2010) – The discovery of three genes that place individuals at high risk of developing age-related macular degeneration ( AMD) has propelled the interest by researchers at the Retina Foundation of the Southwest to gain a deeper understanding of genetic risk factors for AMD.
The Macular Degeneration Clinical and Genetic Database is in its second year of operation. This project is an expansion of the Southwest Eye Registry, the only repository of clinical, genetic, and DNA samples for genetic eye diseases in the southwest. Previous research has implicated high-risk alleles in three genes (CFH, HTRA1, and LOC387715) that increase a person’s susceptibility to develop AMD.
“We not only have the knowledge gained from other studies defining various environmental and health behavior risk factors, but now we actually have identified genetic risk factors that move age-related macular degeneration into more of a genetic realm,” said Dr. Dianna Wheaton, Director of the Southwest Eye Registry.
To date, more than 180 samples from patients with macular degeneration have been collected and processed in the Southwest Eye Registry DNA lab. The database will help our researchers learn more about how genetics plays a role in developing AMD, including the level of risk associated with certain genes as well as determining whether the disease is more aggressive for individuals from a family with a history of macular degeneration.
“There are various factors that we will examine in addition to their genetic background such as: what is their age of onset? Do they develop disease earlier than people who have fewer risk alleles? Are they more likely to have more aggressive disease? Do they respond differently to treatment,” said Dr. Wheaton.
For families who have experienced multiple generations of family members who have lost their vision to AMD, it has been all too clear that genetics plays a role in increasing one’s risk of developing AMD later in life. With more than 1.75 million Americans 40 years and older who have advanced AMD and an expected three million by year 2020, the genetic risks associated with this very prevalent eye disease cannot be ignored.
“The interest, of course, for age-related macular degeneration has always been relatively high, but several things over the past few years have really increased awareness,” said Dr. Wheaton.
Studies show that smoking, obesity, high blood pressure and high levels of dietary fat intake are all modifiable health risk factors for AMD. The macular degeneration database may help identify younger family members who have the high risk alleles, and their involvement in the study can help them learn ways to reduce the risk of developing the disease.
“Everyone should have in mind what the environmental and behavioral risk factors are for AMD, but we tend to not think of those things until we get older and into that age category,” said Dr. Wheaton. “So if one is identified to have these risk alleles and you have a parent who developed AMD, then you’re armed with information at an earlier age where it may be more beneficial to make these lifestyle changes.”
A two-year grant that began in March 2009 from the Rosewood Foundation helped establish the macular degeneration database. The funds supported work to re-structure the database to accommodate environmental and behavioral information from macular degeneration patients, to train staff on genotyping DNA samples for the AMD risk alleles, and to begin gathering data and DNA samples from patients with AMD.
The database also includes individuals with juvenile macular degeneration, commonly known as Stargardt Disease. Stargardt’s is an autosomal recessive form of macular degeneration caused by mutations in the ABCA4 gene. The lab is conducting exploratory work that is very new and may identify additional genes that influence the severity of Stargardt’s.
Dr. Wheaton’s lab is staffed by Kaylie Webb, a Research Associate in her third year, and Ashley Anderson, who completed a summer internship and continues working on the project this fall while completing her college coursework. The research is in the early stages of collecting DNA samples and health and behavioral data from patients. However, there is real benefit to patients and families now as they learn more about the hereditary influences on macular degeneration.
“It is such a worthwhile undertaking,” said Dr. Wheaton. “We’ve probably only just begun…what we can learn from it is so tremendous that you don’t want to abandon the project just because you’ve come to the end of that specific funding, so the research will continue.”
Click here to learn more about the Southwest Eye Registry.