The Massachusetts Eye and Ear/Harvard Medical School Department of Ophthalmology today announced the availability of a comprehensive genetic diagnostic test for inherited eye diseases. The Genetic Eye Disease (GEDi) test uses two DNA sequencing technologies to simultaneously analyze multiple genomic regions for potential disease-causing mutations in 234 genes associated with inherited retinal disease (IRD), early-onset glaucoma and optic atrophy. Mass. Eye and Ear is the first and only location in the northeast to offer this service.
The GEDi test combines two recent technological advances in DNA sequencing: 1) targeted enrichment, which selectively enriches genomic regions for sequencing; and 2) next-generation sequencing (NGS), which can simultaneously analyze multiple DNA templates and samples in parallel. In particular, the GEDi test simultaneously enriches and analyzes genetic content associated with genetic eye disease, namely: 1) exons (expressed or "coding" regions) and select introns (intervening or "noncoding" regions) associated with the 234 nuclear genes in this panel (the nuclear genome consists of our 23 chromosome pairs); and 2) the mitochondrial genome, which is a distinct set of 37 genes found in energy-producing mitochondria within cells. Simultaneously deep sequencing these regions allows for a comprehensive and unbiased genetic analysis of patient samples, and is especially relevant considering the high degree of genetic heterogeneity (many genes with many distinct mutations) associated with IRD. In this way, the GEDi test can provide clinicians and patients with more accurate genetic diagnoses, which can improve genetic counseling and facilitate focal ocular treatments and therapies, including corrective gene therapy clinical trials.
"We are thrilled to be able to offer this thorough clinical genetic diagnostic testing to our patients and to the ophthalmic care community," said Eric Pierce, M.D., Ph.D., Director of the Ocular Genomics Institute (OGI) at Mass. Eye and Ear/Harvard Medical School Department of Ophthalmology. "Comprehensive testing is valuable since genetic diagnoses can be more accurate than those that are based on clinical features alone and can help us better predict the course of the disease."
According to Dr. Pierce, the OGI also offers genetic counseling to patients to explain their diagnosis and potential treatment options so they can make informed decisions about disease management and family planning. He adds, "For many patients, genetic testing and counseling removes the uncertainty and anxiety that comes from living with an undiagnosed disease. It's also very helpful to families who may want to know what the risks are of passing their disease on to their children."
The GEDi diagnostic panel is subdivided into two separate tests: GEDi-R for IRDs (226 genes) and GEDi-O for early-onset glaucoma and optic atrophy (8 genes). Both GEDi genetic diagnostic tests have been validated in compliance with Clinical Laboratory Improvement Amendment (CLIA) requirements, and are offered through the OGI's CLIA-certified Genetic Diagnostic Laboratory.
Some genetic mutations may offer protection against developmental disorders