Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Gene mutation found for eye disease that mimics macular degeneration

05.08.2003


University of Michigan Kellogg Eye Center scientists have been studying a family whose members have an eye disease that looks like age-related macular degeneration (AMD), but that has a rarer pattern of inheritance that results in an exceptionally high incidence of the disease among family members in the study.



In the August issue of Investigative Ophthalmology & Visual Science (IOVS), Kellogg scientist Radha Ayyagari, Ph.D., and her collaborators from the U-M and other institutions identify the gene associated with this unusual macular disease. They report on the Tyr141Cys mutation in a gene called RDS.

According to Ayyagari, the marked similarity between AMD and the AMD-like disease will help researchers learn more about the molecular basis of AMD. The findings could have even greater significance because Ayyagari and her colleagues suspect that some individuals with AMD may also harbor the RDS mutation.


AMD is a progressive disease affecting the macula, the area of the retina responsible for central vision that enables us to drive, read, and identify faces. It affects about 1.65 million individuals in this country each year; the first symptoms tend to appear at age 60 or older.

Ayyagari’s group discovered the mutation by studying members of five generations of a large family, known to researchers as SUNY901. The family has a high incidence of a macular disease that resembles AMD, begins at age 50 or older, and has both wet and dry forms, much like AMD.

But in contrast to AMD, it has an autosomal dominant mode of inheritance, which means that the disease can be passed to a child by either parent and that the child of an affected parent has about a 50 percent chance of inheriting the disease.

The family members who are affected by the disease may have symptoms with varying degrees of severity, but the condition frequently results in permanent loss of central vision. Co-author Shahrokh C. Khani, M.D., a U-M-trained ophthalmologist now at State University of New York at Buffalo, examined many members of the SUNY901 family.

"From the clinician’s point of view, the eye disorder in this family looks just like AMD," says Khani. "It is very similar in clinical behavior, age of onset, and response to treatment; it appears be a kind of mirror of AMD."

According to Ayyagari, an assistant research scientist in the Department of Ophthalmology and Visual Sciences at the U-M Medical School, the rate at which the SUNY901 family inherited the mutation is one of the most dramatic findings of the research.

"Although AMD has a strong genetic component, we do not see the strong patterns of inheritance we have observed in members of this family," observes Ayyagari. For example, in the fourth generation, at least 18 of the 23 members inherited the mutation from a carrier or affected parent. The odds of encountering the mutation versus the unaffected gene is closer to three-to-one, rather than the expected one-to-one ratio.

When researchers discovered that the same mutation occurred in a smaller family (BCM-AD033), they realized, after further analysis, that this family and the SUNY901 family must have a common ancestor. Researchers had already studied the genealogy of the larger family and traced its members to a single ancestor who emigrated from Germany to North America. Ayyagari adds that RDS has been screened extensively in populations worldwide; the only two families known to have the rare mutation are the two families described in the paper.

Khani observes that the detailed family history of the SUNY901 family presented genetic researchers with an unusual opportunity.

"When you can study a family with such a well-preserved genealogy, it is easier to get to the root of the disease," he says. "Most families find it difficult to identify members beyond a first cousin. In this family we think we can identify the first family members to have developed the disease, in the late 1700s."

Scientists want to understand how the mutation in RDS interferes with the healthy functioning of the eye. They believe that the mutation disrupts the normal structure and function of the RDS protein. As scientists gain more understanding of these processes, they will be able to develop therapies and treatments that counteract or circumvent the effects of the mutations.

In addition to Khani and Ayyagari, coauthors of the paper are: Athanasios J. Karoukis, Rajesh Ambasudhan and Tracy Burch of Kellogg; Joyce E. Young and Richard Stockton of SUNY Buffalo; Richard Alan Lewis of Baylor College of Medicine; Lori S. Sullivan and Stephen P. Daiger of the University of Texas Health Science Center; and Elias Reichel of the New England Eye Center at Tufts University.

Kara Gavin | EurekAlert!
Further information:
http://www.iovs.org
http://www.kellogg.umich.edu

More articles from Life Sciences:

nachricht Cryo-electron microscopy achieves unprecedented resolution using new computational methods
24.03.2017 | DOE/Lawrence Berkeley National Laboratory

nachricht How cheetahs stay fit and healthy
24.03.2017 | Forschungsverbund Berlin e.V.

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Giant Magnetic Fields in the Universe

Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.

The results will be published on March 22 in the journal „Astronomy & Astrophysics“.

Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...

Im Focus: Tracing down linear ubiquitination

Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.

Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...

Im Focus: Perovskite edges can be tuned for optoelectronic performance

Layered 2D material improves efficiency for solar cells and LEDs

In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...

Im Focus: Polymer-coated silicon nanosheets as alternative to graphene: A perfect team for nanoelectronics

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...

Im Focus: Researchers Imitate Molecular Crowding in Cells

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to simulate these confined natural conditions in artificial vesicles for the first time. As reported in the academic journal Small, the results are offering better insight into the development of nanoreactors and artificial organelles.

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

International Land Use Symposium ILUS 2017: Call for Abstracts and Registration open

20.03.2017 | Event News

CONNECT 2017: International congress on connective tissue

14.03.2017 | Event News

ICTM Conference: Turbine Construction between Big Data and Additive Manufacturing

07.03.2017 | Event News

 
Latest News

Argon is not the 'dope' for metallic hydrogen

24.03.2017 | Materials Sciences

Astronomers find unexpected, dust-obscured star formation in distant galaxy

24.03.2017 | Physics and Astronomy

Gravitational wave kicks monster black hole out of galactic core

24.03.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>