This article is more than 5 years old. Information may no longer be current.
Test for gene mutation that causes corneal dystrophy now available in US
Click Here to Manage Email Alerts
Avellino Lab USA, developer of a genetic test for the mutation that can cause Avellino corneal dystrophy, recently announced the launch of its diagnostic laboratory, based in Menlo Park, Calif., and the availability of the Avellino-Gene Detection System in the U.S., according to a company press release.
Since 2008, more than 330,000 individuals have been tested in Korea and Japan for the Avellino corneal dystrophy (ACD) gene mutation, and the test is now being introduced to the Western world. Of those already tested, 301 have tested positive, according to Avellino Lab USA Chief Operating Officer
The Avellino-Gene Detection System will help patients and physicians make a more informed decision before going forward with vision correction surgery, such as LASIK, laser-assisted subepithelial keratectomy and photorefractive keratectomy, according to the release.
“There are two genotypes of the Avellino gene mutation, homozygous and heterozygous,”
“In heterozygous individuals, the disease develops more slowly,” she continued. “The granular spots can appear as early as age 12, or much later in life.”
Heterozygous individuals are the primary target group for the genetic test, because they would not be undergoing laser surgery until adulthood, Jensen said.
“If carriers of this mutation choose to have LASIK surgery, the density of the cloudiness can get worse, leading to worse vision and, in some cases, complete loss of sight,” she said.
Research indicates this may occur as soon as 4 months or as late as 17 years after LASIK, according to Avellino Lab USA.
Granular corneal dystrophy type 2 became tagged as ACD in 1988, in a research publication tracing two families (one from the U.S.) to genetic origins in the province of Avellino, Italy, Korney told PCON.
“There is still debate over the nomenclature,” he said.
While the condition is seen in all parts of the world in all ethnic groups, the origin of the actual genetic mutation is not yet known, he said. The worldwide prevalence is unknown because, until now, no testing on large population groups has been performed.
The test involves a simple mouth swab, Jensen said. The sample is then sent to Avellino Lab USA’s certified genetic molecular testing labs, and the physician can expect to see the test results online within 24 to 48 hours.
“If the results are normal, the patient can proceed with LASIK as planned. If the results are not normal, we do not recommend following through with the procedure,” she said.
While there is no cure for ACD, patients who test positive are encouraged to wear lenses that protect against UV light, which may help postpone disease progression, Jensen said. They should also be followed by an eye care professional every 6 months.
Avellino Lab USA recommends that anyone who tests positive should have family members tested. As an autosomal dominant condition, there is a 50% probability of siblings also having it.
Jensen tests all patients at her clinic requesting LASIK. Of 170 patients tested, so far, none have come back positive, she said.
“All optometrists probably won’t test all of their patients,” Korney said, “but if someone has an unknown dystrophy, they may want to test them.” – by Daniel R. Morgan
For more information:
Disclosures: Jensen has no relevant financial disclosures.