MAY 14, 2010
This study reviewed the types, uses, methods and importance of today's molecular genetic testing in pediatric ophthalmology.
Genetic tests with reasonably high sensitivity, high specificity, moderate cost, and quick turnaround times are now available for dozens of inherited eye diseases. Most of it is fee-for-service testing for which insurance companies are increasingly willing to pay for, and reports are always generated. Research-based testing is also available but does not always yield a result. Detection of DNA variants in genes known to cause eye disease must be interpreted using the variability of the human genome, the presence of benign variants (polymorphisms), and the carrier frequency of recessive alleles. Negative results are helpful in some disorders for which most of the causative genes are known but less helpful in those with many undiscovered causative genes or novel mutations. Patients with RPE65-associated Leber congenital amaurosis may be eligible for the current gene therapy trial. Patients with a variety of disorders may benefit from improved surveillance if their genetic diagnosis is known.
Where once no tests were available, there are now many tests but an insufficient number of doctors who are knowledgeable enough to order and interpret them. The authors concluded that ophthalmologists should see this as an opportunity to deliver a message of realistic hope: the exact cause of a child's vision problem can be diagnosed and his or her eligibility for a treatment trial determined with a simple blood test. Doing so not only will contribute to the discovery of additional disease-causing genes, it also will make possible the clinical trial of many exciting new therapies.