Researchers find gene that causes Stargardt blindness
March 3, 1997
Web posted at: 2:40 p.m. EST
FREDERICK, Maryland (CNN) -- Researchers have pinpointed a
gene that causes Stargardt disease, a rare, inherited form of
macular degeneration that strikes younger people.
The discovery may lead to the development of a test for the
disease, which causes blindness in 25,000 young Americans,
and new treatments for macular degeneration, the leading
cause of blindness in Americans over 60 years old.
The study was published Sunday in the March issue of Nature
Genetics by 19 researchers from the University of Utah's
Eccles Institute of Human Genetics, Baylor College of
Medicine in Houston, Johns Hopkins University and the
National Cancer Institute.
Geneticist Mark Leppert, who heads the Utah team, is hopeful
the discovery will lead to a test for the Stargardt disease.
Presently there is no such test.
The victims, commonly between ages 6 and 15, will complain of
poor vision, but doctors often are unable to determine the
cause until the disease has worsened. Within five years, the
victim has lost central reading vision and is legally blind.
Leppert hopes the discovery will also provide clues about
what causes the more common form of macular degeneration in
Macular degeneration, for which there are few treatments,
damages the part of the eye that is responsible for sharp,
Roughly 1.7 million Americans develop age-related macular
degeneration, according to the National Institutes of Health.
That's far fewer than suffer from cataracts. But cataracts
are more easily treated. So macular degeneration ends up
causing more blindness in older people.
The newly identified gene is located in the retina, the rear
interior of the eyeball. A retina affected by macular
degeneration exhibits an accumulation of fatty substances.
The researchers suspect that people with a mutated version of
this gene lack a pump that helps move these fatty substances
out of the retina.
"Eventually it would be nice if we could identify drugs ...
that could reverse or slow down the process once it begins,"
said geneticist Dr. Michael Dean.
Correspondent Eugenia Halsey contributed to this report.
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