Blind No More
Dateline: 03/26/98
Researchers at the Fred Hutchinson Cancer Research Center and Cornell University reported that a genetic defect is responsible for progressive rod-cone degeneration (PRCD) in dogs. PRCD is known to cause blindness in at least four breeds of dogs: Portuguese water dogs, Labrador retrievers, poodles, and cocker spaniels. It is possible that many other breeds may also be affected. If so, PRCD would be caused by a relatively old mutation in the evolutionary history of dogs.
PRCD starts with the deterioration of the retina and results in blindness. PRCD seems to be the "dog version" of retinitis pigmentosa, a leading cause of inherited blindness in human families. RP17, one of several forms of retinitis pigmentosa , appears to be the closest human equivalent. Prior to this study, the general scientific consensus was that a link between the two was unlikely. Since the study, scientists now believe that both diseases come from similar mutations to the underlying gene.
Scientists hope that by identifying the gene responsible for PRCD, a diagnostic test could be developed for the disease in dogs and, eventually, in humans. Further treatment options could be developed using gene therapy techniques. Scientists would insert the normal gene into a harmless "carrier," known as a transfer vector. The vector would then be injected into the organism in the hope that the normal gene would slow the genesis of the disease or even reverse its effects in the diseased cells.
Scientists at the two institutions mentioned above were working on developing a "dog genome project" similar to the Human Genome Project . This is the first time that scientists have been able to use a "gene map" from canines to pinpoint the locus of a disease.
What do you think? How might gene therapy be beneficial to people with degenerative diseases? Is there a down side? Many have argued that the Human Genome Project would be rife with problems. Does this point to the need for the mapping of the human genome? What are the attendant risks and rewards? Come over to the Biology Forum and share your thoughts, opinions, and feelings. 'Til next time...
For additional information see:
Gene Therapy For One Form Of Human Blindness
ScienceDaily report adapted from a news release issued by Cornell University.
