Gene hope for inherited eye disorder
Wednesday April 7th, 2010
By Jane Collingwood
Scientists have found that a patient's genes affect the outcome of treatment
for a rare inherited eye disorder.
Leber congenital amaurosis, or LCA, is a condition that arises in about one in 80,000 births. It causes involuntary eye movements, abnormal pupil responses, and can lead to severe vision loss or blindness.
Gene replacement therapies are being tested and have shown some success. Dr Arlene Drack and colleagues at the University of Iowa, USA, investigated whether gene mutations affect outcomes. They explain that LCA and similar conditions are caused by mutations in at least 15 genes.
Trial results suggest that when LCA is due to a mutation in the RPE65 gene, it may be treatable with a normal copy of the RPE65 gene. However, LCA due to other genetic mutations will not respond well.
Dr Drack said: "The interpretation of DNA variants is complex. Careful, accurate genetic diagnosis leads to effective treatment for patients, and avoids treating patients who cannot benefit from the current therapy."
The study is published in AAPOS, the journal of the American Association of Pediatric Ophthalmology and Strabismus.
Editor Dr David Hunter commented: "It is a dream come true that many of our patients with Leber congenital amaurosis, who until now faced a lifetime of total blindness, now have a prospect of gaining sight.
"But in our enthusiasm to offer this novel treatment to patients, we have to be extremely careful to treat only those patients with the one molecular form that is amenable to gene therapy at present.
"Dr Drack's article highlights this concern and provides a practical approach toward how this can be accomplished."
Drack, A. V. et al. Which Leber congenital amaurosis patients are eligible for gene therapy trials. Journal of AAPOS, Vol. 13, December 2009, Issue 6.
Tags: Eye Health | Genetics | North America
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