Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Genetic testing helps physicians zero in on eye disease

16.09.2005


U-M Kellogg Eye Center scientists are first to screen for multiple retinal disease genes on a single microchip — and it’s cost-effective



Rapid genetic testing for eye disease is becoming a reality, thanks to a technology developed at the University of Michigan Kellogg Eye Center. Scientists have created a first-of-its-kind test on a microchip array that will help physicians hone their diagnoses for patients with the blinding disease known as retinitis pigmentosa (RP). The screening technique has proven to be reliable and cost-effective.

In the September issue of Investigative Ophthalmology & Visual Science (IOVS), scientists at the U-M Department of Ophthalmology and Visual Sciences report on the arRP-I sequencing array, the first technology to screen simultaneously for mutations in multiple genes on a single platform.


This is a novel tool for scientists and physicians alike, says lead author and Kellogg scientist Radha Ayyagari, Ph.D. "For diseases that are associated with multiple genes, like RP, we now have a new and faster method for identifying the underlying genetic basis. This is also useful in analyzing complex patterns of inheritance and for understanding how causative genes might interact with each other."

RP is a group of diseases, affecting one in every 3,500 individuals, in which retinal degeneration leads to blindness or severe vision loss.

Among the outward signs and symptoms are loss of peripheral vision, night blindness, and abnormal results from an electroretinogram (ERG), a test that measures the electrical activity and function of the retina. A patient with the autosomal recessive form of the disease (arRP) has inherited one gene from each parent, neither of whom is affected by RP.

It is nearly impossible to identify which form of the disease a patient has through a clinical examination alone, notes John R. Heckenlively, M.D., a specialist in inherited eye disease who also participated in the study.

"Identifying the precise genetic mutation responsible for an individual’s disease will allow us to provide a precise diagnosis, and this knowledge will also allow us to apply genetic therapies as they are developed," he says.

Some clues to treatments are beginning to emerge in animal models, and scientists expect future therapies to be very specific to the type of RP.

"Perhaps one patient will benefit from dramatically limiting exposure to sun or artificial light, and another will use certain vitamins or supplements to stop progression of the disease," says Heckenlively. "Obtaining a molecular diagnosis is going to be very important in helping to guide gene-based treatments for patients in the coming years," he concludes.

Ayyagari’s study involved 70 individuals with a clinical diagnosis of arRP. Thirty-five had not been previously screened, and 35 others with known genetic mutations were screened to validate the results.

The arRP-I chip contained sequences, or genetic codes, of 11 genes that carry approximately 180 mutations associated with early-onset retinal degenerations. To date more than 30 genes have been identified for various forms of RP. Ayyagari notes that while the size of the chip currently limits the ability to array all known RP genes, larger platforms are likely to be available soon.

The arRP-I chips designed by the Kellogg research team produced 97.6 percent of the sequence analyzed with greater than 99 percent accuracy and reproducibility. The material cost of the arRP-I chip was 23 percent less that of current sequencing methods. That figure does not take into account the substantial savings in time and labor realized by analyzing multiple genes at once. These chips can detect both previously known and novel mutations.

Kellogg scientists and physicians expect that genetic technologies will grow dramatically in the next five years, particularly as additional space becomes available in the recently approved expansion to the Eye Center.

A proposed expansion of the U-M’s eye disease genetic testing and counseling center will allow Ayyagari and Heckenlively to screen large numbers of interested patients, provide counseling and education on the implications of genetic testing, and advance the pace of research toward targeted genetic therapies for RP and other inherited eye diseases.

Betsy Nisbet | EurekAlert!
Further information:
http://www.umich.edu

More articles from Life Sciences:

nachricht New risk factors for anxiety disorders
24.02.2017 | Julius-Maximilians-Universität Würzburg

nachricht Stingless bees have their nests protected by soldiers
24.02.2017 | Johannes Gutenberg-Universität Mainz

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

Im Focus: Three Magnetic States for Each Hole

Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".

Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

Stingless bees have their nests protected by soldiers

24.02.2017 | Life Sciences

New risk factors for anxiety disorders

24.02.2017 | Life Sciences

MWC 2017: 5G Capital Berlin

24.02.2017 | Trade Fair News

VideoLinks
B2B-VideoLinks
More VideoLinks >>>