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Thanks to accelerating advances in computing power and lab instruments, discovering the genetic defect that causes a person’s retinal degenerative disease is continually getting quicker and less expensive. Single genetic variations are the primary cause of most these vision-robbing conditions, and once one is identified, doctors can help the patient better understand the possible course of his or her condition, and which emerging treatments and clinical trials might be most appropriate.Dr. Steve Daiger, an FFB-funded researcher at the University of Texas at Houston, reports that the power of genetic screening technologies has increased nearly 1,000-fold over the last 10 years and is predicted to increase another 100-fold in just a few years more. This acceleration far exceeds Moore’s Law, a historically accurate metric stating that computing power doubles every 24 months. “I estimate that in about five years, a person will be able to have their entire genome sequenced — that is, a geneticist will be able to read all 25,000 of their genes — for about $1,000,” says Dr. Daiger. “That same effort today costs tens of thousands of dollars.” To identify potential disease-causing genes, researchers and testing centers use computers and robotics to quickly scan large amounts of DNA, tiny pieces of which are captured on microscopic beads and placed on microplates for analysis. The DNA is then checked for abnormalities that might lead to disease. These technologies are also helping researchers identify genes that had never before been linked to retinal degeneration. Dr. Daiger estimates that experts will have discovered more than 90 percent of such genes within the next five years. Thus far, he says, scientists have found a little more than 50 percent. “The rate of progress in finding new genes has been truly remarkable,” says Stephen Rose, Ph.D., chief research officer, Foundation Fighting Blindness. “It took us nearly two decades to find the first retinitis pigmentosa gene. That discovery was in 1989. Thanks to Foundation funding over the following two decades, we identified 200 more retinal disease genes, and the rate of acceleration in gene discovery is only getting faster.” Historically, trying to identify the specific genetic variation causing an individual’s retinal disease was often a daunting task, because each of us has about 6.6 billion fundamental pieces of DNA spread across the 25,000 pairs of genes inherited from our parents. These pieces of DNA are called “base pairs,” because they exist as pairs of molecules. Just one alteration in a base pair can cause a devastating retinal disease. What can make the job of finding a single alteration tough is that every person has several thousand altered base pairs, most of which have no effect on a person’s health or well being. For researchers, it can be like trying to find one particular needle in a haystack filled with thousands of needles. Fortunately, researchers don’t need to scan every base pair to find a problem gene. A lot of information can narrow their search including: family history of disease, genetic information from affected and unaffected family members, severity and region of vision loss, and structure of the affected retina. Generally speaking, the more family members affected by a disease, the easier it is to identify the gene alteration. The Foundation currently funds approximately $2.6 million annually in genetic discovery research. If you are interested in learning more about the genetic testing process, click here to access the Foundation’s genetic testing booklet and other informational resources. |
