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 Stiffness matters
22.02.2018 | Albert-Ludwigs-Universität Freiburg im Breisgau

nachricht Separate brain systems cooperate during learning, study finds
22.02.2018 | Brown University

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Developing reliable quantum computers

International research team makes important step on the path to solving certification problems

Quantum computers may one day solve algorithmic problems which even the biggest supercomputers today can’t manage. But how do you test a quantum computer to...

Im Focus: In best circles: First integrated circuit from self-assembled polymer

For the first time, a team of researchers at the Max-Planck Institute (MPI) for Polymer Research in Mainz, Germany, has succeeded in making an integrated circuit (IC) from just a monolayer of a semiconducting polymer via a bottom-up, self-assembly approach.

In the self-assembly process, the semiconducting polymer arranges itself into an ordered monolayer in a transistor. The transistors are binary switches used...

Im Focus: Demonstration of a single molecule piezoelectric effect

Breakthrough provides a new concept of the design of molecular motors, sensors and electricity generators at nanoscale

Researchers from the Institute of Organic Chemistry and Biochemistry of the CAS (IOCB Prague), Institute of Physics of the CAS (IP CAS) and Palacký University...

Im Focus: Hybrid optics bring color imaging using ultrathin metalenses into focus

For photographers and scientists, lenses are lifesavers. They reflect and refract light, making possible the imaging systems that drive discovery through the microscope and preserve history through cameras.

But today's glass-based lenses are bulky and resist miniaturization. Next-generation technologies, such as ultrathin cameras or tiny microscopes, require...

Im Focus: Stem cell divisions in the adult brain seen for the first time

Scientists from the University of Zurich have succeeded for the first time in tracking individual stem cells and their neuronal progeny over months within the intact adult brain. This study sheds light on how new neurons are produced throughout life.

The generation of new nerve cells was once thought to taper off at the end of embryonic development. However, recent research has shown that the adult brain...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

2nd International Conference on High Temperature Shape Memory Alloys (HTSMAs)

15.02.2018 | Event News

Aachen DC Grid Summit 2018

13.02.2018 | Event News

How Global Climate Policy Can Learn from the Energy Transition

12.02.2018 | Event News

 
Latest News

Stiffness matters

22.02.2018 | Life Sciences

Magnetic field traces gas and dust swirling around supermassive black hole

22.02.2018 | Physics and Astronomy

First evidence of surprising ocean warming around Galápagos corals

22.02.2018 | Earth Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>